In calculating the electric
hoist gantry crane bridge steel structure, you must identify the role of the bridge girders or trusses on the same loads that is half the weight of the bridge (without considering the weight of the end beam) related. When determining the weight of the bridge, it is usually use structure, since a similar weight and span
bridge gantry crane drawings can also be used by weight or weight characteristics characteristics table graph.
Determine electric hoist gantry crane bridge metal structure weight method, this method can be calculated when the different structures of the bridge was adopted.
Everyone knows that the most favorable bridge steel bridge on weight in a certain ratio between the span under guaranteed. For example, from the weight of 15 tons of lattice bridge, when a span of 15 meters, the most advantageous height was 15/9.
However, for purposes of placement tray, normally give a smaller area at a height dimension limits, therefore, must provide a relatively high degree of disadvantage of the bridge. For example, for electric hoist
gantry crane lifting capacity of 15 tons of lattice bridge, when a span of 15 meters, it is recommended to take 1:1.
Gantry crane bridge structure should not only respect the allowable stress intensity conditions are met, it should be allowable deflection areas to meet stiffness conditions.
After the bridge height requirement, electric hoist gantry crane designers should take into account, according to the National Bureau of lifting gear inspection regulations applied load bridge deflection is determined under static force, and the calculated stress is determined at full load that is, taking into account all factors into account the dynamic loads and activities identified under constant load.
bridge gantry crane
2013年7月31日星期三
Gantry crane gear What is the purpose?
With the rapid development of modern science and technology, industrial production scale and increased automation, hoist crane s in the modern production process more widely, the role is getting bigger, the crane requirements are also increasing. Especially single girder gantry crane widely used, prompting a number of interdisciplinary advanced design methods appear to promote the modern manufacturing technology and testing technology improves. The fierce competition in the international market has become increasingly dependent on technology competition. These have all contributed to the technical performance of the crane into the new stage of development, the crane is undergoing a huge transformation.
Single girder gantry crane gear correction (modified) The purpose is to avoid the machine cutting gear teeth that occurs when the phenomenon under the cut and shape of the tooth profile by changing the ways to increase the strength of the tooth.
In practice, single girder hoist gantry crane minimum number of teeth pinion gear can be smaller, because the small incision resulting strength of the teeth will not have a significant effect.
In fact can be considered: for a 20 ° involute tooth profile, when the pinion gear wheel with standard high pinion gear, the next cut will occur in the number of teeth than the pinion 14, the pinion wheel and when a short tooth, the occurrence of the pinion number of teeth than 11:00.
In single-girder gantry crane manufacturing, the main use of the zero shift correction, this correction method that is closer to the cutting tool or removed by cutting gear centerline. The main advantage of this method is that you can use when cutting non-corrected standard used gear cutting tools. Axis gantry crane at the same time does not change.
Electric hoist rope wear What are the reasons?
Electric
hoist gantry crane use, rope through drum or pulley when the entire load of pressure to bear on one side of the rope, the radius of curvature of the root thin wire not identical. Also, because the rope bent, thin steel wire rope inside the root will generate force and produce another slip, then contact stress between stocks and shares increases, the share between adjacent wires produce local indentation furrow. When repeated cycles stretch bending, is generated in the deep recesses of stress concentration was broken, constitute internal wear.
Usually thin wire rope surface pressure and the pressure proportional to the tension of the same case, since the electric hoist gantry crane rope different pressure area, the pressure per unit area is different. Under pressure from the surface wear of view, the use of line contact wire rope advantageous than using point contact, the use of surface contact wire rope line contact than using more favorable. In addition, the degree of bending wire rope, velocity, internal wear on the rope are affected. Obviously, the selection line contact or surface contact type of rope is an effective way to reduce internal wear.
Due to vibration, impact caused by collision damage rope surface, called deformation wear, which is a phenomenon of partial wear. If the surface of the wire rope drum impact by other objects, electric hoist bridge gantry crane hoisting rope wrapped around each other to fight, or because the roll center of the pulley and the resulting bite rope deflection phenomenon will cause the wire rope deformation wear. This deformation wear and deformation due to local press, the wire cross-section extending to the sides at the extrusion into a fin-shaped. From outward appearances, wire width expansion, although much reduced wire cross-sectional area, but the local press at the steel surface material hardened, easily broken wire.
In the course of wire rope and the pulley groove outer periphery, drum set, a top hook surface wear caused by the contact part of the external wear. The external worn rope diameter becomes thinner, the outer peripheral surface is polished fine steel. External wear of the rope to bear the load of the wire cross-sectional area decreases, the rope breaking load is reduced accordingly.
Wear a single week than the whole week wear worse, electric hoist gantry crane hook group it should be possible to make a single week of the wire to wear uniform wear all week. Entire length of the wire should be as far as possible uniform wear. Such as cranes wire rope used for the first medium-term, generally extend rope life 30% to 40%.
Usually thin wire rope surface pressure and the pressure proportional to the tension of the same case, since the electric hoist gantry crane rope different pressure area, the pressure per unit area is different. Under pressure from the surface wear of view, the use of line contact wire rope advantageous than using point contact, the use of surface contact wire rope line contact than using more favorable. In addition, the degree of bending wire rope, velocity, internal wear on the rope are affected. Obviously, the selection line contact or surface contact type of rope is an effective way to reduce internal wear.
Due to vibration, impact caused by collision damage rope surface, called deformation wear, which is a phenomenon of partial wear. If the surface of the wire rope drum impact by other objects, electric hoist bridge gantry crane hoisting rope wrapped around each other to fight, or because the roll center of the pulley and the resulting bite rope deflection phenomenon will cause the wire rope deformation wear. This deformation wear and deformation due to local press, the wire cross-section extending to the sides at the extrusion into a fin-shaped. From outward appearances, wire width expansion, although much reduced wire cross-sectional area, but the local press at the steel surface material hardened, easily broken wire.
In the course of wire rope and the pulley groove outer periphery, drum set, a top hook surface wear caused by the contact part of the external wear. The external worn rope diameter becomes thinner, the outer peripheral surface is polished fine steel. External wear of the rope to bear the load of the wire cross-sectional area decreases, the rope breaking load is reduced accordingly.
Wear a single week than the whole week wear worse, electric hoist gantry crane hook group it should be possible to make a single week of the wire to wear uniform wear all week. Entire length of the wire should be as far as possible uniform wear. Such as cranes wire rope used for the first medium-term, generally extend rope life 30% to 40%.
Gantry crane working principle of the safety devices
To ensure that a single girder
gantry crane operation safety and reliability, the crane is equipped with a better safety devices in order to unexpected circumstances, play a protective parts or alert the operator, and thus play a security role.
A hydraulic system, the pressure relief valve: inhibit loop abnormally high pressure in order to prevent damage to the hydraulic pumps and motors, and to prevent is overloaded.
2 luffing jib safety device: When the unexpected accident, boom luffing cylinder loop pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from work oil, the single girder gantry crane jib will not fall, thus ensuring job security.
3 telescopic hoist crane safety device: When unexpected accidents, telescopic boom cylinder circuit of the high-pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from the working oil, the suspension will retract themselves, thus ensuring the safety of operation.
4 height limit device: single girder gantry crane hook to rise from the specified height after touching limit hammer, turn the trip switch, indicator lights that light off around the same time cutting off hook lift, crane extended, the boom volts to the operation of such action to ensure safety. Then just manipulate the hook down, boom boom retracted or looked up (to the Security side operation), etc. handle, lift the weight limit constraint, the operation returns to normal. For special occasions, such as still need to make a small amount of over-winding operation, press the release button on the meter box, this time limit will be lifted role, but this time the operation must be very careful to prevent accidents.
5 outrigger locking device: When unexpected accidents, leading to the single girder overhead gantry crane outrigger vertical cylinder high-pressure hose or pipeline rupture or cutting, hydraulic system can be bi-directional hydraulic lock cylinder two chambers blockade blockade outrigger pressure oil, the legs indented or throw, so as to ensure the safety of the lifting operation.
A hydraulic system, the pressure relief valve: inhibit loop abnormally high pressure in order to prevent damage to the hydraulic pumps and motors, and to prevent is overloaded.
2 luffing jib safety device: When the unexpected accident, boom luffing cylinder loop pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from work oil, the single girder gantry crane jib will not fall, thus ensuring job security.
3 telescopic hoist crane safety device: When unexpected accidents, telescopic boom cylinder circuit of the high-pressure hose or pipe burst or cut off, the hydraulic circuit balancing valves on the work, lock cylinder lower chamber from the working oil, the suspension will retract themselves, thus ensuring the safety of operation.
4 height limit device: single girder gantry crane hook to rise from the specified height after touching limit hammer, turn the trip switch, indicator lights that light off around the same time cutting off hook lift, crane extended, the boom volts to the operation of such action to ensure safety. Then just manipulate the hook down, boom boom retracted or looked up (to the Security side operation), etc. handle, lift the weight limit constraint, the operation returns to normal. For special occasions, such as still need to make a small amount of over-winding operation, press the release button on the meter box, this time limit will be lifted role, but this time the operation must be very careful to prevent accidents.
5 outrigger locking device: When unexpected accidents, leading to the single girder overhead gantry crane outrigger vertical cylinder high-pressure hose or pipeline rupture or cutting, hydraulic system can be bi-directional hydraulic lock cylinder two chambers blockade blockade outrigger pressure oil, the legs indented or throw, so as to ensure the safety of the lifting operation.
Crane accessories bearing structure and function
With the domestic casting industry, the rapid take-off, how to seize the market, look for business opportunities this year, China has become a prime topic of the casting industry. Among the many electric
hoist gantry crane products Rush market,
hoist crane accessories because of its own applications as well as relatively strong market demand characteristics; but at the same time, as technology advances, the development of all walks of life of the bearing castings accuracy, performance, reliability and other aspects of life and the increasingly high demand, and constantly made new demands.
Needle roller bearings with cylindrical rollers of roller bearings, relative to its diameter, roller both thin and long. This is called needle roller. Despite having a smaller cross-section, has a higher load bearing capacity, therefore, especially suitable for the radial space-constrained applications. Needle in the proximal surface contour surface at a slight contraction. Needle and roller line contact results can be modified to avoid damaging edge stresses. In addition to catalogs listed can be used for general engineering bearings, such as: electric hoist gantry crane Drawn cup needle roller bearings with open, closed Needle roller bearings, needle roller bearings with inner ring and without inner ring Needle bearings.
Needle roller bearings are generally not attached to the inner ring. Electric hoist gantry crane journal not hardened and grinding of the occasion, you can use the inner listed in the table. Needle roller bearings, needle roller hardened steel outer ring and cage assembly can not be separated. Lubricant storage free space can be extended relubrication intervals. Bearings generally use single design. But the wider specifications bearing 1522,1622,2030,2538 and 3038 series except that they fitted two roller cage assembly. Bearing outer ring with lubrication holes. According to user needs, the shaft diameter greater than or equal to all the separate 7mm Needle roller bearings can be equipped with a lubrication hole of the outer ring.
Needle roller bearings with seals in the seal can not be installed due to space constraints of the occasion, providing open-ended or closed end Needle roller bearings with seals. Such electric hoist gantry crane bearing equipment polyurethane or synthetic rubber friction seal, which filled with good anti-rust performance lithium grease for operating temperatures from -20 to +100 ℃. Bearing inner ring with seals than the outer width 1mm, this is what makes the bearing shaft relative displacement of the bearing housing with a little work it could ensure a good seal and avoid the risk of bearing contamination. Bearing inner ring also has a greasing hole, according to the needs of the bearing arrangement, supplemented by the outer or inner ring lubrication.
Needle roller bearings with cylindrical rollers of roller bearings, relative to its diameter, roller both thin and long. This is called needle roller. Despite having a smaller cross-section, has a higher load bearing capacity, therefore, especially suitable for the radial space-constrained applications. Needle in the proximal surface contour surface at a slight contraction. Needle and roller line contact results can be modified to avoid damaging edge stresses. In addition to catalogs listed can be used for general engineering bearings, such as: electric hoist gantry crane Drawn cup needle roller bearings with open, closed Needle roller bearings, needle roller bearings with inner ring and without inner ring Needle bearings.
Needle roller bearings are generally not attached to the inner ring. Electric hoist gantry crane journal not hardened and grinding of the occasion, you can use the inner listed in the table. Needle roller bearings, needle roller hardened steel outer ring and cage assembly can not be separated. Lubricant storage free space can be extended relubrication intervals. Bearings generally use single design. But the wider specifications bearing 1522,1622,2030,2538 and 3038 series except that they fitted two roller cage assembly. Bearing outer ring with lubrication holes. According to user needs, the shaft diameter greater than or equal to all the separate 7mm Needle roller bearings can be equipped with a lubrication hole of the outer ring.
Needle roller bearings with seals in the seal can not be installed due to space constraints of the occasion, providing open-ended or closed end Needle roller bearings with seals. Such electric hoist gantry crane bearing equipment polyurethane or synthetic rubber friction seal, which filled with good anti-rust performance lithium grease for operating temperatures from -20 to +100 ℃. Bearing inner ring with seals than the outer width 1mm, this is what makes the bearing shaft relative displacement of the bearing housing with a little work it could ensure a good seal and avoid the risk of bearing contamination. Bearing inner ring also has a greasing hole, according to the needs of the bearing arrangement, supplemented by the outer or inner ring lubrication.
Crane rail joint welding preparations and precautions
Single girder gantry crane rail joint welding, should be carefully cleaned groove and the nearby oil, rust and dirt until the exposed metallic luster. Welding basis for such strong principles, matching basic electrode, the grade J857 (National Institute of Standards 4.2 orbital welding deformation control ends of the rails pre-paving height, according to the rail of the species, length and fixed conditions, and environmental factors such as temperature, using preproduction, with the copper plate and steel plate paving the ends of the rails 30 ~ 40mm, has been making good use of such coupling bolts and pressure plate, tighten the nut of the rail fixed to the rail beam, each set at least near the rail joints 4 fixing points.
When finished welding the bottom rail after the release plate, paving the rail tip portion is reduced to 20mm, and then tighten the gland plate nut. When the welding rail waist-sharing, decreased plate height, waist rail section when finished welding should be removed all the plate, and release plate, this time a small rail joints should be upturned value, rail welding head process, according to resume straight rail, decides whether to tighten the gland plate nuts. In single-girder hoist gantry crane All welding process, must always check with straight steel ruler deformation of rail joints, always adjust the height and tighten loose fitting plate to control the deformation of rail joints. In the fixed rail joints before welding, the two ends of the rails gap is left between the wide and narrow, in order to prevail rail base clearance of not less than 12mm, and it is not too wide, the general control within 15 ~ 18mm . After adjusting the fixed rail joints, in addition to ensuring the tip gap size, you must also make the two ends of the rails aligned, may not have contorted and staggered so on.
In welding single girder bridge gantry crane prior to welding process, should be strictly checked and make sure that two rail centerline in a line, in order to prevent orbital welding is completed, there is usually no direct bending phenomenon. Rail with hook bolts, welded joints of its orbit, according to the method described above with reference to specific circumstances, set up a temporary fixture fixed rail for welding.
Welded rail joint order is bottom-up, after the end of the first rail track waist, rail head, layer by layer carried by road surfacing, the last patch around. Two ends of the range of each track is 40mm, while preheating, preheat and interpass temperature controlled at 300 ℃ ~ 350 ℃. Welding the first layer (primer): Current 120A ~ 130A, to prevent permanent steel plate burn and melt the copper plate, thereby reducing the difficulty of removing the copper plate, shorten the track air time, help maintain the interlayer temperature to prevent quenching; later layers can be used (130 ± 15) A, each finished welding slag must be cleaned before continuing welding;
In each solder wave welding, especially when welding in single girder gantry crane rail base of each solder wave should be used when welding electrode l root end, then use the middle to avoid the broken arc welding, solder wave around two layers The welding should be directed to the contrary; each rail joint welding work should be carried out continuously, so that the rail ends maintained at a high temperature solder (300 ℃ ~ 350 ℃). After welding, stress relieving heat treatment when not cooled prior to beware of rain and other wet; a hot wet cooling copper plate can be removed to facilitate the next reuse.
2013年7月30日星期二
Lifting brushing paint protection requirements
1 protective Term definition: In single-girder gantry crane design protection period, the surface does not exceed the ISO4628-3 rust rust grades in Ri3 level (equivalent to ASTMD610 of six or European standards Re3 grade)
2, A3.08, A3.11, A4.14, A4.15, etc. are ISO12944-5: 2007 Appendix Table A3 and A4 in the matching system number.
3, single girder overhead gantry crane main consideration gloss finish selection and color retention, 4 files, PU412 aromatic polyurethane topcoat, PU413 aliphatic polyurethane topcoat, PU421 polyurethane finish construction machinery, PU420 polyurethane engineering automotive finish .
4, no zinc primer (EPMisc.) consideration was mainly rust resistance and high solids, one can achieve a dry film thickness of 80 microns, optional epoxy zinc phosphate primer, epoxy bottom aluminum tripolyphosphate paint.
5, zinc-rich primer required dry film (or non-volatile parts of) zinc content (not the metal zinc content) ≥ 80%. Such as the use of the level GB_T_6890-2000 zinc (metallic zinc content ≥ 96%), the dry film can be converted into (or non-volatile parts of) zinc content (not the metal zinc content) ≥ 76.80%. Can also be taken as inorganic zinc (zinc silicate) primer.
6, the most commonly used in the paint is epoxy painted iron, because iron thin cloud is not high, such as requiring single girder gantry crane surface appearance, and can be replaced with a good degree of fineness in epoxy thick film painted.
7, exported to Europe's single girder bridge gantry crane to be considered harmful heavy metal coatings (such as lead, chromium, etc.) content issues, zinc-rich primer should use high purity and low heavy metal content of zinc (as zinc ASTMD520 required) should not be used etc. leaded lead chrome yellow pigment.
Crane trolley resistance analysis
Electric
hoist gantry crane can run dolly trolley runs along the jib round, luffing speed, handling, accurate positioning, commonly used in the work of the Change. Luffing jib luffing jib around a fixed hinge axis through in the vertical plane to change the pitch angle, thus changing the amplitude, which is widely used in various types of
jib crane Luffing calculation is based on the percentage change in resistance of different conditions based on analysis. Change resistance are:
(1) electric hoist gantry crane luffing process was hanging items caused by non-horizontal displacement amplitude resistance;
(2) failed to fully balanced weight boom system caused by luffing resistance;
(3) the hoisting rope suspension load deflection amplitude resulting resistance of wind load, the centrifugal force, amplitude, start rotating, the brake force of inertia generated by the combined effect of the article;
(4) acting on the electric hoist gantry crane booms wind load on the system caused by the Change resistance;
(5) the hoist crane boom system when the centrifugal force caused by rotation amplitude resistance;
(6) Since the slope caused by the presence of crane rails luffing resistance;
(7) Change process, the boom system inertial force caused by the radial amplitude resistance;
(8) electric hoist gantry crane boom hinge shaft friction and the efficiency of compensating pulley luffing resistance caused
(1) electric hoist gantry crane luffing process was hanging items caused by non-horizontal displacement amplitude resistance;
(2) failed to fully balanced weight boom system caused by luffing resistance;
(3) the hoisting rope suspension load deflection amplitude resulting resistance of wind load, the centrifugal force, amplitude, start rotating, the brake force of inertia generated by the combined effect of the article;
(4) acting on the electric hoist gantry crane booms wind load on the system caused by the Change resistance;
(5) the hoist crane boom system when the centrifugal force caused by rotation amplitude resistance;
(6) Since the slope caused by the presence of crane rails luffing resistance;
(7) Change process, the boom system inertial force caused by the radial amplitude resistance;
(8) electric hoist gantry crane boom hinge shaft friction and the efficiency of compensating pulley luffing resistance caused
MH type electric hoist gantry crane structure and Scope
With the machinery industry's rapid economic development mode shift, companies should have to consider lifting products, such as electric
hoist gantry crane meticulous precision, enhance scientific and technological content of products that change the original extensive mode of production. Multinationals accounted for lifting high-end chain, local enterprises in the low-end, resulting in foreign big money, we earn a little money, this is the reality.
The past is in the global industrial chain, the other we should know: Now fasteners into the world's first production, although it is at the low end and midrange industry, which is a huge historical progress, some other developing countries jealous, said China is like a huge black hole, to invest in their present that gave attract foreign investment to go and we should not deny yourself the great progress of China electric hoist gantry crane companies in the low end of the global industrial chain after entering no should stop there, you can like and high-end product development.
MH type electric hoist gantry crane is small with a simple cantilever gantry crane, electric hoist CD1 and MD1 type two, the main beam is a combination of steel beams and beams, traveling mechanism mainly consists of motor, brake, reducer , wheels and other components, its structure is simple to install, use, and easy maintenance.
MH type electric hoist gantry crane is small with a simple cantilever bridge gantry crane electric hoist CD1 and MD1 type two, the main beam is a combination of steel beams and beams, traveling mechanism mainly consists of motor, brake, reducer , wheels and other components, its structure is simple to install, use, and easy maintenance. This machine is suitable for factory, railway freight yard, ports, hydropower, etc.: A5 aircraft grade level work, mode of operation and the operating room floor operations, optional user to choose.
The past is in the global industrial chain, the other we should know: Now fasteners into the world's first production, although it is at the low end and midrange industry, which is a huge historical progress, some other developing countries jealous, said China is like a huge black hole, to invest in their present that gave attract foreign investment to go and we should not deny yourself the great progress of China electric hoist gantry crane companies in the low end of the global industrial chain after entering no should stop there, you can like and high-end product development.
MH type electric hoist gantry crane is small with a simple cantilever gantry crane, electric hoist CD1 and MD1 type two, the main beam is a combination of steel beams and beams, traveling mechanism mainly consists of motor, brake, reducer , wheels and other components, its structure is simple to install, use, and easy maintenance.
MH type electric hoist gantry crane is small with a simple cantilever bridge gantry crane electric hoist CD1 and MD1 type two, the main beam is a combination of steel beams and beams, traveling mechanism mainly consists of motor, brake, reducer , wheels and other components, its structure is simple to install, use, and easy maintenance. This machine is suitable for factory, railway freight yard, ports, hydropower, etc.: A5 aircraft grade level work, mode of operation and the operating room floor operations, optional user to choose.
Single and double girder gantry crane used in the structural performance and the difference
Single girder gantry crane simple structure, easy installation, the quality of their small, mostly off-track girder box-shaped frame structure. And double-girder gantry crane compared to the overall stiffness is weaker. Therefore, when the starting weight Q ≤ 50t, span S ≤ 35m, we can use this form. Single girder gantry crane doors legs with L-and C-type forms. L-manufacture and installation convenience, the force is good, the quality of their small, but, lifting cargo space through the legs at a relatively small number. The feet made of C-inclined or curved shape, the purpose is to have large lateral space to pass the goods foot.
Double girder bridge gantry crane carrying capacity, span, overall stability, variety, but the quality of their starting weight with the same single-girder gantry crane compared to the bigger, the cost is higher. According to the main beam structure is different, can be divided into box girders and trusses in two forms. More commonly used box-shaped structure.
(A) single girder and double girder gantry crane use different normal circumstances, since less weight 50t, span 35m or less, no special requirements, should use single girder overhead gantry crane . If you require a large gate leg width, high working speed, or frequently lifting heavy pieces, grew up pieces, you should choose double girder gantry crane.
(2) the length of the span and cantilever span gantry crane crane itself is affecting the quality of the important factors. Selection, to meet the conditions of use and equipment conform span series of standards under the premise should minimize single girder gantry crane span.
Chinese crane will take the characteristics of the road development
With the
hoist crane industry development with Chinese characteristics, to the spirit of arduous struggle, facing the complex world economic situation, the clutter and the achievements of the lifting equipment manufacturing country in the world dominance of single girder
gantry crane business development within the industry hit I laid a foundation.
However, the development of large-type system must be flawed, weak capacity of independent innovation of local enterprises, technology and international standards can not be flat; enterprise development varies greatly, market disorder; single girder gantry crane and other machinery and manage large-scale industrial strength is not enough, low productivity, this series of problems has become under the rapid development of China's industrial potential constraints.
Domestic enterprises in the crane industry make existing products at the same time, it should be long-term view, the example of the above-mentioned industries and enterprises to seize the global economic recovery and China's offshore marine platform market demand is relatively prosperous organic timing, constant innovation, business, core technology, and actively develop new capabilities with single girder bridge gantry crane , as soon as the relevant technology completely break the foreign monopoly of the crane industry efforts to promote better and faster development.
China's infrastructure construction efforts by the gradual increase, our single girder gantry crane industry usher in the golden period of industrial development and vitality injected neonatal period, a national favorable policies to benefit under one of the industries, the development prospect is very impressive. Innovative technologies in the field of crane industry emerging at this stage, close to the technological innovation in order to create a competitive advantage in the industry no longer exists; At the same time, the traditional material needs to gradually shift to the spiritual needs of the market context, the brand gradually into people's vision to become the next high-tech rapid development, creating long-term competitive advantage of enterprise's core values.
However, the development of large-type system must be flawed, weak capacity of independent innovation of local enterprises, technology and international standards can not be flat; enterprise development varies greatly, market disorder; single girder gantry crane and other machinery and manage large-scale industrial strength is not enough, low productivity, this series of problems has become under the rapid development of China's industrial potential constraints.
Domestic enterprises in the crane industry make existing products at the same time, it should be long-term view, the example of the above-mentioned industries and enterprises to seize the global economic recovery and China's offshore marine platform market demand is relatively prosperous organic timing, constant innovation, business, core technology, and actively develop new capabilities with single girder bridge gantry crane , as soon as the relevant technology completely break the foreign monopoly of the crane industry efforts to promote better and faster development.
China's infrastructure construction efforts by the gradual increase, our single girder gantry crane industry usher in the golden period of industrial development and vitality injected neonatal period, a national favorable policies to benefit under one of the industries, the development prospect is very impressive. Innovative technologies in the field of crane industry emerging at this stage, close to the technological innovation in order to create a competitive advantage in the industry no longer exists; At the same time, the traditional material needs to gradually shift to the spiritual needs of the market context, the brand gradually into people's vision to become the next high-tech rapid development, creating long-term competitive advantage of enterprise's core values.
Gantry crane operating environment and walking part of the test
Machinery industry depends not only on the level of product technology, high technical level of equipment will not necessarily apply to a variety of fields,
hoist gantry crane from the perspective of the development, the full description of the development of equipment for the industry is the most Okay, so the crane enterprises should pay attention to market analysis, research and more to meet the market demand, to achieve rapid development of enterprises.
Electric hoist gantry crane operating environment do not belong to their range, but the safe operation of the crane has a direct relationship, it is also a safety inspection of the crane when the essential element. To view its inspection a crane operating range without power lines (especially the high voltage lines), with the crane in operation should maintain adequate safe distance. Otherwise, it should take appropriate measures to restrict the scope of the operation of the crane.
Second, we must check the surrounding buildings, temporary facilities, such as whether interfere with normal operation of the hoist crane boom, counterweight and other parts will collide, especially in the electric hoist gantry crane rails extending or fixed cranes increased displacement time, particular attention should be checked. The crane should also check whether there is enough leg position, whether the underground voids and ground bearing capacity size. Detailed examination of the crane rail, rail block, anti-collision devices at both ends of the track, as well as gnawing rail track temperature and gap.
hoist gantry crane undercarriage inspection checks walking round the main tread, all open gears, couplings, transmission foundation bolt hole and walking axles and other parts, such as walking wheel tread surface hardness of poor quality; may check see massive stripped every thing open gears , couplings shall be equipped with protective cover; transmission if loose foundation bolts should be tightened; keep walking axle hole open.
Electric hoist gantry crane operating environment do not belong to their range, but the safe operation of the crane has a direct relationship, it is also a safety inspection of the crane when the essential element. To view its inspection a crane operating range without power lines (especially the high voltage lines), with the crane in operation should maintain adequate safe distance. Otherwise, it should take appropriate measures to restrict the scope of the operation of the crane.
Second, we must check the surrounding buildings, temporary facilities, such as whether interfere with normal operation of the hoist crane boom, counterweight and other parts will collide, especially in the electric hoist gantry crane rails extending or fixed cranes increased displacement time, particular attention should be checked. The crane should also check whether there is enough leg position, whether the underground voids and ground bearing capacity size. Detailed examination of the crane rail, rail block, anti-collision devices at both ends of the track, as well as gnawing rail track temperature and gap.
hoist gantry crane undercarriage inspection checks walking round the main tread, all open gears, couplings, transmission foundation bolt hole and walking axles and other parts, such as walking wheel tread surface hardness of poor quality; may check see massive stripped every thing open gears , couplings shall be equipped with protective cover; transmission if loose foundation bolts should be tightened; keep walking axle hole open.
2013年7月29日星期一
Gantry crane rope classification
According gantry crane rope twist to classify the following situations:
(1) interactive twist rope
Rope twist and shares the contrary, it is commonly used wire rope, rope and shares themselves as loose twist opposite trend, offset each other, did not reverse the trend of knotting, easy to use. According rope twist, and twist the right and left, respectively, twist rope. Gantry crane used right lay rope.
(2) in the same direction twist rope
Rope twist and shares the same with their own twist and reverse the trend of loose, easy to tie. As better flexibility. Typically used with a rigid rail traction. bridge gantry crane rope recently in the manufacturing process with pre-distortion method, after the elimination of the self into a rope loosely twisted phenomenon. This rope is also known not loose rope.
(3) mixed-twist rope
Half of stocks left, the other half share dextral. The rope used in the overhead gantry crane less.
According gantry crane rope twist to classify the following situations:
(1) interactive twist rope
Rope twist and shares the contrary, it is commonly used wire rope, rope and shares themselves as loose twist opposite trend, offset each other, did not reverse the trend of knotting, easy to use. According rope twist, and twist the right and left, respectively, twist rope. Gantry crane used right lay rope.
(2) in the same direction twist rope
Rope twist and shares the same with their own twist and reverse the trend of loose, easy to tie. As better flexibility. Typically used with a rigid rail traction. bridge gantry crane rope recently in the manufacturing process with pre-distortion method, after the elimination of the self into a rope loosely twisted phenomenon. This rope is also known not loose rope.
(3) mixed-twist rope
Half of stocks left, the other half share dextral. The rope used in the overhead gantry crane less.
Lifting operations several cases of people squeezed collision
Collision is a person who extrusion operations personnel in the operation of the
gantry crane squeeze collisions. In lifting operations are common casualties, which is very dangerous, very serious consequences, often will result in death. Lifting operations extrusion collision people mainly in the following situations:
(1) gantry crane hanging objects run in the process of swinging squeeze collision people. Main reason is: First, as the driver to improper operation, excessive speed change operation mechanism, so that hanging objects have a greater inertia. Second, because the command is incorrect, lifting route unreasonable, resulting in hanging objects swing violently collide squeeze people.
(2) hanging objects placed instability occurs dumping smashing hit people. Reasons: First, because of improper placement of hanging objects, hanging objects to prevent instability on major did not take the necessary safety precautions. Second is due to lifting operations at the scene of mismanagement.
(3) in command or overhaul mobile crane operations are squeezed collisions, that is, as people in the door mechanism and slewing crane operation between institutions, subject to the operation of the lifting machinery extrusion collisions. The reason is: First, because the command station operating personnel improperly; second is due to maintenance operations did not take the necessary safety precautions.
(4) In the roving inspection or maintenance hoist gantry crane operations are squeezed collisions, ie workers and between buildings in lifting machinery, lifting machinery run by extrusion collisions. Main reasons: First, because of inspection staff or maintenance personnel and drivers lack of correlation; second is due to maintenance operations did not take the necessary safety precautions.
(1) gantry crane hanging objects run in the process of swinging squeeze collision people. Main reason is: First, as the driver to improper operation, excessive speed change operation mechanism, so that hanging objects have a greater inertia. Second, because the command is incorrect, lifting route unreasonable, resulting in hanging objects swing violently collide squeeze people.
(2) hanging objects placed instability occurs dumping smashing hit people. Reasons: First, because of improper placement of hanging objects, hanging objects to prevent instability on major did not take the necessary safety precautions. Second is due to lifting operations at the scene of mismanagement.
(3) in command or overhaul mobile crane operations are squeezed collisions, that is, as people in the door mechanism and slewing crane operation between institutions, subject to the operation of the lifting machinery extrusion collisions. The reason is: First, because the command station operating personnel improperly; second is due to maintenance operations did not take the necessary safety precautions.
(4) In the roving inspection or maintenance hoist gantry crane operations are squeezed collisions, ie workers and between buildings in lifting machinery, lifting machinery run by extrusion collisions. Main reasons: First, because of inspection staff or maintenance personnel and drivers lack of correlation; second is due to maintenance operations did not take the necessary safety precautions.
Gantry crane splicing site construction requirements which
Gantry crane is Hengjia in workshops, warehouses and empty field for material lifting material lifting equipment. gantry crane laying on both sides of the bridge along the elevated track longitudinally running, you can take advantage of the space under the bridge lifting material from ground equipment obstacles. Indoor and outdoor industrial and mining enterprises in the iron and steel industry, railways, ports and logistics flow and other departments and sites have been widely used, is the most widely used, the largest number of a lifting machinery.
bridge gantry crane parts splicing What construction requirements
A) the transverse flange plates and web butt welds not arranged in the same section beams, door cranes are staggered welds should be more than 200mm.
2) flange plate, web and the beam transverse butt welds should be the size of the fillet weld stiffeners are staggered, with the large reinforcing plate stagger ≥ 150mm, with small reinforcing plate stagger ≥ 50mm.
Main LIANG Cheng-rail longitudinal fillet welds and fillet welds other arrangement with four longitudinal girder flange plate and the fillet weld web connections, overhead gantry crane with wide flange side rail box girder structure.
Gantry crane bridge in the manufacture, the walkway side of the welding residual stress after the drawing, when the transport and use of the process after the release of residual stress, resulting in two main beams inward lateral bending; And the main beam in the horizontal inertia loads, press lateral stiffness to allow a certain bending conditions, will cause a large bending deformation superposition.
Gantry crane design to determine
Crane for material lifting, transportation, handling and installation of machinery and equipment and other operations.
gantry crane is a machine along the track direction, winches lateral movement along the main beam, for the lifting movement of the lifting hook lifting devices. It features: light weight, lifting weight, installation and removal and transportation is very convenient. Universal gantry crane design has the following options:
1, the curved beam webs webs single girder bridge crane curved structure, which is determined by a longitudinal girders and beams composed of two lateral side, the main beams of thin-walled curved plate structure, that is, from the center of the beam swing around the bend line single web and the upper and lower plate composed, instead of the traditional forms of box girder.
2, box double box beam structure with a two double beam structure box girder beams and two transverse end, a dual beam bridge, in the general run on bridge gantry crane trolley, lifting and horizontal moving objects can be .
3, common gantry crane gantry cranes General girder structure using a U-shaped channel steel rolling, and then with a box beam welding solid web girder is rolled into a U-shaped steel plate, and then welding into the box shaped beams.
Gantry crane design according to the general conditions given task parameters, considering rationality, economy and reliability of such design principles, the above decision after comparing several options in this design uses a single beam structure.
1, the curved beam webs webs single girder bridge crane curved structure, which is determined by a longitudinal girders and beams composed of two lateral side, the main beams of thin-walled curved plate structure, that is, from the center of the beam swing around the bend line single web and the upper and lower plate composed, instead of the traditional forms of box girder.
2, box double box beam structure with a two double beam structure box girder beams and two transverse end, a dual beam bridge, in the general run on bridge gantry crane trolley, lifting and horizontal moving objects can be .
3, common gantry crane gantry cranes General girder structure using a U-shaped channel steel rolling, and then with a box beam welding solid web girder is rolled into a U-shaped steel plate, and then welding into the box shaped beams.
Gantry crane design according to the general conditions given task parameters, considering rationality, economy and reliability of such design principles, the above decision after comparing several options in this design uses a single beam structure.
Crane Installation Preparation and precautions
1, Universal gantry crane to be familiar with before installing random drawings and technical data, according to the technical requirements, eliminate the transportation or errors caused by improper storage and deformation. If structural deformation, corrected before installation.
2, the installation should be checked before corroded, remove rust, dirt and if necessary, re-paint and assembly. Universal gantry crane parts should be flexible rotation of the rotation, the coupling portion of the solid and reliable connection. Bolt securely, pulleys, wheels roll operation should be flexible, bearings, etc. should be marked with the lubrication grease.
3, general handling overhead gantry crane , avoid twisting, bending, impact and other accidents. Lifting girder should be bundled, such as non-bundled away. It must have the underlay strapping. Fundamental beam directly on the ground or drag member.
4, the storage should be placed smoothly and settle pad is, should be placed on a solid surface, not sinking, so universal gantry crane metal structure deformation, when stored in the open air, should be properly kept, to have sunscreen preservative measures, such as There should try to drain the water.
Gantry crane brief characteristics of the power supply system
Gantry crane power system characteristics are as follows:
1, gantry crane power system during normal operation, there is not a current online special protection, just work with the zero line current imbalance. PE line on the ground there is no voltage, so the electrical equipment metal casing then zero protection is connected to the PE exclusive line of protection, safe and reliable.
2, gantry cranes zero line of work is only used as a single-phase lighting load circuit.
3, special protection of PE allowed to break, and do not enter the GFCI.
4, the trunk using leakage protection, zero line of work can not have duplicate grounded while the PE grounding lines are repeated, but without leakage protection, so the TN-S system can also be installed on the supply mains leakage protection.
5, TN-S mode power supply system safe and reliable, suitable for industrial and civil buildings and other low-voltage power supply system. Gantry cranes at construction workers work in front of "leveling" (electricity, water supply, roads and horizon - must TN-S mode power supply system.
6, TN-CS mode power supply system bridge gantry crane at construction temporary power, if the first part is a TN-C mode power supply, and construction specification construction site must use TN-S mode power supply system, you can live in the latter part of the system Total distribution box ceded PE line.
Hoist gear apparatus described in detail
Underside of the hoist crane reducer assembly reference is also used to reduce the speed reducer electric hoist, power transmission, increasing the torque transmission components independently.
After the gear unit housing casting, mechanical processing, the greater the internal stress, and therefore a period of time may be deformed. Then joints not reach the original accuracy requirements, which occurred in leakage. Commonly used method of grinding and scraping for repairs:
1, the first oil release, remove all the parts, joints with flat scraper to remove dirt and rust layer on
2, and then cleaned with kerosene, joints coated in a thin layer of red lead oil grinding.
3, each individual grinding again scraped off the highs and glitches, so that after 2-3 times, the general will meet accuracy requirements.
Joints with the axis of the hole should be in the same plane, otherwise it will affect the accuracy of the hoist gantry crane gear reducer. Requires its flatness of 0.02mm. With a dial indicator bore, if the deviation is too large and should not be based on the original repair joints can be the first plane to about 2mm Zaigua grind joints achieve precision machining and re-bore up drawings.
Bottom of the hoist gear is the assembly reference, the reference is the joining surface of the processing, it requires its flatness 0.15-1.0mm, should be parallel to the bottom face gear joints, the joint surface is not parallel to the bottom surface and the degree of tolerance of 1000mmm is not greater than 0.5mm, joints roughness of not less than 1.6.
Introduction sheave grooves manufacturing specifications
Universal gantry crane pulley from the rim, spokes, hub composed rim rope through the rope groove to carry the entire pulley wheels fixed through the pulley shaft bearing on the rim with the spokes connected to the hub wheel, pulley for rope role is now combined with the pulley structure and size to achieve, rope groove to accommodate the rope as the main part, the force necessary to ensure the smooth passage of rope, but also to ensure that the crane body vibration operating conditions, wire rope pulley is not rolling over quit, pulley rope groove manufacturing process description:
1, the rope groove radius, is about 0.53-0.6 times the diameter of the bearing rope, the common bridge gantry crane wire rope grooves with a sufficient contact area to reduce rope pressure on the rope groove.
2, rope groove side angle of 35 degrees -40 degrees generally allow the axis of the pulley has some skewed to facilitate universal gantry crane rope to wear around the upper and lower pulleys, rope groove side to avoid excessive wear.
3, the rope groove height, to ensure sufficient depth rope groove, the wire rope passes through the slot to prevent the pulley mechanism with the rope running jitter quit.
4, the diameter of the pulley is calculated by common center computing gantry crane rope winding diameter pulley, which is a key dimension affecting life rope, wire rope and metal fatigue fracture occurs, mainly due to the deflection pulleys and off repeatedly when the spool bending caused pulley and hoist crane wire rope diameter ratio is to determine the life of important factors.
2013年7月28日星期日
Gantry crane frame Installation Instructions
gantry crane scene according to the general conditions and circumstances existing cranes, Diaozhu girder, 8-ton hydraulic hoist crane Diaozhu side of the beam, connected with 8 tons of hydraulic lifting beam connecting another collateral. (Main beam of about 6 tons electric hoist, crane slewing radius of 6m, lifting height of 9m, upon inspection 25 tons hydraulic crane performance table, turning radius 6m, lifting height 9m, can lift 12.2 tons. Completely optional to the crane. )
The general gantry crane after assembly tolerance requirements are as follows: Crane Span: ± 8mm.
Crane span relative difference: ± 8mm.
Universal primary beam gantry crane camber F: +0.4 F,-0.1F.
Cantilever bend degree F0: +0.4 F,-0.1F.
Beside the main beam camber f ≤ 15mm.
Universal bridge gantry crane machinery and equipment after installation check all lubrication points and oil is complete, and then clean the gear oil tank, into the oil, the oil should be consistent with the scale of the oil dipstick. When no oil dipstick should be able to cover the teeth of the gear lowest high prevail. Oil and lubricants used in grades should be designed.
Acceptance inspection of track and equipment
1, track inspection
Installation of doors gantry crane track for acceptance before the deal, check whether the track fixed firmly and in accordance with the design and construction specifications for track spacing, elevation, horizontal, parallel to check retest, carts track allowable deviation: two tracks height difference: <3mm two tracks not parallel error: <8mm track center distance error: <8mm wheel center distance range diagonal tracks the difference: <5mm
2, the device checks
Gantry cranes are mounted to the device before the deal, components carefully check to see whether there is defect, bumps, eliminate accumulation of fouling during custody, check the gear oil tank is clean, lubricating oil is in good condition, to ensure that the no problem components ready to install.
3, electric hoist connected with the main beam
The bridge gantry crane into the plant for the sub-structure, first of all electric hoist connected with the main beam. Hoist the inside of the wheel rim flange girder beam track clearance should be between 3 ~ 5mm.
Sprocket chain hoist should be maintained at the same vertical groove surface. Gantry crane in the chain should not be contorted runtime, stuck and severe wear and tear.
Installation of doors gantry crane track for acceptance before the deal, check whether the track fixed firmly and in accordance with the design and construction specifications for track spacing, elevation, horizontal, parallel to check retest, carts track allowable deviation: two tracks height difference: <3mm two tracks not parallel error: <8mm track center distance error: <8mm wheel center distance range diagonal tracks the difference: <5mm
2, the device checks
Gantry cranes are mounted to the device before the deal, components carefully check to see whether there is defect, bumps, eliminate accumulation of fouling during custody, check the gear oil tank is clean, lubricating oil is in good condition, to ensure that the no problem components ready to install.
3, electric hoist connected with the main beam
The bridge gantry crane into the plant for the sub-structure, first of all electric hoist connected with the main beam. Hoist the inside of the wheel rim flange girder beam track clearance should be between 3 ~ 5mm.
Sprocket chain hoist should be maintained at the same vertical groove surface. Gantry crane in the chain should not be contorted runtime, stuck and severe wear and tear.
Gantry crane parts reel design parameters described
Technical difficulties cable reel winding speed is to ensure that the moving speed synchronized with the device, but also to ensure the cable during winding moderate pulling force. Therefore,
gantry crane cable reel design should consider the following factors:
1, cable specifications and types: cable cross-sectional area from 1.0 ~ 240mm2, the cable reel diameter directly affects the axial dimension and power requirements. More than 35mm2 cable section should not select a non-motorized reel (with weight can be relaxed to 50mm2), flat cable can only use a single row axial reel. Cables should be selected YCW type (power cables) and CEFR type (control signal cable), etc., softer and have a certain tensile strength. Cable outer diameter and the unit weight to be accurate.
2, the winding length: Impact gantry crane reel radial dimensions and power demand, the longer the length of the higher power requirements. Non-electric cable reel winding difficult to complete large stroke. Ground anchor position also directly affects the power cable reel selection, common power supply anchor bit ends and the midpoint power supply in two. Non-electric power can not choose the midpoint magnetic coupling type (JQC series).
3, the mobile device may affect the power cable reel speed motor power and the transmission ratio. When the moving speed of bridge gantry crane equipment more than 60 m / min, should be chosen frequency control formula (BP series).
4, installed high-impact electric motor power cable reel, mounting height is higher, the greater the demand for power. The installation must not exceed the design requirements.
These four parameters are gantry crane cable reel design selection is based, should be considered, but also the structure and layout of cable reel way to meet actual demand conditions.
1, cable specifications and types: cable cross-sectional area from 1.0 ~ 240mm2, the cable reel diameter directly affects the axial dimension and power requirements. More than 35mm2 cable section should not select a non-motorized reel (with weight can be relaxed to 50mm2), flat cable can only use a single row axial reel. Cables should be selected YCW type (power cables) and CEFR type (control signal cable), etc., softer and have a certain tensile strength. Cable outer diameter and the unit weight to be accurate.
2, the winding length: Impact gantry crane reel radial dimensions and power demand, the longer the length of the higher power requirements. Non-electric cable reel winding difficult to complete large stroke. Ground anchor position also directly affects the power cable reel selection, common power supply anchor bit ends and the midpoint power supply in two. Non-electric power can not choose the midpoint magnetic coupling type (JQC series).
3, the mobile device may affect the power cable reel speed motor power and the transmission ratio. When the moving speed of bridge gantry crane equipment more than 60 m / min, should be chosen frequency control formula (BP series).
4, installed high-impact electric motor power cable reel, mounting height is higher, the greater the demand for power. The installation must not exceed the design requirements.
These four parameters are gantry crane cable reel design selection is based, should be considered, but also the structure and layout of cable reel way to meet actual demand conditions.
Lifting illegal operation and improvement program
One, close to the limit does not slow down
Universal gantry crane span relatively large, the use of driver control, prone to car line at the end of the beam away from the driver's cab, the driver is difficult to determine the exact location of the car, causing the car near the end of the beam does not slow down, hit the buffers at the end beam stopper, damage to the formation of the track, resulting in loosening the track.
Adjustment method: Use the units should strengthen the system construction, strengthen the common gantry crane operator safety education and skills training.
Second, lifting objects, partial on one side
Lifting heavy loads, partial on one side, the side of the track will be under pressure, long-term this operation will be this side of the track and the load-bearing beams causing serious injury, can cause serious side trajectory of the whole or part of the sinking . This situation allows universal gantry cranes lateral movement occurred during operation, causing the plate and rail loose. (Like two people bickering children, near the weight of people affected by a larger force)
Adjustment method: strengthen the system construction, strengthen the management of hoist crane and enhance the operator's training and management. If one side of the track has already appeared in whole or part sink, should be promptly elevate this side of the track.
Recommendation: direct cause of many accidents because of improper operation of the operator, so the use of units should strengthen the system construction, strengthen the common gantry crane use management, as well as to strengthen the skill of the operator training and safety education. Only the use of units and operations staff pay attention to it, in order to fundamentally reduce the failure rate and the accident rate.
Universal gantry crane span relatively large, the use of driver control, prone to car line at the end of the beam away from the driver's cab, the driver is difficult to determine the exact location of the car, causing the car near the end of the beam does not slow down, hit the buffers at the end beam stopper, damage to the formation of the track, resulting in loosening the track.
Adjustment method: Use the units should strengthen the system construction, strengthen the common gantry crane operator safety education and skills training.
Second, lifting objects, partial on one side
Lifting heavy loads, partial on one side, the side of the track will be under pressure, long-term this operation will be this side of the track and the load-bearing beams causing serious injury, can cause serious side trajectory of the whole or part of the sinking . This situation allows universal gantry cranes lateral movement occurred during operation, causing the plate and rail loose. (Like two people bickering children, near the weight of people affected by a larger force)
Adjustment method: strengthen the system construction, strengthen the management of hoist crane and enhance the operator's training and management. If one side of the track has already appeared in whole or part sink, should be promptly elevate this side of the track.
Recommendation: direct cause of many accidents because of improper operation of the operator, so the use of units should strengthen the system construction, strengthen the common gantry crane use management, as well as to strengthen the skill of the operator training and safety education. Only the use of units and operations staff pay attention to it, in order to fundamentally reduce the failure rate and the accident rate.
How to promote the overall level of construction machinery increased
Vicious competition in recent years has been plagued by construction machinery enterprises,
gantry crane product prices fell year on year can be reflected. Rising costs, profit margins compressed, so that production re-investment, investment in R & D and sales are subject to greater pressure, self-discipline, standardize trade practices highlights the importance of .
Low-carbon environment, save energy, smart green has become the inevitable trend of development of manufacturing industry, the development of intelligent manufacturing equipment has become a major industrial countries, the main areas of competition. Of bridge gantry crane and other machinery manufacturing equipment industry lack of technological innovation, the core technology subject to foreign; industry smaller, industrial organization structure is more lax; weak industrial base, even though they have started equipment manufacturing products market share is still less than 5%.
Transform and upgrade manufacturing, accelerating the development of strategic emerging industries is the national "five" plan clearly an important task. Transform and upgrade traditional industries oriented and strategic emerging industries development needs, focusing on promoting gantry cranes and other lifting products, to achieve a variety of manufacturing process automation, intelligent essence of technology to boost the overall level of intelligence equipment upgrade.
Now the state is continuously improved support for machinery and equipment manufacturing industry development policies and measures, overhead gantry crane industry development policy environment is generally good, the domestic equipment manufacturing enterprises must seize this opportunity, in the "Twelfth Five-Year" period to achieve intelligent field equipment breakthrough.
Low-carbon environment, save energy, smart green has become the inevitable trend of development of manufacturing industry, the development of intelligent manufacturing equipment has become a major industrial countries, the main areas of competition. Of bridge gantry crane and other machinery manufacturing equipment industry lack of technological innovation, the core technology subject to foreign; industry smaller, industrial organization structure is more lax; weak industrial base, even though they have started equipment manufacturing products market share is still less than 5%.
Transform and upgrade manufacturing, accelerating the development of strategic emerging industries is the national "five" plan clearly an important task. Transform and upgrade traditional industries oriented and strategic emerging industries development needs, focusing on promoting gantry cranes and other lifting products, to achieve a variety of manufacturing process automation, intelligent essence of technology to boost the overall level of intelligence equipment upgrade.
Now the state is continuously improved support for machinery and equipment manufacturing industry development policies and measures, overhead gantry crane industry development policy environment is generally good, the domestic equipment manufacturing enterprises must seize this opportunity, in the "Twelfth Five-Year" period to achieve intelligent field equipment breakthrough.
Construction machinery industry has much room for improvement
In recent years, development, universal
gantry crane industry in virtue of technology research and development, product development, reliability studies, manufacturing processes and other aspects of development, so that the amount of foreign markets have no quality of traditional, there are no technical quality of Chinese crane product has changed, but the undeniable fact is that trade was not able to get rid of the status quo big but not strong, in large tonnage
hoist crane market is particularly evident.
With universal gantry cranes and other construction machinery to improve the competitiveness and overseas sales network layout complete, Chinese products in the global market share will significantly increase. It is expected that future industry exports more than 35% average annual growth rate (nearly two years still above 50%), the export market is still sluggish, the current export volume growth is still only continue to accumulate, the future great qualitative change is also worth looking forward to.
Cyclical weakening industry to enhance the industry valuation levels. Although in the past stressed the export smoothing cycle, but there are several factors that can enhance this characteristic. First, the macro-control means the market; Second, the industry's growing portfolio of product offerings and; three major corporate product diversification. Consider universal gantry crane industry gradually weakening cyclical characteristics, combined with its high growth and the current overall market valuation, valuation of construction machinery industry level there room for improvement, can go to 2008 30-35 times.
Our high-end equipment manufacturing industry is still in its infancy, universal gantry crane industry international competitiveness is not strong, especially in the core areas of high dependence on foreign technology. In the industry continues to move towards automation, intelligent case, since the development of industry must boost confidence and greatly enhance the technical level, the early realization of the objectives equipment manufacturing powerhouse.
With universal gantry cranes and other construction machinery to improve the competitiveness and overseas sales network layout complete, Chinese products in the global market share will significantly increase. It is expected that future industry exports more than 35% average annual growth rate (nearly two years still above 50%), the export market is still sluggish, the current export volume growth is still only continue to accumulate, the future great qualitative change is also worth looking forward to.
Cyclical weakening industry to enhance the industry valuation levels. Although in the past stressed the export smoothing cycle, but there are several factors that can enhance this characteristic. First, the macro-control means the market; Second, the industry's growing portfolio of product offerings and; three major corporate product diversification. Consider universal gantry crane industry gradually weakening cyclical characteristics, combined with its high growth and the current overall market valuation, valuation of construction machinery industry level there room for improvement, can go to 2008 30-35 times.
Our high-end equipment manufacturing industry is still in its infancy, universal gantry crane industry international competitiveness is not strong, especially in the core areas of high dependence on foreign technology. In the industry continues to move towards automation, intelligent case, since the development of industry must boost confidence and greatly enhance the technical level, the early realization of the objectives equipment manufacturing powerhouse.
Small and medium enterprises to develop e-commerce mechanical effect is obvious
2013 first-quarter decline in imports of hoist crane . In particular gantry crane dropped significantly, or will no longer be dependent on imports. Indicates that China's crane products intensified international competition, small and medium enterprises to develop electricity supplier crane business effect is obvious, local products are more popular.
With e-commerce to reduce transaction costs and improve transaction efficiency, shorten the transfer time to expand the scope of sales and other advantages, greatly improves the SMEs will gantry crane and other lifting machinery to join the e-commerce market competitiveness. Want to make full use of e-commerce, e-commerce platform also need a good.
In the country to accelerate the development of urbanization, the gantry crane market outlook is still very uncertain. To meet the trend of development of the industry, the domestic small and medium enterprises have joined the ranks of electricity suppliers. Lifting equipment factory store small crane companies favor by reason, but also for a reason.
Single gantry crane products from import and export situation, which is China's small and medium enterprises is definitely a crane good news. One reason is that our product quality improved quickly, out of the country is a fact; the other hand, e-commerce and enterprise, and actively expand sales, lifting equipment factory store with such a platform, opened the network marketing market.
Crane work e-commerce, to promote development of the industry
At present, China crane industry, large enterprises operating in good condition, but small and medium sized enterprises by common
gantry crane market competition and the impact of the price war, it is difficult to progress in sales.
Universal gantry crane with its economic, safe, and reliable characteristics, and has become one of the fastest growing lifting equipment. Crane industry in the introduction of advanced technology and learning, integration of industry resources, the hoist crane began to join electricity supplier for SMEs, and promote the development of the industry at full speed.
Subject to the constraints of technology and design concepts, general gantry crane market demand is great, but selling pressure is still the corporate headache problem. Today, small and medium enterprises in addition to crane services to improve their quality, have begun to try to expand the business electricity supplier, and have achieved some results.
Impact of universal gantry crane sales is because in addition to the quality of service. Crane product quality is excellent, is reflected in the failure rates. Only low repair rate, will be consumers. Chinese enterprises should crane should always pay attention to product quality, developed in line with market demand and consumer products to meet customer needs as the starting point, while in the service of innovation in order to compete in the same industry occupies an advantageous position.
Universal gantry crane with its economic, safe, and reliable characteristics, and has become one of the fastest growing lifting equipment. Crane industry in the introduction of advanced technology and learning, integration of industry resources, the hoist crane began to join electricity supplier for SMEs, and promote the development of the industry at full speed.
Subject to the constraints of technology and design concepts, general gantry crane market demand is great, but selling pressure is still the corporate headache problem. Today, small and medium enterprises in addition to crane services to improve their quality, have begun to try to expand the business electricity supplier, and have achieved some results.
Impact of universal gantry crane sales is because in addition to the quality of service. Crane product quality is excellent, is reflected in the failure rates. Only low repair rate, will be consumers. Chinese enterprises should crane should always pay attention to product quality, developed in line with market demand and consumer products to meet customer needs as the starting point, while in the service of innovation in order to compete in the same industry occupies an advantageous position.
Machinery and equipment manufacturing industry experiencing the best time
China is now the universal
gantry crane and other machinery and equipment manufacturing enterprises the best time to go out, on the one hand, China's equipment manufacturing technology and quality than in the past both have a great deal of progress, and fully meet the export requirements. Other hand, with the construction of China's overseas investment continues to expand, more and more domestic construction unit went out, to undertake a variety of projects overseas.
In addition, because many parts of the south into the second half of the rainy season, universal bridge gantry crane and other lifting machinery sales appear relatively large drop in demand for the northern region of the mine is not much better in some areas due to security incidents into mine shutdowns. Also no large-scale infrastructure projects around the start, local governments more cautious attitude to investment in infrastructure, operation rate year on year decline.
Therefore, in the internal and external situation, the domestic construction machinery enterprises should first be based on expanding domestic demand and hold their own in the market, at the same time, the merger going to be careful when investing, rational, scientific, safe. Universal gantry cranes and other machinery enterprises in restructuring, but also strengthen the independent innovation, to capture the high-end manufacturing, both to replace part of the imports, and export promotion products from low-grade to high-grade promotion.
Ensure that traditional export products to maintain market share, thus stable product quality and perfect after-sale service. Whether universal gantry crane how bad market environment, maintaining a state of mind is equally important development, construction machinery market recovery long way to go, need to force public sector companies jointly.
In addition, because many parts of the south into the second half of the rainy season, universal bridge gantry crane and other lifting machinery sales appear relatively large drop in demand for the northern region of the mine is not much better in some areas due to security incidents into mine shutdowns. Also no large-scale infrastructure projects around the start, local governments more cautious attitude to investment in infrastructure, operation rate year on year decline.
Therefore, in the internal and external situation, the domestic construction machinery enterprises should first be based on expanding domestic demand and hold their own in the market, at the same time, the merger going to be careful when investing, rational, scientific, safe. Universal gantry cranes and other machinery enterprises in restructuring, but also strengthen the independent innovation, to capture the high-end manufacturing, both to replace part of the imports, and export promotion products from low-grade to high-grade promotion.
Ensure that traditional export products to maintain market share, thus stable product quality and perfect after-sale service. Whether universal gantry crane how bad market environment, maintaining a state of mind is equally important development, construction machinery market recovery long way to go, need to force public sector companies jointly.
Construction machinery twists and turns the road to recovery
Since the beginning of construction machinery has been sent to pick up the signal, the road to recovery has twists and turns. The
gantry crane market slowdown in the economic environment, but also to bring some pressure on the recovery, plus urbanization has not fully started, social capital tightening and foreign export situation is grim, and many other problems, leading to the recovery of the construction machinery long way to go.
Has been a huge inventory, excess capacity is pressed in the major equipment manufacturers chest on a boulder, especially in the domestic market is still uncertain overhead gantry crane period. While the domestic construction machinery enterprises profit margins status quo, but it is being constantly compressed, especially single product net sales decrease, then the profitability of the market, corporate earnings will determine whether or not the host.
Therefore, whether the market is corporate profits after the main body is a measure of a country's construction machinery market is a mature one ruler, it can help businesses get more profits, while Chinese construction machinery enterprises in order to accelerate the improvement of their after-market sound construction, gantry cranes and other lifting machinery technology innovation will be a key part, because only the more innovative design and technology patents to mention safeguard earnings after the market, especially for the engineering machinery parts and components. Therefore, to achieve a better corporate profit model, we must rely on to improve the profitability of the market after reducing the dependence on the new machine sales.
The current world economy is slowly recovering, but growth underpowered, gantry cranes and other lifting situation is still severe and complicated, weak demand in major economies, structural adjustment is slow, energy prices rose. For us, shrinking external demand has become an indisputable fact, continue to maintain the rapid growth of exports of machinery products are no longer possible.
Has been a huge inventory, excess capacity is pressed in the major equipment manufacturers chest on a boulder, especially in the domestic market is still uncertain overhead gantry crane period. While the domestic construction machinery enterprises profit margins status quo, but it is being constantly compressed, especially single product net sales decrease, then the profitability of the market, corporate earnings will determine whether or not the host.
Therefore, whether the market is corporate profits after the main body is a measure of a country's construction machinery market is a mature one ruler, it can help businesses get more profits, while Chinese construction machinery enterprises in order to accelerate the improvement of their after-market sound construction, gantry cranes and other lifting machinery technology innovation will be a key part, because only the more innovative design and technology patents to mention safeguard earnings after the market, especially for the engineering machinery parts and components. Therefore, to achieve a better corporate profit model, we must rely on to improve the profitability of the market after reducing the dependence on the new machine sales.
The current world economy is slowly recovering, but growth underpowered, gantry cranes and other lifting situation is still severe and complicated, weak demand in major economies, structural adjustment is slow, energy prices rose. For us, shrinking external demand has become an indisputable fact, continue to maintain the rapid growth of exports of machinery products are no longer possible.
2013年7月26日星期五
About crane accessories flexible coupling performance introduction
About crane accessories flexible coupling performance introduction
Couplings are used to join the two axes of different institutions (master axis and slave axis) so that the joint is rotated to transmit torque universal gantry crane parts. Overloaded power transmission at high speed, some couplings and buffers, vibration and improve the dynamic performance of the role of shafting. Composed by the two halves of the coupling, respectively, and the drive shaft and the driven shaft connected. Most of the general power machine coupling means coupled with the working machine. Compensation is associated with a certain two shaft axis relative offset capability, the maximum amount varies with the model. Inelastic components common gantry crane flexible coupling: large carrying capacity, but do not have the energy absorbing performance, high speed or speed instability or regular, reverse, there is the impact of noise. For low-speed, heavy duty, steady speed occasions. Metallic elastic element common gantry crane flexible coupling when the speed is not stable damping performance good buffer; but because metallic (rubber, nylon, etc.) elastic components of low intensity, short life, carrying capacity is small, not high temperature and low temperature, it is suitable for high-speed, light load and normal occasions. Universal hoist gantry crane metal elastic element flexible coupling: In addition to having a good buffer damping performance, larger carrying capacity, speed and load changes for large and high or low temperature applications.
Safety Precautions
1, jib crane lifting weights, hook wire rope should be kept vertical, oblique tow was hanging objects are not allowed. 2, the heavy lifting should identify the center of gravity and securely tied. The application has an acute angle skid pad.
3, not the heavy lifting off the ground in front of the crane shall make rotary motion.
4, lifting or lowering heavy loads, the speed should be uniform steady speed to avoid drastic changes, causing heavy swing in the air, dangerous. Falling weights, speed not too fast, so as not to break when landing weight.
5, hoist crane case, try to avoid landing arm. Must be ups and downs in the case of lifting arm when lifting weight must not exceed 50% by weight.
6, hoist crane the case is reversed, should pay close attention to whether there are obstacles around, if it should try to avoid obstacles or clear.
7, crane boom shall not have staff to stay, and try to avoid people pass.
8, two cranes operating on the same track, the distance between the two planes should be greater than 3m.
9, two cranes lifting an object together, from the weight of not more than two from the weight of 75% of the total, two cranes walk the line, dipping action to be consistent.
10, hoisting, luffing rope must be checked weekly, and make records, according to the specific requirements of the relevant provisions of lifting cables.
11, empty rows or turning away when the hook to more than 2m from the ground.
12, the wind more than six, they should immediately stop working. TMK arm should go off downwind and appropriately low, hang the hook firmly. Gantry crane shall lay the iron wedge (for rail), and rose to ceiling hook. Meanwhile shut doors and windows, turn off the power, pull a good wind cable wire. After the usual work should also do the same.
13, non-stacking crane platform miscellaneous objects even prevent fall injuries in the operation, frequently used tools should be placed in the operating room dedicated toolbox.
14, the operation is not permitted sudden shift or turn the clock back, so as not to cause heavy swing in the air, are not allowed to operate simultaneously two or more (including auxiliary hook) of the operating mechanism.
15, while driving, the operator shall not leave the controller's hand, a sudden failure of the operation, measures should be taken to a safe landing weight, then cut off the power to carry out repairs. In operation, repair and maintenance is strictly prohibited.
16, one of the crane under the following circumstances shall not lift
1, the weight exceeds the rated lifting capacity crane.
2, heavy weight is unknown.
3, the signal is unknown.
4, heavy strapping is not strong.
5, open operation in case of six (beam five) or more wind and heavy rain, fog and other inclement weather.
6, night work lighting is not good.
7, stayed.
8, badly worn rope off shares and someone appeared on the crane or room for maintenance.
Gantry crane structure
gantry crane hoisting mechanism, trolley traveling mechanism and bridge structures, bridge crane with basically the same. Because large span, crane operating agencies were driven mostly used way to prevent the crane operation and increase the resistance generated skew even accidents. Gantry crane lifting trolley running on the bridge, and some lifting trolley is a jib crane . Bridge on both sides of the legs are generally rigid legs; span of more than 30 m, it is often the side of the rigid leg, and the other side of the bridge by a ball hinge connections and flexible leg, the mast a statically determinate systems , under external loads to avoid lateral thrust caused by the additional stress, can also be compensated bridge gantry crane vertical temperature deformation of the wind area, in order to prevent the strong wind down the line or tip over, with wind measurement instrument and organization and operation of the crane rail clamp interlock. Both ends of the bridge can be without cantilevers; also be cantilevered at one end or both ends of the boom to extend the scope of operation. hoist gantry crane bridge legs at one end, the other end of the outrigger, running directly on the high bench.
Gantry crane control system solutions
Gantry crane control system solutions
gantry crane actuator work required frequent start, braking and reversing, thus requiring its electronic control system has high security and reliability. Traditional electric control system, due to consider the complex inter-agency working condition interlock and protection alarm, using a lot of time relays and relay, the control cabinet wiring is very complicated, to commissioning and maintenance inconvenience. Adopts PLC as controller, you can replace the PLC timer time relay, with the software programming to achieve inter-agency and multi-interlock protection alarm. Greatly reduces the intermediate relay, making it simple to design the system to improve the electrical control reliability. In addition, the PLC can also be achieved through the control of the inverter and the complex process requirements. bridge gantry crane PLC main control functions are: to accept the master controller speed control signal to control the crane walking, lifting movement and speed control. (A) safety interlock and protection of newspaper and other signal processing. (2) lifting, running gear synchronization control (3) hoists detection and closed-loop control (4) Auxiliary systems and power distribution system monitoring 1.3.2 crane monitoring system as microelectronics, computer and control technology continues to push New, PLC has developed into a versatile, intelligent integrated controller. their application not only to achieve automatic control of the production process, but also constitutes a real-time network for industrial environments, allowing the system to a single PLC control extends to large industrial networks dispersion devices, PLC link communication network, to achieve a large number of high-speed data transmission and management, through the SCADA / HMI SCADA management software enables the operation of the hoist crane intelligent management SCADA management software's main functions are: ( 1) Online functions: real-time display operating status, graphic simulation, user-friendly interface for easy operation. (2) failure alarm (3) Automatic monitoring interlock function (4) historical maintenance data records (5) operating statistics and records (6) help function (7) System Report: The system can achieve fault statistics and print reports, operational reports , repetitive failure rate and other relevant data reports.
gantry crane actuator work required frequent start, braking and reversing, thus requiring its electronic control system has high security and reliability. Traditional electric control system, due to consider the complex inter-agency working condition interlock and protection alarm, using a lot of time relays and relay, the control cabinet wiring is very complicated, to commissioning and maintenance inconvenience. Adopts PLC as controller, you can replace the PLC timer time relay, with the software programming to achieve inter-agency and multi-interlock protection alarm. Greatly reduces the intermediate relay, making it simple to design the system to improve the electrical control reliability. In addition, the PLC can also be achieved through the control of the inverter and the complex process requirements. bridge gantry crane PLC main control functions are: to accept the master controller speed control signal to control the crane walking, lifting movement and speed control. (A) safety interlock and protection of newspaper and other signal processing. (2) lifting, running gear synchronization control (3) hoists detection and closed-loop control (4) Auxiliary systems and power distribution system monitoring 1.3.2 crane monitoring system as microelectronics, computer and control technology continues to push New, PLC has developed into a versatile, intelligent integrated controller. their application not only to achieve automatic control of the production process, but also constitutes a real-time network for industrial environments, allowing the system to a single PLC control extends to large industrial networks dispersion devices, PLC link communication network, to achieve a large number of high-speed data transmission and management, through the SCADA / HMI SCADA management software enables the operation of the hoist crane intelligent management SCADA management software's main functions are: ( 1) Online functions: real-time display operating status, graphic simulation, user-friendly interface for easy operation. (2) failure alarm (3) Automatic monitoring interlock function (4) historical maintenance data records (5) operating statistics and records (6) help function (7) System Report: The system can achieve fault statistics and print reports, operational reports , repetitive failure rate and other relevant data reports.
Calculating overhead crane big wheel pressure factors to be considered How to more accurately calculate the overhead crane big wheel pressure:
Calculating overhead bridge crane big wheel pressure factors to be considered
How to more accurately calculate the overhead crane big wheel pressure:
(1) if the maximum lifting load, which should be based on the actual needs of the car position calculation. In general, when the hoist crane lifting the maximum load, often in a car near the middle of the main beam, then the cart wheel pressure is clearly better than the car is in the end when the main beam is much smaller.
(2) If the car runs to the end of the main beam, the load should be based on the actual amount of time to calculate. In general, when the car runs to the end of the main beam, it is usually not lifting the maximum load, then the cart wheel pressure is clearly better than lifting the maximum load is much smaller.
(3) If the car is neither lifted nor maximum load is the minimum load, and run in the middle of the main beam and the end portion.
In summary, in the past on the bridge crane carts wheel pressure calculation method is not perfect, accuracy is poor, resulting in calculated crane wheel pressure is too large, plant design is too conservative and caused a lot of waste. Improve security should be based on the correct algorithm and the use of advanced technological means and the right measures to complete (such as increasing the safety factor, increasing the limit
And alarm measures). This will not only reduce the maximum crane wheel pressure, and can save a lot of ground plant cost.
Universal gantry crane manufacturer of crane hook materials and manufacturing process technology
Universal gantry crane manufacturer of crane hook materials and manufacturing process technology
Universal gantry crane manufacturer recommends the hook block component parts, that is, by the hook, nut, thrust bearings, pulleys, etc. beams and composed a few simple parts. In accordance with the shape of a hook into a single hook and double hook two kinds, the name suggests is to use a single hook to hang a hook cargo hook, it can only lift the lighter lifting cargo, double hook lifting the starting Heavy goods on relatively heavy, but talked hook lifting goods, can not help but think of those as accidental failure of the goods fall, resulting in serious injury or death, or property. So for the hook is quite strict quality requirements, and to achieve the safety performance of the hook, you have to hook the structure from design, material configuration, manufacturing methods and other aspects, and in the manufacture and use of the process to strengthen inspection and maintenance, find any unreasonable situation, it must be scrapped timely updates.
The hook on the material.
In addition to lifting hooks to bear the weight of items outside itself from the hoist crane hoisting mechanism at the moment of starting and stopping the energy of the impact load, but also can not be underestimated, so the hook must have a high mechanical strength and good impact toughness, and general high-carbon steel brittle, usually sensitive to stress concentration and cracks, have adopted relatively good quality low carbon killed steel or low carbon alloy steel and so on.
About the hook manufacturing process knowledge
In accordance with the manufacturing method will generally be divided into forging hook hook hook and laminations, which is forging hook overall manufacturing cost is relatively low, it is also very easy to manufacture, so widely, but forging hook once destroyed, also can be said that all scrapped. The hook is a laminated multi-chip connected to a rectifying rolled plate, the middle with buffered tabletting pressure can bring the energy buffer, the breakage took place even if the individual plates, it will not affect the overall fracture and breakage.
Single girder overhead crane rules
Single girder bridge crane rules
1 before work
a. With single girder overhead bridge crane , cab, the driver before driving succession, response hook, wire rope and safety devices and other components according to the requirements of the check card checks, abnormal, should be excluded.
b. Ground handling single girder overhead crane, the class should be someone responsible for the check card at the request of inspection, abnormal, should be excluded.
c. Operator must confirm to go Taiwan or track when no one can close the main power supply. When the power supply circuit breaker locking or signs, the persons concerned should be removed only after the original closing the main power supply.
(2) work
a. First class lifting weights (or the load reaches the maximum weight) should be hanging height of 0.5 meters from the ground after the heavy down again, check the brake performance, reliable after confirmation, then normal operation.
b. Strictly enforce the "do not hang ten" system:
① command signal is unknown or arbitrary command does not hang;
② does not exceed the rated lifting weight lifting;
③ spreaders unreasonable or not the object is not strong tie to hang suspended;
④ hanging objects floating on someone or put other items are not hanging;
⑤ brake failure or other safety device brake not hanging;
⑥ hanging heavy traffic processed directly without hanging;
⑦ pull Xiegua not hanging crooked;
⑧ explosive objects are not hanging;
⑨ buried object is not suspended;
⑩ angular blocks mouth objects, not pad it really hanging;
c. Abnormal, immediately shut down, cut off the power and check the reason and immediately removed.
3 work
a. The hook rises to a certain height, carts parked in the specified location, the controller handle in the "zero" position; pull knife, cut off the power.
b. Routine maintenance.
c. Do shift work.
Double girder overhead crane rules
Double girder
overhead bridge crane rules
1 before work
a. On the brakes, hook, wire rope and safety devices and other components according to the requirements of the check card check and found abnormal, should be thoroughly removed.
b. Operator must confirm to go Taiwan or track when no one can close the main power supply. When the power supply circuit breaker locking or signs, the persons concerned should be removed only after the original closing the main power supply.
(2) work
a. First class lifting weights (or the load reaches the maximum weight) should be hanging height of 0.5 meters from the ground after the heavy down again, check the brake performance, reliable after confirmation, then normal operation.
b. Operator in the job, should be required for the following operations-ringing alarm.
① lifting, landing weight; starting big car when traveling. gantry crane
Gantry crane
② crane when traveling in clear view through to continuous-ringing alarm;
③ crane traveling close to the cross inside another crane.
④ when lifting heavy objects close to the staff.
c. Operation should be run under a unified command signals.
d. Work in a power outage, should all of the control handle to the "zero" position should be checked prior to re-work the crane movement is normal.
e. Large hoist crane , trolley during normal operation, is strictly prohibited to open anti-vehicle parking brake; transform large trolley movement direction, the handle must be placed in the "zero" position, the agency completely stopped, can the reverse drive.
f. There are two hooks of the crane, in the main, auxiliary hook for hook height with time and the two are similar, the main and auxiliary hook must work alone, so two hooks collision.
g. Two allowed two hook crane hook lifting two objects simultaneously; does not work in the case adjust the brake lifting mechanism.
h. Are not allowed to use extreme position limiter parking is prohibited in the case of a load lifting mechanism to adjust the brake.
i. Strictly enforce the "do not hang ten" system:
① command signal is unknown or arbitrary command does not hang;
② does not exceed the rated lifting weight lifting;
③ spreaders unreasonable or not the object is not strong tie to hang suspended;
④ hanging objects floating on someone or put other items are not hanging;
⑤ brake failure or other safety device brake not hanging;
⑥ hanging heavy traffic processed directly without hanging;
⑦ pull Xiegua not hanging crooked;
⑧ explosive objects are not hanging;
⑨ buried object does not pull hanging;
⑩ angular blocks mouth objects, not pad it really hanging;
j. If abnormal, immediately shut down, check the reason and immediately removed.
3 work
a. The hook rises to a certain height, carts, trolley stops at the specified location, the controller handle in the "zero" position; Pull off the protective box switch handle, cut off the power.
b. Routine maintenance.
c. Do shift work.
1 before work
a. On the brakes, hook, wire rope and safety devices and other components according to the requirements of the check card check and found abnormal, should be thoroughly removed.
b. Operator must confirm to go Taiwan or track when no one can close the main power supply. When the power supply circuit breaker locking or signs, the persons concerned should be removed only after the original closing the main power supply.
(2) work
a. First class lifting weights (or the load reaches the maximum weight) should be hanging height of 0.5 meters from the ground after the heavy down again, check the brake performance, reliable after confirmation, then normal operation.
b. Operator in the job, should be required for the following operations-ringing alarm.
① lifting, landing weight; starting big car when traveling. gantry crane
Gantry crane
② crane when traveling in clear view through to continuous-ringing alarm;
③ crane traveling close to the cross inside another crane.
④ when lifting heavy objects close to the staff.
c. Operation should be run under a unified command signals.
d. Work in a power outage, should all of the control handle to the "zero" position should be checked prior to re-work the crane movement is normal.
e. Large hoist crane , trolley during normal operation, is strictly prohibited to open anti-vehicle parking brake; transform large trolley movement direction, the handle must be placed in the "zero" position, the agency completely stopped, can the reverse drive.
f. There are two hooks of the crane, in the main, auxiliary hook for hook height with time and the two are similar, the main and auxiliary hook must work alone, so two hooks collision.
g. Two allowed two hook crane hook lifting two objects simultaneously; does not work in the case adjust the brake lifting mechanism.
h. Are not allowed to use extreme position limiter parking is prohibited in the case of a load lifting mechanism to adjust the brake.
i. Strictly enforce the "do not hang ten" system:
① command signal is unknown or arbitrary command does not hang;
② does not exceed the rated lifting weight lifting;
③ spreaders unreasonable or not the object is not strong tie to hang suspended;
④ hanging objects floating on someone or put other items are not hanging;
⑤ brake failure or other safety device brake not hanging;
⑥ hanging heavy traffic processed directly without hanging;
⑦ pull Xiegua not hanging crooked;
⑧ explosive objects are not hanging;
⑨ buried object does not pull hanging;
⑩ angular blocks mouth objects, not pad it really hanging;
j. If abnormal, immediately shut down, check the reason and immediately removed.
3 work
a. The hook rises to a certain height, carts, trolley stops at the specified location, the controller handle in the "zero" position; Pull off the protective box switch handle, cut off the power.
b. Routine maintenance.
c. Do shift work.
How to choose the gantry crane
First, the choice of gantry crane
It is consistent with common gantry crane GB/T14406-1993 and GB5905-86 of the relevant provisions.
Under normal circumstances, from the weight of 50t or less, in the span of less than 35m, no special requirements, should use a single main beam. If you require a large gate leg width, high working speed, or frequently lifting heavy pieces, grew up pieces, you should choose double girder gantry crane.
Second, the span and the cantilever length
Span gantry crane crane itself is affecting the quality of the important factors. Selection, to meet the conditions of use and equipment conform span series of standards under the premise of the span should be minimized.
Third, the principle for determining Tread
(A) along a gantry crane to meet stability requirements of the track direction;
(B) the dimensions of the goods to be able to pass the legs flat steel;
(C) pay attention to the track B and the span S proportional relationships, and generally track B = (1/4-1/6) S.
Fourth, determine the pitch size of gantry crane
At work, bridge gantry crane and yard external dimensions of goods and transport vehicles between channels should leave some space dimensions, in order to facilitate loading and unloading operations. General transport vehicles in the span of loading and unloading, should be kept above the door legs with 0.7m spacing. Spreader should not work with the transport vehicles with more than 0.5m spacing, cargo interlude legs, there should be more than 0.5m spacing.
It is consistent with common gantry crane GB/T14406-1993 and GB5905-86 of the relevant provisions.
Under normal circumstances, from the weight of 50t or less, in the span of less than 35m, no special requirements, should use a single main beam. If you require a large gate leg width, high working speed, or frequently lifting heavy pieces, grew up pieces, you should choose double girder gantry crane.
Second, the span and the cantilever length
Span gantry crane crane itself is affecting the quality of the important factors. Selection, to meet the conditions of use and equipment conform span series of standards under the premise of the span should be minimized.
Third, the principle for determining Tread
(A) along a gantry crane to meet stability requirements of the track direction;
(B) the dimensions of the goods to be able to pass the legs flat steel;
(C) pay attention to the track B and the span S proportional relationships, and generally track B = (1/4-1/6) S.
Fourth, determine the pitch size of gantry crane
At work, bridge gantry crane and yard external dimensions of goods and transport vehicles between channels should leave some space dimensions, in order to facilitate loading and unloading operations. General transport vehicles in the span of loading and unloading, should be kept above the door legs with 0.7m spacing. Spreader should not work with the transport vehicles with more than 0.5m spacing, cargo interlude legs, there should be more than 0.5m spacing.
Use the form gantry crane
1 ordinary gantry crane
bridge gantry crane
bridge gantry crane,
This multi-use container crane type and truss structure, the most widely used. You can carry a variety of items and bulk materials into, from the weight of 100 tons, a span of 4 to 39 meters. Grab the ordinary with a gantry crane working level is higher. Common gantry crane mainly refers hook, grab, electromagnetic, hoist gantry crane, but also includes semi-gantry cranes.
2 hydropower station Gantry Crane
Mainly used to lifting and hoisting the gate, but also for the installation. Lifting capacity of 80 to 500 tons, span is small, 8 to 16 m; lifting lower rate of 1 to 5 m / min. This crane lifting, though not often, but once the work is very heavy use, it should be appropriate to increase the working level.
3 shipbuilding overhead gantry crane
Used to berth the hull assembly, standing with two lifting car: a machine with two main hook in the top flange of the rail bridge runs; another has a primary and a secondary hook hook in the bottom flange of the bridge orbit to flip and lifting large hull section. Weight is generally from 100 to 1500 tons; span of 185 meters; lifting speed of 2 to 15 m / min, and 0.1 to 0.5 m / min jog speed.
4 container gantry crane
For the container terminal. Trailer Bridge will quay container unloaded from the ship carrying the container gantry crane tracks
Rail gantry crane
Transported to the yard or rear, by the container gantry crane stacking up or direct loading carried away, can speed up the container carrying the crane bridge or other turnover. Can be 3 to 4 layers stacked high, wide 6 rows of container yard, general use tire, but also useful rail type. Container gantry crane and container straddle compared to its span and height on both sides of the door frame are larger. To meet the transportation needs of ports, this crane working level is higher. Lifting speed of 8 to 10 m / min; span across the container needed to determine the number of rows, the maximum is 60 meters corresponding to 20 feet, 30 feet, 40 feet long container from the weight of approximately 20 tons, 25 tons and 30 tons.
bridge gantry crane
bridge gantry crane,
This multi-use container crane type and truss structure, the most widely used. You can carry a variety of items and bulk materials into, from the weight of 100 tons, a span of 4 to 39 meters. Grab the ordinary with a gantry crane working level is higher. Common gantry crane mainly refers hook, grab, electromagnetic, hoist gantry crane, but also includes semi-gantry cranes.
2 hydropower station Gantry Crane
Mainly used to lifting and hoisting the gate, but also for the installation. Lifting capacity of 80 to 500 tons, span is small, 8 to 16 m; lifting lower rate of 1 to 5 m / min. This crane lifting, though not often, but once the work is very heavy use, it should be appropriate to increase the working level.
3 shipbuilding overhead gantry crane
Used to berth the hull assembly, standing with two lifting car: a machine with two main hook in the top flange of the rail bridge runs; another has a primary and a secondary hook hook in the bottom flange of the bridge orbit to flip and lifting large hull section. Weight is generally from 100 to 1500 tons; span of 185 meters; lifting speed of 2 to 15 m / min, and 0.1 to 0.5 m / min jog speed.
4 container gantry crane
For the container terminal. Trailer Bridge will quay container unloaded from the ship carrying the container gantry crane tracks
Rail gantry crane
Transported to the yard or rear, by the container gantry crane stacking up or direct loading carried away, can speed up the container carrying the crane bridge or other turnover. Can be 3 to 4 layers stacked high, wide 6 rows of container yard, general use tire, but also useful rail type. Container gantry crane and container straddle compared to its span and height on both sides of the door frame are larger. To meet the transportation needs of ports, this crane working level is higher. Lifting speed of 8 to 10 m / min; span across the container needed to determine the number of rows, the maximum is 60 meters corresponding to 20 feet, 30 feet, 40 feet long container from the weight of approximately 20 tons, 25 tons and 30 tons.
Crane Handling Precautions
One,
gantry crane driver and signalman shall have a unified signal. Operators should be dedicated ladder, operating room, closing should be preceded by the controller to zero. Operating room should be wood or rubber insulating mat board.
Second, the gantry crane work, should make the following preparations:
1, check the steel parts are securely connected.
2, check the volume of the rotating part of the field of machine lubrication is good, brakes are sensitive and reliable.
3, check the wiring is correct electrical equipment, insulation is good.
4, Check and test the limit switch is sensitive, good lighting equipment is complete.
5, check the scaffold boards, railings, escalators is in compliance with safety requirements. Rail clamp (or anchor screws) are tightened.
6, after two tripod legs pin and card board is moving.
7, room and operating room fire-fighting equipment are complete and valid.
Third, the driver must be located in the operating room good view position.
Fourth, the hoist crane , luffing, slewing used winches, winch must meet safety requirements, running the motor with the motor must comply with the relevant safety regulations, crane wire rope used must meet the relevant safety requirements.
Fifth, check before driving on track to be within the scope of the ground and run unattended or obstacles, and-ringing hands. Traveling carts must have someone pull the cable, the cable car back and forth to be insulated well hung, sliding freely. When lifting, should be carried empty running, then try hanging from the ground 100-150mm, heavy bondage found incorrect, should be re-tied.
Second, the gantry crane work, should make the following preparations:
1, check the steel parts are securely connected.
2, check the volume of the rotating part of the field of machine lubrication is good, brakes are sensitive and reliable.
3, check the wiring is correct electrical equipment, insulation is good.
4, Check and test the limit switch is sensitive, good lighting equipment is complete.
5, check the scaffold boards, railings, escalators is in compliance with safety requirements. Rail clamp (or anchor screws) are tightened.
6, after two tripod legs pin and card board is moving.
7, room and operating room fire-fighting equipment are complete and valid.
Third, the driver must be located in the operating room good view position.
Fourth, the hoist crane , luffing, slewing used winches, winch must meet safety requirements, running the motor with the motor must comply with the relevant safety regulations, crane wire rope used must meet the relevant safety requirements.
Fifth, check before driving on track to be within the scope of the ground and run unattended or obstacles, and-ringing hands. Traveling carts must have someone pull the cable, the cable car back and forth to be insulated well hung, sliding freely. When lifting, should be carried empty running, then try hanging from the ground 100-150mm, heavy bondage found incorrect, should be re-tied.
Gantry crane cable reel torque motor control part of the technological innovations
gantry crane cable drum drive motor is torque motor, the direction of their work only in one direction so that the cable reel recycling. Walking carts flap side of the cable is fixed by the motor-driven cable reel recycling, and to the other side is the cable tension by turning the motor torque to overcome the invert put the cable reel. In reaching the cable flap at large, to let in the motor drive forward roll, the sudden reversal of motor rotation torque to overcome the pull of full role on the cable, this force is quite large, so it is likely to cause damage to the cable . We rent Yidu projects outside 63T
bridge gantry crane cables because of this causes serious wear and tear. To this end, we Yidu comprehensive mechanization squad leader Zhao Qiushun chef with years of experience in electrical, motor torque control loop for its rectification, to solve this problem, as follows.
Rectification mainly torque motor control loop, the result is to make the motor torque to the cable car traversing at a fixed flap can temporarily stop working, to prevent a sudden change of direction, reducing the moment the cable suffered a big pull. As illustrated in Figure One is the improved electrical schematics, Figure 2 shows the original electrical schematics. We realize this process is mainly used in the running of the two trolley unit conversion limit switch (Figure K1, K2, Model LX19-222) in the cable flap about two meters were installed at the corresponding switch on the bezel , by switching the switch to achieve the collision stopper conversion.
BRIEF DESCRIPTION controls the entire process is as follows: When the carts to move forward, the icon ① circuit connected, time relay ST1 turned its speed make contact ST1 closed, then switch K1A, K2A in the closed state, K3 is limit torque motor brake, brake opens its status is closed, then the torque of the motor control circuit is ON, the motor running. When walking to the cable flap on the 1st stopper at a fixed time, K1 collision stopper, K1A disconnect, K1B closed power control loop torque motor, the motor stopped working. Carts continue to walk through the cable to the 2nd stop tailgate flap, K2 collision stopper, K2A disconnect, K2B closed, the torque motor control circuit through K1B, K2B formation pathway, the motor starts to operate again. This completes the flap around the cable short stops the motor torque is reduced by a large instantaneous cables tension.
Conversely, cars and carts to go back on the opposite. The beginning is K1B, K2B closed to achieve the torque motor is running, the line to the 2nd stopper at, K2 switch collision baffle, K2B disconnect, K2A closed control loop disconnect torque motor, the motor stops working, carts continue Walking back to the 1st baffle, K1 collision baffle, K1B K1A closed off, then torque motor control circuit through K1A, K2A formation pathway, electricity running again in order to achieve the purpose.
In order to prevent the cable carts stopped collapse under the action of gravity, walking in the control of the motor contactors and relays on two time ST1, ST2 (model JST-4), two time delay relay to disconnect Contact ST1, ST2 access roll torque motor control circuit to ensure carts can continue to run after stopping a short time. In addition to the torque motor braking torque motor control circuit limit access only opened its K3 brakes to get through. Also in the brake control circuit added a contactor MZ, its normally open contact access control loop walking carts, only cable reel system is powered motor circuit walk to get through, to prevent problems when walking to pull off the cable.
After rectification where there is a need to pay attention is to check the K1, K2 two changeover switch crank arm direction in the two stopper at the outside, crank arm must remain two switches are kept in the same direction, or torque motor does not will operate normally. Will pull off the cable.
Rectification mainly torque motor control loop, the result is to make the motor torque to the cable car traversing at a fixed flap can temporarily stop working, to prevent a sudden change of direction, reducing the moment the cable suffered a big pull. As illustrated in Figure One is the improved electrical schematics, Figure 2 shows the original electrical schematics. We realize this process is mainly used in the running of the two trolley unit conversion limit switch (Figure K1, K2, Model LX19-222) in the cable flap about two meters were installed at the corresponding switch on the bezel , by switching the switch to achieve the collision stopper conversion.
BRIEF DESCRIPTION controls the entire process is as follows: When the carts to move forward, the icon ① circuit connected, time relay ST1 turned its speed make contact ST1 closed, then switch K1A, K2A in the closed state, K3 is limit torque motor brake, brake opens its status is closed, then the torque of the motor control circuit is ON, the motor running. When walking to the cable flap on the 1st stopper at a fixed time, K1 collision stopper, K1A disconnect, K1B closed power control loop torque motor, the motor stopped working. Carts continue to walk through the cable to the 2nd stop tailgate flap, K2 collision stopper, K2A disconnect, K2B closed, the torque motor control circuit through K1B, K2B formation pathway, the motor starts to operate again. This completes the flap around the cable short stops the motor torque is reduced by a large instantaneous cables tension.
Conversely, cars and carts to go back on the opposite. The beginning is K1B, K2B closed to achieve the torque motor is running, the line to the 2nd stopper at, K2 switch collision baffle, K2B disconnect, K2A closed control loop disconnect torque motor, the motor stops working, carts continue Walking back to the 1st baffle, K1 collision baffle, K1B K1A closed off, then torque motor control circuit through K1A, K2A formation pathway, electricity running again in order to achieve the purpose.
In order to prevent the cable carts stopped collapse under the action of gravity, walking in the control of the motor contactors and relays on two time ST1, ST2 (model JST-4), two time delay relay to disconnect Contact ST1, ST2 access roll torque motor control circuit to ensure carts can continue to run after stopping a short time. In addition to the torque motor braking torque motor control circuit limit access only opened its K3 brakes to get through. Also in the brake control circuit added a contactor MZ, its normally open contact access control loop walking carts, only cable reel system is powered motor circuit walk to get through, to prevent problems when walking to pull off the cable.
After rectification where there is a need to pay attention is to check the K1, K2 two changeover switch crank arm direction in the two stopper at the outside, crank arm must remain two switches are kept in the same direction, or torque motor does not will operate normally. Will pull off the cable.
Construction Hoist compare domestic and international standards
A country's development and construction elevator problems
In recent years, the development of construction hoist is mainly reflected in the appearance of improvement, weight reduction hoists, lifting speed and altitude increase, hoists amount of load increases, improved safety devices and electrical control automation and so on.
Steel, aluminum, aluminum plate and other lightweight materials are used to make the cage weight greatly reduced, in order to reduce the required power transmission mechanism, users save energy created conditions; while hoists drop weight and frequency stepless speed technology commonly used, and also allows hoists lifting speed can be improved; domestic anti-braking load 60kN successful development of safety device for an increase in the amount of load hoists provide a guarantee; hoists powered using transmission slip line so lift height broke the 450m; in electrical control, semi-automatic and fully automatic floor call, hoists stop layer unmanned accurate electronic control system has been tested in a mature and extensive use of export products; construction elevator varieties more and more. It can be said that China's development and construction elevator technological progress, basically to keep up with the beat of the international industry, fully able to meet the needs of the rapid development of the construction industry and has been exported.
However, in the cage load power ratio, reliability and lifetime of components, product design and the use of the concept of security and other aspects of domestic and international advanced level compared to the lifts there are still many gaps, these gaps have resulted in our construction hoist national standards with international advanced standards gap.
2 construction hoist national standards with international advanced standards gap
2005 edition of "Construction Elevator" national standard revision, we have carefully studied the international advanced European standards (EN12159: 2000) and American Standard (ANSI / ASSE 10.4 - 2004). We'd love "is equivalent to" use (identify) European standard, or at least "equivalent" use (equivalent), but unfortunately can not be achieved due to various reasons, is a "modification" use (modify), of which the most important is the overall level of the industry and habits, philosophy (mostly from users) gap. Because different national conditions, some gaps (for example, in the case of unmanned stations can summon each layer cage, it runs automatically and accurately stop layer; each landing must be installed in place by the cage door unlocked layer) can suspended with the international advanced standards, and following gaps should be with the international advanced standards.
2.1 pairs of cage floor space limitations
European standards, according to the cage Rated load 100kg determined by dividing the number of persons carried hoists, each covers an area no larger than 0.25m2; U.S. standards for various rated load hoists the maximum floor area of clearly defined, its purpose is a capacity to prevent overcrowding and ensure safety. At rated load 2 000kg of hoists, for example, by European standards hoists the maximum floor area of 5m2 (1.5m wide, the length is not greater than 3.33m), by American standards cage floor area not exceeding 4.25m2 (1.5m wide when length not greater than 2.8m). In China, in order to meet more users can be loaded dump truck, 2 000kg amount contained in the cage are required to be made until 1.5m × 3.5m 1.5m × 4.2m, which is very safe, because on the site rush hour, hoists passengers are packed. 1996 Edition Construction lifts GB in pairs cage floor space only requires minimum unrestricted caps, 2005 construction elevator GB we can only write "hoists can be manned number of rated load divided by 80kg, rounded tail rounded", " When the cage is used only manned occasions, per capita land use should not exceed 0.25m2 ", why this provision does not cover all of them dual-use goods lifts, because the standard of review when the strong opposition from the user's behalf. Some may think, 2007 edition of "Construction Elevator Safety Regulations" after the implementation of the cage should have overload protection, and then a big cage, the crew will not be overloaded. However, in the development of standards, we must consider the protection of device failure or, in some cases, artificial lift the protection device may - consider "just in case", and user regulations, this is Europe, America's most prominent ideas advanced standards.
2.2 hoists lifting speed limit
Working conditions for maximum lifting speed hoists, American standard regulation 91.44m/min, Europe, and none of our standard provided for (but limited to the current safety device maximum operating speed of only 2m / s, but also to enhance the speed hoists no more than 102m/min). Conditions for the installation of hoists the maximum lifting speed, the European standard specified as ≤ 4 2 m / min (U.S. standard is ≤ 4 0 m / min), the 2005 edition of the standard also provides for the construction elevator ≤ 42m/min (0.7m / s). Lifts OEMs should check their manual, whether expressly provided by GB installation conditions hoists lifting speed.
2.3 Installation conditions hoists rated load limit
Even hoist rated load (working conditions) and then a big, installation conditions of the amount set out in the European standard regulation ≤ 1 000kg (U.S. standard is ≤ 800kg), our failure to make the required standard. As we all know, during the installation process, machine parts (including safety devices) are not fully loaded, the cage should not enter the normal load condition (otherwise, it is a working condition), so that "no installation of hoists for heavy working conditions amount of load is the amount set out their work conditions "is wrong (if the installation conditions of the rated load capacity of the transmission mechanism mistakenly come to be, then the speed is greater than 42m/min lifts, installation conditions as follows lifting speed ≤ 42m / min, it can exceed the carrying capacity of the work conditions of the amount of load). In order to ensure safety, working conditions hoists installed to restrict the amount of load is necessary.
2.4 Loading and unloading of additional force
Cage door threshold and the threshold level (or the boarding platform edge) of the design strength, loading and unloading should be considered vertical force generated when the horizontal force FV and FH, European standards: FV cage should be 50% of the amount of load F, but not less than 2kN, and when F is greater than 20kN, FV = 4 +0.3 F (kN); FH F shall be 20% but not less than 0.5kN, nor more than 2.5kN; FV and FH (as concentrated loads) while acting on the cage floor entrance and exit of the 1/3 width Department. This requirement is very reasonable, our standards should be included.
2.5 Product standards should require product life
In the construction elevator, tower hoist crane revision of national standards, for "Do not use the accident was scrapped" considerations, the drafting group that deal with product life make provision - is based on scientific judgments waste load cycles, the product plus equipment suitable irreversible logger, if unable to do so widespread and effective use of recording devices may require the judge waste year. But both proposals are ultimately not adopted.
As altitude dangerous work product, does not require its service life, reducing and avoiding accidents is very unfavorable. European standards for construction elevator concept is this made life: "manned lifts basic load cycles shall be taken as 1.6 × 105 - intermittent operation (ie 10 years × 40 weeks / year × 40 hrs / week × 10 cycles / hours). " This stipulates that the number of load cycles, also made useful life (10 years). European product used in each 1 600h, life expectancy is only 10 years. In China, according to the lift working day 240 days, working 10h, then 10 years of load cycles is 2.4 × 105, life should not exceed 10
Year (by European standards and less than 7 years). We believe that the inclusion of special equipment products, should provide its service life. In other conditions do not taste of the case, even to use the number of years of life does not belong to specify arbitrary. At present, China has many products to life as a basis for judgment waste, such as waste gas water heater life sentence of 6 years (date of installation). In all sorts of desperation, 2005 edition construction lifts the inclusion of Shi GB
Workers lift machine working level. 2005 edition of "Construction lift" GB 5.1.4 stipulates that the person dual-use goods construction elevator machine working level A5 ~ A6. For ordinary people who under normal use dual-use goods lifts, load cycles is taken as 1.25 × 105 <CT ≤ 2.5 × 105, according to GB / T 3811 " bridge crane design specifications", the use of class U4, load status is taken as Q3, Thus the whole working-level A5 (special, heavy work status of the whole working-level desirable for the A6, specifically determined by the manufacturer).
Since construction hoist the national standard has not yet clearly defined life, to ensure the safe use of lifts in some provinces and cities building department has begun planning for the long era of specialists in lifts for safety assessment. For example, the provisions of the relevant departments of Shanghai tower hoist crane , construction hoist evaluation period, that the whole working-level A5 product, after 10 years of use reassessed annually (including ultrasonic flaw detection, thickness measurement profiles, structural stress testing, etc.); A6 machine working level products for 15 years after an annual basis. Thus many OEMs issue a certificate to user requirements, all construction elevator machine working class as A6. Product-level machine work must be carefully identified, should be selected based on the work of product design level truthfully reply, otherwise it would be safety hazards exist, the user ultimately irresponsible.
3 Conclusion
In summary, our current construction hoist the national standard is behind the international advanced standards, although the 2005 construction elevator GB version has been incorporated into a number of European and American standard content, but overall there is a gap.
Greatest experience of the European standard, the standard setters fully consider the case based on the idea of possible (or even misuse will occur) security risks, so as to formulate effective targeted preventive measures. Our product designers, product standards setters, the use of on-site managers, we must first learn, adhering to is this people-oriented, safety first concept and implementation in practical work. Same time, through the whole industry is constantly striving to further improve our product design, manufacturing quality and on-site scientific management level, which is the standard of our products as soon as possible with the international foundation. Existing national standards have not been prescribed some security restrictions or requirements directly related, OEMs and enterprise standards should make provision for product manuals, to ensure the safety of construction lift assembly and disassembly, use, maintenance; majority only the design, manufacture, management, and use of consensus in order to become the national standard and is consciously implement the provisions.
In recent years, the development of construction hoist is mainly reflected in the appearance of improvement, weight reduction hoists, lifting speed and altitude increase, hoists amount of load increases, improved safety devices and electrical control automation and so on.
Steel, aluminum, aluminum plate and other lightweight materials are used to make the cage weight greatly reduced, in order to reduce the required power transmission mechanism, users save energy created conditions; while hoists drop weight and frequency stepless speed technology commonly used, and also allows hoists lifting speed can be improved; domestic anti-braking load 60kN successful development of safety device for an increase in the amount of load hoists provide a guarantee; hoists powered using transmission slip line so lift height broke the 450m; in electrical control, semi-automatic and fully automatic floor call, hoists stop layer unmanned accurate electronic control system has been tested in a mature and extensive use of export products; construction elevator varieties more and more. It can be said that China's development and construction elevator technological progress, basically to keep up with the beat of the international industry, fully able to meet the needs of the rapid development of the construction industry and has been exported.
However, in the cage load power ratio, reliability and lifetime of components, product design and the use of the concept of security and other aspects of domestic and international advanced level compared to the lifts there are still many gaps, these gaps have resulted in our construction hoist national standards with international advanced standards gap.
2 construction hoist national standards with international advanced standards gap
2005 edition of "Construction Elevator" national standard revision, we have carefully studied the international advanced European standards (EN12159: 2000) and American Standard (ANSI / ASSE 10.4 - 2004). We'd love "is equivalent to" use (identify) European standard, or at least "equivalent" use (equivalent), but unfortunately can not be achieved due to various reasons, is a "modification" use (modify), of which the most important is the overall level of the industry and habits, philosophy (mostly from users) gap. Because different national conditions, some gaps (for example, in the case of unmanned stations can summon each layer cage, it runs automatically and accurately stop layer; each landing must be installed in place by the cage door unlocked layer) can suspended with the international advanced standards, and following gaps should be with the international advanced standards.
2.1 pairs of cage floor space limitations
European standards, according to the cage Rated load 100kg determined by dividing the number of persons carried hoists, each covers an area no larger than 0.25m2; U.S. standards for various rated load hoists the maximum floor area of clearly defined, its purpose is a capacity to prevent overcrowding and ensure safety. At rated load 2 000kg of hoists, for example, by European standards hoists the maximum floor area of 5m2 (1.5m wide, the length is not greater than 3.33m), by American standards cage floor area not exceeding 4.25m2 (1.5m wide when length not greater than 2.8m). In China, in order to meet more users can be loaded dump truck, 2 000kg amount contained in the cage are required to be made until 1.5m × 3.5m 1.5m × 4.2m, which is very safe, because on the site rush hour, hoists passengers are packed. 1996 Edition Construction lifts GB in pairs cage floor space only requires minimum unrestricted caps, 2005 construction elevator GB we can only write "hoists can be manned number of rated load divided by 80kg, rounded tail rounded", " When the cage is used only manned occasions, per capita land use should not exceed 0.25m2 ", why this provision does not cover all of them dual-use goods lifts, because the standard of review when the strong opposition from the user's behalf. Some may think, 2007 edition of "Construction Elevator Safety Regulations" after the implementation of the cage should have overload protection, and then a big cage, the crew will not be overloaded. However, in the development of standards, we must consider the protection of device failure or, in some cases, artificial lift the protection device may - consider "just in case", and user regulations, this is Europe, America's most prominent ideas advanced standards.
2.2 hoists lifting speed limit
Working conditions for maximum lifting speed hoists, American standard regulation 91.44m/min, Europe, and none of our standard provided for (but limited to the current safety device maximum operating speed of only 2m / s, but also to enhance the speed hoists no more than 102m/min). Conditions for the installation of hoists the maximum lifting speed, the European standard specified as ≤ 4 2 m / min (U.S. standard is ≤ 4 0 m / min), the 2005 edition of the standard also provides for the construction elevator ≤ 42m/min (0.7m / s). Lifts OEMs should check their manual, whether expressly provided by GB installation conditions hoists lifting speed.
2.3 Installation conditions hoists rated load limit
Even hoist rated load (working conditions) and then a big, installation conditions of the amount set out in the European standard regulation ≤ 1 000kg (U.S. standard is ≤ 800kg), our failure to make the required standard. As we all know, during the installation process, machine parts (including safety devices) are not fully loaded, the cage should not enter the normal load condition (otherwise, it is a working condition), so that "no installation of hoists for heavy working conditions amount of load is the amount set out their work conditions "is wrong (if the installation conditions of the rated load capacity of the transmission mechanism mistakenly come to be, then the speed is greater than 42m/min lifts, installation conditions as follows lifting speed ≤ 42m / min, it can exceed the carrying capacity of the work conditions of the amount of load). In order to ensure safety, working conditions hoists installed to restrict the amount of load is necessary.
2.4 Loading and unloading of additional force
Cage door threshold and the threshold level (or the boarding platform edge) of the design strength, loading and unloading should be considered vertical force generated when the horizontal force FV and FH, European standards: FV cage should be 50% of the amount of load F, but not less than 2kN, and when F is greater than 20kN, FV = 4 +0.3 F (kN); FH F shall be 20% but not less than 0.5kN, nor more than 2.5kN; FV and FH (as concentrated loads) while acting on the cage floor entrance and exit of the 1/3 width Department. This requirement is very reasonable, our standards should be included.
2.5 Product standards should require product life
In the construction elevator, tower hoist crane revision of national standards, for "Do not use the accident was scrapped" considerations, the drafting group that deal with product life make provision - is based on scientific judgments waste load cycles, the product plus equipment suitable irreversible logger, if unable to do so widespread and effective use of recording devices may require the judge waste year. But both proposals are ultimately not adopted.
As altitude dangerous work product, does not require its service life, reducing and avoiding accidents is very unfavorable. European standards for construction elevator concept is this made life: "manned lifts basic load cycles shall be taken as 1.6 × 105 - intermittent operation (ie 10 years × 40 weeks / year × 40 hrs / week × 10 cycles / hours). " This stipulates that the number of load cycles, also made useful life (10 years). European product used in each 1 600h, life expectancy is only 10 years. In China, according to the lift working day 240 days, working 10h, then 10 years of load cycles is 2.4 × 105, life should not exceed 10
Year (by European standards and less than 7 years). We believe that the inclusion of special equipment products, should provide its service life. In other conditions do not taste of the case, even to use the number of years of life does not belong to specify arbitrary. At present, China has many products to life as a basis for judgment waste, such as waste gas water heater life sentence of 6 years (date of installation). In all sorts of desperation, 2005 edition construction lifts the inclusion of Shi GB
Workers lift machine working level. 2005 edition of "Construction lift" GB 5.1.4 stipulates that the person dual-use goods construction elevator machine working level A5 ~ A6. For ordinary people who under normal use dual-use goods lifts, load cycles is taken as 1.25 × 105 <CT ≤ 2.5 × 105, according to GB / T 3811 " bridge crane design specifications", the use of class U4, load status is taken as Q3, Thus the whole working-level A5 (special, heavy work status of the whole working-level desirable for the A6, specifically determined by the manufacturer).
Since construction hoist the national standard has not yet clearly defined life, to ensure the safe use of lifts in some provinces and cities building department has begun planning for the long era of specialists in lifts for safety assessment. For example, the provisions of the relevant departments of Shanghai tower hoist crane , construction hoist evaluation period, that the whole working-level A5 product, after 10 years of use reassessed annually (including ultrasonic flaw detection, thickness measurement profiles, structural stress testing, etc.); A6 machine working level products for 15 years after an annual basis. Thus many OEMs issue a certificate to user requirements, all construction elevator machine working class as A6. Product-level machine work must be carefully identified, should be selected based on the work of product design level truthfully reply, otherwise it would be safety hazards exist, the user ultimately irresponsible.
3 Conclusion
In summary, our current construction hoist the national standard is behind the international advanced standards, although the 2005 construction elevator GB version has been incorporated into a number of European and American standard content, but overall there is a gap.
Greatest experience of the European standard, the standard setters fully consider the case based on the idea of possible (or even misuse will occur) security risks, so as to formulate effective targeted preventive measures. Our product designers, product standards setters, the use of on-site managers, we must first learn, adhering to is this people-oriented, safety first concept and implementation in practical work. Same time, through the whole industry is constantly striving to further improve our product design, manufacturing quality and on-site scientific management level, which is the standard of our products as soon as possible with the international foundation. Existing national standards have not been prescribed some security restrictions or requirements directly related, OEMs and enterprise standards should make provision for product manuals, to ensure the safety of construction lift assembly and disassembly, use, maintenance; majority only the design, manufacture, management, and use of consensus in order to become the national standard and is consciously implement the provisions.
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