JB/T 7688.1-1995 General requirements for technical conditions of metallurgical cranes
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
General Requirements
1 Subject Content and Scope of Application
JB/T 7688.1—95
This standard specifies the general technical requirements, test methods and inspection rules for metallurgical cranes. This standard is mainly applicable to special cranes for metal smelting, rolling and hot processing, including open-hearth charging bridge cranes, ground charging cranes, material box cranes, ingot stripping cranes, whole mold cranes, cover cranes, clamp cranes, plate turning cranes, forging cranes, heating furnace loading and unloading cranes, material box-electromagnetic cranes, and material box-grab cranes. Other similar metallurgical cranes can also be used for reference.
2 Reference standards
GB 986
GB1102
Packaging, storage and transportation pictorial symbols
Technical conditions for high-quality carbon structural steel
Carbon structural steel
Basic technical requirements for rotating electrical machines
Basic forms and dimensions of weld grooves for gas welding, manual arc welding and gas shielded weldingBasic forms and dimensions of weld grooves for submerged arc weldingRound strand steel wire rope
GB/T1228
GB/T 1229
GB/T 1230
GB/T 1231
GB1591
GB3323
GB3632
GB3633
GB3811
GB 4879
High-strength large hexagon bolts for steel structures
High-strength large hexagon nuts for steel structures
High-strength washers for steel structures
Technical conditions for high-strength large hexagon bolts, large hexagon nuts and washers for steel structuresTechnical conditions for cold-rolled cylindrical helical compression springsTechnical conditions for hot-rolled cylindrical helical springs
Sampling inspection of cylindrical helical springs
Low-alloy structural steel
Radiographic photography and quality classification of steel fusion-welded butt jointsType dimensions of torsion shear type high-strength bolt connections for steel structuresTechnical conditions for torsion shear type high-strength bolt connections for steel structuresDesign specification for cranes
Rust-proof packaging
GB 4942. 2
GB5905
GB 5972
GB5973
Protection degree of low-voltage electrical enclosures
Crane test specifications and procedures
Practical specifications for inspection and scrapping of wire ropes for lifting machinery Wedge joints for wire ropes
Approved by the Ministry of Machinery Industry of the People's Republic of China on 1995-06-16 544
Implemented on 1996-07-01
GB 5974. 1
Ordinary thimbles for wire ropes
Heavy thimbles for wire ropes
GB 5974. 2
GB5975
GB5976
GB6067
Pressing plates for wire ropes
Wire rope clamps
Safety regulations for lifting machinery
GB 6164. 1
GB6334
GB6974
GB8918
GB8923
GB9286
GB10051
GB10095
GB10183
GB 10089
GB 11345
GB 11352
Crane spring buffer
DC electromagnetic block brake
Glossary of terms for crane machinery
High-quality steel wire rope
JB/T 7688.1-95
Surface rust grade and rust removal grade of steel before painting Cross-cut test of paint and varnish film
Lifting hook
Precision of involute cylindrical gear
Manufacturing tolerance of bridge and gantry cranes and track installation Precision of cylindrical worm and worm gear
Manual ultrasonic flaw detection method and classification of flaw detection results of steel welds Carbon steel castings for general engineering
GB/T 12469
Welding quality assurance Requirements and defect classification of steel fusion welded joints GB/T 13384
GB/T14405
GB/T 14407
General technical conditions for packaging of electromechanical products
General bridge crane
Technical conditions for driver's cabs of general bridge and gantry cranesPainting colors and safety signs for mining, engineering, lifting and transportation machinery productsJB2299
JB/T3241
JB 4315
SWP type split bearing seat cross shaft universal couplingCrane electronic control equipment
Integral fork cross shaft universal coupling
JB5513
JB/T 6392.1
Crane wheel type size, tread shape and track matchingCrane wheel technical conditions
JB/T 6392.2
JB/T 6406. 1
Types, basic parameters and dimensions of electric hydraulic block brakes JB/T 6406.2
Technical conditions for electric hydraulic block brakes
JB/T 7017
Hydraulic buffers for cranes
JB/T7687.1~7687.4Lifting hook accessories ZB J19 010
ZB J19 011
ZB J80 006
ZB J80 007
ZB K26 007
ZB K26 008
Crane reducer
Crane base reducerwwW.bzxz.Net
Cast pulley for crane
Cast drum for crane
Technical conditions for YZ series three-phase asynchronous motors for lifting and metallurgyTechnical conditions for YZR series three-phase asynchronous motors for lifting and metallurgyRolled pulley
JT5028
JB/ZQ 4382
3 Technical requirements
Technical conditions for gear coupling
The design and manufacture of metallurgical cranes (hereinafter referred to as cranes) shall comply with the relevant provisions of GB3811, this standard and product drawings. 3.1 Environmental conditions
JB/T 7688.1-95
3.1.1 The power supply of the crane is generally three-phase AC, with a frequency of 50Hz and a voltage of 380V. The upper limit of the voltage fluctuation allowed for motors and electrical appliances is 10% of the rated voltage, and the lower limit (at peak current) is 15% of the rated voltage. The internal voltage loss of the crane should not exceed 5% for ingot stripping cranes, clamp cranes, integral mold cranes with guide frames and plate breaking and flipping cranes, and should not exceed 4% for other types of cranes in this standard.
If there are special requirements for the power supply, it can be determined by negotiation between the supply and demand parties according to the needs of the user. 3.1.2 The altitude of the installation and use site of the crane shall not exceed 2000m (if it exceeds 1000m, the motor capacity shall be checked according to the relevant provisions of GB755).
3.1.3 The working environment temperature and humidity of the crane a. The working environment temperature of the crane is generally 10~1050; b. The relative humidity shall not exceed 50% at a temperature of 1040C. Note: If it exceeds the above requirements, the supply and demand parties shall negotiate and resolve it according to the needs of the user. 3.1.4 The site where the crane is used shall not have flammable, explosive and corrosive gases and shall comply with the provisions of relevant standards and documents. 3.1.5 The installation of the crane running track shall generally comply with the requirements of GB10183. In case of special circumstances, it may be specified separately as needed. 3.2 Performance in use
3.2.1 The lifting capacity of the crane shall reach the rated lifting weight (G,). For cranes with material boxes, grabs, electromagnetic suction cups and special picking devices, etc., the rated lifting weight is the sum of the weight of the picking device and the lifted objects. 3.2.2 Parameters related to the use of the crane shall comply with relevant standards and product drawings and the requirements put forward by the user in the order contract. 3.2.3 For cranes (or lifting mechanisms) with a hook as the picking device, the braking distance of the lifted objects during the descending brake (the controller is running stably at the lowest gear of the descending speed, and after being pulled back to zero, the sliding distance from the brake power failure to the stop of the heavy object) should not be greater than 1/65 of the rated lifting speed per minute.
3.2.4 For cranes (or lifting mechanisms) with hooks as the picking device, when the working level of the lifting mechanism is M4~M6 and the rated speed is above 5m/min, an electrical braking method should be used to ensure that the lifting mechanism is within (0.2~~1.0)G, when the range is lowered, the motor speed before braking drops to less than 1/3 of the synchronous speed, and it should be able to run stably at this speed. For cranes with other picking devices, the supply and demand parties shall negotiate and determine according to user needs.
3.2.5 Static rigidity of cranes
The vertical static deflection caused by the rated lifting weight and the deadweight of the trolley in the middle of the span of the main beam or the auxiliary main beam shall meet the following requirements: when the working level of the crane is A4~A5, it shall not be greater than S/800 (S is the span of the crane); a.
b. When the working level of the crane is A6~A7, it shall not be greater than S/1000; c. When the working level of the crane is A8, it shall not be greater than S/1200. 3.2.6 Dynamic rigidity of cranes
When the trolley is in the middle of the span, the full-load natural frequency of the main beam (or auxiliary main beam) shall not be less than 2Hz. Verification is only carried out when the user or design (generally for cranes with a span greater than 30m or a large lifting payload) has requirements. 3.2.7 The radiation temperature of the hoisted objects on the crane hook shall not exceed 300C. 3.3 Materials
3.3.1 The materials of the important metal structural parts of the crane shall be the carbon structural steel specified in GB700, or the low alloy steel specified in GB1591. When the plate thickness is 8≤20mm, the mechanical properties shall be not less than Q235-B steel; when it is >20mm, the mechanical properties shall be not less than Q235-C steel or 16Mn steel.
Note:! Important metal structural parts refer to the main beam, auxiliary main beam, end beam, trolley frame, lifting beam, running mechanism trolley frame and other parts. ② When 16Mn steel is used, the impact energy is required to be not less than 27J at the lowest working environment temperature (longitudinal trial production), which shall be proposed or supplemented when ordering steel.
3.3.2 The welding rods, welding wires and welding flux used for welding components shall be compatible with the materials of the welded parts. 3.3.3 Before painting, the materials of important metal structural parts shall be subjected to surface rust removal by shot blasting (blasting), and shall reach the grade ÷ specified in GB8923, and other components shall reach the grade Sa2 or St2. Sa2-
3.4 Welding
JB/T7688.1-95
3.4.1 The form and size of the weld groove shall comply with the provisions of GB985 and GB986. If there are special requirements, they shall be indicated on the drawing. 3.4.2 The welding quality of the outside of the weld shall not be lower than the ear grade requirements in the defect classification of GB/T12469. 3.4.3 The butt welds of the lower flange plate and web of the main beam, auxiliary main beam, etc. shall be subjected to non-destructive testing. When testing by radiography, it shall not be lower than grade 1 in the defect classification of GB3323, and when testing by ultrasonic testing, it shall not be lower than grade 1 in the defect classification of GB11345 (the inspection grade is B). 3.4.4 For off-track box beams and single web beams with secondary trusses, T-shaped steel should be used for the upper flange part. Otherwise, the connection between the main waist plate and the compression flange plate should be made of double-sided continuous fillet welds, and full penetration is required. 3.4.5 Radiographic inspection should be used for non-destructive testing of welded coil body joint welds. The circumferential butt welds and longitudinal butt welds of the roll body should be non-destructive testing after passing the external inspection. 100% inspection of the circular butt welds should be carried out, and the radiographic inspection should not be lower than level II in the defect classification of GB3323, and the ultrasonic inspection should not be lower than level 1 in the defect classification of GB11345 (inspection level B). 20% inspection of the longitudinal butt welds, but at least 160mm should be inspected at both ends of the roll, and the radiographic inspection should not be lower than level II in GB3323, and the ultrasonic inspection should not be lower than level 1 in GB11345 (inspection level B). 3.5 Bolt connection
3.5.1 When high-strength bolts are used for component joints, they should be tightened with a torque wrench. After tightening, the required tightening torque should be achieved and the contact surface should fit tightly.
3.5.2 The dimensions of non-shear high-strength bolts, nuts and washers should comply with the provisions of GB/T1228, GB/T1229 and GB/T1230 respectively, and their technical conditions should comply with the provisions of GB/T1231. If shear high-strength bolts are used, they should comply with the provisions of GB3632 and GB3633.
3.6 Main Components
3.6.1 Wire Rope and Its Fasteners
3.6.1.1 It is recommended to use wire ropes that meet or have performance not lower than 6×25Fi+IWR and 6×36SW+IWR in GB8918 or 6T (25) + 7×7 and 6W (36) in GB1102. 3.6.1.2 The rings, pressure plates, joints and rope clamps of the wire ropes shall meet the requirements of GB5974.1, GB5974.2, GB5975, GB5973 and GB5976 respectively.
3.6.1.3 The fixed connection of the wire rope end shall comply with the provisions of Article 2.2.9 of GB6067. If the rope clamps in GR5976 are used, the method of using the rope clamps shall follow the recommended method in Appendix A of the standard. 3.6.1.4 The pressure plate device for fixing the wire rope on the drum must be tightened and must not be loose. 3.6.2 Pulley
3.6.2.1 When using a cast pulley, a pulley that meets or has performance not lower than that specified in ZBJ80006 should be selected. Cast steel pulleys are recommended. 3.6.2.2 When using a rolled pulley, it is recommended to use a pulley specified in JT5028. 3.6.3 Drum
3.6.3.1 When using a cast drum, a drum that meets or has performance not lower than that specified in ZBJ80007 should be selected. Cast steel drums are recommended. 3.6.3.2 When using a welded drum, its material should not be lower than Q235-C steel in GB700, or 16Mn steel in GB1591. The joint welds of the simplified body should comply with the provisions of Article 3.4.5. 3.6.3.3 For double motor drive and double drum, the deviation of drum diameter shall not be greater than h11: 3.6.4 Coupling
3.6.4.1 The technical conditions for the use of gear coupling shall comply with the provisions of JB/ZQ4382. Drum gear coupling is recommended. 3.6.4.2 Universal coupling shall comply with or have performance not lower than the provisions of JB/T3241 and JB5513. 3.6.4.3 Friction limit torque The friction plates in the coupling shall be in uniform contact, and the contact area shall not be less than 75%. Each friction surface shall be well lubricated. The limit torque adjustment spring shall be easy to install and adjust. 3.6.4.4 When the pin limit torque coupling is used, the diameter of the safety shear pin shall be determined according to the limit shear torque. The installation and replacement of the safety shear pin shall be simple.
3.6.5 Brake
JB/T 7688.1-95
Crane should adopt DC electromagnetic block brakes that meet the requirements of GB6334, generally adopt electric hydraulic block brakes that meet the requirements of JB/T6406.1 and 3.6. 5. 1
JB/T6406.2, and DC electromagnetic block brakes should be used preferentially for hoisting mechanism. 3.6.5.2 The material of steel brake wheel should be not less than 45 steel specified in GB699 or ZG310-570 steel specified in GB11352, with surface heat treatment hardness of 45~55HRC, and hardness of 2mm deep should be not less than 40HRC. 3.6.6 Reducers and gears
Reducers that meet or have performance not lower than ZBJ19010 or ZBJ19011 should be selected. If other types of reducers are used, the gear accuracy should meet the following requirements:
8. The accuracy of parallel axis involute cylindrical gear pairs should not be lower than 8-8-7 in GB10095; b. The accuracy of planetary gear pairs in planetary reducers should not be lower than 7 in GB10095; when the worm reducer adopts Archimedean tooth shape, the accuracy of its transmission pair should not be lower than 8-8-7 in GB10089. If arc tooth cylindrical worm or arc surface worm transmission is adopted, the accuracy of its transmission pair should not be lower than 7 in GB10089; d. When open gears are used, the accuracy of gear pairs used in rotating mechanisms should not be lower than 9 in GB10095, and not lower than 8 in other mechanisms. The maximum allowable value of tooth surface roughness Ra is 12.5gm; e
The cover and base of the reducer for the main lifting mechanism should not be made of cast iron. 3.6.7 Wheel
3.6.7.1 The matching of wheel type, size, tread shape and track should be in accordance with the provisions of JB/T6392.1. The technical conditions should comply with the provisions of JB/T6392.2. Cranes should use forged wheels or rolled wheels. 3.6.7.2 After the wheel is installed, the circular runout on its reference end face (a groove about 1.5mm deep is machined on the outer side of the assembled wheel as a mark) shall not exceed the provisions of Table 1.
Wheel diameter, mm
End face circular runout, tem
250~500
3.6.7.3 The wheel should be able to rotate flexibly after installation. 3.6.8 Pick-up device
3.6.8.1 When using forged hooks, the following requirements should be met: >500~～800
Hooks that meet or have performance not lower than that specified in GB10051 should be used; a.
>800~900
b. Lifting hook accessories that meet or have performance not lower than that specified in JB/T7687.1~~7687.4 should be used. 3.6.8.2 The type and shape of the electromagnetic suction cup should be selected according to the requirements of the hoisted objects, and its suction surface should be flat. 3.6.9 Buffer device
3.6.9.1 The crane trolley operating mechanism should use hydraulic buffers or spring buffers. When using spring buffers, follow the provisions of GB6164.1. When using hydraulic buffers, it is advisable to use buffers specified in JB/T7017. 3.6.9.2 For non-standard spring buffer devices, the selected cylindrical helical springs shall comply with the requirements of GB1239.2 and GB1239.4, and the sampling inspection shall comply with the provisions of GB1239.5.
3.6.10 Bridge
3.6.10.1 The main beam and auxiliary main beam shall have an camber, and the camber degree at the mid-span shall generally be (0.9/1000～1.4/1000)S. For cranes with guide frame structures and forging, it shall be (1.1/1000~1.5/1000)S. The maximum camber shall be controlled within the range of S/10 at the mid-span. The bridge inspection conditions shall comply with the provisions of Appendix A of GB/T14405.
3.6.10.2 The horizontal curvature of the main beam and the auxiliary main beam 2 (see Figure 2) shall not exceed S,/2000 (S, is the measured length from the first large rib plate at both ends) for the straight-track box beam and the semi-offset box beam centered on the track, measured at the large rib plate about 100mm away from the upper flange plate, and the beam leaving the walkway shall be convex to the walkway side. For fully off-track box beams, single web beams and truss beams, the requirements for tracks in Articles 3.6.10.9 and 3.6.10.10 shall be met. 3.6.10.3 The local flatness of the webs of the main beam and auxiliary main beam shall comply with the provisions of Article 4.6.3 of GB/T14405. 548
JB/T 7688.1—95
3.6.10.4 The horizontal deflection of the upper flange plate of box beams, single web beams and truss beams shall comply with the provisions of Article 4.6.4 of GB/T14405. 3.6.10.5 The vertical deflection of the web of box beams, single web beams and truss beams shall comply with the provisions of Article 4.6.5 of GB/T14405. 3.6.10.6 The straightness of truss beam components 1≤1.51/1000 (1 is the length of the member), see Figure 1. Figure 1
3.6.10.7 The diagonal difference ID,-D21, 1D-D,1 measured by the reference point of the wheel on the bridge. See Figure 2. Its value is: when the wheel is guided, it should not be greater than 5mm, and when there is a horizontal wheel guide under one end beam, it should not be greater than 6mm. This value is also allowed to be measured and controlled before the running mechanism is assembled. S
3.6.10.8 The trolley track should be a whole track welded together. After welding, the height difference and lateral misalignment at the joint should not be greater than 1mm. The weld should be smooth and free of cracks. For the track that is not welded together, it should comply with the provisions of Article 4.6.8 of GB/T14405. It is recommended to use a 45° bevel joint at the track joint.
3.6.10.9 The position deviation of the trolley track centerline of the off-track box beam, single web beam and truss beam to the centerline of the web of the rail beam shall comply with the provisions of Article 4.6.9 of GB/T14405.
3.6.10.10 The limit deviation of the trolley track gauge K shall not exceed the following provisions (see Figure 3): a.
For cranes with Gn≤50t (without guide frame), the symmetrical straight-track box beam and semi-deviant-track box beam shall be ±2mm at the span end and ±2mm at the mid-span when s≤19.5m and ±?mm when s≥19.5m:
b. Other types of beams shall be ±3mm.
JB/T 7688.1-95
3.6.10.11 The height difference between the two trolley tracks on the same section perpendicular to the trolley running direction, see Figure 3, shall meet the following requirements:
When K≤2m, hs3mm
b.2m
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