This standard applies to bridge cranes with devices for lifting, buffering and turning forgings. JB/T 7688.10-1995 Technical conditions for metallurgical cranes Forging cranes JB/T7688.10-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
Forging Cranes
Subject Content and Scope of Application
This standard specifies the technical requirements, test and inspection rules for forging cranes. JB/T7688.10-95
This standard applies to bridge cranes (hereinafter referred to as cranes) with devices for lifting, buffering and turning forgings. 2 Reference Standards
GB1348 Ductile Iron Castings
JB/T6967 General Technical Conditions for Electroslag Welding
JB/T7688.1 General Requirements for Technical Conditions for Metallurgical Cranes 3 Technical Requirements
Except for the following requirements, other technical requirements shall comply with the relevant provisions in JB/T7688.1. 3.1 Environmental Conditions
The minimum working environment temperature of the crane is -5°C and the maximum is not more than 10°C. 3.2 Performance in use
3.2.1 The rated lifting capacity of the crane is the sum of the mass of the tipper and the largest workpiece to be lifted. 3.2.2 The main and auxiliary trolleys of the crane should generally work together. However, it is allowed to lift items separately. 3.3 Main components
3.3.1 The load buffer and release device of the lifting mechanism on the main trolley (as shown in Figure 1) should meet the following requirements: The material of the pressure plate and the support plate in the load buffer device should not be lower than 35 steel in GB699, and the maximum allowable surface roughness Ra is 25μm:
b. Plate conical springs should be used, and their material should not be lower than 60Si2Mn steel. If forged steel is used, the maximum allowable surface roughness Ra is 25μm after processing; when rolled plates are used, processing is not required. The heat treatment hardness of the spring is 40~49HRC. After rolling, the distance between each circle is 1~~2mm;
The spring shall be subjected to load-deformation test as specified in the drawing, and shall not have permanent deformation under 1.8 times the rated load;cOther main mechanism parts in the load buffer and release device shall not be lower than 20 steel in GB699, and the main structural parts shall not be lower than Q235-C steel in GB700.
3.3.2 Pick-up device
3.3.2.1 Main hook device
a. The material of the main hook shall not be lower than DG20 steel in GB10051.1, and the material of the hook nut shall match it;b. For double hooks with large lifting capacity (generally 80t or more), it is allowed to open a hole on the hook body to pass the hook pin shaft to suspend the sling without affecting the performance of the hook. The maximum allowable value of the hole surface roughness Ra is 6.3μm;c. The hook mouth should be equipped with an anti-drop safety card, which should be flexible and reliable; Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 588
1996-07-01 Shicheng
JB/T 7688. 10--95
The hook mouth should be equipped with a replaceable anti-wear hook pad. 3
1-beam; 2-pressing plate (or partition): 3 balance beam; 4-butt rod; 5-butt; 6 press plate: 7-spring; 8-axle bolt; 9---lower butt; 10---support rod; 11-wire rope; 12-connecting rod 13-pull rod; 14-lever Figure 1
3.3.2.2 Auxiliary hook device
A load buffer device should be provided for the auxiliary hook device, and its conical spring, press plate and support plate should comply with the provisions of Articles 3.3.1a and b. The hook material shall comply with the requirements of 3.3.2.1.
3.3.3 Turner
The turner shall comply with the following requirements (see Figure 2): A—A Amplification
121314
1. Motor; 2—conical spring: 3—shaft sleeve; 4—hanging device: 5—worm gear reducer; 6-brake; 7—coupling; 8—chain, 9—sprocket; 10—gear; 11—frame; 12—worm gear; 13 limit torque device; 14-spring Figure 2
JB/T 7688.10—95
The material of the turner and the hook suspension shaft shall be equipped with anti-wear sleeves, and the material shall be QT450-10 ductile iron in GB1348; a. The conical spring and its pressure plate and support plate in the buffer device shall be the same as those in Article 3.3.1; b. The friction surface contact of the friction type limit torque device (including the limit torque coupling) shall be uniform and the lubrication shall be good; c. The material of the turner frame shall be The material should not be lower than Q235-C steel or 16Mn steel in GB1591; d.
The material of the sprocket should not be lower than ZG340-640 steel in GB11352, and ZG35CrMo steel in JB/ZQ4297 is preferred: e.
f. The material of the chain link and the connecting pin should not be lower than 45 steel in GB699, and heat-resistant and wear-resistant alloy steel should be used. The chain link should not have cracks, and the maximum allowable value of the surface roughness R of the chain link is 25μm; a detachable pin bolt connection pair is set every 12 to 13 links in the chain, and other pin connection pairs should be welded and fixed. 3.3.4 When electroslag welding is used for the main parts such as the drum, the weld should comply with the relevant provisions in JB/T6967. The weld should be fully penetrated and normalized after welding. 3.3.5 The crane bridge should use two-section pin-hinged end beams, and the two sections should be able to swing relative to each other. Lubricable pin-hinged connection pairs should be used. The material of the pin should not be lower than 45 quenched and tempered steel in GB699. 3.3.6 The driver's cab should be heat-insulated. The driver's cab hanger should have good rigidity, and buffers should be installed at the connection between the hanger and the driver's cab. 3.4 Assembly
3.4.1 The load buffer and release device of the main trolley hoisting mechanism should be assembled according to the following requirements: The performance and height of each group of springs (two stacked in one group) should be consistent; a.
During assembly, the spring should be given the specified preload and deformation; the spring pressure plate and support plate should be leveled, and the spring should not be stuck after being loaded, and should be able to retract and retract freely; c.
d. Adjust the release device so that each hinge point can rotate flexibly, then adjust the upper and lower bumpers. When the impact force exceeds the specified value, the limit switch is powered off:
3.4.2 The assembly of the material turner shall comply with the following requirements: a. The assembly of the spring in the material turner is the same as that in 3.4.1; b. Connect each section of the chain with a threaded pin and tighten the nut to fix it. After connection, each section of the chain should be able to rotate flexibly with each other. The chain and sprocket should be well meshed, and the chain link should be able to rotate on the sprocket by itself; ℃. Adjust the spring of the friction type limit torque device (or limit torque coupling) to achieve the required limit torque. 3.5 Electrical equipment
The crane should adopt a ground control console and be controlled on the ground through a wired remote control device. The wired remote control device should generally include three parts: a receiver, a transmitter, and a multi-core hanging cable used as a channel. 3.6 Safety and hygiene
3.6.1 The main lifting mechanism should be equipped with a release device. When the load exceeds the rated lifting weight, the brake can be temporarily released. And the main lifting motor can transition to the descending reverse braking state. 3.6.2 The tipping mechanism of the material turner should be equipped with a friction limit torque device (or limit torque coupling). When the rotation torque exceeds 1.25 times the rated torque, the spring is compressed and the friction surface slips. 3.6.3 The lower half of the cable led down from the cable drum on the trolley should be wrapped with asbestos rope. 3.6.4 The workpiece shall not be lifted when the anvil of the forging equipment has not left the forging. 3.7 Lubrication
The pin joints of the chain should be coated with grease, and the others shall comply with Article 3.11 of JB/T7688.1. 4 Test
4.1 Visual inspection
In addition to the provisions of Article 4.1 of JB/T7688.1, the visual inspection of the crane should also include the inspection of the tipper. 4.2 Qualification test
During the test, the load should be gradually loaded to the rated lifting weight. Perform action tests and tests in all directions at standard voltage and rated speed of the motor. 590
JB/T 7688.10—95
In addition to verifying the contents specified in Article 4.2 of JB/T7688.1, the items listed in Table 1 should also be included. Table 1
Item name
Chain speed
Release device of main hoisting mechanism
Limit torque device of tipping mechanism
4.3 Loading capacity test
4.3.1 Static load test
Unit of measurement
Required value
As per design drawing
As per Article 3.6.1 of this standard
As per Article 3.6.2 of this standard
Limit deviation
When testing the static load of the crane, load 1,4G, and add the load to the sling. Static load tests of the main and auxiliary trolley hoisting mechanisms should be carried out separately. When testing the main trolley hoisting mechanism, drive the auxiliary trolley to the end of the bridge frame, and when testing the auxiliary trolley hoisting mechanism, drive the main trolley to the end of the bridge frame. Other test requirements shall be in accordance with the relevant provisions of Article 4.3.1 of JB/T7688.1. 4.3.2 Dynamic load test
The dynamic load test of the crane shall be in accordance with 1.2G loading. For the main trolley main lifting mechanism, when the lifting weight exceeds 1.2G, the brake release device begins to slip, and it is guaranteed that the brake will not be released when 1.0G. Other test requirements shall be in accordance with the relevant provisions of Article 4.3.2 of JB/T7688.1. 4.3.3 Test of material turner
The test shall be carried out in accordance with the following provisions:
a. Hang the material turner on the main hook, hang the turning chain on the auxiliary hook, and lower them to the working position, and then lift the entire test piece equivalent to 1.2 times the maximum forging weight; b. Start the chain slewing mechanism, and the test piece shall be turned over for no less than 10 minutes. During the test, the spring of the friction type limit torque device shall be gradually tightened. When the torque value exceeds the rated torque, the root limit torque device begins to slip.
If each component completes its functional test, and no damage to the mechanism or machine parts is found in the subsequent visual inspection, and no looseness or damage is found in the connection, the test is considered to be qualified. Inspection rules
According to Chapter 5 of JB/T7688.1.
6Marking, packaging, transportation and storage
According to Chapter 6 of JB/T7688.1.
7Warranty period
According to Chapter 7 of JB/T7688.1.
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This standard was proposed and managed by the Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Taiyuan Heavy Machinery Plant, and Beijing Hoisting and Conveying Machinery Research Institute participated in the drafting. The main drafter of this standard was Zhao Yonghua.
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