This standard specifies the technical requirements, test methods and inspection rules for material box-grab cranes. JB/T 7688.13-1995 Technical conditions for metallurgical cranes Material box-grab cranes JB/T7688.13-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
-Box-Grab Cranes
1 Subject Content and Scope of Application
This standard specifies the technical requirements, test methods and inspection rules for box-grab cranes. JB/T7688.13--95
This standard applies to cranes with box pickers and grabs as picking devices (hereinafter referred to as cranes). The grab is mainly used to load the box.
2 Reference Standards
JB/T7688.1
JB/T7688.6
JB/T7688.12
3 Technical Requirements
Technical Conditions for Metallurgical Cranes-General Requirements Technical Conditions for Metallurgical Cranes-Integral Cranes Technical Conditions for Metallurgical Cranes-Box-Electromagnetic Cranes Except for the following requirements, other technical requirements shall comply with the relevant provisions in JB/T7688.1. 3.1 Environmental conditions
The crane should work indoors, and its working environment temperature should be at least -10℃ and not more than +50℃. 3.2 Performance
The rated lifting capacity of the main lifting mechanism of the crane should include the mass of the material box, and the rated lifting capacity of the auxiliary lifting mechanism does not include the mass of the grab bucket. 3.3 Main components
3.3.1 The materials of the crank, arm and connecting rod in the opening and closing mechanism of the material box taker shall comply with the provisions of Article 3.3.1 of JB/T7688.12. 3.3.2 The materials of the structural parts of the material box taker shall comply with the provisions of Article 3.3.2 of JB/T7688.12. 3.3.3 The bucket removal device shall meet the following requirements: a. The materials of the upper and lower beams and the pins of each rotating hinge shall not be lower than 42CrMo steel in GB3077. b.
Main structural parts such as support rods and particle plates should be made of Q235-C steel or 16Mn steel, and the cutting edge plate should not be lower than ZGMn13-2 steel in GB5680.
For four-rope double-jaw grab, if the bulk density of the grabbed object is greater than 1.2t/m, and the particle size is greater than 60mm or the material is relatively solid, c.
The grab edge should have a tooth plate.
d. For grabbing objects with a particle size greater than 100mm and extremely uneven particle size (such as grabbing material heads, scrap steel, large pieces of ore, etc.), it is recommended to use a multi-plate grab.
3.3.4 If a cable drum is used, it should comply with the provisions of Article 3.3.5 of JB/T7688.6. 3.4 Assembly
3.4.1 The assembly requirements of the material box supporter shall comply with the requirements of 3.4.1 and 3.4.2 of JB/T7688.12. 3.4.2 The gap between the double jaws of the four-rope grab after closing should not be greater than 2mm. 3.4.3 After the positioning plate is assembled, it should be able to make the grab reach the maximum opening degree, and its position should be fixed after it is determined. 3.4.4 After the grab is assembled, each rotation point should move flexibly without jamming. 3.5 Safety
Approved by the Ministry of Machinery Industry on June 16, 1995
Implementation on July 1, 1996
JB/T7688.1395
3.5.1 The material box supporter and the grab shall not work at the same time. 3.5.2 The pulleys used for lifting and opening and closing in the grab shall be equipped with a wire rope anti-slip device. 3.6 Lubrication
The grab bucket should be lubricated at points, and the rest should be in accordance with Article 3.11 of JB/T7688.1. 4 Test
4.1 Visual inspection of the crane In addition to the provisions of Article 4.1 of JB/T7688.1, the material box support and grab bucket should also be inspected. 4.2 Qualification test
During the test, the load should be gradually loaded to the rated lifting weight, and it is allowed to be loaded in place at one time. Perform action tests and tests in all directions at standard voltage and rated speed of the motor. In addition to verifying the contents specified in Article 4.2 of JB/T7688.1, the contents specified in Table 1 should also be verified. Table 1
4.3 Load-bearing capacity test
4.3.1 Static load test
Project name
Opening and closing range of the pick-up arm
Opening and closing speed of the pick-up arm
Opening and closing limiter of the pick-up arm
Opening and closing range of the grab bucket
Closing time of the grab bucket
Measurement unit
According to the relevant provisions of Article 4.3.1 of JB/T7688.1. During the test, load at 1.25G. 4.3.2 Dynamic load test
Required value
According to the design drawings
According to the design drawings
Accurate and reliable
According to the design drawings
According to the design drawings
Limit deviation
During the dynamic load test of the crane, load at 1.1G. The main lifting mechanism can be loaded directly on the material box support. The auxiliary lifting can be based on the full load test of the grab bucket, and then add a heavy object with a larger bulk density. Other requirements are in accordance with the relevant provisions of Article 4.3.2 of JB/T7688.1. 4.3.3 Grab bucket grab rate test
For double-plate grab buckets with relatively uniform particle size of the grabbed materials (generally more than 90% within 30mm, and the largest one does not exceed 100mm), it is carried out in accordance with Article 5.2.2 of GB/T14405. 5 Inspection rules
According to Chapter 5 of JB/T7688.1.
Marking, packaging, transportation and storage
According to Chapter 6 of JB/T7688.1.
7 Warranty period
According to Chapter 7 of JB/T7688.1. bZxz.net
Additional remarks:
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; Beijing Hoisting and Conveying Machinery Research Institute participated in the drafting. The main drafter of this standard was Zhao Yonghua.
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