This standard specifies the technical requirements, test and inspection rules for cover-lifting cranes. This standard is applicable to the cranes used to open and close the cover of the soaking furnace in the primary rolling mill. JB/T 7688.7-1995 Technical conditions for metallurgical cranes Cover-lifting cranes JB/T7688.7-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
Uncovered Cranes
Subject Content and Scope of Application
This standard specifies the technical requirements, test and inspection rules for uncovered cranes JB/T 7688.7-95
This standard applies to cranes used to open and close the furnace cover of a soaking furnace in a primary rolling mill (hereinafter referred to as cranes). 2 Reference Standards
GB3766 General Technical Conditions for Hydraulic Systems
JB: T7688.1 Technical Conditions for Metallurgical Cranes General Requirements ZBK26007 Technical Conditions for YZ Series Three-Phase Asynchronous Motors for Lifting and Metallurgy 3 Technical Requirements
Except for the following requirements, other technical requirements shall comply with the relevant provisions of JB/T7688.1. 3.1 Environmental Conditions
The minimum working ambient temperature of the crane shall be -10°C and the maximum shall not exceed 1065°C. 3.2 Main parts (as shown in Figure 1)
1-Operating mechanism: 2-Lifting device; 3-Reducer; 4-Motor: 5 Connecting rod; 6-Brake 7-Crank Figure 1
Approved by the Ministry of Machinery Industry of the People's Republic of China on 1995-06-16 and implemented on 1996-07-01
JB/T 7688.7-95
3.2.1 The material of the crank, connecting rod and lifting device (lifting ring or lifting clamp) of the lifting mechanism should not be lower than 45 steel, and chromium alloy steel should be used. 3.2.2 The lifting device in the lifting mechanism should be able to work synchronously, and the initial position of the eccentric wheel should comply with the requirements of the drawing. 3.2.3 If the lifting mechanism adopts hydraulic transmission, it should comply with the relevant requirements of GB3766. 3.2.4 A closed and insulated driver's cab should be used, and an air conditioner should be installed. 3.2.5 The crane should be equipped with a furnace cover suspension alignment device, which should be accurate and reliable. 3.2.6 The three-phase asynchronous motor in ZBK26007 can be used to drive the lifting mechanism. 3.3 Assembly
3.3.1 The installation deviation of the lifting device (lifting ring or lifting clamp) shall comply with the following provisions. The limit deviation of the lifting distance L is shown in Table 1:
Lifting distance L.
Limit deviation
>4～5
>9～10
The load-bearing working surface (ring surface or clamp surface) of the lifting device should be kept horizontal, and the height difference of each group of working surfaces after installation should not be greater than L/1000. 3.3.2 The limit deviation of the crane span is ±3mm, and the span detection conditions shall be in accordance with Appendix A of GB/T14405. 3.4 Safety and hygiene
3.4.1 The lifting mechanism shall be equipped with a lowering limiter. 3.4.2 The lifting mechanism and the trolley running mechanism shall have an interlocking device to ensure that the trolley can only be started when the lifting mechanism is not working. 3.4.3 The lifting mechanism and the gas supply device of the soaking furnace should be interlocked. When the furnace cover is opened, the gas supply to the soaking furnace must be cut off. 3.4.4 The heat insulation device of the mechanism should be set on the lower plane of the crane bridge. 3.5 Rust removal and rust prevention
Generally in accordance with JB/T7688.1, but heat-resistant anti-rust paint should be used. 3.6 Lubrication
It is advisable to use point lubrication. Others are in accordance with Article 3.11 of JB/T7688.1. 4 Test
4.7 The visual inspection of the crane is in accordance with Article 4.1 of JB/T7688.1. 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 under standard voltage and rated speed of the motor. In addition to verifying the relevant contents specified in Article 4.2 of JB/T7688.1, the following items should also be verified: a. a. Interlocking device between the operation of the lifting mechanism and the operation of the trolley; b. Interlocking device between the operation of the lifting mechanism and the gas supply of the soaking furnace; Alignment device between the lifting mechanism and the furnace cover.
The verification results of the above devices should be accurate and reliable. 4.3 Loading capacity testwww.bzxz.net
4.3.1 Static load test
According to the relevant provisions of Article 4.3.1 of JB/T7688.1. The test load is 1.25Gm. 4.3.2 Dynamic load test
When the crane is tested for dynamic load, it is loaded at 1.1G, and the furnace cover should be used as the load. Other requirements shall be in accordance with the relevant provisions of Article 4.3.2 of JB/T7688.1.
5 Inspection rules
According to the provisions of Chapter 5 of JB/T7688.1.
Marking, packaging, transportation and storage
According to the provisions of Chapter 6 of JB/T7688.1.
Warranty period
According to Chapter 7 of JB/T7688.1.
Additional remarks:
JB/T 7688.7—
This standard was proposed and managed by 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 is Zhao Yonghua.
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