This standard specifies the technical requirements, test and inspection rules for heating furnace loading and unloading cranes. This standard applies to bridge-type and ground-type loading and unloading cranes that use horizontal clamps as the loading device to heat the billet fed into the horizontal heating furnace. JB/T 7688.11-1995 Technical conditions for metallurgical cranes Heating furnace loading and unloading cranes JB/T7688.11-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
Heating Furnace Loading and Unloading Cranes
1 Subject Content and Scope of Application
JB/T7688.11-95
This standard specifies the technical requirements, test and inspection rules for heating furnace loading and unloading cranes. This standard applies to bridge-type and ground loading and unloading cranes (hereinafter referred to as cranes) that use horizontal clamps as the picking device to heat the bad materials fed into the horizontal heating furnace.
2 Reference standards
JB/T7688.1 General requirements for technical conditions of metallurgical cranes
JB/T7688.2 Technical conditions of metallurgical cranes JB/T7688.3
Technical conditions of metallurgical cranes
3 Technical requirements
Open-hearth charging bridge crane
Ground charging crane
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 shall be -5°C and the maximum shall not exceed +105°C. 3.2 Performance in use
The lifting capacity of the crane shall be the mass of the object being clamped. 3.3 Metal structural materials
The materials of the guide frame and guide rod of the crane shall comply with the provisions of Article 3.3 of JB/T7688.1. 3.4 Main Components
3.4.1 The crankshaft, connecting rod and pull rod of the clamp lever swing mechanism shall be made of no less than 45 steel in GB699. The limit deviation of the distance between the upper and lower axes of the crankshaft shall not be greater than 0.5mm. 3.4.2
The material of the clamp lever shall be alloy cast steel, or ZG340-640 steel not less than GB11352. 3.4.3
The material of the anti-tilt roller of the crane shall comply with the provisions of Article 3.4.3.3 of JB/T7688.2. It is recommended that the clamp jaws be made of alloy heat-resistant steel as the clamp plate, the hardness of the clamp teeth is 50~55HRC, and the rate hardening layer depth is 4~5mm. 3.4.4
The requirements for the guide frame and guide rod of the crane shall comply with the provisions of Articles 3.4.3 and 3.4.4 of JB/T7688.2. 3.4.5
3.4.6 If the opening and closing mechanism of the clamp rod is hydraulically driven, the hydraulic system shall comply with the relevant requirements of GB3766. 3.4.7 The requirements for the bridge frame of the ground loading and unloading crane shall comply with the relevant provisions of Article 3.3.8 of JB/T7688.3. 3.5 Assembly
3.5.1 After the sections of the clamp rod are connected, their joint surfaces shall be in close contact. If it is a conical surface, the contact area shall be not less than 75%. 3.5.2 Adjust the opening and closing mechanism of the clamp to ensure the required opening degree of the clamp and make the mechanism flexible and reliable. 3.5.3 The installation of the guide frame, guide rod, guide frame rotation mechanism, clamp rod rotation mechanism and anti-tipping roller on the guide frame shall comply with the provisions of Articles 3.5.1 to 3.5.9 of JB/T7688.2.
Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 592
Implemented on July 1, 1996
JB/T7688.11-95
3.5.4 The span limit deviation of the ground loading and unloading crane and the limit deviation of the track gauge measured by the trolley wheels shall comply with the provisions of Articles 3.4.6 and 3.4.7 of JB/T7688.3.
3.6 Safety and sanitation
3.6.1 The worm gear reducer used for the slewing mechanism on the main trolley of the bridge loading and unloading crane and the trolley of the ground loading and unloading crane shall be equipped with an overload limiting device, and its limit torque shall be 1.25 times the rated torque. 3.6.2 The main lifting mechanism of the bridge loading and unloading crane shall be equipped with a lower limit position limiter. 3.6.3 The guide rod and trolley slewing mechanism of non-slip ring collectors should be equipped with slewing limiters to prevent the power supply cable from being twisted or pulled off. 3.6.4 The trolley of the bridge loading and unloading crane and the trolley of the ground loading and unloading crane should be equipped with a handwheel device that can move the trolley to prevent the clamp rod from being withdrawn from the furnace in case of sudden power failure.
3.6.5 The swing mechanism of the staggered rod should be equipped with a swing buffer device. The clamp device should be equipped with a jaw limit device. For cranes with a driver's cab, a clamp clamping signal device should also be installed in the room. 3.6.6
3.6.7 The lower slewing platform of the bridge loading and unloading crane should be equipped with a heat insulation protective enclosure. 3.7 Lubrication
3.7.1 The mechanism in the guide frame of the bridge loading and unloading crane and the operating mechanism of the ground loading and unloading crane should be centrally lubricated, or point lubrication can be used.
The guide rod, guide rail or guide slide should be lubricated with dry oil. 4 Tests
4.1 Visual inspection
In addition to the provisions of Article 4.1 of JB/T7688.1, the visual inspection of the crane shall also include the guide rod, guide frame (bridge type) and clamp system.
4.2 Qualification test
It is recommended to use the gradual loading method during the test, and it is also allowed to load to the rated lifting weight 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, it should also include the items listed in Table 1 of this standard.
Project name
Slewing working range of guide rod (lower platform) of bridge loading and unloading crane and trolley of ground loading and unloading crane
Working speed
or frequency||t t||Guide rod or trolley rotation speed
Clamp rod rotation speed
Clamp rod swing frequency
Handwheel device for moving the main trolley of bridge loading and unloading crane or the trolley of ground loading and unloading crane
Clamp opening and closing mechanism
Indication signal for clamping the wrong clamp
4.3 Load-bearing capacity test
4.3.1 Static load test
Measurement unit
Times/min
Required valuebzxZ.net
As specified in the design drawings
Can move the trolley flexibly and conveniently
Flexible and reliable
Flexible and reliable
In addition to the requirements of 4.3.1 in JB/T7688.1, the static load test of the crane shall also meet the following requirements; a.
Limit deviation
Park the empty trolley (wheelbase center) in the middle of the span, with the clamp rod perpendicular to the trolley running direction, and determine the measurement base point; during the test, press 1.25G, load, and add the load to the clamp. After unloading, check whether there is permanent deformation at the base point in the main span; 593
JB/T7688.11—95
For bridge-type loading and unloading cranes, if there is an auxiliary trolley, it should be parked at the end of the span before testing. 4.3.2 Dynamic load test
In addition to the relevant requirements of Article 4.3.2 of JB/T7688.1, the dynamic load test of the crane shall also meet the following requirements: a.
During the test, press 1.1G. Load, add the load to the clamp; for bridge-type loading and unloading cranes, the main and auxiliary trolleys should be tested separately; the clamp The swing mechanism and slewing mechanism of the rod, the opening and closing mechanism of the clamp, the guide rod slewing mechanism of the bridge loading and unloading crane, and the slewing mechanism of the ground loading and unloading crane should be tested repeatedly for 5 times each. During the test, each mechanism is required to operate smoothly and meet the functional requirements of each mechanism. When the clamp rod slewing is linked with the trolley running mechanism, no jamming is allowed.
Inspection rules
According to Chapter 5 of JB/T7688.1.
Marking, packaging, transportation and storage
According to Chapter 6 of JB/T7688.2.
Warranty period
According to Chapter 7 of JB/T7688.1.
Additional remarks:
This standard is proposed and managed by the Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. This standard is drafted by Taiyuan Heavy Machinery Plant and participated in by the Beijing Hoisting and Conveying Machinery Research Institute. The main drafter of this standard is Zhao Yonghua.
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