This standard specifies the technical requirements, test and inspection rules for open-hearth furnace charging bridge cranes. This standard applies to bridge cranes that use a material box pick-up rod as a pick-up device to charge open-hearth furnaces. JB/T 7688.2-1995 Technical conditions for metallurgical cranes Open-hearth furnace charging bridge cranes JB/T7688.2-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
Open-hearth Charging Bridge Cranes
Subject Content and Scope of Application
JB/T 7688. 2-95
This standard specifies the technical requirements, test and inspection rules, etc. for open-hearth charging bridge cranes. This standard applies to bridge cranes (hereinafter referred to as cranes) that use a material box pick-up rod as a pick-up device to charge an open-hearth furnace. 2 Reference Standards
GB1176 Technical Conditions for Cast Copper Alloys
GB3766 General Technical Conditions for Hydraulic Systems
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 ambient temperature of the crane shall be -10°C and the maximum shall not exceed +55°C. 3.2 Performance in use
3.2.1 The rated lifting capacity of the crane is the sum of the mass of the material box and the material being lifted. 3.2.2 The main trolley and auxiliary trolley of the crane shall not be used at the same time. 3.3 Materials of metal structures
The materials of the guide frame and guide rod of the crane shall comply with Article 3.3 of JB/T7688.1. 3.4 Main components
3.4.1 The material of the crankshaft and connecting rod of the boom swing mechanism shall not be lower than 45 steel in GB699. 3.4.2 The material of the front and rear sections of the boom is recommended to be chromium-molybdenum steel with appropriate mechanical properties, and the middle section of the boom can be made of ZG270-500 steel not lower than GB11352.
3.4.3 Guide frame
3.4.3.1 When the guide frame adopts a cylindrical structure, it shall meet the following requirements: a.
The dimensional deviation of the bent and formed cylinder shall be in accordance with the provisions of Figure 1 and Table 1; Figure 1
Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 558
Implemented on July 1, 1996
>2 000--2 500
≥2500-3000
≥3000
JB/T7688.2—95
When the cylinder wall thickness is the following value, the roundness is 830
Curved edge C
The misalignment e (see Figure 2) between the cylinder and the cylinder of each section, or the cylinder joint edge, shall not be greater than 10% of the cylinder thickness, but not more than 2mm; Figure 2
The transverse weld of the cylinder shall be subjected to ultrasonic testing, and its defect level shall not be lower than Level II in GB11345 (inspection level is B). 3.4.3.2 When the guide frame adopts a truss structure, the straightness of its components shall comply with the provisions of Article 3.6.10.6 of JB/T7688.1. 3.4.3.3 The material of the anti-tipping roller on the guide frame shall not be lower than 45 steel in GB699, with a hardness of 260-280HBS and a hardened layer depth of 1.5mm.
3.4.3.4 The guide rail plate for the guide rod (fixed in the square hole of the large gear of the slewing mechanism) shall be made of cast manganese brass, tin bronze or aluminum iron bronze. It is recommended to use ZCuA18Mn13Fe3 in GB1176. 3.4.3.5 After the guide rod guide rail plate is fixed, its center line shall be parallel to the center line of the guide frame, and its parallelism error shall not exceed 3mm; the symmetry error between the guide rail plate and the center line of the square hole of the guide part shall not exceed 0.5mm. The distance deviation of the contact surface of the symmetrical guide rail plate is 22mm, and the verticality tolerance of the contact top surface of the guide rail plate shall not be less than grade 8. The maximum allowable value of the roughness Ra of the contact top surface of the guide rail plate is 6.3um. 3.4.4 Guide rod
3.4.4.1 The straightness tolerance of the guide rod shall be as specified in Table 2. Table 2
Component length
Straightness tolerance
4 000~8 000bzxZ.net
8 000-~12 000
≥12 000～16 000
3.4.4.2 The distance deviation of the top surface of the guide rail (fixed on the guide rod) is -.:mm; the parallelism error of each set of symmetrical top surfaces shall not exceed 0.5mm; the symmetry error between the top surface and the center line of the guide rod shall not exceed 0.5mm. The verticality tolerance of the top surface shall be Grade 8. The maximum allowable value of the roughness Ra of the top surface of the guide rail is 3.2um. 3.4.5 If the lifting rod locking mechanism adopts hydraulic drive, its hydraulic components shall meet the requirements of GB3766. 3.5 Assembly
Assembly diagram of crane trolley is shown in Figure 3.
3.5.1When the guide frame is connected to the trolley frame, the verticality error of the guide frame centerline to the trolley wheel support surface (with the bent plate processing plane of the four wheels as the base push point) shall not exceed 1/2000.
If high-strength bolts are used to connect the trolley frame and the guide frame, there should be at least two locating pins on each side that match the holes. 559
JB/T7688.2—95
1-Transmission vertical shaft; 2-Universal coupling; 3-Bearing frame: 4-Small gear; 5-Large gear; 6-Limit switch; 7-Bearing frame; 8-Guide rod, 9-Guide frame; 10-Trolley Figure 3
3.5.2 The center line of the guide rail plate in the guide frame should be parallel to the center line of the guide frame, and the parallelism error should not exceed 3mm3.5.3 The coaxiality error of the upper and lower supports on the guide frame should not exceed 0.5mm, and the verticality error of the support surface to its axis should not exceed 1/2000
3.5.4 The gap between the guide rail plate and the guide rod track should be 1~~1.5mm. 3.5.5 The verticality error of the guide rod after installation shall not exceed 12000 (the base push point for inspection is the end of the guide frame), and there shall be no jamming when the upper and lower supports slide.
3.5.6 After the slewing mechanism transmission vertical shaft is connected with a universal coupling, the upper and lower position difference should not be greater than 4mm. 3.5.7 For the lifting guide rod picking device, the rolling bearing under the sling nut should be in close contact with the crossbeam. 3.5.8 The reducer and open large gear used in the slewing mechanism should be fixed to the foundation base, and no displacement should be generated during lifting and braking, or the impact force during lifting and braking should be transmitted to the foundation base through special connectors. 3.5.9 After the anti-tilt anti-roller on the guide frame is installed, the gap between its rolling tread and the lower flange plate of the main beam should be 3~~8mm. 560
JB/T 7688.2-95
3.5.10 After the sections of the lifting rod are connected, the connecting cone surface should be in close contact, and the contact area should be not less than 75%. 3.5.11 Adjust the stroke of the hydraulic pusher or other locking devices in the lifting rod locking mechanism to make the lock box accurate and reliable. 3.6 Electrical equipment
It is allowed to use a set of control equipment for the main lifting mechanism and auxiliary lifting mechanism, auxiliary trolley and material rod rotating mechanism, and its circuit must ensure that only one of the mechanisms can be controlled at the same time.
3.7 Safety and hygiene
3.7.1 The worm gear reducer on the main trolley should be equipped with a torque overload limiter, and its limit torque is 1.25 times the rated torque.
3.7.2 The main lifting mechanism should also be equipped with a lower limit position limiter. 3.7.3 The guide rod rotating mechanism that does not use slip ring collectors but uses cable power supply should be equipped with a rotation limiter, and the number of rotations should be limited to prevent the cable from being tangled or pulled off.
3.7.4 The main trolley should be equipped with a handwheel device that can move the trolley to prevent the material rod from being withdrawn from the furnace in the event of a sudden power outage. 3.7.5 The driver's cab should be equipped with a material box locking indication signal device. 3.7.6 The lower slewing platform should be equipped with a heat-insulating protective enclosure. 3.8 Lubrication
It is recommended to use centralized lubrication for the mechanism in the guide frame, and dry oil lubrication should be used for the guide rod and guide rail. 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 inspections of the guide frame, guide rod and material rod. 4.2 Qualification test
During the test, it is recommended to use a gradual loading method, allowing loading to the rated lifting weight at one time. Perform action 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 3 of this standard. Table 3
Item Name
Working range of lower platform rotation
Guide rod rotation speed
Working speed
Lifting rod rotation speed
Lifting rod swing frequency
Main trolley movement handwheel device during power failure
Material box locking mechanism
Material box locking indication signal
4.3 Load-bearing capacity test
Static load test
Measurement unit
Times/min
Required value
As specified in the design drawing
Can move the trolley flexibly and conveniently
Flexible and reliable
Sensitive and accurate
In addition to the requirements of Article 4.3.1 of JB/T7688.1, the static load test of the crane shall also meet the following requirements: a.
Before the test, park the auxiliary trolley at the end of the span;
Limit deviation
b. Park the unloaded main trolley in the middle of the span, and make the material loading lever perpendicular to the running direction of the trolley to determine the measurement base point. c. During the test, load at 1.25G, based on the amount added to the material box, drive the main trolley to the middle of the span, and after unloading, check whether there is any permanent deformation at the base point of the main beam in the middle of the span.
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: 561
JB/T 7688.2-95
During the test, the load shall be 1.1G, and the main trolley shall be loaded in the material box; the main trolley and the auxiliary trolley shall be tested separately: b.
The swing, rotation, locking mechanism and other actions of the material box lifting rod shall be tested repeatedly 5 times, c.
During the test, each mechanism shall operate smoothly and meet the functional requirements of each mechanism. When the rotation and lifting mechanism are linked, the guide rod is not allowed to be blocked.
5 Inspection rules
According to Chapter 5 of JB/T7688.1.
6 Marking, packaging, transportation and storage
In addition to the requirements of Chapter 6 of JB/T7688.1, the following requirements shall be added: The guide rod must be wrapped and mounted. It must not be damaged or permanently deformed during transportation; a.
The guide rail plate of the guide rod must be rust-proof packaged. h.
7 Warranty period
According to the provisions of Chapter 7 of JB/T7688.1.
Additional instructions:
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 the Beijing Hoisting and Conveying Machinery Research Institute participated in the drafting. The main drafter of this standard is Zhao Yonghua.
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