JB/T 7688.8-1995 Technical conditions for metallurgical cranes - Ingot removal cranes
Some standard content:
Mechanical Industry Standard of the People's Republic of China
Technical Conditions for Metallurgical Cranes
Debonding Cranes
1 Subject Content and Scope of Application
This standard specifies the technical requirements, test and inspection rules, etc. for debonding cranes. JB/T 7688.8—95
This standard applies to bridge debonding cranes (hereinafter referred to as cranes) with spiral debonding mechanisms (mechanical debonding), wire rope debonding mechanisms or hydraulic debonding mechanisms. Mainly used to separate the steel ingot from the ingot film and to transport it. 1. 2 Reference standards
GB699 Technical conditions for high-quality carbon structural steel
GB3077 Technical conditions for alloy structural steel
GB3766 General technical conditions for hydraulic systems
GB5680 Technical conditions for high manganese steel castings
GB7631.2 Classification of lubricants and related products (Class L), Part 2: Group H (hydraulic systems)JB/T7688.1 Technical conditions for metallurgical cranes General requirementsJB/T7688.2 Technical conditions for metallurgical cranes Open-hearth charging bridge cranesJB/T 7688. 51
Technical conditions for metallurgical cranes
Clamp cranes
Technical conditions for metallurgical cranes Integral mold cranesJB/T 7688.61
JB/ZQ4297 alloy cast steel
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 crane should work indoors. The minimum working environment temperature is -10°C and the maximum is not more than 1065°C. 3.2 Performance
3.2.1 The lifting capacity of the crane should reach the rated lifting weight, and the ingot stripping force, pre-rod ejection force and small clamp pull-up force should reach the design rated value. The rated lifting weight should be the sum of the mass of the clamped steel ingot and the steel ingot mold. 3.2.2 It is allowed to hang a hook or electromagnetic suction cup on the large clamp for auxiliary lifting work. 3.3 Metal structure materials
The materials of the guide frame and clamp rod (column) of the crane shall comply with the provisions of Article 3.3 of JB/T7688.1. 3.4 Welding of assemblies
For assemblies using electroslag welding, annealing or quenching and tempering treatment shall be carried out after welding according to the performance requirements. The welds shall be subjected to ultrasonic flaw detection and shall not be lower than Level 1 in the defect level classification of GB11345 (inspection level is B). 3.5 Main components
3.5.1 The material of the transmission square shaft in the spiral stripping mechanism shall not be lower than 45 steel in GB699, and the square shaft and square hole shall fit well. Approved by the Ministry of Machinery Industry of the People's Republic of China on June 16, 1995 578
Implemented on July 1, 1996
JB/T 7688.8-95
3.5.2 The material of the hollow screw in the spiral stripping mechanism shall not be lower than ZCuZn25AI6Fe3Mn3 in GB/T1176. The material of the inner screw shall not be lower than 35CrMo steel in GB3077. The screw shall adopt trapezoidal thread, and the maximum allowable value of its thread surface roughness Ra is 6.3μm.
3.5.3 The material of the large sleeve in the stripping mechanism shall not be lower than ZG340-640 in GB11352. It is recommended to use alloy cast steel according to performance requirements. The casting shall not have defects such as cracks, sand holes, pores, looseness, etc. that affect the performance. 3.5.4 The material of the ejector rod in the stripping mechanism shall not be lower than 50 steel in GB699, with an overall hardness of 255-286 HBS, and the surface hardness of the end face of the ejector head shall be 45-50 HRC.
3.5.5 The ratchet pawl in the ratchet pawl stopper or the synchronizer shall meet the following requirements: a. The number of pawls shall not be less than 2, and the number of ratchet teeth shall generally be 6-30. b. The material of the pawl and its fixing pin shall not be lower than 45 steel in GB699, with a surface hardness of 50-55 HRC. The pawl fixing pin and ratchet snap ring shall be locked and shall not be loosened. c.
d. After the ratchet is installed, it shall be able to rotate flexibly on the shaft, and its radial swing shall not be greater than 0.15 mm. The pawl shall be tightly attached to the ratchet tooth surface and shall rotate flexibly.
3.5.6 If the guide frame adopts a simple structure, the requirements for the simple structure shall comply with the provisions of Article 3.4.3.1 of JB/T7688.2. When a rectangular guide frame is used, its transverse welds shall be subjected to ultrasonic testing and shall not be lower than Level II in GB11345 (inspection level is B). 3.5.7 The material of the guide rod (column) and the upper counterweight guide rail of the guide frame shall not be lower than ZG340-640, and it is advisable to use ZGMn13-4 steel in GB5680. The material of the guide rail guide plate on the counterweight and the load-bearing wing frame shall not be lower than 45 steel. The maximum allowable value of the contact surface roughness Ra of the guide rail and the guide rail guide plate is 6.3um. The limit deviation of the top distance between the two guide rails is +3mm, and the limit deviation of the width of the guide rail slideway is 2mm. 3.5.8 The material of the circular track of the upper rotating trolley of the wire rope debonding crane shall not be lower than 40CrNiMo steel in GB3077, with a hardness of 269~302HBS. The rail joint weld shall not have defects such as cracks and slag inclusions. The maximum allowable value of the rail head roughness Ra is 6.3um. 3.5.9 Clamping device
3.5.9.1 The technical requirements of the small clamp shall comply with the provisions of Article 3.4.7 of JB/T7688.5. 3.5.9.2 The material of the large clamp shall not be lower than ZG220-500 steel in GB11352, and it is advisable to adopt ZG35CrMo steel in JB/ZQ4297. The head shall be clad with wear-resistant and heat-resistant alloy, and preheating shall be performed before welding. The cladding electrode used shall comply with the relevant requirements of Article 3.4.7.6 of JB/T7688.5, with a cladding thickness of 8 to 10 mm and no cracks. 3.5.9.3 The left and right half clamps of the large clamp shall be symmetrical, and it is advisable to be equipped with synchronization devices (such as fan-shaped tooth synchronization devices and pull rod synchronization devices, etc.). And the half clamps shall act in a coordinated manner.
3.5.10 Hydraulic system and its components
3.5.10.1 The hydraulic system and its components of the crane shall generally comply with the requirements of GB3766. When the inlet temperature of the hydraulic pump exceeds 60°C, special measures shall be taken, such as setting up an oil filter cooling record. When the lowest ambient temperature is -10°C, the equipment must also be able to work normally. The system shall also be equipped with an oil over-temperature indication signal.
3.5.10.2 The hydraulic system shall use hydraulic oil with a high flash point and moderate viscosity. For mechanisms with fire hazards, flame-retardant hydraulic oil should be used. Generally, L-HM46 or 1.-HS46 hydraulic oil in GB7631.2 is selected. 3.5.10.3 The main oil cylinder of the hydraulic stripping mechanism is recommended to adopt a differential circuit system. 3.5.10.4 The oil tank shall not leak oil, and the welds shall be subjected to leakage tests. 3.5.10.5 The pipe connection welds in the system shall be welded by argon arc welding. The inner wall of the pipe should be smooth, free of rust, scale and other defects. The bending part should not have cracks, unevenness and unevenness.
3.5.11 The driver's cab and electrical room of the crane should be insulated and heat-insulated. There must be a cold air blower or air conditioner in the room. 3.5.12 The requirements for cable winding devices and collectors shall comply with Article 3.3.5 of JB/T7688.6. 3.6 Assembly
The assembly of the mechanism of the ingot stripping crane is shown in the schematic diagrams of Figures 1 to 4. 3.6.1 When the trolley frame is connected to the guide frame (the guide cylinder of the spiral ingot stripping crane, the rectangular guide frame of the hydraulic ingot stripping crane and the wire rope ingot stripping crane, etc.), the verticality error of the guide frame center line to the trolley wheel support surface should not be greater than 1/2000. 579
JB/T 7688.8—95
3.6.2 The center line of the simple guide frame, the symmetric center line of the rectangular guide frame and the symmetric center line of the guide rail slide groove should coincide, and the limit deviation should not be greater than 3mm in length. The guide rails and guide rail slides should be parallel, and the parallelism error should not be greater than 3mm. The guide rails and slides on both sides should be evenly hooked, and the value is 2~~3mm. 3.6.3 The ratchet device to prevent the wire rope from loosening shall meet the following requirements: the ratchet centerline shall be parallel to the drum axis, and the parallelism error shall not be greater than 0.5/1000; the ratchet bearing seat shall be horizontal, and the relative difference with the drum bearing seat shall not be greater than 0.5mm; b.
The ratchet pawl shall be tightly attached to the ratchet, and the gap shall not be greater than 0.20mm. The pawl shall move flexibly and shall not loosen after being locked. 3.6.4 Requirements for limit torque device
3.6.4.1 The friction surface of the friction limit torque device shall have good contact and its contact surface shall not be less than 75%; all springs must be adjusted evenly so that the slipping torque reaches the specified value. When adjusting, first tighten all the springs in each circle, and then loosen them evenly. 3.6.4.2 When using a pin coupling, the end face of the pin sleeve and the end face of the fixed pin shall be flush, and the pin shall not swing in the sleeve hole. 3.6.5 Stripping mechanism
3.6.5.1 In the transmission of the spiral stripping mechanism, the installation of the rectangular shaft shall meet the following requirements: a.a. The square shaft shall not be bent, the middle should not be greater than 1 mm, and the verticality error should not be greater than 2mm when the end is installed; b. The distance from the square shaft to the guide slides on both sides should be equal, and the deviation should not be greater than 3mm; c. The square shaft and the lower bearing sleeve should be concentric, the clearance around should be even, and the deviation should not be greater than 4mm. When installing the bearing sleeve, the coaxiality error between the hole and the shaft should not be greater than 1mm;
d. The distance from the end faces of the two wing plates of the wing frame to the center of the sleeve should be equal, and the deviation should not be greater than 2mm. The clearance between the end face and the slide rail should be even and not greater than 2mm.
1-Trolley upper part: 2-Guide frame: 3-Driver's room and electrical room: 4-Large clamp: 5-Small clamp: 6-Mover Figure 1 Spiral de-spindle (mechanical) crane trolley 580
JB/T7688.8-95
1-Guide frame; 2-Electrical room; 3-Platform: 4-Platform, 5-Trolley running mechanism; 6-Driver's room; 7-Spindle de-spindle mechanism; 8-Brake; 9-Electric motor, 10-Trolley frame; 11-Coupling: 12-Reel device: 13-Reducer Figure 2 Hydraulic de-spindle crane trolley
3.6.5.2 The installation of hydraulic de-spindle mechanism shall meet the following requirements; a. Before installation, important parts such as oil cylinder and oil tank must be cleaned and dried. Pay attention to remove rust and stains, and no iron filings, cotton yarn, oxide scale, etc. should be left inside. The seals must not be scratched or squeezed during assembly. The oil suction tank and the oil return tank should be installed on the same horizontal plane. The height difference between the two oil tank covers should not be greater than 5mm in their entire length. The pipelines prepared on site should use seamless steel pipes of no less than 20 steel. The bending radius of the pipe should not be less than 6 times its outer diameter when cold-bending, and not less than 3 times the outer diameter of the pipe when hot-bending. C. The pipeline should be installed twice, that is, it should be removed after each pre-installation and sandblasted. Then it should be flushed, dried, oiled and pressure tested. After the above treatment, it can be finally installed on the system, and all pipelines should be fixed with pipe clamps. d. For valves, valve groups, indicators and other parts, if stains are found, they should be cleaned with kerosene and reassembled. Pay attention to the direction during installation. The oil inlet and oil return positions must not be installed incorrectly.
JB/T7688.8--95
e. Before the oil pump and the motor are installed, the coaxiality error of their axis centerline shall not be greater than 0.1mm. When connecting the motor, pay attention to the direction of the oil pump and do not connect it incorrectly.
f. The sensitivity and accuracy of the pressure gauge and indicating valve in the hydraulic system should be calibrated. g. The guide roller should be gently placed on the triangular track of the roller, and should not be too loose or too tight when moving. 3.6.5.3 In addition to the relevant requirements of Article 3.6.5.2, the hydraulic part of the wire rope stripping mechanism should also make the valve seat of the large clamp opening and closing hydraulic station face the driver's cab for easy observation by the driver.
3.6.6 Clamping device
3.6.6.1 The wire ropes used for hanging the large and small clamps and the wire ropes used for lifting and opening and closing on both sides of the large clamp must be adjusted evenly, and the opening degree on both sides of the large and small clamps should be equal.
3.6.6.2 The two tongs of the clamp should work synchronously. When using a pull rod type tong, the pull rod can be used for adjustment, and it should be ensured that the synchronous pull rod does not get stuck when the tong is opened.
3.6.6.3 The lifting and opening and closing pulleys should rotate flexibly. 3.6.7 Balance (counterweight)
3.6.7.1 The column used for guiding the counterweight should be vertical, and its verticality error should not be greater than 1/2000 (the inspection reference point is the end of the column). 3.6.7.2 The counterweight should be kept horizontal, and there should be no obstruction when lifting and lowering, and its horizontality error should not be greater than 1/1000. 3.6.7.3 When the counterweight is at the lowest position, the distance from its bottom surface to the top surface of the guide tube bracket is 150~～200mm. 3.6.7.4 If the counterweight is insufficient, it is allowed to fill the counterweight with heavy objects until the design requirements are met. 1- oil tank; 2- piston rod; 3- sleeve; 4- pulley; 5- ingot stripping cylinder; 6- large clamp cylinder; 7- large clamp bed; 8- guide groove frame; 9- large clamp; 10 push rod; 11- small clamp; 12- cross beam; 13- roller Figure 3 Hydraulic ingot stripping mechanism
JB/T7688.8-95
920 21 22 23
1-Guide slider; 2-Guide rail; 3·-Leg 4-Pulley of large clamp system: 5--Cylinder of large clamp and synchronous gear; 6-Push rod; 7-Roller; 8-Spring; 9-Beam; 10-Small clamp; 11-Large clamp; 12-Wire rope of large clamp system; 13-Balance pulley of large clamp system; 14-Axle sleeve seat; 15 Drum of push rod system: 16~-Wire rope of push rod system: 17-Balance pulley of push rod system; 18-Pulley of push rod system: 19-Brake: 20-Open gear: 21 Reducer: 22-Coupling; 23-Motor: 24-Balance wire rope; 25-Guide pulley of large clamp system: 26-Simple diagram of large clamp system reel 4 Wire rope stripping mechanism
3.7 Electrical equipment
3.7.1 Screw stripping crane generally adopts DC motor and electronic control equipment. 3.7.2 The electrical circuits of different types of stripping methods must meet the requirements of the production process. 3.8 Safety and hygiene
3.8.1 The wire rope winding system of the wire rope stripping mechanism should be equipped with a tension limiting device, which should be able to automatically cut off the lifting power when the wire rope tension (stripping force) exceeds the maximum limit. Each load controller is equipped with two pressure heads, which are connected to two circuits respectively. If one of them fails, it can still work.
If an electronic scale device is used, its indicating instrument should be installed in the driver's cab and can indicate the size of the stripping force. 3.8.2 The clamp should have a synchronous device for opening and closing the left and right half clamps. 3.8.3
The main lifting mechanism should be equipped with a ratchet pawl device to prevent the wire rope from slacking (or to ensure the synchronization of the two sets of motors). The main lifting mechanism should have a torque limit coupling. The crane's position limit shall comply with the following requirements:
The opening and closing of the clamp shall be equipped with an opening and closing limit device;
The ejector mechanism shall be equipped with an ejector travel limit device; The slewing trolley of the crane shall be equipped with a slewing limit device: The main lifting mechanism shall have a lower limit position limiter; Cranes with counterweights shall be equipped with buffers and limit devices for the upper and lower travel terminals of the counterweight lifting. The crane shall not start the lifting mechanism and the ejector mechanism at the same time. For hydraulic de-ingoting cranes, an oil over-temperature alarm signal device shall be installed in the driver's cab. 583
JB/T 7688.8--95
3.8.8 The wing frame of the spiral de-ingoting crane shall be equipped with upper and lower travel terminal buffers. 3.8.9 The temperature of the electrical room shall not exceed 45C. A heat insulation protective plate shall be installed on the bottom surface of the driver's cab platform. 3.9 Lubrication
It is recommended to use centralized lubrication for the mechanisms in the guide frame, and dry oil lubrication is recommended for the guide rods, wing frames, guide rails or slides of the counterweight. 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 should also include inspections of the guide rods, guide frames and de-chaining systems. 4.2 Qualification test
During the test, the lifting mechanism can be loaded to the rated lifting weight once. The ejection force of the ejection mechanism ejector rod should be gradually loaded to the rated value. Perform action tests in all directions under 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
Opening degree of large and small clamps
Stroke of top rod
Pole extension speed
Small clamp pulling speed
Clamp opening and closing rate
Slewing speed of slewing trolley
Wire rope tension limiting device of wire rope stripping mechanism
Oil over-temperature alarm signal device of hydraulic stripping crane
Electronic weighing device
Each limit device
4.3 Load-bearing capacity test||tt| |4.3.1 Static load test
Measurement unit
or m/s
times/min
Required value
According to the design drawing
According to the design drawingbzxZ.net
According to Article 3.8.1 of this standard
Accurate and reliable
Sensitive and accurate
Accurate and reliable
Limit deviation
★10%
When the crane is statically loaded, load it at 1.4G, and the load is applied to the tongs. During the test, the top rod is raised to the upper position, and the auxiliary trolley is opened to the end of the main beam. Others are in accordance with Article 4.3.1 of JB/T7688.1. During the test, the spring of the limit torque coupling should be tightened gradually. When the lifting weight exceeds 1.4G, the limit torque coupling begins to slip, and it should be ensured that it does not slip when the load is 1.2G. 4.3.2 Dynamic load test
During the dynamic load test of the crane, load 1.2G. Others shall comply with the relevant provisions of Article 4.3.2 of JB/T7688.1. 4.3.3 Ingot stripping mechanism test
The test is carried out according to the following provisions:
a. Lower the large tongs to the working position, open and close them repeatedly 3 times during the test, and the limit switch is required to be normal and the opening of the large tongs meets the requirements. Then use the large tongs to clamp the entire steel ingot equivalent to 1.2Gn; b. Lower the small tongs and the ejector head to the working position, and test the opening of the small tongs and the ejector system. The ejector head indicator and limit switch should be sensitive and normal, the opening degree of the small clamp and the ejector rod stroke should meet the requirements, and then the small clamp is used to clamp the test load equivalent to the rated pull-out force, and the pull-out force of the small clamp should meet the design requirements;
The ejector rod ejection force is tested with P, (P, is the rated output force), and the test can be carried out by the resistance strain sensor method or the following hydraulic c.
JB/T 7688.8-95
method (see Figure 5). During the test, a bottom plate 2 is placed on the ingot mold, and the jack 3 is placed on the steel plate, and the pressure gauge 7 is installed on the check valve 6. When the jack piston head rises, the large clamp 4 clamps the ingot mold 1, and the ejector rod 5 presses the piston head of the jack, and the pressure value can be read from the pressure gauge and then converted into the ejector rod ejection force.
1-ingot mold; 2-bottom plate; 3-oil pressure jack; 4-large clamp: 5-rod; 6-check valve: 7-pressure gauge Figure 5
The ejection force of the ejector can be calculated as follows:
Where: P-ejection force, kN;
F-piston area, cm;
A-pressure gauge reading. Pa or MPa.
If it is a hydraulic stripping mechanism, the pressure gauge in the high-pressure system of the mechanism can be used for testing directly (no jack is required). 4.3.4 Debugging of hydraulic system
If the stripping crane adopts hydraulic drive, its hydraulic system should be filled with oil and vented, and the low-pressure system and high-pressure system should be debugged. The entire hydraulic system should work normally and smoothly, without oil leakage, and can meet various functional requirements. 4.3.5 Working state test
If conditions permit, after the dynamic load test of the ingot stripping crane, it is advisable to test strip the hot ingot according to the normal operating procedures, and the workload is to strip one furnace of ingots. 5 Inspection rules
According to the provisions of Chapter 5 of JB/T7688.1
6 Marking, packaging, transportation and storage
The hollow screw, screw, inner screw, etc. in the spiral stripping mechanism must be well packaged and must not be damaged or permanently deformed during transportation and storage.
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 Transportation Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Taiyuan Heavy Machinery Plant, and the Beijing Hoisting and Transportation Machinery Research Institute participated in the drafting of this standard. The main drafter Zhao Yonghua.
Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.