This standard specifies the type, basic parameters and dimensions, technical requirements, test methods, acceptance rules, packaging and marking of ZPQ pneumatic disc brakes. This standard applies to normally closed brakes with spring-loaded brakes and pneumatic brake releases, with a braking torque of 365~21990N·m; an allowable speed of 675~2315r/min; and an operating ambient temperature of -40~100℃. This brake is suitable for mechanical equipment such as mining, metallurgy, engineering and ships. JB/T 8435-1996 Pneumatic disc brake JB/T8435-1996 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Pneumatic Disc Brake
Subject Content and Scope of Application
JB/T 8435:96
This standard specifies the type, basic parameters and dimensions, technical requirements, test methods, acceptance rules, packaging and marking of ZPQ type pneumatic disc brake (hereinafter referred to as brake). This standard is applicable to normally closed brakes with spring tightening and pneumatic release, with a braking torque of 365~~21990N·m, an allowable speed of 675~~2315r/min, and a working environment temperature of 401100C. This brake is suitable for mechanical equipment such as mining, metallurgy, engineering and ships.
Reference standards
GB531 Rubber Shore A hardness test method GB1184 Shape and position tolerance
Standards for end-note tolerances
GB1239 Cylindrical helical spring
GB/T13384 General technical conditions for packaging of electromechanical products JB3063 Powder metallurgy friction materials
JB/T6653 Flat steel wire cylindrical helical compression spring 3 Types, basic parameters and dimensions
3.1 Type
The structural type of the brake is shown in Figures 1 and 2. This brake is a normally closed disc brake with spring tightening and pneumatic release. It is driven by an air chamber and has two structures: single disc and double disc. 3.2 Basic parameters and dimensions
The basic parameters and dimensions of the brake should comply with the provisions of Table 1. 3.3 Model and marking
Marking example:
Friction disc specification code
Number of friction discs
-Brake
The marking of a pneumatic disc brake with 1 friction disc and 200mm friction disc specification is: ZPQ120Brake
The marking of a pneumatic disc brake with 2 friction discs and 200mm friction disc specification is: ZPQ220Brake
Approved by the Ministry of Machinery Industry of the People's Republic of China on September 3, 1996318
Implemented on July 1, 1997
JB/T 8435--96
Figure 1 Single friction disc disc brake
JB/T843596Www.bzxZ.net
Figure 2 Double friction disc disc brake
JB/T8435--
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108178
06~08~99
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4 Technical requirements
JB/T 8435--96
4.1 Brakes shall comply with the requirements of this standard and be manufactured in accordance with the drawings and technical documents approved through the prescribed procedures. 4.2 Materials and accessories shall comply with the provisions of current standards or technical documents. 4.3 The time from the start of braking to the maximum braking torque is 0.3 to 0.5 seconds. 4.4 During braking, the maximum temperature in the middle of the friction plate should not be greater than 100°C. 4.5 Friction disc
4.5.1 After all friction plates are riveted, the end face full runout error of the friction plate surface shall meet the 8-level accuracy requirements specified in GB1184, and the H rivet head shall be more than 2mm lower than the friction surface.
4.5.2 The friction disc shall be statically balanced, and its balance accuracy level shall not be lower than G6.3. 4.5.3 The surface of the friction plate shall not be stained with oil. 4.5.4 The dynamic friction coefficient of the friction plate shall not be less than 0.28; the compressive strength shall not be less than 1.9MPa; the hardness shall be 35~55H13; the hardness difference of a single plate shall not be greater than 12 HB.
4.5.5 The shearing force between the joint surface of the friction plate seat plate and the powder metallurgy sintered block shall not be less than 0.3MPa. 4.5.6 The sliding speed of the friction plate shall not be less than 20m/s. 4.6 Spring
4.6.1 The spring shall have a quality inspection certificate from the manufacturer and can only be used after passing the re-inspection. The quality of the material shall comply with the relevant provisions of the corresponding material standard.
4.6.2 The allowable deviation of the spring load shall comply with the Class 1 accuracy requirements specified in GB1239. 4.6.3 The free height limit deviation of the spring and the free height difference of the springs used for the same set of brakes are shown in Table 24.6.4 In the free state, the verticality error of the spring axis to the two end faces is shown in Table 2. 4.6.5 The spring life should be not less than 105 times. Table 2
Free height of spring feed
4.7 Sealing ring
Free height
Limit deviation
Verticality
The hardness of the sealing ring is 70±5 Shore, and the operating temperature range is -48~～+135C. 4.8 Assembly
4.8.1Bolts and nuts must be tightened according to the specified preload. 4.8.2All friction surfaces must be free of oil stains. 4.9 Quality assurance
The difference in free height of springs used in the same set of brakes
If the user complies with the relevant regulations on product storage and installation and use, the manufacturer shall repair or replace the springs free of charge for the user if they are damaged or cannot work normally due to poor manufacturing quality within 1 year from the date of shipment from the manufacturer or within 10 months of installation and use (except for normal wear of friction plates).
5 Test method
Check the material properties of the friction plates in accordance with the provisions of JB3063. 5.2 Conduct static balance test of friction disc on static balance test bench. 5.3 Conduct fatigue life test of spring on testing machine. 5.4 Use corresponding testing instruments to check dimensional accuracy and appearance quality of sealing ring; check its hardness according to GB531322
5.5 Type test
JB/T8435-96
Install the brake on the test bench, brake at a frequency of 2 times per minute, and change the friction disc speed from low to high in sequence; then change the additional moment of inertia, still change the friction disc speed from low to high, brake at the same frequency, and perform the following operations respectively: a.
Measure the braking torque;
Measure the time from gas line cut-off to reaching the maximum braking torque; h.
Measure the temperature of the middle part of the friction plate through the thermocouple installed in the bottom friction disc. 6 Acceptance rules
6.1 Basic rules
6.1.1 During the production process, any inspection procedures and equipment can be used to control quality, but the quality of the finished brake must be guaranteed to comply with the provisions of this standard.
6.1.2 The user can inspect the brakes delivered by the supplier according to this standard to determine whether the delivered products are qualified. 6.2 Inspection items
6.2.1 After assembly, the compressed air ventilation test is carried out with the maximum allowable working pressure, and the pressure is maintained for 30 minutes. There shall be no obvious leakage; when the minimum working pressure is ventilated, the brake shall open and close flexibly and there shall be no sticking. 6.2.2 Type tests are only carried out when new products are put into production and when the formula of the friction material is changed. The brakes shipped out of the factory are only subject to factory inspection, and no type tests are carried out.
7 Packaging and marking
7.1 Appropriate anti-rust measures shall be taken for the exposed machined surfaces of the brake. The air inlet of the cylinder shall be sealed with a plug. Under normal transportation and storage conditions, no rust will occur within 1 year from the date of leaving the factory. 7.2 The brakes leaving the factory should be packaged and comply with the provisions of GB/T13384. 7.3 The packaging mark should include the following:
Manufacturer name;
Product name and model specifications;
Consignee and address;
Net weight and gross weight.
7.4 The following technical documents should be attached:
Product instruction manual;
Product certificate;
Packing list.
Additional instructions:
This standard was proposed and coordinated by the National Technical Committee for Standardization of Mining Machinery. This standard was drafted by Taiyuan Heavy Machinery Plant. The main drafters of this standard are Shen Jigang, Wang Xiaoming, Cong Peishan, Zhang Chonghuan and Guo Ming. 323
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