Some standard content:
ICS83.140.50
Registration No.: 4059-1999
Chemical Industry Standard of the People's Republic of China
HG2950-1999
Rubber diaphragms forbrake
chamber in automobiles
Published on August 12, 1999
Implementation on October 1, 2000
Published by the State Administration of Petroleum and Chemical Industry
HG2950-1999
This standard is revised from the chemical industry standard HG2950--1.987 Rubber diaphragms for brake chamber in automobiles based on domestic production and use conditions.
The technical differences between this standard and HG2950-.1987 are: the product structure and size are changed to meet the requirements of the drawings to meet the requirements of the growing automotive industry; - the tensile strength and elongation at break of the vulcanized rubber are appropriately adjusted to expand the use of synthetic rubber; GB/T7759 is used instead of GB1683 for compression permanent deformation test, and the compression permanent deformation performance index is adjusted; the performance index of the adhesive strength between chemical rubber and fabric is adjusted; - the sampling method is adjusted to make it more reasonable and feasible. From the date of implementation, this standard will replace HG2950-1987 at the same time. Appendix A of this standard is the appendix of the standard. This standard was proposed by the Technical Supervision Department of the former Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Sealing Products Sub-Technical Committee of the National Technical Committee for Standardization of Rubber and Rubber Products. The drafting units of this standard are: Northwest Rubber and Plastic Research and Design Institute of the Ministry of Chemical Industry, Guizhou Dazhong Rubber Co., Ltd., and Zhongnan Rubber Group. The main drafters of this standard are: Wang Baoyong, Sun Liping, Tan Yiyang, and Zhang Lijun. This standard was issued as the national standard GB7525--87 "Rubber diaphragms for brake chambers in automobiles" in 1987, and was adjusted to a mandatory chemical industry standard in 1997. The original GB7525--87 was abolished and renumbered as HG/2980--87.
Chemical Industry Standard of the People's Republic of China
Rubber diaphragms for brake chamber in automobiles
Rubber diaphragms for brake chamber in automobiles
HG 2950-1999
Replacement HG2950-1987
This standard specifies the requirements, sampling, test methods, marking, packaging, transportation and storage of rubber diaphragms for brake chambers in automobiles. This standard applies to rubber diaphragms for brake chambers in automobiles. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. G13/T528—1998 Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber (egvISO37:1994) GB/T531--1992 Vulcanized rubber Shore A hardness test method (negISO7619:86) GB/T 532--1997bzxZ.net
Determination of adhesion strength of vulcanized rubber or thermoplastic rubber to fabrics (idtISO36:1993) GB/T 1682—1994
2828-1987
GB/T 2941—1991
Determination of low-temperature brittleness of vulcanized rubber Single specimen method Batch inspection Count sampling procedure and sampling table (applicable to inspection of continuous batches) Standard temperature, humidity and time for environmental conditioning and testing of rubber specimens GB/T
3512—1983 (89) Rubber hot air aging test method GB/T5721-1993
General provisions for marking, packaging, transportation and storage of rubber sealing products GB/T5723—1993
77591996
98651996
3 Requirements
3. Materials
Determination of dimensions of test specimens and products for testing vulcanized rubber or thermoplastic rubber Vulcanized rubber or thermoplastic rubber
ISO 815 :1991)
Determination of compression set at room temperature, high temperature and low temperature (eqv Preparation of samples and test pieces of vulcanized rubber or thermoplastic rubber ISO 4661/1:1993)
The materials used to manufacture rubber diaphragms shall comply with the relevant standard requirements. 3.2 Physical properties of vulcanized rubber
The physical properties of vulcanized rubber shall comply with the requirements of Table 1. Approved by the State Administration of Petroleum and Chemical Industry on August 12, 1999 Part 1: Physical tests (idr
Implementation on October 1, 2000
Hardness, Nar A: degrees
Tensile strength, MPa
Elongation at break, %
HG2950—1999
Table 1 Physical properties of vulcanized rubber
Physical properties
Positive shrinkage set, 70℃ ×22h, %
Critical temperature, C
Hot air aging, 70℃×70h
Hardness change, Shore A, degree
Tensile strength change rate, %
Tear elongation change rate, %
Vulcanizer adhesive and fabric bonding strength, kN/m3.3Product size
Product size should meet the requirements of the drawing.
3.4Product appearance quality
Except for other Unless otherwise specified, the product appearance quality shall comply with the requirements of Table 2. Maximum
Not higher than
Not less than
Table 2 Product Appearance Quality
Defect Name
Fabric Breakage
Edge Damage
Edge Burrs
Irrigation Marks (including water ripples and slight pitting) Fabric Missing Around
Cumulative Defects
5～+10
Allowed, but the convexity is Bubbles no larger than 0.3mm, no longer than 1.5mm, with a diameter of 2~3mm, or no deeper than 0.5mm are not allowed to be more than 2. No longer than 3mm, no wider than 1.5mm, or no deeper than 0.5mm are not allowed to be more than 2. No longer than 3mu, no wider than 1.5mm, or no deeper than 0.5mm are not allowed to be more than 2. No longer than 1mm, no longer than 1/6 of the circumference, and no higher than 1 is allowed. mm
Allowed to exist, but cracks are not allowed
The cumulative length is not allowed to be greater than 1/6 of the circumference
The total number of defects in No. 2, 3, and 1 is not allowed to exceed 4.3.5 Product life
The product life is 250,000 times: After the life test, the sample is kept at 0.6±MPa pressure for 1min, and the pressure drop value is not more than 30kPa.
4 Sampling
4.1 The same rubber material produced continuously shall be a batch of no more than 5000kg.4.2 The same type of products produced continuously under the same process conditions and delivered for inspection at one time shall be a batch of no more than 10,000 pieces. 4. 3 Physical property test of vulcanized rubber The required number of samples shall be randomly selected from each batch of products, or any sample can be randomly selected from each batch of rubber materials. Samples shall be prepared according to the specified process conditions and factory inspection shall be carried out according to item 14 in Table 1. 4.4 Type inspection shall be carried out when any of the following situations occurs. - When the product is transferred to another factory for production or the new product is finalized and identified; 4
HG2950-1999
After formal production, if there are major changes in materials and processes that may affect product performance; - When the product is discontinued for more than three months and production is resumed, ~ When the factory inspection results are significantly different from the last type inspection; When the national quality supervision agency proposes a type inspection requirement. 4.5 Unless otherwise specified, the dimensions of each batch of products shall be sampled and inspected according to the general inspection level I in GB/T.2828, and the AQ1. value is 4.0. 4.6 The appearance of the product shall be inspected piece by piece.
4.7 The life inspection of the product shall be carried out no less than once every six months. 4.8 When the product fails the appearance quality inspection, the product is considered unqualified. When the physical properties and product life of the vulcanized rubber are unqualified, double the samples should be taken for re-inspection of the unqualified items. If they are still unqualified, the batch of products is considered unqualified.
5 Test method
5.1 Preparation of vulcanized rubber test specimens
Perform in accordance with GB/T9865.
5.2 Hardness
Test in accordance with GB/T531.
5.3 Tensile strength and elongation at break
Test in accordance with GB/T528.
5.4 Compression permanent deformation
Perform the test in accordance with GB/T7759 using a Type B test specimen. 5.5 Hot air aging
Test according to GB/T3512.
5.6 Brittle temperature
Test according to GB/T1682.
5.7 Adhesion strength between vulcanized rubber and fabric
Test according to GB/T532.
5.8 Appearance quality of the product
Measured by visual inspection or measuring tool with a graduation value of 0.02mm. 5.9 Product size measurement
Measured according to GB/T5723.
5.10 Product life
Tested according to Appendix A.
6 Marking, packaging, transportation and storage
6.1 Unless otherwise specified. Marking, packaging, transportation and storage shall comply with GB/T5721. 6.2 Unless otherwise specified, each package box shall contain products of the same specification. 6.3 Under the conditions specified in 6.1 and 6.2, the product storage period is - years. 5
HG2950—1999
Appendix A
(Standard recording)
Life test method for automobile brake air weight rubber diaphragm Product life test device is shown in Figures A1 and A2. Handicap gauge
Total pressure gauge
Integral gauge
Dividual pressure gauge
Starting speed switch
Starting sub-switch
Figure A1. Test device for the life test of rubber diaphragm of automobile brake chamber (front view) A2 Specimen
HG2950—1999
Limit switch
Brake chamber assembly
One pressure gauge
Figure A2. Test device for the life test of rubber diaphragm of automobile brake chamber (front view) Two pieces should be randomly selected from a batch of products that meet the requirements of 3.1, 3.2, 3.3 and 3.4. Unless otherwise specified, the structure of the sample is divided into "type" and 【type, as shown in Figure A3, and its main dimensions shall comply with the provisions of Table A1. Type
Fiber fabric
A3 Preparation before the test
HG 2950—1999
Fiber spider fabric
Main dimensions of the sample
40. 50. 7
Before assembling the sample, the dimensions and appearance of the main parts of each air chamber shall comply with the relevant regulationsA4 Test conditions
Unless otherwise specified, the test conditions shall comply with the provisions of GB/T2941.A5 Test steps
A5.1 Fix the required brake air case on the bracket, install the samples in the brake air chambers respectively, and calibrate the positions of the piston and the sample so that they are in the self-mounting state respectively. Tighten with a clamp to ensure that the sample is under a pressure of 0.6±aiMPa, maintain the pressure for 1min, and the pressure drop value is not greater than 10kPa. A5.2 Adjust the nut on the limit seat so that its stroke reaches (28±2) mm. A5.3 Turn on the power supply and air source, and adjust the pressure regulating valve to make the air pressure 0.6±9:1MPa. A5.4 Maintain the working frequency of (15±1) times/min and the air intake time of each time is not more than 0.6s. A5.5 Reset the counter to zero and start the test. A5.6 When the counter reading reaches 250,000 times (it can also be converted by the actual test time), the test should be stopped. A5.7 The sample is kept under pressure of 0.6!iMPa for 1 min, observe the pressure drop. 8
(Beijing) Xindengzi No. 039
People's Republic of China
Chemical Industry Standard
Automobile Brake Chamber Rubber Diaphragm
HG 2950-1999
Published and distributed by Chemical Industry Press
(No. 3 Huixinli, Chaoyang District, Beijing, Postal Code 100020)httpr//eijp.con.tm
Distributed by Xinhua Bookstore Beijing Distribution Office
Printed by Chemical Industry Press Printing Plant
Printed and bound by Chemical Industry Press
Format 850×1230 mm 1/16 Printing Sheet Number of Words 16 dry words August 2000 First Edition August 2000 First printing in Beijing in June Book number: 155025: 0041
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