GB/T 5764-2011 (GB/T5764-2011)

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GB/T 5764-2011: PDF in English (GBT 5764-2011)

GB/T 5764-2011
GB
ICS 43.040.40
Q 69
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
Replacing GB/T 5764-1998
Clutch facings for automobiles
ISSUED ON. JULY 20, 2011
IMPLEMENTED ON. MARCH 1, 2012
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the People’s Republic of China;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Terms and definitions ... 5 
4 Classification ... 6 
5 Requirements ... 6 
6 Test methods ... 8 
7 Inspection rules ... 15 
8 Marks, packaging, transportation and storage ... 17 
Appendix A (Informative) Recommendation form for the basic dimensions of
facings ... 19 
Appendix B (Normative) Fixture for the bending test ... 20 
Foreword
This Standard is drafted according to the rules given in the GB/T 1.1-2009.
This Standard replaces GB/T 5764-1998 Clutch facings for automobiles.
Compared with GB/T 5764-1998, the major technical changes are as follows.
— ADD the “Terms and definitions” (SEE Chapter 3 of this version);
— ADD the “Classification according to the manufacturing process” (SEE
Chapter 4 of this version);
— ADD the “Flatness requirements and test methods” (SEE the Sections
5.3 and 6.3 of this version);
— CONSIDER the friction property requirements specified in the 1998
version as those for the Class I facings. CHANGE the coefficient of friction
at 200°C from “0.15~0.60” to “0.20~0.60”. ADD the requirement for the
coefficient of friction at 250°C, which is “0.20~0.60”. ADD the requirement
for the allowable deviation of the coefficient appointed, which is “± 0.14”.
MODIFY the wear at 150°C and 200°C from “0.75 and 1.00” to “0~0.60
and 0~0.80”. ADD the requirement for the wear at 250°C, which is
“0~1.20” (SEE Table 4 in this version and Table 2 in the 1998 version);
— ADD the requirement for the Class II facings’ friction property;
— ADD the requirement for the Class II facings’ flexural property (SEE Table
6 in this version and Table 3 in the 1998 version);
— ADD the requirements and test methods for the rotate bursting test
strength (SEE the Sections 5.6 and 6.6 of this version);
— RECOMPILE the inspection rules. ADD the contents and items of the type
inspection (SEE Chapter 7 of this version and Chapter 5 of the 1998
version);
— DELETE the Appendixes A and B of the 1998 version. MODIFY the
Appendix C of the 1998 version to be Appendix A of this version;
— ADD the Appendix B “Recommendation form for the basic dimensions of
facings”.
The consistent degree between this Standard and JIS D4311-1995 (confirmed
in 2006) Clutch facings for automobiles is not equivalent.
This Standard was proposed by China Building Materials Federation.
Clutch facings for automobiles
1 Scope
This Standard specifies the terms and definitions, classification, requirements,
test methods, inspection rules, marks, packaging, transportation and storage of
the clutch facings for automobiles.
This Standard applies to the dry friction clutch facings for automobiles
(hereinafter referred to as “facings”).
2 Normative references
The following documents are essential to the application of this document. For
dated references, only the versions with the dates indicated are applicable to
this document. For undated references, only the latest versions (including all
the amendments) are applicable to this document.
GB/T 2828.1 Sampling procedures for inspection by attributes – Part 1.
Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot
inspection (GB/T 2828.1-2003, ISO 2859-1. 1999, IDT)
GB 5763-2008 Brake linings for automobiles
JB/T 7498 Coated abrasives – Abrasive paper
JC/T 1065 Constant speed friction test machine
3 Terms and definitions
The terms and definitions defined in the GB 5763-2008 and the following ones
apply to this document.
3.1 Max flexibility (δ)
It refers to the distance of the top or bottom surface of the test specimen’s span
center deviated from the original position, at the instant when the test specimen
fractures in the process of the bending test.
3.2 Max strain (e)
TAKE the complete facing which is defect-free in appearance quality as the test
specimen. Carefully CLEAR the projections on both surfaces.
6.3.2 Test equipment
6.3.2.1 Standard flat plate. The accuracy is above Level 3.
6.3.2.2 Pre-pressing fixture (ring). It shall meet the load specified in Table 3.
The error shall not be greater than ± 1%. The flatness shall be less than 0.05mm.
6.3.2.3 Feeler gauge. The division value shall not be greater than 0.01mm.
6.3.3 Test procedures
6.3.3.1 LIE the facing’s working surface face-down and flat on the standard
flat plate. Any part of the test specimen cannot exceed the outer edge of the
standard flat plate.
6.3.3.2 SELECT appropriate pre-pressing fixture (ring) according to the
dimensions of the test specimen. LIE the pre-pressing fixture flat on the facing
to be tested. ENSURE that any part of the test specimen has been completely
covered by the fixture and has been centered with the test specimen. USE a
feeler gauge to check the clearance between test specimen’s working surface
and flat plate. According to the requirements, respectively MEASURE 6 points
on the inner hole and excircle along the circumference with the interval of 60°.
6.3.4 Result representation
TAKE the maximum value among 12 measured clearance values as the
flatness value of the facing.
6.4 Friction property test
6.4.1 Test specimen
6.4.1.1 PREPARE two test specimens from the same facing.
6.4.1.2 The dimensions of the test specimens are 25mm × 25mm. The
allowable deviation is within the range of -0.2mm ~ 0mm.
6.4.1.3 The test specimens are as thick as the facings. The thickness
difference between two test specimens shall below 0.2mm.
6.4.2 Test equipment and instruments
6.4.2.1 Constant speed friction test machine. The properties and accuracy
shall conform to the provisions specified in the JC/T 1065.
6.4.2.2 Micrometer. The division value shall not be greater than 0.01mm.
6.4.3 Test conditions
6.4.3.1 The pressure applied to the test specimens shall be 0.49MPa.
6.4.3.2 The disk materials shall conform to the provisions specified in the JC/T
1065. USE the abrasive paper with the granularity of P240 specified in the JB/T
7498 to process the disk surfaces, so as to ensure that there are no defects on
the disk surfaces, such as obvious scratches, rust, pits, etc.
6.4.3.3 The friction direction shall be the same with that of the facings.
6.4.4 Test procedures
6.4.4.1 PLACE two test specimens in the support arm of the test specimens.
RUN in below 100°C, until the contact surface is up to more than 95%. USE a
micrometer to measure the thickness of the test specimens. DETERMINE the
thickness after the test specimens cool down to room temperature. MEASURE
5 points on each test specimen. TAKE the arithmetic mean value.
6.4.4.2 When the test temperature is at 100°C, DETERMINE the friction when
the disk rotates at 5,000rpm according to the requirements specified in the
Section 6.4.3 of this Standard. After the friction test, MEASURE the thickness
of the test specimens according to the Section 6.4.4.1 of this Standard.
6.4.4.3 At the test temperature of 150°C, 200°C, 250°C and 300°C,
respectively CONDUCT the same test according to the Section 6.4.4.2 of this
Standard. However, the maximum test temperatures of various facings shall
conform to the provisions specified in Tables 4 and 5. When conducing the test
at various temperatures, the disk temperature shall rise up to the specified test
temperature within 1,500rpm. The increase of the disk temperature mainly
relies on the friction heat of the test specimens. When the disk temperature
cannot come up to the specified test temperature within 1,500rpm, it is allowed
to use an auxiliary heating device.
6.4.4.4 After determining the maximum test temperature, DETERMINE the
friction when the disk rotates at 3,000rpm according to the requirements
specified in the Section 6.4.3 of this Standard.
6.4.4.5 After the test, USE the visual observation method to inspect the
appearance of the test specimens and the disk friction surface.
6.4.5 Calculation
6.4.5.1 CALCULATE the coefficient of friction at various test temperatures
according to the Equation (1).
the length of the test specimens is less than 55mm, 40mm ± 0.5mm can be
taken as well. During sampling, AVOID the grooves in the facings.
6.5.2 Test equipment
6.5.2.1 Flexural property test machine. The load line speed is (10 ± 1) mm/min.
The load value is within the range of 10% to 90% of the full range. The minimum
division value is 1N.
6.5.2.2 For the details of the test fixture, SEE Appendix B. The dimensions
shall conform to the following requirements.
– The distance between fulcrums shall ...
......
 
(Above excerpt was released on 2016-09-02, modified on 2021-06-07, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/GBT5764-2011