Foreword
This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 5764-2011 Clutch facings for automobiles. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect to GB/T 5764-2011:
a) The clause "Scope" is modified (see Clause 1 hereof; Clause 1 of Edition 2011);
b) The normative references GB/T 23263 (see 5.7.1 hereof), JC/T 2268 (see 5.7.2 hereof) and GB/T 26125 (see 5.7.3 hereof) are added;
c) The clause “Classification” is deleted (see Clause 4 of Edition 2011);
d) The thickness difference requirement for each facing in "dimensional deviation" is modified (see 4.2 hereof, 5.2 of Edition 2011);
e) The "friction performance" is modified (see 4.4 hereof; 5.4 of Edition 2011);
f) The contents of "Type l facing" in "Requirements" are deleted (see 5.4 to 5.6 of Edition 2011);
g) The "harmful composition" is added (see 4.7 hereof);
h) The determination method of "limit of harmful composition" is added (see 5.7 hereof);
i) The "Inspection rules" is modified (see Clause 6 hereof; Clause 7 of Edition 2011);
j) The clause "Marking, packaging, transportation and storage" is modified (see Clause 7 hereof; Clause 8 of Edition 2011).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This document was proposed by China Building Materials Federation.
This document is under the jurisdiction of the National Technical Committee on Non-metallic Mineral Products of Standardization Administration of China (SAC/TC 406).
This document was firstly issued in 1986, firstly revised in 1998 and secondly revised in 2011, this is the third revision.
Clutch facings for automobiles
1 Scope
This document specifies the requirements, test methods, inspection rules, as well as marking, packaging, transportation and storage of clutch facings for automobiles.
This document is applicable to winding-type dry friction clutch facings for automobiles (hereinafter referred to as "facings").
2 Normative references
The following documents contain requirements which, through reference in this text, constitute provisions of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
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 5763 Brake linings for automobiles
GB/T 23263 Determination of asbestos in products
GB/T 26125 Electrical and electronic products - Determination of six regulated substances (lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyls, polybrominated diphenyl ethers)
JB/T 7498 Coated abrasives - Abrasive paper
JC/T 1065 Constant speed friction test machine
JC/T 2268 Measurement of copper and other elements in brake friction materials
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 5763 and the following apply.
3.1
max flexibility
distance between the top or bottom surface of the test piece span center and the original position at the moment of fracture of the test piece during bending test
3.2
max strain
e
deformation amount of the maximum outer fiber per unit length in the center of the span of the test piece at the moment of fracture of the test piece during bending test
3.3
rotate bursting test strength
limit rotate velocity of facing rotated on a rotation strength tester according to the specified angular acceleration to until it breaks
3.4
coefficient of dynamic friction
μd
ratio of dynamic friction force to normal force of friction facing under specified conditions
4 Requirements
4.1 Appearance
4.1.1 After processing, the surface of the facing shall be flat and free of defects such as blistering, fissure, oil stains, bump, buckling, and distortion.
4.1.2 Whether the facings are deeply processed or not shall be determined through negotiation between the supplier and the purchaser.
4.2 Dimensional deviation
The basic dimension of the facing is shown in Annex A or shall be determined by the purchaser, the dimensional deviation and thickness difference of each facing shall meet those specified in Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
5 Test methods
6 Inspection rules
7 Marking, packaging, transportation and storage
Annex A (Informative) Recommended basic dimensions for facings
Annex B (Normative) Bending test fixture
