Road vehicles - Brake linings –
Test methods for effects of heat on dimensions and form of disc brake pads
1 Scope
This document describes two methods for measuring the effects of heat on dimensions and form of disc brake pads, i.e., hot press board method and supply box method, to determine the relationship between dimensional change and temperature and its heat conduction.
Dimensions include:
——thickness;
——some contour dimensions of disc brake pads, any change to which may lead to brake failure
This document applies to disc brake pads of pressed or bonded type with solid back boards of width not greater than 120 mm, height not greater than 80 mm and thickness not greater than 20 mm.
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 5620 Road vehicles - Vocabulary and definition for braking of automotive vehicles and their trailers
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 5620 and the following apply.
3.1
growth
permanent change in external dimensions of friction materials when they are cooled to room temperature after high temperature cycle
3.2
swell
temporary external dimensions change because friction materials are easily exposed to elevated temperature environment
4 Symbols
For the purposes of this document, the symbols given in Table 1 apply.
Contents
Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols
5 Test methods
