1 Subject Content and Application Scope
This standard specifies test items, test method and procedure of bench test for trucks and buses brake assembly (hereafter referred to as brake).
This standard is applicable to hydraulic or air running brake for trucks and buses which the total mass is within 1800 kg~30000 kg.
2 Normative references
GB/T 3730.1 Motor vehicles and trailers — Types — Terms and definitions
GB/T 5620.1~5620.2 Terms and Definitions of Braking of Automotive Vehicles and Their Trailers
QC/T 556 Automotive Brake - Temperature Measurement and Thermocouple Attachment
3 Terms
3.1 Braking period
Elapsed time from staring a braking to starting next braking in a continuous braking procedure
3.2 Constant input mode
A control mode to make the pressure of the input pipe constant in a braking procedure
3.3 Constant output mode
A control mode to make the brake moment outputted by a brake constant in a braking procedure
3.4 Initial temperature of brake
Temperature of brake drum (disc) or brake lining when starting braking; when multiple brakes are tested simultaneously, the highest temperature shall be adopted
3.5 Maximal brake moment
The maximal value (MBmax) of the vertical coordinates in the brake moment - braking time curve (brake moment - vertical coordinate, braking time - horizontal ordinate) in a braking procedure
3.6 Minimal brake moment
The maximal value (MBmin) of the vertical coordinates in the brake moment - braking time curve (brake moment - vertical coordinate, time-varying - horizontal ordinate) in a braking procedure
3.7 Mean brake moment
The vertical coordinate gained with the method of the area enclosed by main braking procedure, brake moment and braking time, being divided by the main braking time in a braking procedure
3.8 Braking time
The acting time of a brake includes build-up time of braking force, main braking time and release time
3.9 Scuffing
Braking under the condition of continuous power input
