1 Scope
This standard specifies the performance requirements and bench test methods of passenger car service brake.
This standard is applicable to service brake assembly and friction lining (filler block) assembly for M1 category vehicle specified in GB/T 15089.
2 Normative References
The following normative documents contain provisions which, through reference in this standard, constitute provisions of this standard. For dated reference, subsequent amendments to, or revisions of, any of these publications do not apply. However, all parties coming to an agreement according to this standard are encouraged to study whether the latest editions of these documents are applicable. For undated references, the latest edition of the normative document referred to applies.
GB/T 15089 Classification of Power-driven Vehicles and Trailers (GB/T 15089-2001, eqv ITU ECE R.E.3)
QC/T 556 Automotive Brake-Temperature Measurement and Thermocouple Installation
3 Terms and Definitions
The following terms and definitions are applicable to this standard.
3.1
Braking period
The time from starting a braking to starting next start of braking in a continuous braking process.
Note: The unit of braking period is in second (S).
3.2
Initial braking temperature
The temperature of brake drum (disc) or friction lining (filler block) when starting braking.
Note: The unit of initial braking temperature is in ℃.
3.3
Average braking torque
The ordinate value gained with the method of the area covered by the changing curve of braking torque with braking time, being divided by the active braking time during a braking process; it is detailed in Annex A.
Note: The unit of initial braking temperature is in N?m.
3.4
Maximum braking torque
The maximum value of longitudinal coordinate on the changing curve of braking torque with braking time during a braking process; it is detailed in Mmax of Annex A.
Note: The unit of maximum braking torque is in N?m.
3.5
Minimum braking torque
The minimum value of longitudinal coordinate on the changing curve of braking torque with braking time during a braking process; it is detailed in Mmin of Annex A.
Note: The unit of braking torque is in N?m.
3.6
Average braking pressure
The ordinate value gained with the method of the area covered by the changing curve of braking pressure with braking time, being divided by the active braking time in a braking process; it is detailed in Annex A.
Note: The unit of baverage braking pressure is in MPa.
3.7
Average braking torque over average braking pressure
The ratio of average braking torque and average braking pressure during the process of a braking.
3.8
Baking final temperature
The maximum temperature of brake drum (disc) or friction lining (filler block) during the process of a braking or after the braking is terminated.
Note: The unit of braking final temperature is in ℃.
3.9
Fade rate
The decreasing and increasing degree of braking torque in the fade test; it is expressed in percentage, and calculated according to Formula (1) and Formula (2).
