Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard replaces QC/T 564-2008 Performance requirements and bench test methods for passenger car brake and has the following main technical differences from QC/T 564-2008:
——the definitions of “average braking torque” and “average braking pressure” are modified (see 3.3 and 3.6; 3.3 and 3.6 of Edition 2008);
——the terms “invariable input mode” and “invariable output mode” as well as their definitions are added (see 3.13 and 3.14);
——the evaluation indexes, i.e. reference speed and stability for speed for evaluation of braking torque in efficiency test are modified (see 4.1.1, 4.1.3 and 4.1.8; 4.1.1, 4.1.2 and 4.1.5 of Edition 2008);
——efficiency test at normal temperature is added (see 4.1.2, 4.1.7, 7.1.4 and 7.1.13);
——one-way pipeline failure test is added (see 4.1.4 and 7.1.7);
——thermal efficiency test after fade test is added (see 4.1.5c) and 7.1.9.3);
——quantitative evaluation methods and indexes for braking drag after fade recover test are added (see 4.1.5 d) and 7.1.9.6.1);
——the braking efficiency test after abrasion test is added (see 4.2.2 and 7.2.5);
——the calculation method of rotational inertia for one-way pipeline failure test is added (see 6.3.2);
——the initial braking temperature for abrasion test is modified (see 7.2.4, 7.2.3 of Edition 2008).
This standard was proposed by and is under the jurisdiction of National Technical Committee of Auto Standardization (SAC/TC 114).
The previous editions of this standard are as follows:
——JB 3980-85 and JB 4200-86;
——QC/T 564-1999 and QC/T 582-1999;
——QC/T 564-2008.
Performance requirements and test methods for passenger car service brake
1 Scope
1.1 This standard specifies the terms and definitions, performance requirements, test requirements, test preparation and test methods of passenger car service brake assembly.
1.2 This standard is applicable to the service brake assembly and friction lining (pad) assembly for Category M1 vehicles specified in GB/T 15089.
2 Normative references
The following referenced documents are indispensable for the application 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 - Braking of automotive vehicles and their trailers - Vocabulary
GB/T 15089 Classification of power-driven vehicles and trailers
QC/T 556 Automotive brake - Temperature measurement and thermocouple attachment
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 5620 and the following apply.
3.1
braking period
period from the beginning of a braking to that of the next braking in a continuous braking process
Note: the braking period is in the unit of s.
3.2
initial braking temperature
temperature of brake drum (disc) or friction lining (pad) at the beginning of braking
Note: the initial braking temperature is in the unit of ℃.
3.3
average braking torque
ordinate value obtained by dividing the area enclosed by braking torque and effective braking time by the effective braking time during a braking, see Annex A
Note: the average braking torque is in the unit of N·m.
3.4
maximum braking torque
the maximum ordinate value of braking torque on the braking torque - braking time curve within the effective braking time where the specified braking pressure is reached during a braking, see Mmax in Annex A
Note: the maximum braking torque is in the unit of N·m.
3.5
minimum braking torque
the minimum ordinate value of braking torque on the braking torque - braking time curve within the effective braking time where the specified braking pressure is reached during a braking, see Mmin in Annex A
Note: the minimum braking torque is in the unit of N·m.
3.6
average braking pressure
ordinate value obtained by dividing the area enclosed by braking pressure and effective braking time by the effective braking time during a braking, see Annex A
Note: the average braking pressure is in the unit of MPa.
3.7
average braking torque over average braking pressure
the ratio of the average braking torque to the average braking pressure during a braking
3.8
final braking temperature
the maximum temperature of brake drum (disc) or friction lining (pad) during or after a braking
Note: the final braking temperature is in the unit of ℃.
3.9
fade rate
falling or rising degree of braking torque in fade test, which is expressed in percentage and calculated using Equations (1) and (2):
(1)
(2)
Where,
Fa, max and Fa, min——the fade rate, %;
MF1——the average braking torque value during the first braking in fade test, N·m;
PF1——the average braking pressure value during the first braking in fade test, MPa;
MFmin——the average braking torque value corresponding to the braking with the minimum average braking torque over average braking pressure except the first braking in fade test, N·m;
PFmin——the average braking pressure value corresponding to MFmin in fade test, MPa;
MFmax——the average braking torque value corresponding to the average braking torque over average braking pressure larger than the maximum braking torque in the first braking in fade test, N·m;
PFmax——the average braking pressure value corresponding to MFmax in fade test, MPa.
Note: Fa, min value is ignored where the values of average braking torque over average braking pressure in all brakings are less than that in the first braking.
3.10
recover rate
rising or falling degree of braking torque in the last braking in relation to that in the reference test during recover test, which is expressed in percentage and calculated using Equation (3):
(3)
Where,
Re——the recover rate, %;
MB——the arithmetic average of average braking torque in three reference tests, N·m;
PB——the arithmetic average of average braking pressure in three reference tests, MPa;
Mend——the average braking torque value during the last braking in recover test, N·m;
Pend——the average braking pressure value during the last braking in recover test, MPa.
3.11
stability for speed
difference between the braking torques corresponding to different initial braking speeds and the reference value in efficiency test, which is expressed in percentage and calculated using Equation (4):
(4)
Where,
Vstm——the stability for speed of the initial braking speed mkm/h in relation to the initial braking speed nkm/h in efficiency test, %;
Mn——the average braking torque where the initial braking speed is nkm/h under the specified braking pressure in efficiency test, N·m;
Mm——the average braking torque where the initial braking speed is mkm/h under the specified braking pressure in efficiency test, N·m.
3.12
stability for braking torque
the ratio of the minimum braking torque to the maximum braking torque during the same braking in efficiency test, which is calculated using Equation (5):
(5)
Where,
K——the stability for braking torque;
Mmax——the maximum braking torque value during the same braking, N·m;
Mmin——the minimum braking torque value during the same braking, N·m.
Note: the braking torque is converted to the value measured under the same braking pressure.
3.13
invariable input mode
control mode to make the pressure of the input pipeline constant during a braking
3.14
invariable output mode
control mode to make the braking torque output from the tested brake constant during a braking
4 Performance requirements
4.1 Brake performance test
4.1.1 The first efficiency test
Carry out test according to 7.1.2, where the initial braking speed is 100km/h [Vmax (Vmax is the maximum design speed of the car, the same below) for the vehicle with a maximum design speed less than 100km/h], the average braking torque value of the sample under the specified braking pressure shall not be less than 80% of the design lower limit (it shall be less than 72% of the design value or subject to the negotiation between the supplier and the purchaser where the design lower limit is not specified). The absolute value of stability for speed of the initial braking speed 30%Vmax in relation to the initial braking speed 100km/h (Vmax for the vehicles with Vmax less than 100km/h) shall not be greater than 10%. The stability for braking torque shall not be less than the value specified in Table 1.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Performance requirements
5 Test requirements
6 Test preparation
7 Test methods
Annex A (Normative) Evaluation method of braking torque
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009 Directives for standardization - Part 1: Structure and drafting of standards.
This standard replaces QC/T 564-2008 Performance requirements and bench test methods for passenger car brake and has the following main technical differences from QC/T 564-2008:
——the definitions of “average braking torque” and “average braking pressure” are modified (see 3.3 and 3.6; 3.3 and 3.6 of Edition 2008);
——the terms “invariable input mode” and “invariable output mode” as well as their definitions are added (see 3.13 and 3.14);
——the evaluation indexes, i.e. reference speed and stability for speed for evaluation of braking torque in efficiency test are modified (see 4.1.1, 4.1.3 and 4.1.8; 4.1.1, 4.1.2 and 4.1.5 of Edition 2008);
——efficiency test at normal temperature is added (see 4.1.2, 4.1.7, 7.1.4 and 7.1.13);
——one-way pipeline failure test is added (see 4.1.4 and 7.1.7);
——thermal efficiency test after fade test is added (see 4.1.5c) and 7.1.9.3);
——quantitative evaluation methods and indexes for braking drag after fade recover test are added (see 4.1.5 d) and 7.1.9.6.1);
——the braking efficiency test after abrasion test is added (see 4.2.2 and 7.2.5);
——the calculation method of rotational inertia for one-way pipeline failure test is added (see 6.3.2);
——the initial braking temperature for abrasion test is modified (see 7.2.4, 7.2.3 of Edition 2008).
This standard was proposed by and is under the jurisdiction of National Technical Committee of Auto Standardization (SAC/TC 114).
The previous editions of this standard are as follows:
——JB 3980-85 and JB 4200-86;
——QC/T 564-1999 and QC/T 582-1999;
——QC/T 564-2008.
Performance requirements and test methods for passenger car service brake
1 Scope
1.1 This standard specifies the terms and definitions, performance requirements, test requirements, test preparation and test methods of passenger car service brake assembly.
1.2 This standard is applicable to the service brake assembly and friction lining (pad) assembly for Category M1 vehicles specified in GB/T 15089.
2 Normative references
The following referenced documents are indispensable for the application 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 - Braking of automotive vehicles and their trailers - Vocabulary
GB/T 15089 Classification of power-driven vehicles and trailers
QC/T 556 Automotive brake - Temperature measurement and thermocouple attachment
3 Terms and definitions
For the purposes of this standard, the terms and definitions given in GB/T 5620 and the following apply.
3.1
braking period
period from the beginning of a braking to that of the next braking in a continuous braking process
Note: the braking period is in the unit of s.
3.2
initial braking temperature
temperature of brake drum (disc) or friction lining (pad) at the beginning of braking
Note: the initial braking temperature is in the unit of ℃.
3.3
average braking torque
ordinate value obtained by dividing the area enclosed by braking torque and effective braking time by the effective braking time during a braking, see Annex A
Note: the average braking torque is in the unit of N·m.
3.4
maximum braking torque
the maximum ordinate value of braking torque on the braking torque - braking time curve within the effective braking time where the specified braking pressure is reached during a braking, see Mmax in Annex A
Note: the maximum braking torque is in the unit of N·m.
3.5
minimum braking torque
the minimum ordinate value of braking torque on the braking torque - braking time curve within the effective braking time where the specified braking pressure is reached during a braking, see Mmin in Annex A
Note: the minimum braking torque is in the unit of N·m.
3.6
average braking pressure
ordinate value obtained by dividing the area enclosed by braking pressure and effective braking time by the effective braking time during a braking, see Annex A
Note: the average braking pressure is in the unit of MPa.
3.7
average braking torque over average braking pressure
the ratio of the average braking torque to the average braking pressure during a braking
3.8
final braking temperature
the maximum temperature of brake drum (disc) or friction lining (pad) during or after a braking
Note: the final braking temperature is in the unit of ℃.
3.9
fade rate
falling or rising degree of braking torque in fade test, which is expressed in percentage and calculated using Equations (1) and (2):
(1)
(2)
Where,
Fa, max and Fa, min——the fade rate, %;
MF1——the average braking torque value during the first braking in fade test, N·m;
PF1——the average braking pressure value during the first braking in fade test, MPa;
MFmin——the average braking torque value corresponding to the braking with the minimum average braking torque over average braking pressure except the first braking in fade test, N·m;
PFmin——the average braking pressure value corresponding to MFmin in fade test, MPa;
MFmax——the average braking torque value corresponding to the average braking torque over average braking pressure larger than the maximum braking torque in the first braking in fade test, N·m;
PFmax——the average braking pressure value corresponding to MFmax in fade test, MPa.
Note: Fa, min value is ignored where the values of average braking torque over average braking pressure in all brakings are less than that in the first braking.
3.10
recover rate
rising or falling degree of braking torque in the last braking in relation to that in the reference test during recover test, which is expressed in percentage and calculated using Equation (3):
(3)
Where,
Re——the recover rate, %;
MB——the arithmetic average of average braking torque in three reference tests, N·m;
PB——the arithmetic average of average braking pressure in three reference tests, MPa;
Mend——the average braking torque value during the last braking in recover test, N·m;
Pend——the average braking pressure value during the last braking in recover test, MPa.
3.11
stability for speed
difference between the braking torques corresponding to different initial braking speeds and the reference value in efficiency test, which is expressed in percentage and calculated using Equation (4):
(4)
Where,
Vstm——the stability for speed of the initial braking speed mkm/h in relation to the initial braking speed nkm/h in efficiency test, %;
Mn——the average braking torque where the initial braking speed is nkm/h under the specified braking pressure in efficiency test, N·m;
Mm——the average braking torque where the initial braking speed is mkm/h under the specified braking pressure in efficiency test, N·m.
3.12
stability for braking torque
the ratio of the minimum braking torque to the maximum braking torque during the same braking in efficiency test, which is calculated using Equation (5):
(5)
Where,
K——the stability for braking torque;
Mmax——the maximum braking torque value during the same braking, N·m;
Mmin——the minimum braking torque value during the same braking, N·m.
Note: the braking torque is converted to the value measured under the same braking pressure.
3.13
invariable input mode
control mode to make the pressure of the input pipeline constant during a braking
3.14
invariable output mode
control mode to make the braking torque output from the tested brake constant during a braking
4 Performance requirements
4.1 Brake performance test
4.1.1 The first efficiency test
Carry out test according to 7.1.2, where the initial braking speed is 100km/h [Vmax (Vmax is the maximum design speed of the car, the same below) for the vehicle with a maximum design speed less than 100km/h], the average braking torque value of the sample under the specified braking pressure shall not be less than 80% of the design lower limit (it shall be less than 72% of the design value or subject to the negotiation between the supplier and the purchaser where the design lower limit is not specified). The absolute value of stability for speed of the initial braking speed 30%Vmax in relation to the initial braking speed 100km/h (Vmax for the vehicles with Vmax less than 100km/h) shall not be greater than 10%. The stability for braking torque shall not be less than the value specified in Table 1.
Contents of QC/T 564-2018
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Performance requirements
5 Test requirements
6 Test preparation
7 Test methods
Annex A (Normative) Evaluation method of braking torque