GB 21670-2025Technical requirements and testing methods for passenger car braking systems (English PDF)

Foreword

This document was drafted in accordance with the provisions of GB/T 1.1-2020 "Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents".

This document replaces GB 21670-2008 "Technical requirements and testing methods for passenger car braking systems". In addition to structural adjustments and editorial changes, the major technical changes compared to GB 21670-2008 are as follows:

"Safety concept", "Composite electronic vehicle control system", "Upper-level control", "Control range", "Different types of braking systems", "Unloaded", "Fully loaded", as well as their definitions (see Chapter 3 of the 2008 edition);

transmission device, brake, component of braking system, graduated/modulatable braking, wheel/axle load, hydraulic braking system with stored energy, traction battery, state-of-charge, automatically commanded braking, selective braking, nominal value, full cycling, electronic control system, unit, transmission links (see Chapter 3; Chapter 3 of the 2008 edition);

c) ADD the terms "Braking system", "Braking signal", "Emergency braking signal", "Energy source", "Electrical storage device", "Electrical supply", "State of an electrical storage device", "Performance of an electrical storage device", "Electrical transmission braking system", "Brake demand value", "Effect of aging", "Energy management system", as well as their definitions (see Chapter 3);

d) CHANGE the symbols and abbreviations (see Chapter 4; Appendix A of the 2008 edition);

e) CHANGE the requirements related to electromagnetic compatibility (see 5.1.1.4 f) CHANGE the functional safety requirements for electronic brake control systems (see 5.1.3, Appendix A; 4.1.3, Appendix D of the 2008 edition);

g) RCHANGE the requirements for energy sources other than driver force (see 5.2.4;

4.2.4 of the 2008 edition), adding the requirements for ETBS transmission failure [see 5.2.4 d)];

h) CHANGE the requirements for the difference in braking demand values [see 5.2.8 i) CHANGE the requirements for releasing the parking brake [see 5.2.10, 5.2.19 d);

graphic marking for hydraulic transmission braking systems, using GB/T 5345 to replace GB/T 14168 (see 5.2.13; 4.2.13 of the 2008 edition);

edition], adding the requirements for alarm devices for vehicles equipped with ETBS [see 5.2.14 c) and e)];

m) CHANGE the requirements for energy supply to auxiliary equipment (see 5.2.16;

n) ADD the requirements for braking action achieved by releasing the accelerator pedal for vehicles with Type A and both Type A and Category B electric regenerative braking systems [see 5.2.18 f)];

with electronic transmission [see 5.2.19 b); 4.2.19.2 of the 2008 edition]; CHANGE the requirements for energy supplied to the electronic transmission device of the parking braking system [see 5.2.19 c); 4.2.19.3 of the 2008 edition];

malfunctions) occur in the braking system of a passenger car (4.2.21.1.3 of the 2008 edition);

r) ADD the requirement that the ETBS warning signal still illuminates as required even when the battery is affected by environmental conditions (e.g., temperature) and aging effects [see 5.2.21 c) 3)];

s) CHANGE the requirement for brake light illumination (see 5.2.22; 4.2.21.6 of the t) ADD the requirement for emergency braking signaling (see 5.2.23);

u) ADD the special requirements for ETBS (see 5.2.24);

v) ADD braking and runout test requirements for vehicles equipped with a temporary spare wheel/tire (see 5.2.25, Appendix E);

w) ADD the requirement for Category M1 vehicles to be equipped with an anti-lock braking system (see 5.2.26);

vehicle speed and the specified vehicle speed (see 6.1.1.2; 5.1.1.2 of the 2008 edition);

ab) CHANGE the power release type O test requirement (see 6.1.4.2; 5.1.4.2 of the ac) CHANGE the transmission gear requirement for the type O test (see 6.1.5.1.4;

ad) CHANGE the start time and conditions for the hot performance test (see 6.1.5.2;

with a category B electric regenerative braking system [see 6.1.5.2 c), 5.1.5.2.4 of the 2008 edition];

with a category B electric regenerative braking system (see 6.1.5.3.2; 5.1.5.3 of the 2008 edition);

ag) DELETE the requirements for braking force distribution between axles (see 5.5 ah) DELETE the types of anti-lock braking systems equipped (see 5.6.1 of the 2008 edition);

ai) ADD the requirements for the response time of vehicles equipped with ETBS during emergency braking [see 6.3 c)];

al) ADD the calculation method for kpeak (the maximum value of the "adhesion coefficient-slip ratio" curve) and klock (the adhesion coefficient value when the slip ratio is 100%) (see 6.5.5.1 ~ 6.5.5.3);

am) ADD the requirements for the power transmission braking system's electrical supply and storage device (see 6.6);

an) CHANGE the overall test requirements (see 7.1; Chapter 7 of the 2008 edition);

ao) CHANGE the requirements for the test site and test equipment (see 7.2; 7.1 of ap) CHANGE the requirements for the test vehicle (see 7.3; 7.2 of the 2008 edition);

aq) CHANGE the requirements for static test data and documentation inspection (see ar) CHANGE the test method for inspecting the brake circuit (see 7.4.2.3; 7.3.2.3 of as) CHANGE the test method for inspecting brake lining wear (see 7.4.3.2; 7.3.3.2 at) ADD the inspection method for evaluating the wear condition of the brake drum and brake disc surfaces (see 7.4.3.3);

au) CHANGE the test method for inspecting the parking braking system (see 7.4.4.2;

control force and pipeline pressure (brake demand value and braking force) (see 7.4.7; 7.3.7 of the 2008 edition);

ax) ADD the test method for vehicles equipped with ETBS equipment (brake demand value and braking force) (see 7.4.7.2);

az) ADD the test method for additional inspection of service braking systems with electronic transmission (see 7.4.11.3);

bb) ADD the test method for inspection of emergency braking signals (see 7.4.14.3);

bc) ADD the test method for additional inspection of ETBS (see 7.4.18);

during dynamic testing (see 7.4.1.2 of the 2008 edition);

be) CHANGE the power-disengaged Type O test method (see 7.5.3.1; 7.4.3.1 of the (bf) CHANGE the power-engaged Type O test method (see 7.5.3.2; 7.4.3.2 of the bg) DELETE the test method for brake force distribution (see 7.4.4.8 of the 2008 edition);

bh) DELETE the test methods related to class 2 and class 3 ABS (see 7.4.5 and 7.4.6 bi) CHANGE the response time test method (see 7.5.7.3; 7.4.7.3 of the 2008 edition);

bk) ADD the braking signal test method (see 7.5.9);

bl) ADD the test method of emergency braking signal (see 7.5.10);

bm) ADD the test method for checking the ETBS performance of an electrical storage device (see 7.5.11);

bn) ADD the test method for checking the ETBS electrical supply (see 7.5.12);

bo) ADD the braking and runout test method for vehicles equipped with a temporary spare wheel/tire (see 7.5.13);

bp) CHANGE the requirements for determination of same type (see Chapter 8;

Chapter 6 of the 2008 edition);

bq) ADD the implementation and transition period recommendations of the standard (see Chapter 9);

br) DELETE the inertia dynamometer test method for brake friction linings (see

Appendix C of the 2008 edition);

bs) ADD the requirements for the functional safety test report of the brake electronic control system (see Appendix B);

bt) ADD the requirements for the functional safety description of the brake electronic control system (see Appendix C);

bu) ADD the requirements for the braking and runout test of vehicles equipped with a temporary spare wheel/tire (see Appendix E);

bv) CHANGE the requirements for test reports and related diagrams (see Appendix F; Appendix E of the 2008 edition).

This document was proposed by AND shall be under the jurisdiction of the Ministry of Industry and Information Technology of the People's Republic of China.

This document was first issued in 2008. This is the first revision.

1 Scope

This document specifies the structural and functional requirements, test and performance requirements, type identification requirements for passenger car braking systems; describes the corresponding test methods.

This document applies to Category M1 vehicles as specified in GB/T 15089.

2 Normative references

The contents of the following documents, through normative references, constitute essential provisions of this document. For dated references, only the version corresponding to that date applies to this document. For undated references, the latest version (including all amendments) applies to this document.

3 Terms and definitions

The terms and definitions defined in GB/T 5620 and GB/T 34590.1, as well as the following terms and definitions, apply to this document. All braking systems equipped on a vehicle. A combination of components consisting of a control device, a transmission device, a brake that gradually decelerates or stops a moving vehicle, or holds a stopped vehicle stationary. Components directly controlled by the driver to provide the energy required for braking or control to the transmission device. Note: This energy may include the driver's physical strength, other energy sources controlled by the driver, or a combination of different energies. The combination of components that connects the control device and the brakes and provides a functional connection between the two. Note 1: Transmission devices may be mechanical, hydraulic, pneumatic, electric, or hybrid. Note 2: When braking force is provided or assisted by an energy source other than the driver's own physical strength, the energy accumulator is considered part of the transmission device. Note 3: The transmission device has two independent functions: control transmission and energy transmission. When used alone in this document, the term "transmission" has both "control transmission" and "energy transmission." The combination of components in the transmission device that controls the operation of the brakes, including the control function and the required energy accumulator. The combination of components that provides the energy required for the brakes to function, including the energy accumulator required for brake operation. The component that generates a force that opposes the direction of motion of the vehicle. […]

4 Symbols and abbreviations

5 Structural and functional requirements

6 Test and performance requirements