Test methods of hydraulic braking systems for motor vehicles
1 Scope
This document specifies the test conditions and test methods of hydraulic braking systems for motor vehicles.
This document is applicable to Categories M and N vehicles with hydraulic braking system specified in GB/T 15089.
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
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB 12676 Technical requirements and testing methods for commercial vehicle and trailer braking systems
GB/T 15089 Classification of power-driven vehicles and trailers
GB 21670 Technical requirements and testing methods for passenger car braking systems
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB 12676, GB 21670, GB/T 5620 and GB/T 15089 apply.
4 Test conditions
4.1 Road conditions
4.1.1 Road surface
The test road surface shall be a straight and solid asphalt or concrete road surface or other road surface with the same adhesion coefficient, and the road surface with high adhesion coefficient shall be kept clean and dry during the test. The adhesion coefficient of road surface with high adhesion coefficient should be about 0.8, and that of road surface with low adhesion coefficient should be less than or equal to 0.3.
4.1.2 Gradient
In general, the road surface shall be flat, and the gradient on any 50m long road in the longitudinal direction shall be less than 1%. The gradient for parking test shall meet the requirements of relevant clauses.
4.1.3 Camber
The camber of road surface shall be less than 2%.
4.2 Environmental conditions
The wind speed shall not exceed 5m/s.
The ambient temperature shall not exceed 35℃.
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test conditions
4.1 Road conditions
4.2 Environmental conditions
4.3 Test vehicle
4.4 Test equipment
5 Test methods
5.1 General requirements
5.2 Pre-test and static check
5.3 Basic performance test under no load
5.4 Performance test in case of failure
5.5 Basic performance test under full load
5.6 Braking and off-tracking tests of vehicles equipped with temporary spare wheels/tyres
5.7 Additional test of braking system with assistant energy
5.8 Test data processing
Annex A (Normative) Pre-test and static check
A.1 Check of components
A.2 Check of control lever of braking system
A.3 Check of alarm signals
A.4 Check of line pressure relationship
A.5 Additional check of service braking system with electronically controlled transmission devices
Annex B (Normative) Basic performance test under no load
B.1 Service braking cold performance (Type O) test with dynamic disengagement
B.2 Service braking cold performance (Type O) test with dynamic engagement
Annex C (Normative) Performance test in case of failure
C.1 General requirements
C.2 Circuit failure test
C.3 Assistance failure test
C.4 Electronically controlled transmission device failure test
C.5 Electric component failure test
Annex D (Normative) Basic performance test under full load
D.1 Service braking cold performance (Type O) test with dynamic disengagement
D.2 Service braking cold performance (Type O) test with dynamic engagement
D.3 Response time test
D.4 Type II test
D.5 Parking braking system test
D.6 Type I test
Annex E (Normative) Braking and off-tracking tests of vehicles equipped with temporary spare wheels/tyres
E.1 General requirements
E.2 Test methods
Annex F (Normative) Additional test of braking system with assistant energy
F.1 General requirements
F.2 Vacuum assisted system
F.3 Hydraulic power assisted system
F.4 Full power hydraulic braking system
Annex G (Normative) Test data processing
