GB/T 46581-2025 Road vehicles - Brake lining friction materials - Test method for brake wear particle emission English, Anglais, Englisch, Inglés, えいご
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ICS 13.220.10
CCS H 57
National Standard of the People's Republic of China
GB/T 46581-2025
Road vehicles - Brake lining friction materials - Test method for brake wear particle emission
道路车辆 制动衬片摩擦材料 磨损颗粒物排放量测试方法
Issue date: 2025-10-31 Implementation date: 2026-05-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms and Definitions
4 Abbreviations
5 NEDC Brake Cycle Test Method
5.1 Measurement Conditions
5.2 Measurement Method
5.3 Test Report
6 WLTP Brake Cycle Test Method
6.1 Brake Emissions Family
6.2 Test System
6.3 Brake Cycle
6.4 Test Preparation
6.5 Test Method
6.6 Test Report
Appendix A (Normative) WLTP Brake Cycle
Appendix B (Normative) Braking Events in the WLTP Brake Cycle
1 Scope
This document describes the test methods for measuring wear particulate emissions from brake lining friction materials for road vehicles, namely the NEDC brake cycle test method and the WLTP brake cycle test method.
This document applies to brake linings for vehicles of categories M1 and N1. Brake linings for other types of vehicles may be used for reference.
2 Normative References
The following documents contain provisions that, through normative reference in this text, constitute essential provisions of this document. For dated references, only the edition corresponding to that date applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 5620 Road vehicles—Motor vehicles and towed vehicles—Braking vocabulary
GB/T 13554-2020 High efficiency particulate air filter
GB/T 15089 Classification of power-driven vehicles and trailers
GB/T 29064 Road vehicles—Brake lining friction materials—Evaluation method for friction performance of automotive brake systems
QC/T 556 Temperature measuring method of automobile brake and installation requirements for thermocouple
QC/T 564 Performance requirements and bench test methods for service brakes of passenger cars
3 Terms and Definitions
For the purposes of this document, the terms and definitions given in GB/T 5620, GB/T 15089, and the following apply.
3.1
NEDC brake cycle
New European Driving Cycle brake cycle
One cycle includes 4 urban driving phases and 1 extra-urban driving phase.
3.2
WLTP brake cycle
Worldwide harmonized Light vehicles Test Procedure brake cycle
A driving cycle consisting of 10 phases and 303 braking events, with a total duration of 15,826 seconds.
3.3
particle size
The aerodynamic diameter of a sphere with a density of 1,000 kg/m³.
3.4
particulate concentration
The mass of suspended particulate matter per unit volume at the temperature and pressure conditions of collection.
Note: Generally expressed as the number or mass of fine particles per unit volume or mass of a gas or liquid, according to the type and size of the particles.
3.5
cascade impactor
A device that blows sample gas from fine nozzles or slits towards a plate, causing particles to deposit on the plate by inertial forces.
3.6
brake emissions family
A set of brakes considered to have similar emission characteristics by design, taking into account parameters such as the caliper, brake disc (drum), brake lining, and other vehicle characteristics.
3.7
mass in running order
The total mass of the vehicle with its fuel tank filled to at least 90% capacity, including the mass of the driver, fuel, and liquids. With standard equipment fitted as prescribed by the manufacturer, it also includes the mass of the bodywork, cab, transmission, spare wheel, and tools.
3.8
aerosol
A dispersion system consisting of solid and/or liquid particles suspended in air.
3.9
response time (t₉₀)
The time difference between the start of a change in the measured value at the reference point and the time when the measurement system response reaches 90% of its final reading.
Note: The system response time (t₉₀) consists of system delay time and system rise time. In this document, the inlet of the sampling nozzle is defined as the reference point.
3.10
friction braking share coefficient
The ratio of the total energy absorbed by the full friction brake system during a driving cycle to the total change in vehicle kinetic energy during braking events (excluding road load) in the same driving cycle.
3.11
standard conditions
Conditions where the pressure is equal to 101.325 kPa and the temperature is equal to 273.15 K (i.e., 0°C).
3.12
specific friction work
The actual friction work applied to the test brake during a specified deceleration event in the brake emissions test process.
4 Abbreviations
The following abbreviations apply to this document (see Table 1).
Table 1 Abbreviations
5 NEDC Brake Cycle Test Method
5.1 Measurement Conditions
5.1.1 Brake Components
The condition of each brake component during the measurement shall be in accordance with GB/T 29064.
5.1.2 Inertia
The setting and calculation of inertia shall be in accordance with QC/T 564.
5.1.3 Temperature
Thermocouples shall be installed according to QC/T 556 for temperature measurement. When installing thermocouples on the brake disc, they shall be installed at a depth of 1 mm from the disc surface at the center of the friction path. When installing thermocouples on the brake lining, they shall be installed at a depth of 1 mm from the friction surface at the center of the lining friction face (if there is a groove in the center, then 10 mm from the groove). After running-in, the thermocouple depth shall be readjusted to ensure it remains 1 mm from the friction surface.
5.1.4 Wear Particulate Collection Apparatus
5.1.4.1 Apparatus Structure
