Codeofchina.com is in charge of this English translation. In case of any doubt about the contents of English translation, the Chinese original shall be considered authoritative.
This standard replaces GB/T 12542-1990 Motor Vehicles—Cooling Capacity for Engine Cooling System—Test Method on Road, with the major differences as follows:
——the contents concerning applicable scope in "1 Scope" are modified;
——the definitions concerning the thermal balance of motor vehicles are added in 3.2~3.10;
——the test measurement parameters and the installation of sensor are specified in 5.7;
——the use of substitution device of load trailer is specified in 5.8 and 5.9;
——four test conditions are added in 6.4.1, 6.4.2, 6.4.3, and 6.4.4;
——the judgment method for thermal balance is modified in 6.5.
In this standard, Annex B is normative, while Annex A and Annex C are informative.
This standard is proposed by the National Development and Reform Commission.
This standard is under the jurisdiction of the National Technical Committee on Automobiles of Standardization Administration of China.
The previous edition replaced by this standard is:
——GB/T 12542-1990.
Thermal Balance Capacity On-road Test Method for Motor Vehicles
1 Scope
This standard specifies the thermal balance capacity on-road test method for motor vehicles.
This standard is applicable to various motor vehicles equipped with forced circulation liquid-cooled engine and manual transmission, and may serve as the reference for other automobiles.
2 Normative References
The following document contains provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding any corrigendum), or revisions of, any of these publications do not apply. However, parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standard indicated below. For any undated references, the latest edition of the document referred to applies.
GB/T 12534 Motor Vehicles—General Rules of Road Test Method
3 Terms and Definitions
For the purpose of this standard, the following terms and definitions apply.
3.1
environment temperature
the air temperature at the height of 1.5m in the ambient environment where the motor vehicle travels
3.2
cooling mediums
the substances with cooling effect, including engine coolant, engine oil, transmission oil, drive axle oil.
3.3
thermal balance
the difference between the environment temperature and the temperature of the parts (spare part, assembly, motor vehicle) of the system gets stable
3.4
motor vehicles thermal balance
the thermal balance of the power assembly (engine, transmission, drive axle) of the motor vehicle
3.5
cooling constants
the difference between the cooling medium's temperature and the environment temperature when the motor vehicle reaches thermal balance
3.6
allowed maximum cooling medium temperature
the maximum allowable temperature of the cooling medium when the power assembly (engine, transmission, and drive axle) is under normal operation
3.7
extreme use conditions
the maximum torque or the maximum power of long-time output at low gear and full throttle of motor vehicle
3.8
usual use conditions
the common service conditions of motor vehicles like running at high speed, climbing at high speed, and long-time idling.
3.9
extreme use allowed environment temperature
the maximum allowable environment temperature restricted by the maximum allowable temperature of cooling medium under the extreme service conditions of motor vehicles
3.10
usual use allowed environment temperature
the maximum allowable environment temperature restricted by the maximum allowable temperature of cooling medium under the usual service conditions of motor vehicles
4 Test Conditions
4.1 The test shall be conducted in a rainless and fogless environment with the environment temperature not lower than 30℃ and the wind speed not greater than 3m/s. If the environment temperature is lower than 30℃, the meteorological parameters during test, like environment temperature, humidity, and atmospheric pressure, shall be recorded in detail.
4.2 According to the requirements of GB/T 12534, the test road shall have long enough high-speed track with a longitudinal slope less than 0.1%.
4.3 Generally, the "+"-shaped wind-break wall is 4m long and 2.5m high. See Annex A.
4.4 See Table 1 for the main instruments and equipment used in test.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Test Conditions
5 Test Preparation
6 Test Method
7 Test Report
Annex A (Informative) Structural Diagram of "+"-shaped Wind-break Wall
Annex B (Normative) Measurement Parameters and Installation Requirements for Temperature Sensor
Annex C (Informative) Test Record Sheet
