This document is developed in accordance with the rules given in GB/T 1.1-2020 Directives for standardization - Part 1: Rules for the structure and drafting of standardizing documents.
This document replaces GB/T 23920-2009 Tri-wheel vehicles and low-speed goods vehicles—Determination method of maximum speed. In addition to structural adjustments and editorial changes, the following main technical changes have been made with respect GB/T 23920-2009:
——Requirements for window and auxiliary device test of test vehicle are added (see 4.1.5 hereof);
——Requirements for measurement parameters, units and accuracy are added (see 4.2 hereof);
——Test atmospheric conditions and relative humidity requirements are added (see 4.4 hereof);
——Requirements for wind speed are modified (see 4.4.2 hereof; 3.1.3 of Edition 2009);
——Requirement for determining the maximum vehicle speed under the condition of no load, maximum design loading mass (or maximum design gross mass) (see 4.5.1 hereof; 3.1.1.5 of Edition 2009);
——Requirements for loading load are added (see 4.5.2 hereof);
——Requirements for speed change control during test are added (see 5.2.4 hereof);
——Requirements for recording and calculating relevant measured values of road test are added (see 5.2.5 hereof);
——The method of drum bench test is added (see 5.3 hereof));
——Contents at least included in the measurement report are modified (see Annex A hereof; Annex A of Edition 2009);
——Determination of driving resistance on chassis dynamometer is added (see Annex B hereof).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the China Machinery Industry Federation.
This document is under the jurisdiction of the National Technical Committee on Low-speed vehicle of Standardization Administration of China (SAC/TC 234).
The previous editions of this document are as follows:
———This document was firstly issued in 2009 with the serial number of GB/T 23920-2009;
——This edition is the first revision.
Low-speed vehicles—Determination method of maximum speed
1 Scope
This document provides the method for determining the actual maximum driving speed of low-speed vehicles.
This document is applicable to low-speed vehicles (hereinafter referred to as vehicles).
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 (including any amendments) applies.
GB 21377-2015 Tri-wheel vehicles—Limits and measurement methods for fuel consumption
3 Terms and definitions
For the purposes of this document, no terms and definitions apply.
4 Test conditions
4.1 Vehicles
4.1.1 The vehicle shall be filled with fuel according to the instructions.
4.1.2 The fuel handling system shall be adjusted to make the engine power and speed meet the requirements of the manufacturer. Any device that can change the engine speed and/or vehicle driving speed through adjustment shall be adjusted to the state that can make the engine speed and/or vehicle driving speed reach the highest.
4.1.3 The tire with the largest outer diameter allowed by the manufacturer shall be used, and the inflation pressure shall be the tire pressure recommended by the vehicle manufacturer when driving on the road.
4.1.4 The vehicle fuel tank shall be filled with fuel and the radiator shall be filled with coolant.
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4.1.5 If there are windows in the cab of the test vehicle, the window shall be closed. The ventilation device in the cab shall be turned off, unless otherwise specified. Except for the equipment necessary for test and the daily operating parts of the vehicle, the lighting devices and auxiliary devices on the vehicle shall be turned off.
4.2 Measurement parameters, unit and accuracy
4.2.1 See Table 1 for the main measurement parameters, unit and accuracy requirements of road test.
Table 1 Measurement parameters, unit and accuracy of road test
Parameter Unit Accuracy
Time s ± 0.1s
Length m ± 0.1%
Atmosphere temperature °C ± 1°C
Atmospheric pressure kPa ± 1 kPa
Speed km/h ± 1% or ± 0.1 km/h (the maximum value of both instruments and equipment is selected)
Mass kg ± 0.5%F·S
4.2.2 See Table 2 for the main measurement parameters, unit and accuracy requirements of drum bench test.
Table 2 Measurement parameters, unit and accuracy requirements of drum bench test
Parameter Unit Accuracy
Inertia simulation - ± 0.4%F·S
Traction in suction mode - ± 0.2%F·S
Atmosphere temperature °C ± 0.5°C
Atmospheric pressure kPa ± 0.1 kPa
Speed km/h ± 0.05 km/h
Mass kg ± 0.5%F·S
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Test conditions
5 Test methods
Annex A (Nominative) Measurement report of actual maximum driving speed
Annex B (Nominative) Setting of driving resistance on chassis dynamometer
Table A.1 Record of maximum driving speed (road test)
Table A.2 Record of maximum driving speed (drum bench test)
Table B.1 Comparison table of calculation constant and equivalent inertia
Table B.2 Specified speed point, initial calculated sliding speed and final calculated sliding speed
