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All technical contents of this standard, except those specified in 3.1.2.4, are compulsory.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB 15742-2001 Performance requirements and test methods of horn for motor vehicles. The following main technical changes have been made with respect to GB 15742-2001 (the previous edition):
——Mopeds of types L1 and L2 are added into the “Scope” as applicable models (see Clause 1);
——To facilitate standard using, the IEC 651 and IEC 225 in the “Normative references” are changed to GB/T 3785.1 and GB/T 3241 respectively (see Clause 2 and Clause 2 of Edition 2001);
——The sound pressure level (SPL) limit of mopeds is added (see 3.1.2);
——The original requirements on frequency spectrum and sound pressure level specified in 3.1.2.3 are modified according to China‘s national conditions (see 3.1.2.3 and 3.1.2.3 of Edition 2001);
——The test method for durability is modified, with the requirement “the horn is allowed to be adjusted once in the test” being changed to “the horn is not allowed to be adjusted in the test” (see 3.2.7.2 and 3.2.7.2 of Edition 2001);
——For vehicles of types M and N as well as motorcycles with a power of greater than 7 kW, the lowest sound pressure level of complete vehicle is modified from 93 dB (A) to 87 dB (A) [see 4.1.2 c) and 4.1.2 b) of Edition 2001];
——Textual formulation in Annex A is modified.
This standard was proposed by and is under the jurisdiction of the Ministry of Industry and Information Technology of the People's Republic of China.
This standard was issued in November 1995 as first edition, and then revised in January 2001 for the first time and this is the second revision.
Performance requirements and test methods of horn for motor vehicles
1 Scope
This standard specifies the performance requirements and test methods of electric horns and air horns for motor vehicles as well as the loading performance requirements and test methods of horns.
This standard is applicable to motor vehicles of types M, N and L.
Note: Motor vehicles of type L include mopeds of types L1 and L2.
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 of the referenced document (including any amendments) applies.
GB/T 3241 Electroacoustics - Octave-band and fractional-octave-band filters
GB/T 3785.1 Electroacoustics - Sound level meters - Part 1: Specifications
3 Performance requirements and test methods
3.1 Performance requirements
3.1.1 General requirements
The horn shall emit a continuous and uniform sound. For pneumatic and electro-pneumatic horns, the time taken, from the moment the horn is pushed to the moment the sound pressure level reaches the value specified in 3.1.2, shall not exceed 0.2 s.
3.1.2 Sound pressure level
3.1.2.1 Under the conditions specified in 3.2.3.1, the A-weighted sound pressure level at 2 m from the horn shall meet the following requirements:
a) For mopeds, it shall be no less than 90 dB(A) and no greater than 115 dB(A);
b) For horns of motorcycles with a power no greater than 7 kW, it shall be no less than 95 dB(A) and no greater than 115 dB(A);
c) For horns of vehicles of types M and N as well as motorcycles with a power of greater than 7 kW, it shall be no less than 105 dB(A) and no greater than 118 dB(A).
3.1.2.2 Under the conditions specified in 3.2.3.2, the A-weighted sound pressure level of pneumatic and electro-pneumatic horns at 2 m from the horn shall not exceed 125 dB(A).
3.1.2.3 The total sound pressure level within the frequency band from 1,800 Hz to 3,550 Hz shall be greater than the sound pressure level of each component with a frequency exceeding 3,550 Hz.
3.1.2.4 Horns used on vehicles of types M and N as well as motorcycles with a power of greater than 7 kW can be used on motorcycles with a power of no greater than 7 kW. Horns used on motorcycles with a power no greater than 7 kW can be used on mopeds.
3.1.2.5 If multi-tone horn is used and each of the acoustic transmit units may work alone, then the provisions specified in 3.1.2.2, 3.1.2.3 and 3.1.2.4 shall be met when each of the units works alone; and in case all units work simultaneously, the total sound pressure level shall not exceed the maximum value specified in 3.1.2.1.
3.1.3 Durability
3.1.3.1 Horns used on mopeds and motorcycles with a power of no greater than 7 kW shall be capable of being used for 10,000 times.
3.1.3.2 Horns used on vehicles of types M and N as well as motorcycles with a power of greater than 7 kW shall be capable of being used for 50,000 times.
3.1.3.3 After the durability test, the horn shall meet the requirements of 3.1.1, 3.1.2.2 and 3.1.2.3, and its sound pressure level is allowed to be 5 dB(A) lower than that of the horn before the test.
3.2 Test methods
3.2.1 Test environment
3.2.1.1 The test shall be performed in an anechoic room, and it may also be performed in a hemi-anechoic room or on an open field (see Annex A). In case of performing the test on an open field, the background noise and wind noise shall be at least 10 dB(A) lower than the sound pressure level of the horn being tested. The test shall be performed in good weather. Unless otherwise specified, the ambient temperature shall be 23 °C ± 5 °C during the test.
3.2.1.2 During the test, no one shall linger near the horn and microphone except the instrument personnel. During instrument observation, pointer swing irrelevant to the measured sound pressure level shall be ignored.
3.2.2 Test instrument
3.2.2.1 Sound pressure level measurement shall be performed with a sound level meter (extra fine grade) that meets the requirements of GB/T 3785.1. During measurement, the fast time constant “F” shall be used. And in case of measuring the total sound pressure level, the “A” measuring gear shall be used, with a reference sound pressure of 20 μ Pa.
3.2.2.2 Frequency spectrum of sound shall be obtained via Fourier transforming of the sound signal. 1/3 octave-band filter is allowed to be used in accordance with those specified in GB/T 3241. Sound pressure level at the center frequency of 2,500 Hz shall be calculated through the mean square value of the sound pressure at 1/3 center frequency of 2,000 Hz, 2,500 Hz and 3,150 Hz, generally, only the Fourier transformation is used.
3.2.2.3 The electrical measuring instrument shall be with an accuracy of Grade 0.5.
3.2.3 Test conditions
3.2.3.1 Test conditions for the electric horns are:
a) In case the nominal voltages are 6 V, 12 V and 24 V, the test voltage shall be measured from the output end of the power supply, taking them as 6.5 V ± 0.1 V, 13 V ± 0.1 V and 26 V ± 0.2 V respectively;
b) If rectifier power is adopted for the test, the voltage AC component measured from the power supply terminal shall not exceed 0.1 V (peak/peak value) when the horn is operating;
c) The wiring resistance (including the connector and contact resistance) is:
Nominal voltage 6 V: resistance ≤ 0.05 Ω;
Nominal voltage 12 V: resistance ≤ 0.10 Ω;
Nominal voltage 24 V: resistance ≤ 0.20 Ω.
3.2.3.2 Pneumatic and electro-pneumatic horns shall be tested under the pressure or voltage specified by the manufacturer.
3.2.4 Horn installation during the test
3.2.4.1 The horn shall be tightly installed on the metal base frame according to the installation method specified by the manufacturer. The mass of the base frame shall be at least 10 times that of the horn and not less than 30 kg.
3.2.4.2 The horn shall be at the same height as the microphone, preferably, with a height of 1.15 m~1.25 m. The centerline of the microphone's maximum sensitivity shall coincide with the direction of the highest sound pressure level of the horn.
3.2.4.3 The distance between the microphone diaphragm and the horn sound exit plane shall be 2 m ± 0.01 m. If the horn has multiple sound outlets, the sound exit plane closest to the microphone shall be used.
3.2.5 General test requirements
Under the conditions specified in 3.2.1~3.2.4, subject the horn to phonate continuously for no more than 30 s, then check the continuous sound performance of the horn and the starting performance of the pneumatic and electro-pneumatic horns, they shall meet those specified in 3.1.1.
3.2.6 Sound pressure level test
Under the conditions specified in 3.2.1 to 3.2.4, the sound pressure level of the horn shall be checked in accordance with those specified in 3.1.2.
3.2.7 Durability test
3.2.7.1 Test conditions
The horn shall be tested under the following conditions:
a) The ambient temperature shall be 15 ° C ~ 30 ° C during the test;
b) If the test is carried out in an anechoic room or a hemi-anechoic room, it shall be ensured that the heat of the horn generated during the test can be dissipated normally in the anechoic room or the hemi-anechoic room;
c) The horn shall be cooled with an air flow of approximately 10 m/s during the test.
3.2.7.2 Test method
The durability test of the horn shall be performed in a cycle of honking for 1 s and then pausing for 4 s, and during the test, the horn is not allowed to be adjusted.
4 Loading performance requirements and test methods
4.1 Performance requirements
4.1.1 Horns mounted on motor vehicles shall meet the requirements specified in “Clause 3 Performance requirements and test methods”.
4.1.2 The horn shall be mounted in the front of the motor vehicle and its sound pressure level shall meet the following requirements:
a) For mopeds, it shall be no less than 75 dB(A) and no greater than 112 dB(A);
b) For motorcycles with a power of no greater than 7 kW, it shall be no less than 83 dB(A) and no greater than 112 dB(A);
c) For vehicles of types M and N as well as motorcycles with a power of greater than 7 kW, it shall be no less than 87 dB(A) and no greater than 112 dB(A).
4.2 Test method
4.2.1 Test environment and test instrument
The test environment and test instrument shall comply with the relevant requirements of 3.2.
4.2.2 Instrument installation
The microphone of the measuring instrument shall be placed close to the longitudinal central plane of the vehicle, and the impact of the following factors on the measurement results shall be taken into consideration:
a) components used to fix the horn to a vehicle;
b) position of the horn on the motor vehicle;
c) rigidity of the horn mounting bracket;
d) shape and material of the front structure of the vehicle that may affect the sound pressure level of the horn and used for shielding.
4.2.3 Measurement conditions of sound pressure level
The following conditions shall be met in terms of sound pressure level measurement:
a) The sound pressure level shall be measured at a position 7 m away from the vehicle front;
b) The maximum sound pressure level shall be measured at a position 0.5 m~1.5 m from the ground;
c) The vehicle shall be parked on a flat surface wherever possible in case of measurement;
d) For horns driven by DC power, the engine shall be turned off during the test.
Foreword i
1 Scope
2 Normative references
3 Performance requirements and test methods
4 Loading performance requirements and test methods
Annex A (Normative) Requirements for hemi-anechoic rooms and open fields
