1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2012 SAE International All rights reserved. No part of this pub
3、lication may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970
4、(outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J331_201201SURFACEVEHICLERECOMMENDEDPRACTICEJ331 JAN2012 Issued 1975-05Revised 2012-
5、01 Superseding J331 JAN2000 Sound Levels for Motorcycles FOREWORDThis recommended practice establishes a method for measuring total motorcycle sound pressure levels under full throttle acceleration and closed throttle deceleration. Factors which contribute to total motorcycle sound include those fro
6、m the exhaust, intake, mechanical components, tires/road interface and others. SAE J47 is recommended for measuring the maximum total motorcycle sound pressure level under wide open throttle acceleration and closed throttle deceleration. SAE J47 is intended to capture the maximum total sound pressur
7、e of a motorcycle but is not intended to reflect real in use operating conditions. SAE J331 is intended to capture the sound pressure emitted during a typical in-use acceleration or deceleration of a motorcycle. Two other standards address measurement of exhaust sound pressure levels of stationary m
8、otorcycles; SAE J1287 is recommended for off-highway motorcycles, and SAE J2825 is recommended for on-highway motorcycles.RATIONALEThis Revised Document has been changed as follows:a. Format has been changed to comply with the new SAE Technical Standards Board Format.b. References have been updated.
9、 c. Specifications for sound level meter calibrator have been added. d. The specification for the microphone windscreen has been changed. e. The term “sound level” has been replaced with “sound pressure level” throughout the document to avoid possible confusion with sound power level. f. Figure 1 ha
10、d been redrawn. g. The English unit dimensions have been changed slightly for consistency with SAE J47. 1. SCOPE This SAE Recommended Practice establishes the test procedure, environment, and instrumentation for determining the sound levels of motorcycles under full throttle acceleration and closed
11、throttle deceleration. SAE J331 Revised JAN2012 Page 2 of 8 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Availab
12、le from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J47 Maximum Sound Level Potential for Motorcycles SAE J184 Qualifying a Sound Data Acquisition System SAE J213 Motorcycle Classificat
13、ions SAE J1349 Engine Power Test Code - Spark Ignition and Compression Ignition As Installed Net Power Rating 2.1.2 ANSI Publication Available from American National Standards Institute, 25 West 43rd Street, New York, NY 10036-8002, Tel: 212-642-4900, www.ansi.org.ANSI S1.4-1983 Specification for So
14、und Level Meters 3. DEFINITIONS 3.1 MANUAL TRANSMISSION A transmission having multiple discrete gear ratios which are individually selectable by the vehicle operator. 3.2 AUTOMATIC TRANSMISSION A transmission which does not have multiple discrete gear ratios individually selectable by the vehicle op
15、erator. 3.3 RATED ENGINE SPEED The engine speed in revolutions per minute at which the engine delivers its maximum net brake power as defined in SAE J1349 as determined by the manufacturer. 3.4 LONGITUDINAL PLANE OF SYMMETRY As defined in SAE J213. SAE J331 Revised JAN2012 Page 3 of 8 4. INSTRUMENTA
16、TION 4.1 The following instrumentation shall be used where applicable: 4.1.1 A sound level meter which meets the Type 1 or Type S1A requirements of ANSI S1.4-1983. As an alternative to making direct measurements using a sound level meter, a microphone or sound level meter may be used with recorder o
17、r other indicating instrument, provided that the system meets the requirements of SAE J184. 4.1.2 A sound level calibrator with an accuracy of 0.5dB dB conforming to IEC942 (1988) Class 1 and/or ANSI S1.401984 (see 9.6.4). 4.1.3 An engine speed tachometer, or other means of determining engine speed,
18、 with a steady-state accuracy of 3% at 60% and 100% of rated engine speed. 4.1.4 A speedometer with steady-state accuracy of 3% at a vehicle speed of 50 km/h (31 mph). 4.1.5 An anemometer with steady-state accuracy of 10% at a wind speed of 5.5 m/s (12 mph). 4.1.6 An acceptable windscreen may be use
19、d with the microphone. To be acceptable, the screen shall not affect the microphone response more than 1 dB for frequencies of 63 to 4000 Hz and 1.5 dB for frequencies of 4000 to 10000 Hz, taking into account the orientation of the microphone. 5. TEST SITE 5.1 The test site (Figure 1) shall be a fla
20、t open space accommodating a straight vehicle path and the following points: On the vehicle path a. The microphone target point b. Acceleration point - a point 7.5 m (25 ft) prior to the microphone target point c. End point - a point 30 m (100) beyond the microphone target point d. A point 15 m (50
21、ft) prior to the microphone target point e. A point 15 m (50 ft) beyond the microphone target point Off the vehicle path f. Microphone point - a point 15 m (50 ft) from the vehicle path on the perpendicular line which passes through the microphone target point g. Measurement area SAE J331 Revised JA
22、N2012 Page 4 of 8 FIGURE 1 - TEST SITE 5.2 The measurement area (G) within the test site shall be a triangular area defined by the microphone point (F) and the points D and E. The surface of the ground within the measurement area shall be Portland cement or bituminous asphalt concrete, dry and free
23、from snow, soil, or other extraneous material. 5.3 The test site shall be free of large sound reflecting surfaces (other than the ground) such as parked vehicles, signboards, buildings, or hillsides, located within 30 m ( 100ft) of the measurement area. 5.4 The vehicle path shall be on relatively sm
24、ooth Portland cement or bituminous asphalt concrete, dry and free of extraneous material such as gravel, snow, or ice and of sufficient length for acceleration, deceleration, and stopping of the vehicle (see 7.1.4). 5.5 The microphone of the sound level measurement system shall be located above the
25、microphone point. The microphone shall be positioned 1.2 m 0.02 m (4 ft in) above the ground plane. The microphones reference axis shall be perpendicular to the vehicle path. (Also see 9.6 and 9.6.1.) 5.6 The test site layout in Figure 1, for purposes of clarity, illustrates an approach from left to
26、 right. Sound level measurements are to be made on both sides of the vehicle; therefore, it will be necessary to establish either a sound microphone location on the opposite side of the vehicle path with a corresponding clear area, or to use approaches from both directions with corresponding acceler
27、ation points and end points. A = Microphone target point B = Acceleration point C = End point D = Center for radius of clear area E = Same as D F = Microphone point G = Measurement area Dimensions are m (ft) SAE J331 Revised JAN2012 Page 5 of 8 6. TEST MASS 6.1 At the start of the test series, the v
28、ehicle shall be filled with fuel to not less than 75% capacity and other fluids to a nominal, full capacity. 6.2 The combined mass of the test rider and test equipment used on the vehicle shall be not more than 90 kg (198.5 lb) or less than 75 kg (165.4 lb). If necessary, the vehicle/rider shall be
29、laden with additional mass to compensate for any difference between the actual driver/equipment mass and the required 75 kg (165.4 lb) minimum. 7. PROCEDURE 7.1 The following test shall be performed with sufficient runs (see 8.4) to establish maximum sound levels under acceleration:7.1.1 Vehicles wi
30、th manual transmissions shall proceed along the vehicle path in second gear at a constant approach speed which shall correspond to an engine speed of 60% of rated engine speed or a speed of 50 km/h (31 mph) whichever is slower. When the front of the vehicle reaches the acceleration point, the thrott
31、le shall be rapidly and fully opened to accelerate the motorcycle along the vehicle path until the front of the vehicle reaches the end point, or until rated engine speed is reached, at which time the throttle shall be rapidly and fully closed. 7.1.2 Vehicles with automatic transmissions shall use a
32、 standing start procedure. The front of the vehicle shall be at the acceleration point and with the transmission in the lowest selectable range, the throttle shall be rapidly and fully opened to accelerate the motorcycle along the vehicle path, until the front of the vehicle reaches the end point, o
33、r until rated engine speed is reached, at which time the throttle shall be rapidly and fully closed. 7.1.2.1 Some motorcycles with automatic transmissions may have the ability to select gears manually on an individual basis for specific operating conditions. If such motorcycles function in normal in
34、 use conditions with an automatic transmission which passes automatically and sequentially from one gear to the next, such motorcycles shall be allowed to conduct this procedure in accordance with point 7.1.2 7.1.3 The maximum engine speed attained during each run shall be recorded. 7.1.4 Wheel slip
35、 or front wheel lifting which affects the maximum sound level shall be avoided. 7.2 Unless it is apparent that maximum noise occurs during acceleration, the following test shall be performed with sufficient runs to establish maximum sound levels under deceleration: 7.2.1 For the test under decelerat
36、ion, the vehicle shall approach the end point from the reverse direction in the gear used and at the average maximum engine speed attained in the test under acceleration. When the front of the vehicle reaches the end point, the throttle shall be rapidly and fully closed and the vehicle allowed to de
37、celerate along the vehicle path until one half of rated engine speed or the point 15 m (50 ft) past the microphone target point is reached, whichever comes later. 7.3 Before measurements begin, sufficient preliminary runs shall be made to familiarize the rider with the vehicle and to allow the engin
38、e to reach normal operating temperature. The engine temperature shall be within the normal operating range prior to each run. 7.4 The longitudinal plane of symmetry of the test vehicle shall remain on the vehicle path for all test runs. SAE J331 Revised JAN2012 Page 6 of 8 8. MEASUREMENTS 8.1 The so
39、und level meter shall be set for fast response and for the A-weighting network. 8.2 The ambient sound level (including wind effects) at the test site, due to sources other than the vehicle being measured, shall be at least 10 dB lower than the peak sound level produced by the vehicle under test. 8.3
40、 Measurements shall be made only when the wind speed is below 5.5 m/s (12 mph). 8.4 The following measurements shall be made for both the acceleration and, if conducted, deceleration test modes: 8.4.1 Measurements shall be taken for both sides of the vehicle. 8.4.2 The meter shall be observed during
41、 each test as the vehicle is accelerating and decelerating. The highest sound level observed for each side during each test run shall be recorded. 8.4.3 Sufficient test runs shall be made until at least four recorded measurements for each test mode and each side of the vehicle are within a 2 dB rang
42、e. The sound level for that side and test mode shall be the arithmetic average for the first four measurements within a 2 dB range. 8.5 The sound level reported for the vehicle shall be the sound level of the side and test mode with the highest average sound level. 9. GENERAL COMMENTS 9.1 Technicall
43、y competent personnel should select the equipment, and the test should be conducted only by trained and experienced persons familiar with the current techniques of sound measurement. 9.2 While making sound level measurements, not more than one person other than the rider and the observer reading the
44、 meter shall be within 15 m (50 ft) of the vehicle or microphone. The additional person shall be directly behind the meter observer on a line through the microphone and the observer. 9.3 The test rider should be fully conversant with and qualified to ride the machine under test, and be familiar with
45、 the test procedure. 9.4 It should be noted that error in the engine speed indicator as well as error due to operator response time may result in sound level measurement error. 9.5 Tachometers having steady-state accuracy within 3% of actual engine speed at 60% and 100% of the rated engine speed are
46、 commercially available and are included on some motorcycles as original equipment. This class of tachometers is regarded as being sufficiently accurate for general sound level measurements. In circumstances where very accurate sound level measurements are necessary, accurate engine speed determinat
47、ion is essential, and consideration must be given to the accuracy and response time of the engine speed measurement system. Special care must be taken not to exceed rated engine speed. Exact engine speed measurement must be based on the time interval for not less than one complete engine cycle; for
48、example, two crankshaft revolutions for a four-stroke engine. SAE J331 Revised JAN2012 Page 7 of 8 9.6 Proper use of all test instrumentation is essential in obtaining valid measurements. Operating manuals or other literature furnished by the instrument manufacturer should be referred to for both re
49、commended operation of the instrument and precautions to be observed. Specific items to be considered are: 9.6.1 The type of microphone, its directional response characteristics, and its orientation relative to the ground plane and source of noise. 9.6.2 The effects of ambient weather conditions (for example, temperature, humidity, and barometric pressure) on the performance of all instruments. 9.6.3 Proper signal levels, ter
