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 there
2、from, 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 2013 SAE International All rights reserved. No part of this p
3、ublication 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: +1 724-776-497
4、0 (outside USA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org SAE values your input. To provide feedback on this Technical Report, please visit http:/www.sae.org/technical/standards/J2425_201307 SURFACE VEHICLE RECOMMENDED PRACTICE J2425 JUL2013 Issued 1998-01 Re
5、vised 2013-07 Superseding J2425 JUL2004 Steering Control Systems - Laboratory Test Procedure Heavy Trucks RATIONALE This procedure was revised to provide clarification to select setup parameters and several test situations that may arise, as well as commonize instrumentation and test conditions to E
6、CE R-12 Occupant Protection - Steering Column Displacement. 1. SCOPE This SAE Recommended Practice describes a laboratory test procedure for evaluating the characteristics of heavy truck steering control systems under simulated driver impact conditions. The test procedure employs a torso-shaped body
7、 block that is impacted against the steering wheel. 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 Available from
8、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 J211-1 Instrumentation for Impact Test - Part 1: Electronic Instrumentation SAE J211-2 Instrumentation for Impact Test - Part 2: Photographi
9、c Instrumentation SAE CRP-13 Heavy Truck Crashworthiness (Phase III-Testing and Analysis for Recommended Practice Development Results), April 1997 ECE R-12 Occupant Protection Steering Column Displacement 3. ITEMS TO BE DETERMINED 3.1 Impact velocity of the body block. 3.2 Resultant force during the
10、 impact. SAE J2425 Revised JUL2013 Page 2 of 7 4. TEST EQUIPMENT FOR INSTRUMENTATION 4.1 Body Block The complete body block shall have the following characteristics: 4.1.1 Spring Rate 107-143 kg/cm (600-800 lb/in), when the chest is loaded by a 10.0 cm wide by 38.0 cm long (4 in by 15 in) beam, 90 d
11、eg to the longitudinal axis of the body block, and parallel to the backing plate (Figure 1). The center of the beam is placed 45.7 0.63 cm (18.0 0.25 in) from the top of the head, centered laterally, and preloaded to 2.26 kg (5 lb) including the weight of the beam, to establish baseline penetration.
12、 Test speed is 25.0 5 cm/minute (10 2 in/minute). The load is measured when the beam has moved 12.7 cm (0.50 in) into the body block from the baseline and the spring rate is obtained by doubling this load. FIGURE 1 - TEST BEAM LOCATION 4.1.2 Weight The body block shall weight 33.97 +2.26 -0 kg (75 +
13、5 -0 lb). 4.1.3 Body block center of gravity The center of gravity of the complete body block shall be 55.12 0.63 cm (21.7 0.25 in) from the top of the head. 4.1.4 Moment of inertia The moment of inertia around the lateral axis through the center of gravity of the complete body block shall be 23 2.3
14、 cm-kg sec2(20 2 in-lb sec2). 4.1.5 Configuration of the body block is shown in Figures 2-4. SAE J2425 Revised JUL2013 Page 3 of 7 FIGURE 2 - MOLD INSERT SAE J2425 Revised JUL2013 Page 4 of 7 FIGURE 3 - BACKBOARD AND BASE SAE J2425 Revised JUL2013 Page 5 of 7 FIGURE 4 - BODY BLOCK PROFILE 4.2 Instru
15、mentation Two unidirectional accelerometers shall be placed symmetrically in the transverse plane of the center of gravity of the body block. Other methods with regard to the number and positioning of the measuring accelerometers shall be allowed, such as by dividing the test apparatus into separate
16、 parts at the center of gravity of which accelerometers are placed to measure the acceleration horizontally and parallel to the longitudinal axis of the vehicle. The peak resultant force may be measured by mounting a 3-axis load cell between the steering wheel and column or may be calculated from un
17、idirectional accelerometers mounted on the body block. All measurements should be recorded and filtered according to the most recent version of SAE J211. 4.3 Any test equipment is satisfactory which can produce the minimum body block-to-steering wheel impact velocity of 24 km/h (15 mph) and which in
18、sures the body block is moving parallel to the vehicle horizontal reference, with translational (not rotational) motion, in side view at impact. (See Figure 5.) The direction of impact velocity, in the plan view, is parallel to the longitudinal vehicle axis. SAE J2425 Revised JUL2013 Page 6 of 7 FIG
19、URE 5 - STEERING WHEEL/BODY BLOCK IMPACT CONFIGURATION 4.4 The steering wheel shall be mounted in the actual vehicle, vehicle buck, or on a fixture that is at least as rigid as the actual vehicle mounting. 4.5 If a load cell is used, it must be mounted between the column and the steering wheel. 5. T
20、EST PROCEDURE 5.1 It is recommended that the steering wheel be turned so that its most rigid spoke is aligned with the direction of the impact velocity thus producing the worst-case force on the body block. 5.2 In the case of an adjustable steering wheel, the test will be made with the wheel adjuste
21、d to the manufacturers design position. In case the manufacturers design position is not known, a location midway between the limits of its range of adjustment can be used. Other positions may be tested based on engineering judgement. 5.3 The body block at impact is positioned as shown in Figure 5.
22、The body block is centered laterally in relation to the steering wheel hub. The vertical relationship between the steering wheel and the body block shall be such that the center of gravity of the body block is at the same level as the lower edge of the steering wheel rim, within 25 mm ( 1 in). 5.4 A
23、ll parts under test shall be installed using the design attachment points and production parts or simulations thereof torqued to the proper value. In the case of the addition of a load cell between the steering wheel and steering column as stated in section 4.2, the attachment design and torque shal
24、l be represented as well as possible. 5.5 All parts and the body block shall be stabilized at an ambient temperature ranging between 20 5 C (60 to 77 F) for 4 h immediately prior to testing. 21.7 (55.1 cm) SAE J2425 Revised JUL2013 Page 7 of6. NOTES 6.1 Marginal Indicia A change bar (l) located in t
25、he left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous issue of this document. An (R) symbol to the left of the document title indicates a complete revision of the document, including technical revisions. Change bars and (R) are not used in original publications, nor in documents that contain editorial changes only. PREPARED BY THE SAE TRUCK CRASHWORTHINESS COMMITTEE
