1、SURFACE VEHICLE RECOMMENDED PRACTICE J1801 OCT2014 Issued 1993-06 Reaffirmed 2014-10 Superseding J1801 NOV2007 Brake Effectiveness Marking for Brake BlocksTruck and BusRATIONALE J1801 has been reaffirmed to comply with the SAE five-year review policy. _ SAE Technical Standards Board Rules provide th
2、at: “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 therefrom, is the sole responsibility of the user.” S
3、AE 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 2014 SAE International All rights reserved. No part of this publication may be reproduced, stored in a retrie
4、val 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 (outside USA) Fax: 724-776-0790 Email: Custome
5、rServicesae.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/J1801_201410 ForewordMarking methodology in this SAE Recommended Practice is intended to provide the identificationmeans to assis
6、t in the selection of replacement brake blocks. The normal and hot effectiveness rating values areintended to permit basic frictional performance comparisons between various different brake block lining materials,based on dynamometer test data from the reference full size brake assembly, as specifie
7、d in SAE J1802.This SAE Recommended Practice is intended as a guide toward standard practice and is subject to change tokeep pace with experience and technical advances.1. Scope1.1 This SAE Recommended Practice provides the method to assign numerical values of brake effectiveness,using data from sin
8、gle station inertia dynamometer effectiveness tests, and to identify a uniform procedure tomark these values on the edge of brake blocks in excess of 12.7 mm (0.51 in) in thickness.1.2 The edge markings are intended to provide relevant and meaningful data on the normal and hot effectivenessof brake
9、blocks, using the reference full size brake assembly, to aid in the characterization of these brake blockfrictional properties.1.3 This edge marking methodology is intended to permit accurate identification of the effectiveness values overthe full wear life of the brake block. This is accomplished b
10、y means of permanent markings on one edge of thebrake block.1.4 PurposeThe purpose of this document is to provide a uniform method for marking numerical values ofnormal and hot effectiveness, on the edge of the brake blocks, based on test data developed by SAE J1802and obtained from the reference fu
11、ll size brake assembly on a single station brake dynamometer.2. References2.1 Applicable PublicationThe following publication forms a part of this specification to the extent specifiedherein. Unless otherwise indicated, the latest issue of SAE publications shall apply.2.1.1 SAE PUBLICATIONAvailable
12、from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001.SAE J1802Brake Block Effectiveness Rating3. Effectiveness Determination3.1 The brake effectiveness, for this document, is a nondimensional value that is the average calculated from aminimum of three inertia dynamometer brake tests. Brake ef
13、fectiveness is the ratio of the brake frictionaloutput to brake force input as determined by the SAE J1802 test procedure.3.2 The normal effectiveness values from a minimum of three dynamometer tests are arithmetically averaged toobtain the normal effectiveness rating.3.3 Similarly, the hot effectiv
14、eness values from a minimum of three dynamometer tests are arithmetically averagedto obtain the hot effectiveness rating.3.4 Both the normal effectiveness and hot effectiveness value are determined from the same dynamometer test run.4. Marking4.1 This procedure utilizes markings that are recessed in
15、to one edge (or side) of the brake block. Refer to Figure 1.4.2 The numerical normal and hot effectiveness values shall consist of three-digit numbers in the range of 001through 999, without a decimal point, (e.g., 8.9 would be marked 089), recessed to a depth of 0.2 mm(0.008 in) minimum, and 3.5 to
16、 5.0 mm (0.14 to 0.20 in) in height.4.3 The three-digit effectiveness numbers shall be separated by a dash (e.g., 089 093), and located in a 50 mmx 6 mm (2.0 in x 0.24 in) zone, centered in the middle 50 mm (2.0 in) of the edge (or side) of the block. Referto Figure 1.The first number shall indicate
17、 normal effectiveness; the second shall indicate hot effectiveness.4.4 The 50 mm (2.0 in) zone shall be divided into nine equal spaces; each space shall be 5.6 mm (0.22 in) in width.Refer to Figure 1.4.5 The 50 mm (2.0 in) zone shall be identified by a vertical line at each end of the zone; the two
18、vertical lines shallbe parallel and at least one half the thickness of the block, up from the ID of the block. Refer to Figure 1.SAE INTERNATIONAL J1801 Reaffirmed OCT2014 Page 2 of 3_ FIGURE 1BRAKE BLOCK MARKING PROCEDUREPREPARED BY THE SAE TRUCK AND BUS FOUNDATION BRAKE SUBCOMMITTEE OF THESAE TRUCK AND BUS BRAKE COMMITTEESAE INTERNATIONAL J1801 Reaffirmed OCT2014 Page 3 of 3_
