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 ther
2、efrom, 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 2017 SAE International All rights reserved. No part of this
3、publication 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: +1 724-776-49
4、70 (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:/standards.sae.org/J2899_201706 SURFACE VEHICLE RECOMMENDED PRACTICE J2899 JUN2017 Issued 2013-12 Revised 2017-06
5、 Superseding J2899 DEC2013 Brake Adjustment Limit for Air Brake Actuators RATIONALE Field Inspections on Spring Brake actuators with many years in field are often very corroded and it is difficult to read text that may have been stamped into the spring housing. Alternate methods of affixing a tag or
6、 label to the spring brake often fail over time as the tags and or labels fall off either from impact or corrosion. Some Spring Brake Actuators have an Aluminum Center Section that can have the marking permanently cast into the part. This marking remains readable despite excessive corrosion and cann
7、ot come loose. This new revision to the recommended practice allows manufactures to have the option of placing the stroke marking on the center section. The location is similar to the servicing instructions from SAE J1817, but is applicable for all sizes. This should make adoption of this guideline
8、easier for manufactures that use a different center section for each stroke size, but the same Spring Housing. Manufactures that use a different Spring Housing for each stroke size may also maintain the current stroke marking location on the spring housing. 1. SCOPE This SAE Recommended Practice app
9、lies to S-CAM, Wedge, and Disc air brake actuators where the stroke can be measured without disassembly from the brake. 1.1 Purpose This document defines the air brake actuator rated stroke markings and its conversion to the air brake actuator rated stroke and brake adjustment limit. 2. REFERENCES 2
10、.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. SAE INTERNATIONAL J2899 JUN2017 Page 2 of 5 2.1.1 SAE Publications Available from SAE International, 400
11、Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org. SAE J1817 Long-Stroke Air-Brake Actuator Marking SAE J1953 Brake-Stroke Indicator Design Guideline for Cam or Disc Air-Brake Actuators SAE J1469 Air Brake Actuator
12、Test Procedure, Truck-Tractor, Bus, and Trailers 3. DEFINITIONS References to “Actuator” will mean “Air Brake Actuator” if not specified. 4. RATED STROKE MARKINGS Rated stroke markings identify the rated stroke and brake adjustment limit for an air brake actuator in a standardized format. 4.1 Locati
13、on Rated stroke markings are to be located on the pressure housing base for service chamber brakes as shown in Figure 1. For Spring Brakes the markings are to be located either on the spring housing base as shown in Figure 1 or on the Spring Brake Center section as shown in Figure 2. All units are t
14、o be marked per column “Rated Stroke Marking” as shown in Figure 3. 4.2 Visibility The rated stroke marking is to be permanently stamped or embossed on the housing or on a corrosion resistant tag permanently affixed or bonded to the housing. The font height of the stroke marking is to be at least 3/
15、8 inch (10 mm) tall and at least 3 times the size of any other characters located on the same tag or within a 1/2 inch (12 mm) from the stroke marking if located directly on the housing. The stamped impression/embossed character are to be a minimum of 0.012 inch (0.31 mm) deep/high and visually conf
16、irmed it can be located and read if painted over with up to 0.008 inch (0.2 mm) of paint. It must also be readable after completing the SAE J1469, Section 14, salt spray test procedure. 4.3 Marking Definition The corresponding rated stroke marking character matching the actuator rated stroke is show
17、n in Figure 3. If the actuator has a different rated stroke than shown in Figure 3, then the Rated Stroke marking will be a two-decimal number representing the brake adjustment limit based on 80% of the rated stroke rounded to the nearest 1/8 inch (3 mm) increment. Figure 1 SAE INTERNATIONAL J2899 J
18、UN2017 Page 3 of 5 Figure 2 Rated Stroke Marking Actuator Rated Stroke Brake Adjustment Limit A 1.50 inch (38 mm) 1.25 inch (32 mm) B 1.75 inch (44 mm) 1.38 inch (35 mm) C 2.00 inch (51 mm) 1.50 inch (38 mm) D 2.25 inch (57 mm) 1.75 inch (44 mm) E 2.50 inch (64 mm) 2.00 inch (51 mm) F 3.00 inch (76
19、mm) 2.50 inch (64 mm) G 3.25 inch (83 mm) 2.62 inch (67 mm) H 3.50 inch (89 mm) 2.75 inch (70 mm) X.XX Other X.XX inch Figure 3 RATED STROKE MARKING SAE INTERNATIONAL J2899 JUN2017 Page 4 of 5 5. AIR BRAKE ACTUATOR CLAMP BAND DIAMETER 5.1 Relationship between actuator clamp band outside diameter to
20、air brake actuator size is shown in Figure 4. See Figure 5 for graphical definition of the service clamp band outside diameter. This diameter excludes the clamp fastener and is measured on a surface at least 1 inch (25 mm) away from the clamp fastener. On actuators without clamps, the outside diamet
21、er is the maximum diameter on the housing at the location shown in Figure 5. Standard Type S-CAM Actuators Applies to Specialty Type S-CAM Actuators* Standard Rated Stroke S-CAM Actuator Clamp Band Outside Diameter 0.20 inch ( 5 mm) 6 5-7 1.50 inch (38 mm) 4.63 inch (117 mm) 9 8-10 1.75 inch (44 mm)
22、 5.38 inch (137 mm) 12 11-13 1.75 inch (44 mm) 5.81 inch (148 mm) 16 14-17 2.25 inch (57 mm) 6.50 inch (165 mm) 20 18-21 2.25 inch (57 mm) 6 .91 inch (176 mm) 24 22-26 2.50 inch (64 mm) 7.34 inch (186 mm) 30 27-32 2.50 inch (64 mm) 8.22 inch (209 mm) 36 33-37 3.00 inch (76 mm) 9.13 inch (232 mm) Fig
23、ure 4 Figure 5 - Service Chamber Clamp Band OD SAE INTERNATIONAL J2899 JUN2017 Page 5 of 5 6. NOTES 6.1 Revision Indicator A change bar (l) located in the left margin is for the convenience of the user in locating areas where technical revisions, not editorial changes, have been made to the previous
24、 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 AND BUS BRAKE ACTUATOR COMMITTEE OF THE TRUCK AND BUS BRAKE AND ADVANCED DRIVER ASSISTANCE SYSTEMS STEERING COMMITTEE
