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 2017 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:/standards.sae.org/J1335_201706 SURFACE VEHICLE RECOMMENDED PRACTICE J1335 JUN2017 Issued 1990-04 Reaffirmed 2009-
5、04 Revised 2017-06 Superseding J1335 APR2009 Hydraulic Cylinder No-Load Friction Test RATIONALE This standard is revised to clarify the test procedure, to add an allowable contamination level and to include ISO 4406 as a reference. 1. SCOPE Applies to hydraulic cylinders which are components of Off-
6、Road Self-Propelled Work Machines defined in SAE J1116. 1.1 Purpose To provide a laboratory method for determining the static and dynamic friction of a hydraulic cylinder at no-load conditions. 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the
7、 extent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or +1 724-776-4970 (outside USA), www.sae.org.
8、 SAE J1116 Categories of Off-Road Self-Propelled Work Machines SAE J1276 Standardized Fluid for Hydraulic Component Tests 2.1.2 ISO Publications Copies of these documents are available online at http:/webstore.ansi.org/ ISO 4406 Hydraulic Fluid Power - Fluids - Method for coding the level of contami
9、nation by solid particles SAE INTERNATIONAL J1335 JUN2017 Page 2 of 3 3. DEFINITIONS 3.1 STATIC BREAKAWAY PRESSURE The minimum pressure that initiates movement of the piston under no external load. 3.2 DYNAMIC DRAG PRESSURE The minimum pressure differential across the cylinder that is required to ma
10、intain constant velocity after breakaway at no load. 4. TESTING CONDITIONS 4.1 Accuracy of Measurement The accuracy of measurements unless otherwise stated shall be: a. Temperature 3 C (5 F) b. Pressure 2% c. Flow 2% d. Time 2% e. Length 2% 4.2 Test Temperature The test temperature shall be 20 C (68
11、 F) unless otherwise specified. 4.3 Test Fluid The test fluid shall be SAE 1276 unless otherwise specified. 4.4 Contamination Level Test system shall have a contamination level not to exceed ISO 4406 Code -/17/14. 5. TEST EQUIPMENT 5.1 Use a fluid power source capable of delivering a pressure necess
12、ary to overcome the static breakaway pressure of the cylinder. 5.2 Use a means of indicating pressure at the rod and piston ports and flow in the piston port. SAE INTERNATIONAL J1335 JUN2017 Page 3 of 3 6. TEST PROCEDURE 6.1 Cycle the cylinder until the fluid and apparatus temperatures are stabilize
13、d. 6.2 Position the cylinder horizontally with the barrel restrained and the rod end free. Locate the piston at the stroke midpoint of the cylinder under test. Install pressure measuring instrumentation in the rod end and piston end port and install the flow meter at the piston end port of the cylin
14、der. 6.3 After allowing a minimum of 2 minutes to permit the rod and piston seals to settle in normal static positions, gradually apply increasing pressure to the rod end port of the cylinder until cylinder starts to move. Record the pressure at this point. This is the static breakaway pressure. Onc
15、e the rod is moving keep a constant flow to the cylinder and record the pressure and flow. These pressures are used to determine the dynamic drag pressure. The flow rate during the dynamic drag test must be at a minimum to insure that pressure drops through the lines and the connections do not influ
16、ence the results. 6.4 Record on the data sheet the time elapsed between 6.1 and 6.3 as follows: a. The fluid temperature b. The static breakaway pressure c. The flow rate during the dynamic drag pressure test d. The inlet and outlet pressures to determine the dynamic drag pressure. Repeat this test
17、a minimum of three times. 6.5 Repeat the previous test for the reverse direction, applying increasing pressure to the piston end of the cylinder. 6.6 Record on the data sheet as follows: a. The fluid temperature b. The static breakaway pressure c. The flow rate during the dynamic drag test d. The in
18、let and outlet pressures to determine the dynamic drag pressure. Repeat this test a minimum of three times. 7. NOTES 7.1 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 mad
19、e 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 CTTC C1, HYDRAULIC SYSTEMS COMMITTEE
