1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14291 Determination of Push-on and Pull-off Forces of Small Diameter Hoses Copyright 2012 General Motors Company All Rights Reserved September 2012 Originating Department: North American Engineering Standards Page 1 of 4 1 Scope Note: Nothing in thi
2、s standard supercedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. These tests shall be used to determine the push-on and pull-off forces of hoses with inside diameters 35 mm. In th
3、e case of hoses with a change in cross section, e.g., widening at one end, these tests must be performed on the respective hose ends. 1.1.1 Summary of Test Method. 1.1.1.1 Push-on Force. Hose specimens are pushed onto a mandrel using a tensile testing machine and the maximum force measured. 1.1.1.2
4、Pull-off Force. Hose specimens are pulled from a mandrel using a tensile testing machine and the maximum force measured. 1.2 Foreword. Not applicable. 1.3 Applicability. Not applicable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Stan
5、dards/Specifications. ISO 7500-1 2.2 GM Standards/Specifications. None 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Test Equipment. 3.2.1.1 Suitable tensile testing machine to ISO 7500-1 Class 1. 3.2.1.2 Steel mandrels with chrome plated surfaces, of appropriate diameters for tes
6、ting the push-on and pull-off forces (see Figure 1 and Figure 2). 3.2.1.2.1 Hoses with Nominal Inside Diameter 5 mm. For these hoses, the diameter of the test mandrels shall be 1 mm larger than the nominal inside diameter of the hose. In the case of nominal inside diameters between full millimeter s
7、teps, the diameter shall be rounded down to the next full or half millimeter. For example: Hose diameter 7.3 means a mandrel diameter of 8.0 mm Hose diameter 6.8 means a mandrel diameter of 7.5 mm Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for Resal
8、eNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14291 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 2 of 4 3.2.1.2.2 Hoses with Nominal Inside Diameter 5 mm. For hoses with a smaller diameter, it shall be rou
9、nded up or down to the next full or half millimeter. The test mandrel shall be 0.5 mm larger accordingly. For example: Hose diameter 4.2 mm means a mandrel diameter of 4.5 mm Hose diameter 4.3 mm means a mandrel diameter of 5.0 mm Mean roughness value Ra = 0.2 m. Maximum roughness value Rmax = 1.0 m
10、. 21 R 1D0.010 . 10 .2Figure 1: Mandrel for Testing Pull-off Force R 1D0.010 .21060 . 10 . 1Figure 2: Mandrel for Testing Push-on Force 3.3 Test Vehicle/Test Piece. 3.3.1 Test Material. Hose sections shall be used as test pieces. The hose sections used to determine push-on force shall have a length
11、of 40 mm, and those used to determine pull-off force 50 mm minimum. For initial sample approval and arbitration purposes, a minimum of five test pieces from at least three complete components shall be tested, for routine quality control a minimum of three test pieces. 3.4 Test Time. Not applicable.
12、3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW1429
13、1 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 3 of 4 4 Procedure 4.1 Preparation. 4.1.1 Test Sample Preparation. For initial sample approval and arbitration purposes, the minimum time between manufacturing and testing shall be seven (7) days, for routine quality con
14、trol at least 72 h. The test pieces shall be stored without strain at +23 C 5 C for at least 8 h prior to the tests. 4.2 Conditions. 4.2.1 Environmental Conditions. Not applicable. 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements
15、 shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. 4.3.1 Test Procedure: General Preparation. The test shall be performed at +23 C 5 C. At the discretion of the GM engineer specifying the test, lubricants may be required to be applied to either the hose sam
16、ples or the test mandrel. The lubricant to be used, and the method of application shall be specified by the GM engineer. This requirement and any other modification to the test method specified by the GM engineer shall be documented in the test report. 4.3.2 Test Procedure: Push-on Force. The test p
17、ieces shall be mounted 5 mm onto the appropriate test mandrel by hand and then pushed on over a further distance of 10 mm by a tensile testing machine, at a speed of 25 5 mm/minute. The maximum forces occurring during this process shall be measured. 4.3.3 Test Procedure: Pull-off Force. The test pie
18、ces shall be pushed 20 mm onto the appropriate test mandrel by hand, clamped in a tensile testing machine and removed at a speed of 100 mm/minute 10 mm/minute. The maximum forces occurring thereby shall be measured. 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Not applicab
19、le. 5.3 Test Documentation. 5.3.1 Evaluation and Rating. The arithmetical mean of the various tests shall be calculated. The mean value and at least 90% of the individual values must lie within the respective nominal limits. The measured value shall be expressed in newtons, rounded to the nearest in
20、tegral number. 5.3.2 Report. With reference to this test procedure, the results of the measurements shall be presented in a test report. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated wit
21、h its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. Not applicable. 8 Coding Syste
22、m This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW14291 Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING S
23、TANDARDS GMW14291 Copyright 2012 General Motors Company All Rights Reserved September 2012 Page 4 of 4 9 Release and Revisions This standard was originated in August 2005. It was first approved by the Global Elastomers Team in December 2006. It was first published in February 2007. Issue Publication
24、 Date Description (Organization) 1 FEB 2007 Initial publication. 2 SEP 2012 5 Year Refresh. (Global Elastomers Subsystem Leadership Team) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
