1、 SURFACE VEHICLE RECOMMENDED PRACTICE J2432 MAR2015 Issued 2000-01 Revised 2015-03 Superseding J2432 NOV2012 Performance Testing of PK Section V-Ribbed Belts RATIONALE This latest revision of SAE J2432 accomplishes the following: Revised backside pulley sizes in durability tests to properly replicat
2、e real world failure modes. Increased belt dryout time in the noise test to accommodate all belt constructions. Revise cold temperature tolerance specification to align with the accuracy and calibration limits of the test equipment. 1. SCOPE The following information covers accessory drive belt test
3、ing methods and includes test configurations, pulley diameters, power loads, and guidance for interpreting test data. Belt construction definitions are also documented. This information has been prepared from existing literature, including standards and data supplied by Producers and Users of V-ribb
4、ed belts. 1.1 Purpose This SAE Standard is intended to provide methods to evaluate the performance of V-ribbed belt constructions. 1.2 Test Sample Size The number of test samples should be agreed between each Producer and User. 1.3 Test Conditions Any variation or change in the test conditions outli
5、ned in this specification must be agreed between the Producer and User. _ 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
6、 for any particular use, including any patent infringement arising therefrom, 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.
7、 Copyright 2015 SAE International All rights reserved. No part of this 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 DOCUM
8、ENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: +1 724-776-4970 (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/J2432_201
9、503 SAE INTERNATIONAL J2432 Revised MAR2015 Page 2 of 28 1.4 Belt Test Lengths The test belt length is 1200 mm 10 mm. Test data from belts of this length will be considered valid for all belt lengths of the same construction and specification. 1.5 Definition of Construction Specification The belt Pr
10、oducers test data on belts of a certain construction shall be considered valid for evaluation of all belts, with respect to the Producers cross section dimensions, material specifications, and method of manufacture. 1.6 Pulley Construction Unless otherwise specified, all pulleys used on test fixture
11、s should be machined steel pulleys. 1.7 Pulley Tolerances Pulleys should be manufactured to SAE measurement pulley tolerances as shown in SAE J1459, except diameter over balls (DOB) tolerance must be held to 0.1mm and the groove angles must be held to 0.5 degrees. 1.8 Definitions 1.8.1 Profiled (Cut
12、/Ground) Belts a. Rib layer - Outer layer of belt typically in contact with pulley grooves. The rib layer consists of rubber mixed with fiber. Ribs may be on one side or both sides of the belt. The rib layer provides the friction to carry the load between the accessory and the belt. b. Adhesion laye
13、r(s) - Interior layer(s) of material between the cord and adjacent layers. Its purpose is to provide a bond between individual cords, the cord layer, and adjacent layers. It can be on one side of the cord, both sides of the cord, or not present at all. c. Cord layer - Interior layer consisting of in
14、dividual strands of yarn that carry the tensile load on the belt. The cord layer defines the tensile modulus of the belt. d. Back layer - Outer layer of belt material opposite of the rib layer. The back layer has no rib profile. The purpose of the back layer is to provide a running surface for routi
15、ng pulleys and may also provide friction to carry the load between flat pulleys and the belt. The back layer also provides support for the cord layer. e. Fabric layer - Optional internal or external to the back layer of the belt. Typically used to provide support for the cord layer. 1.8.2 Molded Bel
16、ts - otherwise same as profiled belts with the exception of: a. Rib layer - Outer layer of belt material typically in contact with the pulley grooves. For molded belts, the rib layer consists of a fiber free rubber rib cross section with a surface layer for noise abatement. The surface layer can be
17、a fabric sheet, glued on flock, a polymer sheet, a cellulose sheet, rubber, or potentially other treatments. SAE INTERNATIONAL J2432 Revised MAR2015 Page 3 of 28 Figure 1 - Belt cross-section 2. REFERENCES 2.1 Applicable Documents The following publications form a part of this specification to the e
18、xtent specified herein. Unless otherwise indicated, the latest issue of SAE publications shall apply. Specification SAE J2432 shall prevail in the event of any conflict relative to belt testing between the publications below and Specification SAE J2432. 2.1.1 SAE Publications Available from SAE Inte
19、rnational, 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 J1459 V-Ribbed Belts and Pulleys 2.1.2 ASTM Publications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken,
20、 PA 19428-2959, Tel: 610-832-9585, www.astm.org ASTM D 412 Test Methods for Rubber Properties in Tension ASTM D 573 Test Method for Rubber - Deterioration in an Air Oven ASTM D 575 Test Methods for Rubber Properties in Compression ASTM D 1149 Test Method for Rubber Deterioration - Surface Ozone Crac
21、king in a Chamber (Flat Specimens) ASTM D 4485 Standard Specification for Performance of Engine Oils SAE INTERNATIONAL J2432 Revised MAR2015 Page 4 of 28 3. HIGH TEMPERATURE, CONSTANT TENSION TEST 3.1 Purpose To test the belts durability under high temperature, high load conditions. This test was de
22、veloped to reflect the increased use of automatic tensioners on automotive accessory drives. These systems have constant tension and therefore do not exhibit slip conditions resulting from loss of tension due to belt stretch. Increased belt length will increase belt life on the test stand. Therefore
23、, belt length has been limited to reduce test variability and provide comparable data from each manufacturer to the users. NOTE: This test can be run in conjunction with 9) Noise Test. Interruptions for inspections or noise testing are allowed. 3.2 Test Configuration See Figure 2. 3.2.1 Test Paramet
24、ers Driven Torque = 20 Nm 1 Nm Belt Effective Length = 1200 mm 10 mm Steady State Driver Speed = 4900 rpm, within 100 rpm Number of Belt Ribs = 6 Operating Belt Tension (around pulley 2) = 629 N 31 N Belt load setup, as per Figure 2: Option 1: Belt loaded at W1 (reference) = 923 N 5%, as needed to o
25、btain proper operating belt tension Option 2: Belt loaded at W2 (reference) = 713 N 5%, as needed to obtain proper operating belt tension 3.2.2 Test Chamber Temperature 121 C 5 C 3.3 Test Stand The Four Pulley Hot Test stand is shown in Figure 2. SAE INTERNATIONAL J2432 Revised MAR2015 Page 5 of 28
26、Figure 2 - High temperature, constant tension test layout 3.3.1 Tension Constant tension will be maintained with a dead weight device or equivalent. The operating belt tension (steady state, loaded, dynamic) should be obtained at either span around pulley 2, having applied the 20Nm of torque at pull
27、ey 3 and the recommended load at either W1 or W2. The static tension may be measured on the belt, with the stand at rest, noting however that it will be a different value depending on the chosen loading option (W1 vs. W2). 3.3.2 Motor The test stand is driven by a motor sized to handle a minimum of
28、the sustained torque applied to the driven pulley plus system losses at the RPM indicated in 3.2.1. 3.3.3 Power Absorber The driven pulley is to be attached to a power absorption unit capable of handling the torque indicated in 3.2.1. SAE INTERNATIONAL J2432 Revised MAR2015 Page 6 of 28 3.3.4 Temper
29、ature Control The test stand temperature should be mapped with a running belt, over a 2 h period, and proven to be capable of no more than 5C variation throughout the test area. The test stand must have at least five thermocouples; one near each of the four pulleys, and one in the center of the driv
30、e layout. It is recommended that stands be recertified when modified or annually if no modifications are performed. 3.3.5 Miscellaneous A control capable of shutting down the test under specified conditions is required. The test stand belt alignment entry angle should be less than 0.5 degrees at eac
31、h grooved pulley. 3.4 Test Description 3.4.1 Prior to start of test, remove any grease, rubber, or other foreign material from the pulley grooves. 3.4.2 Weigh the belt and install the belt on the test fixture. Apply the required belt tension. The belt tension must be constant throughout the test. 3.
32、4.3 Start the machine. Adjust the torque to the proper setting. Temperatures should be properly monitored to maintain constant temperature. Set the test stand control to stop the machine if the temperature goes outside of the specified tolerance. Use the thermocouple in the center of the drive layou
33、t for temperature monitoring. 3.4.4 Set the test stand control to stop the machine if the driven pulley speed has dropped 4% from the target driver pulley speed. 3.4.5 Inspect belts daily (minimum), recording test h, chamber temperature and belt temperature. Note any evidence of edge cord pop out, p
34、illing, and belt cracks. When belt is found to be failed (see 3.5.1), weigh the belt and revert to the last inspection for time to failure. Belts should be weighed upon completion of all testing. Belt weights should be taken when the belt reaches ambient temperature. 3.5 High Temperature, Constant T
35、ension Test Performance Guidelines 3.5.1 Failure Criteria A belt shall be considered failed when one or more of the following conditions occur: a. Belt breakage, (fracture of cord) b. Belt chunking, loss of rib stock c. Delamination of belt layers d. Belt fraying or tensile cord separation (edge cor
36、d popout in 2 places, 25mm long) e. Maximum number of B or C level cracks = 8 (see Figure 2) f. Loss of belt traction capacity (4% slip) g. In-line crack across the belt rib cross section h. Weight loss in excess of 10% of original weight at end of test i. Pilling rating “high“ (see 7.6 for definiti
37、on) SAE INTERNATIONAL J2432 Revised MAR2015 Page 7 of 28 3.5.2 Acceptance Criteria a. The belt manufacturer and user will agree on acceptance/rejection criteria and may agree on other failure criteria. 4. HOT AND COLD CYCLING TEST 4.1 Purpose To test a belts durability under high temperature, high l
38、oad; and low temperature, no load conditions. 4.2 Test Specification Summary NOTE: The Hot and Cold Segments of this test use the same geometric configuration as shown in Figure 2. 4.2.1 Test Parameters (Hot Segment) Driven Torque = 20 Nm 1 Nm Temperature = 121 5 C Belt Effective Length = 1200 mm 10
39、 mm Steady State Driver Speed = 4900 rpm, within 100 rpm Number of Belt Ribs = 6 Operating Belt Tension (around pulley 2) = 629 N 31 N Belt load setup, as per Figure 2: Option 1: Belt loaded at W1 (reference) = 923 N 5%, as needed to obtain proper operating belt tension Option 2: Belt loaded at W2 (
40、reference) = 713 N 5%, as needed to obtain proper operating belt tension 4.2.2 Test Parameters (Cold Segment) Driven Torque = no torque reaction load is to be applied Temperature = -40C +0C / -5C Belt Effective Length = 1200 mm 10 mm Driver Speed = 1500 rpm, within 30 rpm Number of Belt Ribs = 6 Bel
41、t Tension = 267 N 13 N Belt Hubload setup, per Figure 2: Option 1: Belt loaded at W1 (reference) = 392 N 5%, as needed to obtain proper operating belt tension Option 2: Belt loaded at W2 (reference) = 417 N 5%, as needed to obtain proper operating belt tension 4.3 Test Fixture Setup 4.3.1 Hot Fixtur
42、e Setup The four pulley stand is shown in Figure 2. 4.3.1.1 Tension Constant tension will be maintained with a dead weight device or equivalent. For the Hot Segment, the operating belt tension (steady state, loaded, dynamic) should be obtained at either span around pulley 2, having applied the 20Nm
43、of torque at pulley 3 and the recommended load at either W1 or W2. The static tension may be measured on the belt, with the stand at rest, noting however that it will be a different value depending on the chosen loading option (W1 vs. W2). 4.3.1.2 Motor The test stand is driven by a motor sized to h
44、andle a minimum of the sustained torque applied to the driven pulley plus system losses at the RPM indicated in 4.2.1. SAE INTERNATIONAL J2432 Revised MAR2015 Page 8 of 28 4.3.1.3 Power Absorber The driven pulley is to be attached to a power absorption unit capable of handling the torque indicated i
45、n 4.2.1. 4.3.1.4 Temperature Control The test stand temperature should be mapped with a running belt, over a 2 h period, and proven to be capable of no more than 5 C variation throughout the test area. The test stand must have at least five thermocouples; one near each of the four pulleys, and one i
46、n the center of the drive layout. Use a thermocouple in the center of the drive layout for temperature monitoring. It is recommended that stands be recertified when modified or annually if no modifications are performed. 4.3.1.5 Miscellaneous A control capable of shutting down the test under specifi
47、ed conditions is required. Test stand belt alignment entry angle should be less than 0.5 degrees at each grooved pulley. 4.3.2 Cold Fixture Setup The four pulley stand is shown in Figure 2. 4.3.2.1 Tension The tension will be maintained with a dead weight device or equivalent. For the Cold Segment,
48、since no torque is applied at any pulley during the test, a static tension measurement is acceptable. 4.3.2.2 Motor The test stand is driven by a motor capable of meeting RPM requirements indicated in 4.2.2. 4.3.2.3 Miscellaneous A control capable of shutting down the test under specified conditions is required. The test stand belt entry angle should be less than 0.5 degrees at each grooved pulley. 4.4 Test Procedure 4.4.1 Hot Test Procedure 4.4.1.1 Prior to start of test, remove any grease, rubber, or other foreign material from the pulley grooves. 4.4.1.2 Weigh the belt and install the
