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 reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2006 SAE International All rights reserved. No part of this publication m
3、ay 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: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J2115 REV. AUG2006 SURFACE VEHICLE STANDARD Issued 1993-06 Revised 2006-08 Superseding J2115 JUN2000 (R) Air Brake Performance and Wear Test Code Commercial Vehicle Inertia Dynamometer RATIONALE This revision of the
5、SAE J2115 includes several enhancements and fine-tuning relative to the previous version. The main objectives for the revision were to bring it closer to the FMVSS 121 dynamometer test, focus on air brake systems, and to update the wear sections to reflect current industry practices for durability t
6、esting. This revision limits the scope to air-braked vehicle applications only. There are provisions for disc and drum brakes. The test conditions include parameters and response characteristics for the servo controller on the inertia-dynamometer. The test setup provides an alternate method for meas
7、uring drum or disc bulk temperature using a 9-thermocouple array. Wear sections reflect better current industry practice for assessing wear characteristics versus temperature. The wear sections include intermediate effectiveness evaluation at the corresponding temperature step as well as a baseline
8、temperature of 100 C. These effectiveness sections help assess any changes or trends on brake output as an effect of the material wear and the temperature history during previous sections. Temperature steps are better harmonized with International Standards for disc brakes. Lastly, Appendix A indica
9、tes the FMVSS 121 performance requirements during the different test sections for air brake systems used on different tractors, trailers or other commercial vehicle applications. 1. SCOPE This SAE Standard provides test procedures for air and air-over-hydraulic disc or drum brakes used for on-highwa
10、y commercial vehicles over 4536 kg (10 000 lb) of GVWR. This recommended practice includes the pass/fail criteria of Standard No. 121. 1.1 Purpose To provide an FMVSS121-based performance test and a wear and performance at increasing brake temperatures for disc and drum assemblies. 2. REFERENCES 2.1
11、 Applicable Publications The following publications form a part of this specification to the extent specified herein. Unless otherwise indicated, the latest version of SAE publications shall apply. 2.1.1 Federal Publications Available from the Superintendent of Documents, U. S. Government Printing O
12、ffice, Mail Stop: SSOP, Washington, DC 20402-9320. 49CFR571 Code of Federal Regulations Sec. 571.121 Standard No. 121 (Revised as of October 1, 2004) Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-S
13、AE J2115 Revised AUG2006 - 2 - 3. TESTS This document procedure includes the following inertia-dynamometer tests: 3.1 FMVSS121-based performance. 3.2 Wear and Performance at increasing temperatures. 4. INSTRUMENTATION, EQUIPMENT, AND TEST CONDITIONS Inertia should be equivalent to the loading condit
14、ions at which the brake normally operates within + 1% or - 1%. Calculate rotational speeds based on the Static Loaded Radius (SLR) for the tires normally used to carry such loads. Calculate the dynamometer inertia on the SLR and half the Gross Axle Weight Rating (GAWR). 4.1 Thermocouples 4.1.1 Plug
15、Type Thermocouple Plug style thermocouple as shown in Figure 1. 4.1.2 Lining Thermocouple 4.1.2.1 Install thermocouple in brake shoe lining as shown in Figures 2 and 3 for drum brakes. 4.1.2.2 Install thermocouple in brake pad lining as shown in Figure 5 for disc brakes (adjust installation location
16、 for groves, chamfers) 4.1.3 Drum/Disc Thermocouple(s) Note the two methods indicated below are not equivalent and may produce different results. 4.1.3.1 Standard method for drum or disc: Install thermocouple in drum or disc as shown in Figures 3, 4 and 6. Copyright SAE International Provided by IHS
17、 under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 3 - FIGURE 1 THERMOCOUPLE CONSTRUCTION FIGURE 2 BRAKE SHOE THERMOCOUPLE INSTALLATION Copyright SAE International Provided by IHS under license with SAENot for ResaleN
18、o reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 4 - FIGURE 3 DRUM THERMOCOUPLE AND SINGLE WEB SHOE THERMOCOUPLE LOCATION FIGURE 4 DRUM OR DISC THERMOCOUPLE INSTALLATION FIGURE 5 PAD THERMOCOUPLE LOCATION Copyright SAE International Provided by IHS unde
19、r license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 5 - FIGURE 6 - DISC 4.1.3.2 Optional method for drum or disc: Install a 3x3 thermocouple array in drum or disc as shown in Photographs 1, 2 and 3. Place a group of three t
20、hermocouples every 120 degrees around the drum or disc circumference. PHOTOGRAPH 1 DISC INSIDE DIAMETER Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 6 - PHOTOGRAPH 2 DI
21、SC OUTSIDE DIAMETER PHOTOGRAPH 3 DRUM 4.2 Cooling Air Cooling air velocity shall be 609 - 730 m/min (2000 2400 ft/min) and directed uniformly and continuously over the brake at a temperature between 24 C (75 F) and 38 C (100 F), except as specified in wear sections (see 7.6 and 7.7, below). 4.3 Brak
22、e Pressure Control 4.3.1 Pressure response time of less than 0.25 seconds to reach 414 kPa (60 psi) during onset of deceleration (brake apply). Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J21
23、15 Revised AUG2006 - 7 - 4.3.2 Maximum overshoot of 14 kPa (2 psi) that does not last over 0.2 seconds. 4.3.3 Control pressure within + 7 kPa (+1 psi). 4.3.4 Control of Average (not instantaneous) deceleration (as defined) + 0.1m/sec2(+ 0.33 ft/sec2) with a maximum pressure modulation of 138 kPa/sec
24、 (20 psi/sec) after onset of deceleration. 4.3.5 Do not exceed 745 kPa (108 psi) during the brake application. 5. DEFINITIONS 5.1 Anti-lock braking system (ABS) Portion of the service brake system that automatically controls the degree of rotational wheel slip on one or more road wheels of the vehic
25、le during braking. The ABS system uses wheel speed sensors, a control unit and pressure modulating valves to perform the braking control. 5.2 Average Deceleration Rate The change in velocity divided by the time elapsed measured from the onset of deceleration to final speed. Use the same interval (st
26、art and end points) for both, the change in velocity and the elapsed time. 5.3 Cooling Air Velocity Compute the cooling air velocity by dividing the airflow (cubic meter/min) inside the duct before the plenum by the open area (square meter) remaining around the brake in the plenum measured at right
27、angles to the nominal airflow direction. 5.4 Cycle Time Time elapsed from the initiation of one application to the initiation of the next. The times allotted for Brake Power and Recovery of Section 6 (FMVSS121-based dynamometer test) are calculated based on the nominal application durations for the
28、specified speeds and decelerations rounded to the nearest second. 5.5 Gross Axle Weight Rating (GAWR) The specified load-carrying capacity of a single axle system measured at the tire-ground interface. 5.6 Wheel Load Wheel load is one-half of the GAWR. 5.7 Initial Brake Lining Temperature (IBLT) Tem
29、perature of friction material of hottest brake shoe or pad 18 seconds before any brake application. This is used only for the FMVSS121-based performance portion of test (Section 6). 5.8 Maximum Pressure Maximum line pressure applied from the point at which the instantaneous deceleration exceeds 95%
30、of the specified Average Deceleration Rate (5.2, above) during onset of deceleration until the final speed. 5.9 Minimum Pressure Minimum line pressure applied from the point at which the instantaneous deceleration exceeds 95% of the specified Average Deceleration Rate (5.2, above) during onset of de
31、celeration until the final speed. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 8 - 5.10 Pressure Force per unit area exerted by the compressed air in the brake applicat
32、ion mechanism. 5.11 Retardation Torque Measure the average reference torque from the time the specified air pressure is reached until the brake is released. 5.12 Retardation Force Divide the Retardation Torque (5.11, above) by the static loaded tire radius to determine the retardation force. 5.13 Re
33、tardation Force Ratio Multiply the Retardation Force (5.12, above) by 2 and divide by the GAWR to determine the Retardation Force Ratio. 5.14 Snub Brake application to decrease speed to a value greater than 0 km/h (not a full stop). 6. FMVSS121-BASED DYNAMOMETER TEST 6.1 Burnish Adjust brake per bra
34、ke manufacturer specification. If required, adjust the brake up to three times during the burnish procedure. 6.1.1 Warm to 177 C (350 F) by performing the listed events until temperature after stop exceeds 177 C (350 F). Reduce cycle time (below 90 sec) if required to reach temperature. TABLE 1 Cycl
35、es Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time 64.4 km/h (40 mph) 0 km/h (0 mph) 3.0 m/sec (10 ft/sec) 90 sec First burnish. TABLE 2 Cycles Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time200 64.4 km/h (40 mph) 0 km/h (0 mph) 3.0 m/sec (10 ft/sec) 1
36、77 C (350 F) 6.1.2 Warm to 260 C (500 F) by making stops until the temperature after stop exceeds 260 C (500 F). Reduce cycle time (below 60 sec) if required to reach temperature. TABLE 3 Cycles Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time 64.4 km/h (40 mph) 0 km/h (0 mph)
37、 3.0 m/sec (10 ft/sec) 60 sec Second burnish. TABLE 4 Cycles Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time200 64.4 km/h (40 mph) 0 km/h (0 mph) 3.0 m/sec (10 ft/sec) 260 C (500 F) 6.1.3 Cool brake by rotating at 10 RPM until brake cools below 38 C (100 F). Copyright SAE Int
38、ernational Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 9 - 6.2 Performance Adjust brake per brake manufacturer specification, if required. 6.2.1 Warm to 80 C (176 F) by performing the listed even
39、ts until the temperature after stop exceeds 80 C (176 F). TABLE 5 Cycles Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time 64.4 km/h (40 mph) 0 km/h (0 mph) 3.0 m/sec (10 ft/sec) 90 sec Brake Retardation. TABLE 6 Cycles Initial Speed Final Speed Average Deceleration Pressure IB
40、LT Cycle Time1 80.5 km/h (50 mph) 0 km/h (0 mph) 138 kPa (20 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0 km/h (0 mph) 207 kPa (30 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0 km/h (0 mph) 276 kPa (40 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0 km/h (0 mph) 345 kPa (50 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0
41、km/h (0 mph) 414 kPa (60 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0 km/h (0 mph) 483 kPa (70 psi) 80 C (176 F) 1 80.5 km/h (50 mph) 0 km/h (0 mph) 552 kPa (80 psi) 80 C (176 F) Brake Power, Hot Stop and Recovery. TABLE 7 Cycles Initial Speed Final Speed Average Deceleration Pressure IBLT Cycle Time1 8
42、0.5 km/h (50 mph) 24.1 km/h (15 mph) 2.7 m/sec (9 ft/sec) 80 C (176 F) 9 80.5 km/h (50 mph) 24.1 km/h (15 mph) 2.7 m/sec (9 ft/sec) 72 sec 1 32.2 km/h (20 mph) 0 km/h (0 mph) 4.3 m/sec (14 ft/sec) 66 sec 1 48.3 km/h (30 mph) 0 km/h (0 mph) 3.7 m/sec (12 ft/sec) 122 sec 19 48.3 km/h (30 mph) 0 km/h (
43、0 mph) 3.7 m/sec (12 ft/sec) 60 sec 7. WEAR AND EFFECTIVENESS AT TEMPERATURE 7.1 Wear Test Preparation Prepare a new set of brake shoes or pads and drum or disc with thermocouples. Weigh and measure brake shoes or pads. Weigh and measure brake drum or disc. 7.2 Wear Burnish 7.2.1 Warm to 100 C (212
44、F) by making snubs at 60 second intervals until temperature after snub exceeds 100 C (212 F). TABLE 8 Cycles Initial Speed Final Speed Average Deceleration Pressure Initial Drum Initial Disc 64.4 km/h (40 mph) 32.2 km/h (20 mph) 0.9 m/sec (3 ft/sec) Copyright SAE International Provided by IHS under
45、license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J2115 Revised AUG2006 - 10 - 7.2.2 Wear Burnish TABLE 9 Cycles Initial Speed Final Speed Average Deceleration Pressure Initial Drum Initial Disc 1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 138 kPa (20
46、psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 276 kPa (40 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 414 kPa (60 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 552 kPa (80 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50
47、mph) 0.5 km/h (0.3 mph) 690 kPa (100 psi) 100 C (212 F) 100 C (212 F)200 64.4 km/h (40 mph) 32.2 km/h (20 mph) 0.9 m/sec (3 ft/sec) 177 C (350 F) 200 C (392 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 138 kPa (20 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 276 kPa (40 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 414 kPa (60 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 552 kPa (80 psi) 100 C (212 F) 100 C (212 F)1 80.5 km/h (50 mph) 0.5 km/h (0.3 mph) 690 kPa (100 psi)
