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 2011 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: +1 724-776-4970 (outside U
4、SA) Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedbackon this Technical Report, please visit http:/www.sae.org/technical/standards/J1505_201107SURFACEVEHICLERECOMMENDEDPRACTICEJ1505 JUL2011 Issued 1985-05 Revised 2011-07 Super
5、seding J1505 APR2004 Brake Force Distribution Test Procedure - Trucks and Buses RATIONALE New stopping distance regulations will require a shift in brake force distribution. In addition, new types of brakes such as air disc have different pressure onset and torque output characteristics that can eff
6、ect low pressure brake force distribution. This procedure therefore will become a more important tool for measuring and comparing brake force distribution on trucks and buses. Experience with the original procedure has shown that test organizations using it would benefit from changes in data recordi
7、ng and safety procedures. 1. SCOPE This SAE Recommended Practice provides the test procedure and instructions for air braked single unit trucks, buses, and combination vehicles. It also provides recommendations for: a. Instrumentation and equipment b. Vehicle preparation c. Calculating distribution
8、of brake force 1.1 Purpose This procedure provides a method to determine the brake force distribution and threshold pressures for trucks and buses with a GVWR greater than 4536 kg (10 000 lb). Other equipment and procedures could be used to determine approximate relative work or energy being absorbe
9、d by a vehicles brakes. A “performance based brake tester” can determine low pressure/low speed torques of different brakes. A “temperature/thermal balance” can show relative temperatures of brakes, thus indicating approximate energy absorbed. SAE J1505 Revised JUL2011 Page 2 of 12 2. REFERENCES 2.1
10、 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. 2.1.1 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001,
11、 Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org.SAE J225 Brake Force Distribution Field Test Procedure for Truck and Bus (field test procedure) SAE J1626 Braking, Stability, and Control Performance Test Procedures for Air- and Hydraulic-Brake Equipped Trucks, Tr
12、uck-Tractors and Buses SAE J1854 Brake Force Distribution Performance GuideTruck and Bus SAE J2115 Air Brake Performance and Wear Test Code Commercial Vehicle Inertia Dynamometer 2.2 Related Publication The following publication is provided for information purposes only and is not a required part of
13、 this SAE Technical Report. 2.2.1 FMVSS Publication Available from The Superintendent of Documents, U.S. Government Printing Office, Washington, DC 20402. FMVSS (Federal Motor Vehicle Safety Standard) 121 Air Brake Systems 3. INSTRUMENTATION, EQUIPMENT, AND FACILITIES 3.1 Each vehicle should be equi
14、pped with: 3.1.1 A speed measuring device capable of measuring vehicle speed to within 0.32 km/h (0.2 mph). 3.1.2 A means of measuring time to within 0.1 s between two speeds such as a strip chart recorder or digital timer that receives a signal from the speed measuring device. 3.1.3 Two pressure tr
15、ansducers and a recording device accurate to within 3.5 kPa (0.5 psi). Note, pressure sensors should be calibrated daily to insure accuracy at low pressures. 3.1.4 Brake lining thermocouples as per SAE J2115 and a suitable temperature readout device accurate to within 11 C (20 F). If brake lining th
16、ermocouples are not used, a contact pyrometer or other method may be used to ensure that adequate cooling time is provided between tests to ensure that brake heating and fade do not contaminate results. 3.1.5 Valving to allow brakes on each axle or axle set to be operated, controlled, and evaluated
17、independently. Valving must not disturb the inherent pressure differentials in the vehicle brake system and provide driver override capability.3.1.6 An external application system (see Figure 1) that can apply the braking system with a constant input is recommended. (Use of the drivers foot to apply
18、 the brakes may increase variation in the test results). This system must be designed, installed, and utilized in such a way as to take into account the inherent pressure differentials in the vehicle brake system. SAE J1505 Revised JUL2011 Page 3 of 12 FIGURE 1 - EXTERNAL SYSTEM FOR BRAKE APPLICATIO
19、N 3.1.7 A system such as a treadle stop may be used provided that the brakes are applied at a controlled rate so as to minimize pressure overshoot during the brake application. Caution must be exercised when applying the brakes on individual axles during partial system testing. The stopping ability
20、of the vehicle will be reduced. 3.1.8 Measure and record ambient temperature and wind conditions, including wind speed and direction. 3.1.9 Test should be run on a straight 3.6 m (12-ft) wide roadway with a dry Portland cement concrete or equivalent surface to reduce the likelihood of wheel lock-up.
21、 The vehicle shall be aligned with the center of the roadway at the beginning of each stop. The roadway should be dry and flat with no more than a 1% grade in all directions, including crown. Due to reduced stopping ability of the vehicle, the roadway should either be part of a circular path, or mus
22、t contain sufficient run-out area, so in event of unanticipated braking force reduction or equipment failure, the vehicle has sufficient track length to coast to a stop. 4. VEHICLE INFORMATION AND DATA 4.1 Vehicle information sheet (Figure 2) to be filled in prior to starting test. 4.2 Test data she
23、et (Figure 3) to be used as a work sheet during testing. 4.3 Vehicle information and test data sheets may be used for or extended to single unit trucks, buses, or multiple combination vehicles. SAE J1505 Revised JUL2011 Page 4 of 12 Test No.:_ Test Date(s) From: _ To: _ Test Organization: _ Test Loc
24、ation: _ Vehicle Year, Make, and Model: _ Vehicle VIN: _ D.O.M: _ Wheelbase, mm (in): _ Trailer Year, Make, and Model: _ Trailer VIN: _ GAWR Vehicle: Front _ Rear _ Trailer _ Weight Distribution: Vehicle: Front _ Rear _ Trailer _ Trailer Axles (s) _ Gross Total _ BRAKES: Type1Size Make Lining Make L
25、ining Edge Codes Vehicle: Front _ _ _ _ _ Rear _ _ _ _ _ Trailer: _ _ _ _ _ BRAKE DRUM/ROTOR: Type2Make Weight (optional) Dust Shields (Y/N) Vehicle: Front _ _ _ _ Rear _ _ _ _ Trailer: _ _ _ _ ACTUATION DETAILS: Slack Adjusters Adjustment Air Chamber Length or Wedge Stroke Cam4Make/Model/Size Angle
26、 Type3551 kPa (80 psi) Rotation Vehicle: Front _ _ _ _ _ Rear-fwd. _ _ _ _ _ Rear-rear _ _ _ _ _ Trailer: Front _ _ _ _ _ Rear _ _ _ _ _ TIRES:PSI Size Type5Data Book SLR mm (in) Vehicle: Front _ _ _ _ Rear-fwd. _ _ _ _ Rear-rear _ _ _ _ Trailer: Front _ _ _ _ Rear _ _ _ _ SPECIAL CONDITIONS: Specia
27、l conditions or equipment, which might affect brake performance: _ _ _ (1) Cam, disc, wedge, etc. (2) Cast or composite drum, vented or non-vented rotor, etc. (3) Automatic, manual, etc. (4) With or opposite forward drum rotation (5) Single or dual, radial or bias-ply, etc. (6) If stroke cannot be m
28、easured (disc, wedge brakes), leave section blank. Refer to manufacturers manual to assure proper adjustment is maintained. FIGURE 2 VEHICLE INFORMATION SHEET SAE J1505 Revised JUL2011 Page 5 of 12 Vehicle: _ Trailer: _ Total Weight: _ lb (kg) 35 kPa(5 psi)69 kPa(10 psi)103 kPa(15 psi)138 kPa(20 psi
29、)207 kPa(30 psi)276 kPa(40 psi)Front 1234Rear 1234All 12341 -_ 2 -_ 3 -_ 4 -_Coastdown Deceleration Times (seconds):Operational BrakesRun #CONTROL LINE PRESSURE, kPa (psi)Measured Deceleration Times, seconds:Control Glad-hand Pressure at Trailer Brake ThresholdIncreasing Pressure: LF _ RF _Decreasin
30、g Pressure: LF _ RF _ Overall Average _ = ThresholdAverage: LF _ RF _ PressureControl Glad-hand Pressure at Trailer Brake ThresholdIncreasing Pressure: LF _ RF _ LR _ RR _Decreasing Pressure: LF _ RF _ LR _ RR _ Overall Average _ = ThresholdAverage: LF _ RF _ LR _ RR _ PressureStart Odom: Date: Time
31、: Amb. Temp: Wind Vel.: Wind Dir.: Finish Odom: Date: Time: Amb. Temp: Wind Vel.: Wind Dir.: Driver: Observer: FIGURE 3 - BRAKE FORCE DISTRIBUTION TEST DATA SHEET SAE J1505 Revised JUL2011 Page 6 of 12 5. VEHICLE CONDITION Brake force distribution may be determined for any lining condition new or in
32、 service; however, to ensure the accuracy and validity of results, the following conditions should be met: 5.1 Inspect the brake lining and mating surface. Replace if abnormal conditions exist or worn beyond manufacturers recommended limits. Adjust brakes to manufacturers specifications. 5.2 Lining
33、to drum or disc contact should be at least 90% of contact area. If contact area is not at least 90%, burnish procedure may be continued as specified in 5.6 until contact area is at least 90%. 5.3 Inspect tires and replace if worn beyond manufacturers recommended limits or abnormal tire condition. Ad
34、just tire pressure per vehicle manufacturers load recommendations. 5.4 All components between the air compressor and each of the brake chambers must be functioning properly. 5.5 Initial testing each day should be preceded by a series of brake snubs which will warm the hottest brake to 93 to 149 C (2
35、00 to 300 F). 5.6 In order to satisfy SAE J1854 guidelines, the vehicle brakes shall be burnished prior to testing with the procedure as specified in SAE J1626 Section 11 or FMVSS 121 Section 6.1.8. 6. BRAKING DISTRIBUTION TESTS 6.1 Install and secure instrumentation and test equipment in the test v
36、ehicle. One of the pressure transducers should be installed at the axle under test, down stream of any relay, proportioning valves, ABS, or other valving; the other should be installed at the tractor to trailer, truck to trailer control glad-hand, or on the primary pressure line from the foot valve
37、on a straight truck as the reference transducer. The axle pressure transducer is moved from axle-to-axle as necessary and is used to ensure that brakes are fully activated (i.e., at steady-state) before data collection occurs. The reference pressure transducer is used to ensure that the desired inpu
38、t level is achieved. All data is related back to the reference level for braking force distribution calculations. 6.2 Weigh the test vehicle in the as-tested configuration on an axle-by-axle or axle-set basis. Weight should be distributed approximately in accordance with GAWRs (Gross Axle Weight Rat
39、ing) and be sufficient to prevent wheel lock-up of one axle with respect to the others. 6.3 Determine the glad-hand (reference) pressure level at which braking starts to occur at each brake by raising the vehicle and rotating the wheel by hand while gradually increasing input to the brake system. Re
40、cord the glad-hand (reference) pressure level at which the brake torque is first evident on Figure 3. Continue to increase pressure to approximately 276 kPa (40 psi) and then slowly decrease it until the point at which the brake is shown to be fully released by rotation of the wheel by hand. Record
41、the glad-hand (reference) pressure level at brake release on Figure 3. The average of these two recorded values is defined as the brake threshold pressure. Calculate the threshold pressure for each brake and average these values for each axle or tandem set. 6.4 Test the braking on each axle (or axle set) of the combination vehicle independently using the following procedure. 6.4.1 Bring all of the vehicles brakes to the desired initial temperature (93 to 149 C 200 to 300 F hottest brake is recommen
