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 2009 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 SURFACE VEHICLE RECOMMENDED PRACTICE J1626-1 JUN2009 Issued 2009-06 Recommended Practice for Braking, Stability, and Control Performance Test Procedure for Air-Brake-Equipped Truck-Tractors RATIONALE This series of S
5、AE Recommended Practices have been developed by the Truck and Bus Vehicle Deceleration and Stability Subcommittee combined with the Brake Systems Subcommittee sponsored by the Brake Committee. These SAE Recommended Practices are intended as a guide toward industry practice and are subject to change
6、so as to keep pace with experience and technical advances. The usage of these recommended practices are limited to vehicles equipped with air brake systems and hydraulic brake vehicles with a GVWR greater than 10 000 lb. The current SAE J1626 included air and hydraulic type brake vehicle test proced
7、ures combined in one document. With the complexity of this document as combined, it was determined to better serve our industry that the subcommittee should rewrite this document into separate procedures. As described in the parent document, SAE J1626, there are a minimum of five documents required
8、for air- and hydraulic-braked vehicles noted below in the References Section. This procedure addresses the truck-tractor air brake combination vehicle. In summary, the following changes were addressed; a. Scope separated this document into the truck-tractor procedure b. References added the new sepa
9、rate procedure numbers and included other new references as appropriate including SAE J360 (Truck and Bus Grade Parking Performance Test Procedure) and SAE J1729 (Parking Brake Drawbar Pull Test Procedure. c. Test Conditions snub burnish conditioning procedure will be conducted with the transmission
10、 in gear. This was a procedure change. Included brake adjustment clarification and recommended intervals. d. Test Sequence this was revised to follow FMVSS 121 truck-tractor test sequence. e. Test Procedures included maximum braking speed test to the stability and controls test. An optional test was
11、 added to initiate additional stops at a fully exhausted reservoir pressure at or near 0 psi during the failed system reservoir stops. f. Data Sheets added the procedure changes and updates as appropriate for clarification. SAE J1626-1 Issued JUN2009 Page 2 of 22 1. SCOPE This Recommended Practice p
12、rovides a road test procedure for truck-tractors, to evaluate their compliance with Federal Motor Vehicle Safety Standard (FMVSS) 121; Air Brake Systems. Units of measure are English in lieu of metric to be consistent with FMVSS 121. 2. REFERENCES 2.1 Applicable Publications The following publicatio
13、ns 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 SAE Publications Available from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) o
14、r 724-776-4970 (outside USA), www.sae.org. SAE J1626 Braking, Stability, and Control Performance Test Procedures for Air- and Hydraulic-Brake-Equipped Trucks, Truck-Tractors and Buses SAE J293 Truck and Bus Grade Parking Performance Requirements SAE J299 Stopping Distance Test Procedure SAE J360 Tru
15、ck and Bus Grade Parking Performance Test Procedure SAE J693 Truck Overall Widths Across Dual Tires SAE J971 Brake Power Rating Test CodeCommercial Vehicle Inertia Dynamometer SAE J1729 Parking Brake Drawbar Pull Test ProcedureTruck and Bus SAE J2503 Drawbar Pull Performance Criteria 2.1.2 ASTM Publ
16、ications Available from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959, Tel: 610-832-9585, www.astm.org. ASTM E 1136 Specification for a Radial Standard Reference Test Tire ASTM E 1337 Standard Test Method for Determining Longitudinal Peak Braking Coeffici
17、ent of Paved Surfaces Using a Standard Reference Test Tire 2.1.3 FMVSS Publication Available from the Superintendent of Documents, U.S. Government Printing Office, Mail Stop: SSOP, Washington, DC 20402-9320. FMVSS 121 Air Brake Systems SAE J1626-1 Issued JUN2009 Page 3 of 22 3. DEFINITIONS 3.1 Truck
18、 Tractor For the purpose of this standard is a truck designed to tow a semi-trailer through a fifth wheel located over the rear axle(s). This document uses this kind of towed vehicle for the truck-tractors tests at GVWR. 3.2 Snub Means the braking deceleration of a vehicle from a higher speed to a l
19、ower speed that is greater than zero. 3.3 Stopping Distance Means the distance traveled by a vehicle from the point of application of force to the brake control to the point at which the vehicle reaches a complete stop. 3.4 Unloaded Vehicle Weight (UVW) Is the weight of a motor vehicle with standard
20、 equipment, maximum capacity of engine fuel, oil, and coolant. 3.5 Vehicle Combination Weight For the purpose of this standard is the combined weight of a truck-tractor and the semi-trailer it is towing. 3.6 Gross Axle Weight Rating (GAWR) Is the maximum rated capacity of a single axle system (axle
21、with tires, wheels, and suspension) as measured at the tire-road interface as stated on the vehicle certification label. 3.7 Gross Vehicle Weight Rating (GVWR) Is the maximum rated capacity of a single vehicle as stated on the vehicle certification label. Liftable axles shall be down for GVWR tests.
22、 Unless otherwise specified, vehicles are loaded to GVWR as follows: 3.7.1 Truck-tractors are to be loaded to GVWR using a single axle unbraked control trailer. The control trailer has a single axle with a gross axle weight rating of 18 000 lb and a length, measured from the transverse centerline of
23、 the axle to the centerline of the kingpin, of 258 in 6 in. All ballast on the control trailer is placed directly above the kingpin. Load distribution is to be in proportion to the tractors GAWRs, with the trailer axle as close as possible to 4500 lb. Adjust the load distribution by altering the fif
24、th wheel position, if applicable. The center of gravity height of the ballast should be at least 24 in above the top of the tractor fifth wheel. In the case where the tractor fifth wheel cannot be adjusted as specified without exceeding a GAWR, reduce the amount of ballast so that the axle load does
25、 not exceed the guidelines of 3.7.2, maintaining the load proportioning as close as possible to the specified proportioning. 3.7.2 Actual vehicle test weight is to be within +2/-0% of the weight specified in 3.7.1. Axle weights are to be within 2% of their proportional share of the test weight. 3.8
26、Lightly Loaded Vehicle Weight (LLVW) 3.8.1 Truck Tractor LLVW is the unloaded vehicle weight (UVW) plus up to 500 lb including driver, observer, and instrumentation. An additional 1000 lb can be allotted for vehicles that require a rollbar for testing purposes. Liftable axles shall be lifted for LLV
27、W vehicle tests. 3.9 Full Brake Application 3.9.1 Air Full Brake Application means an application of the brake control (treadle or brake pedal) in which pressure in any of the valves output circuits reaches 85 psi, or the brake control has reached maximum displacement, within 0.2 sec after applicati
28、on is initiated. SAE J1626-1 Issued JUN2009 Page 4 of 22 3.10 Initial Brake Temperature (IBT) Means the average temperature of the service brakes on the hottest axle of the vehicle 0.2 mile before any brake application. 3.11 Maximum Drive - Through Speed Means the highest possible constant speed at
29、which the vehicle can be driven through 200-ft arc of a PFC no greater than 0.5 in a 500-ft radius curve without leaving the 12-ft lane. 3.12 Peak Friction Coefficient (PFC) Means the ratio of the maximum value of longitudinal force to the simultaneous vertical force occurring prior to wheel lockup,
30、 as the braking torque is progressively increased, as measured using the procedure in ASTM E 1337. 3.13 Unbraked Control Trailer Is a single axle semi-trailer with a GAWR of 18 000 lb and a length, measured from the transverse centerline of the axle to the centerline of the kingpin, of 258 in 6 in a
31、nd ballast CG height should be at least 24 in above the top of the tractors fifth wheel and trailer axle weight of 4500 lb (defined in FMVSS 121). 3.14 Wheel Lockup Means 100% wheel slip. 3.15 Antilock Brake System (ABS) Means a portion of a service brake system that automatically controls the degre
32、e of rotational wheel slip during braking by: (a) sensing the rate of angular rotation of the wheels; (b) transmitting signals regarding the rate of wheel angular rotation to one or more controlling devices which interpret those signals and generate responsive controlling output signals; and (c) tra
33、nsmitting those controlling signals to one or more modulators which adjust brake actuating forces in response to those signals. 4. INSTRUMENTATION AND EQUIPMENT 4.1 Anemometer or equivalent device to measure wind velocity. Twenty-five (25) mph range with 1 mph accuracy at 15 mph, maximum non-lineari
34、ty of 2 mph over the range and visual output resolution of 1 mph. 4.2 Ambient temperature device to record ambient test temperatures, 32 F to 100 F range with 0.5 F accuracy at 70 F, maximum non-linearity 1.0 F over the range, and visual output resolution of 1 F. 4.3 Tire pressure gauge, 1.0% of ind
35、icated value. 4.4 Brake lining thermocouples, 10.0 F at 300 F, maximum non-linearity of 20 F over the range and visual output resolution of 5 F, installed per SAE J971, and display for brake lining temperature. 4.5 Fifth wheel, optical or other equivalent device to measure and display (or record) ve
36、hicle speed, 0.5 mph, and stopping distance accuracy of 1% of indicated value, and visual output resolution of 0.1 ft. 4.6 A device to indicate first brake control (treadle or brake pedal) movement, 1.0% of indicated value, and full brake control displacement, or brake control pressure, 1% of indica
37、ted value, versus time, capable of 0.1 seconds resolution. 4.7 Wheel lockup detector or equivalent measuring device providing an electrical indication of wheel rotation (or wheel lockup) to a continuous recorder or digital data recorder. The lockup detector or measuring system must provide an indica
38、tion for wheels that lockup above 10 mph, + 1 mph, -0 mph. Measure wheel velocity or identify wheel lockup of 1 second duration or more. SAE J1626-1 Issued JUN2009 Page 5 of 22 4.8 Decelerometer or equivalent device to measure vehicle deceleration rate, 1G range with 0.5 fpsps (feet per second per s
39、econd) accuracy at 32.2 fpsps, maximum non-linearity of 0.5 fpsps over the range, and visual output resolution of 0.5 fpsps. 4.9 Solenoid valve(s) with a 0.5 (+0.1/-0.0) in diameter ports and/or with equivalent exhaust capacity to deplete the reservoir with the air compressor charging at engine RPM
40、to attain vehicle test speed. 4.10 Pressure, 1.0% of the indicated value, for measuring brake control pressure and system pressure. 4.11 Static Retardation Force (Drawbar Pull) Parking Brake Test Refer to SAE J1729 for required instrumentation and equipment. 4.12 Grade Holding Parking Brake Test Ref
41、er to SAE J360 for required instrumentation and equipment. 4.13 Weighing scales, 1.0% of indicated weight. 4.14 A continuous recorder, ie, an oscillograph or computer utilizing a digital data acquisition system and/or equivalent system, to make a permanent, supplemental record of service brake pedal
42、 force, parking brake force, deceleration, lockup, distance and speed versus time, with the same accuracies as the above direct reading instrumentation or as otherwise indicated. 5. VEHICLE INFORMATION The vehicle information will be contained on Data Sheet 1. 6. TEST CONDITIONS AND FACILITIES 6.1 A
43、mbient air temperature must be between 32 and 100 F. 6.2 Wind velocity should not exceed 15 mph. Stops must not be performed with a tail wind component in excess of 5 mph. 6.3 Unless otherwise specified, the transmission shall be in the highest gear appropriate for a speed of 40 mph during burnish s
44、nubs and test stops conditioning. 6.4 All vehicle openings (doors, windows, hood, etc.) must be closed except as required for instrumentation purposes. 6.5 Unless otherwise specified, the brake control can be applied and modulated at any desired rate. 6.6 Service and emergency stopping distance test
45、s are conducted on a straight 12-ft (+0/-2 in) wide roadway with a PFC no greater than 0.9 (dry Portland cement concrete or equivalent surface). The vehicle shall be aligned with the center of the roadway at the beginning of each stop. The roadway shall be marked on both sides. 6.7 Stability and con
46、trol tests are performed on a 12-ft (+0/-2 in) wide lane curved on a 500-ft radius (to lane centerline) on a surface with a PFC no greater than 0.5. The arc length must be at least 300 ft. A 100-ft approach to the arc is recommended to properly align the vehicle to the lane. Lane boundaries are defi
47、ned by 12 to 18 in high vertical markers (such as cones) on a 20-ft spacing with the inside edge of the markers placed on the 12-ft wide lane boundaries. 6.8 For truck tractor tests that utilize the control trailer, a 50 in3 reservoir shall be attached to the tractors control glad-hand. Tractor prot
48、ection valve to be in the bobtail position for bobtail tests and the towing position for towing the control trailer. 6.9 Roadway shall be flat with no more than a 1% grade in all directions, including crown. SAE J1626-1 Issued JUN2009 Page 6 of 22 6.10 Tires must be inflated to the pressure specifie
49、d by the vehicle manufacturer for the gross vehicle weight rating, measured cold (at the beginning of each test day). 6.11 Initial Brake Temperature (IBT) Reference 3.10 for definition. The IBT must be between 150 and 200 F for each stability and control, service, emergency stops and parking brake tests. Warm brakes to the required temperature by making 40-20 mph snubs at 10 fpsps. 6.12
