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 entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, 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.QUESTIONS REGARDING THIS DOCUMENT: (412) 772-8512 FAX: (412) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (412) 776-4970 FAX: (412) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1993 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001RECOMMENDEDPRACTICESubmitted for recognition as an American National Sta
4、ndardJ46REAF.OCT93Issued 1973-07Reaffirmed 1993-10-18Superseding J46 JUN80WHEEL-SLIP BRAKE-CONTROL SYSTEM ROAD TEST CODEForewordThis reaffirmed document has been changed only to reflect the new SAE Technical Standards Boardformat.1. ScopeThe test code establishes wheel-slip brake-control system capa
5、bilities with regard to:1.1 Vehicle stability, maneuverability, and system function on various road surface conditions, including variablefriction surfaces as well as uniform friction surfaces.1.2 Vehicle stopping distance on various road surface conditions.1.3 Not covered by this SAE Recommended Pr
6、actice are:a. Radio frequency interference testingb. Extensive power consumption testing1.4 PurposeThis document establishes a uniform procedure for the road test of wheel-slip brake-controlsystems on passenger cars, trucks, buses, and combination vehicles.2. ReferencesThere are no referenced public
7、ations specified herein.3. Instrumentation and Equipment3.1 Decelerometer.3.2 Brake temperature instrumentation.3.3 Vehicle velocity and wheel-speed instrumentation.3.4 Odometer.3.5 Tire pressure gage.3.6 Stopping distance instrumentation.3.7 Vehicle yaw measuring device.SAE J46 Reaffirmed OCT93-2-3
8、.8 Articulation restraints for trailers (optional where applicable).3.9 Means for disabling wheel-slip control system.3.10 System pressure instrumentation (optional where applicable).3.11 Vehicle stabilizer (optional when needed for vehicle stability).3.12 Means to designate the point at which the b
9、rakes are applied (such as a detonator).4. Facilities3.7 m (12 ft) wide road surfaces of various friction levels are required with sufficient space on allsides for approach, spin-out, and recovery conditions. See Figures 1, Figure 2 and Figure 3.4.1 Road surface description and suggested (guidelines
10、 only) lengths of uniform surface facilities assuming that allthe brakes are working normally and the maximum speed is as indicated in Table 1.4.2 Pylons as required.5. Vehicle Preparation5.1 Inspect the brake-friction elements and replace if over 25% are worn or if any abnormal condition exists.Sev
11、erity of test sequences may require frequent checks to avoid overadjustment of the brakes.5.2 Install and calibrate equipment. See Figure 4 for brake thermocouple installation method.5.3 Install ballast if necessary to simulate the desired vehicle loading condition.5.4 Inspect tires and replace if a
12、n objectionable wear condition exists. Adjust tire pressure per vehiclemanufacturers load recommendations on vehicles 4500 kg (10 000 lb) GVWR or under. For vehicles withGVWR greater than 4500 kg (10 000 lb), use maximum vehicle manufacturers recommended pressure.5.5 On vehicles equipped with adjust
13、able power systems, adjust the system to maximum recommended cutoutpressure.5.6 On articulated vehicles, install articulation restraints.TABLE 1MAXIMUM SPEEDSurfaceSuggestedLengthmSuggestedLengthftAssumed Max (1)Speedkm/h1. Recommend moving up to speed in steps.Assumed Max(1)SpeedmphVery low frictio
14、nsmooth ice or equivalent 122 400 32 20Low frictionwet jennite or equivalent 122 400 48 30Medium frictionwet asphalt or wet concrete 91 300 64 40High frictiondry asphalt or dry concrete 122 400 97 60Specialgraded loose gravel 76 250 48 30SAE J46 Reaffirmed OCT93-3-FIGURE 1SPLIT-FRICTION SURFACE TEST
15、 FACILITYFIGURE 2CHANGING-FRICTION SURFACE TEST FACILITYFIGURE 3LANE CHANGE TEST FACILITY (LOW-FRICTION SURFACE)SAE J46 Reaffirmed OCT93-4-FIGURE 4TYPICAL PLUG THERMOCOUPLE INSTALLATIONS6. General Notes6.1 During all phases of this procedure, note and record any unusual braking or handling character
16、istics of thevehicle, such as sustained lockup of a controlled wheel, activation of a warning signal, application of asecondary or parking brake system, excessive lateral deviation, etc.SAE J46 Reaffirmed OCT93-5-6.2 Initial Brake TemperatureThe brake temperature occurring within 0.32 km (0.2 mile)
17、of initiating the stop(average temperature of brakes on hottest axle, brakes off).6.2.1 When not otherwise specified, initial brake temperature shall be 66 to 93 C (150 to 200 F).6.3 On vehicles so equipped, charge the system power supply pressure (vacuum) to maximum before each teststop and note th
18、e system pressure (vacuum) at the end of the stop.6.4 Brake applications are to be made in normal driving gear. On vehicles with manual transmission, disengagethe clutch.6.5 Stopping Distanceis defined as the distance traveled between the point at which the driver starts to movethe braking control a
19、nd the point at which the vehicle comes to rest. Since stopping distance on a given roadsurface varies approximately as the square of initial speed, comparative checks will require that the vehiclespeed at which the brake control is initially moved be within 1% of the nominal value for each test con
20、dition.Alternatively, speed variation up to a suggested maximum of 5% can be tolerated by multiplying eachmeasured stopping distance by the square of the initial speed ratio (nominal speed/actual speed).6.6 Vehicle “Yaw“is defined as the vehicles angular deviation between the point at which the brak
21、e control isactuated and the point at which the vehicle comes to rest. (That is, one complete revolution in clockwisedirection would be a yaw of +360 degrees, while a quarter of a revolution in the counter-clockwise directionwould be 90 degrees.) For combination vehicles, the yaw angle of each vehic
22、le is to be noted.6.7 Vehicle lateral deviation is defined as the greater of the distance between a reference point on the front and therear of the vehicle at the longitudinal centerline and the centerline of the lane in which a stop is to becompleted. For combination vehicles, the lateral deviation
23、 of each vehicle is to be noted.6.8 Vehicle deceleration is defined as the value at which the decelerometer is nearly constant for the majority ofthe stopping distance on any given surface condition.6.9 Steering corrections may be made during tests.6.10 Unless otherwise specified, vehicle testing is
24、 to be conducted at unloaded and loaded GVWR conditions.6.11 Clear tires of stones and foreign material except where not possible for special surfaces.6.12 Brake pedal application shall be made as rapidly as possible for each test.7. Procedure7.1 For vehicles with new linings and drums or with brake
25、s giving inconsistent results, burnish brakes as follows:7.1.1 For passenger cars and vehicles 4500 kg (10 000 lb) GVW and under, burnish brakes by making at least 200stops from 64 km/h (40 mph) at 3.7 m/s2 (12 ft/s2). Stop interval shall be as required to achieve121C(250F).NOTE The 1.6 km (1 mile)
26、maximum must be observed even though the initial temperature exceeds121C (250F).SAE J46 Reaffirmed OCT93-6-7.1.2 For vehicles over 4500 kg (10 000 lb) GVW, make 500 brake applications (transmission in neutral or clutchdisengaged) in accordance with Table 2. When, during any series, the hottest brake
27、 reaches260C(500F), continue at that snub condition for an accumulated total of 500 burnish snubs, except that ahigher or lower energy snub condition shall be followed when necessary to maintain a temperature of260C 10 C (500 F 50 F). Record temperature immediately following each snub.7.1.3 After bu
28、rnishing, adjust brakes per manufacturers specifications.7.2 Constant Friction Surface TestRecord vehicle stopping distance, final lateral deviation, and yaw whilemaking the indicated number of rapid application stops for each of the speed and constant friction surfaceconditions listed as follows. A
29、lternate on and off stops, sampling both directions if two directions are used.The number of stops is the suggested minimum. Safety considerations may warrant deletion of hazardous “off“stops.7.2.1 Four stops “on“ and four stops “off“ from 32 km/h (20 mph) on a very low-friction surface (if availabl
30、e).7.2.2 Four stops “on“ and four stops “off“ from 32 km/h (20 mph) on a low-friction surface.7.2.3 Four stops “on“ and four stops “off“ from 48 km/h (30 mph) on a low-friction surface.7.2.4 Four stops “on“ and two stops “off“ from 32 km/h (20 mph) on a medium-friction surface.7.2.5 Four stops “on“
31、and two stops “off“ from 64 km/h (40 mph) on a medium-friction surface.7.2.6 Four stops “on“ and four stops “off“ from 48 km/h (30 mph) on a special-friction surface.7.2.7 Four stops “on“ and two stops “off“ from 32 km/h (20 mph) on a high-friction surface.7.2.8 Four stops “on“ and two stops “off“ f
32、rom 64 km/h (40 mph) on a high-friction surface. Optional for passengervehicles under 4500 kg (10 000 lb).7.2.9 Four stops “on“ from 97 km/h (60 mph) on a high-friction surface.TABLE 2BRAKE APPLICATIONSSeries SnubsSnub Conditions, at 1.6 km(1 mile) Intervals at3m/s2 (10 ft/s2)(or Maximum PossibleLes
33、s Than 10)km/hSnub Conditions, at 1.6 km(1 mile) Intervals at3m/s2 (10 ft/s2)(or Maximum PossibleLess Than 10)mph1 175 64 to 32 40 to 202 25 72 to 32 45 to 203 25 80 to 32 50 to 204 25 88 to 32 55 to 205 25 97 to 32 60 to 20SAE J46 Reaffirmed OCT93-7-7.3 Split Friction Surface TestRecord vehicle sto
34、pping distance, final lateral deviation, and yaw for eight rapidapplication stops from 32 km/h (20 mph) and eight from 64 km/h (40 mph), starting in line with and centered onthe split of two different friction surfaces (Figure 2). One side of the vehicle is to be on the very low- or low-friction sur
35、face, while the other side is to be on the medium- or high-friction surface used in 7.2. The high-friction surface should be at least twice the lower-friction surface as measured by locked wheel deceleration orstopping distance. Reverse stop direction each stop (that is, first stop with left side of
36、 vehicle on lower-frictionsurface, second stop with right side on lower-friction, etc.).7.3.1 Four stops “on“ from 32 km/h (20 mph) with lower-friction on left side.7.3.2 Four stops “on“ from 32 km/h (20 mph) with lower-friction on right side.7.3.3 Four stops “on“ from 64 km/h (40 mph) with lower-fr
37、iction on left side.7.3.4 Four stops “on“ from 64 km/h (40 mph) with lower-friction on right side.7.4 Changing Friction Surface TestRecord vehicle deceleration, final lateral deviation, and yaw for four rapidapplication stops from 64 km/h (40 mph) while traveling from one surface friction condition
38、to another (Figure3). One surface is to be very low- or low-friction, while the other is to be medium- or high-friction. The high-friction surface should be at least twice the lower-friction surface as measured by the locked wheel decelerationor stopping distance. Two stops are to be made on the low
39、-to-high friction surfaces and two stops on the high-to-low friction surfaces. The brakes are to be applied to achieve the friction transition at approximately three-fourths of the initial speed at the axle that is being tested.NOTE During high-to-low friction, watch for wheel lockup and during low-
40、to-high friction, watch fordeceleration rates that are appropriate for each surface.7.4.1 Two stops from 64 km/h (40 mph) on lower-to-high friction surfaces.7.4.2 Two stops from 64 km/h (40 mph) on high-to-lower friction surfaces.7.5 Lane Change Test, If ApplicableMake the lane change maneuver on th
41、e low-friction course detailed inFigure 3 with the vehicle in the unloaded condition.7.5.1 Drive through the lane change course at a constant speed without braking. Increase the speed for eachsuccessive drive through until the pylons are hit. Determine the maximum drive-through speed that the lanech
42、ange can be made without hitting any pylons for at least three of six consecutive identical drive-throughruns. Repeat if necessary. Record the speed for each of the six drive-through runs and the number ofpylons hit, if any.7.5.2 Drive to the brake application point of the lane change course at a co
43、nstant speed, make a rapid applicationstop, and steer through the course (Figure 3). Increase the initial braking speed for each successive brakingrun until the pylons are hit. Determine the maximum initial braking speed that the lane change can be madewithout hitting any pylons for at least three o
44、f six consecutive identical braking runs. Repeat if necessary.Record the initial braking speed for each braking run and the number of pylons hit, if any. Also recordapplication error, stopping distance, final vehicle lateral deviation, and final vehicle yaw. The brakeapplication error, E, must be wi
45、thin 1.5 m (5 ft) to be used in determining maximum braking speed.SAE J46 Reaffirmed OCT93-8-7.5.3 LANE CHANGE PERFORMANCEThe lane change performance is the ratio of the maximum braking speed, Vb,to the maximum drive through speed, Vd (see Equation 1):(Eq. 1)8. Report Forms8.1 Vehicle Information Sh
46、eet, Figure 5.P VbVd-=SAE J46 Reaffirmed OCT93-9-FIGURE 5VEHICLE INFORMATION SHEETSAE J46 Reaffirmed OCT93-10-8.2 Performance Test Data Sheet, Figure 6.FIGURE 6WHEEL-SLIP CONTROL PERFORMANCE TEST DATA SHEETSAE J46 Reaffirmed OCT93-11-8.3 Lane Change Test Data Sheet, Figure 7.FIGURE 7WHEEL-SLIP CONTR
47、OL LANE CHANGE TEST DATA SHEETPREPARED BY THE SAE TRUCK AND BUS ANTI-LOCK SUBCOMMITTEE OF THE SAE TRUCK AND BUS BRAKE COMMITTEESAE J46 Reaffirmed OCT93RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThe test code establishes wheel slip brake control syst
48、em capabilities with regard to:Vehicle stability, maneuverability, and system function on various road surface conditions, includingvariable friction surfaces as well as uniform friction surfaces.Vehicle stopping distance on various road surface conditions.Not covered by this SAE Recommended Practice are:a. Radio frequency interference testingb. Extensive power consumption testingReference SectionThere are no referenced publications specified herein.Developed by the SAE Truck and Bus Anti-Lock SubcommitteeSponsored by the SAE Truck and Bus Brake Committee
