SAE J 1232-1978 Passenger and Light Truck Tire Traction Device Profile Determination and Classification.pdf

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.TO PLACE A DOCUMENT ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.s

3、ae.orgCopyright 2000 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 StandardJ1232REAF.SEP2000Issued 1978-07Reaffirmed 2000-09Superseding J12

4、32 JUL1978Passenger and Light Truck Tire Traction Device Profile Determination and ClassificationForewordThis Document has not changed other than to put it into the new SAE Technical Standards BoardFormat. References added as Section 2. All other section numbers have changed accordingly.1. ScopeThe

5、purpose of this SAE Recommended Practice is to set up a guide as to body, frame, andwheelhouse clearances required to accommodate tire traction devices (e.g., tire chains), and to provide ameans of classifying these devices according to their maximum profile. In addition, it enables the vehiclemanuf

6、acturer to specify the proper traction devices for each vehicle.This report is intended to apply to passenger cars and light trucks up to 4535 kg (10 001 lb) GVW. Thisdocument is not to be construed as approving traction device operation at conditions exceedingmanufacturers specifications, although

7、short periods of such operations may be required for test purposes.2. ReferencesThere are no referenced publications specified herein.3. Equipment3.1 Test VehiclePassenger car or light truck capable of running a tire of a size recommended by the tractiondevice manufacturer for the size of a traction

8、 device under consideration. A light truck with rear fenders andbed removed is a convenient test vehicle. Static vertical load on the tire shall be from 85 to 95% of the testtires T&RA (Tire and Rim Association) load at 180 kPa (26 psig) cold, or vehicle manufacturersrecommendations. All road testin

9、g should be conducted on smooth, hard surfaced roads.3.2 Profile Measurement (Method 1)A means of measuring the dynamic profile of the traction device and tiremust be provided. A high speed (500 frames per second minimum) motion picture camera has provensatisfactory. The center of the lens system sh

10、ould be placed on the intersection axis of a maximum sidewallplane and a plane normal to the sidewall plane containing the maximum tire radius (point C, Figure 1). Thecamera may be pivoted about the lens center to show a profile view of at least the sidewall, half the tread, andthe traction device.

11、Appropriate measurement scales should appear in the framing for scaling the fly-off.These scales should be in the radial tire plane incorporating the tire section of interest. Generally, the largestprofile will be obtained at the rear of the tire. Figure 2 shows a typical test setup.3.3 Profile Meas

12、urement (Method 2)An alternate method involves moving guided abradable material (e.g., a25 mm (1 in) thick plank of 2.4 to 3.2 kg/m3(1.5 to 2 lb/ft3) rigid polyurethane foam) into the rotating tireagainst a stop. The guides become part of the unsprung mass and must be rigidly attached to the axlesup

13、port. After being sculptured by the traction device, the running clearance can be measured statically.Figure 3 shows a typical test setup.SAE J1232 Reaffirmed SEP2000-2-FIGURE 1PASSENGER TIRE CHAIN DYNAMIC PROFILECONSTRUCTION (TYPICAL CROSS-SECTION)FIGURE 2SAE J1232 Reaffirmed SEP2000-3-FIGURE 34. T

14、raction Device InstallationAll traction devices shall be new or with less than 5 km operation. Tractiondevices should be installed to the same degree of fit that can reasonably be expected in the field. Thefollowing procedures are designed to accomplish this. Deflation or tools not furnished by the

15、device or vehiclemanufacturer are not allowed. Before installing, lay the traction device flat and remove any twists or kinks.4.1 Traction Devices with Incremental AdjustmentTraction devices with incremental adjustment should beinstalled in accordance with the manufacturers instructions, driven 0.1

16、km or more, and adjusted as tightly aspossible. When this full tight condition is obtained, each side member shall be loosened one increment to theone link loose configuration. The test is conducted at this one link loose condition. Side member asymmetryshould be a maximum of one increment with the

17、looser member on the outside of the tire. Dangling endsshould be secured to the side members or handled per manufacturers instructions.4.2 Traction Devices with Infinitesimal AdjustmentIn accordance with manufacturers instructions, center thecross members on the tire with equal drape on each shoulde

18、r making sure that each cross member is lying flat.Close the fasteners and take up all slack. Drive 0.1 km or more and retighten.SAE J1232 Reaffirmed SEP2000-4-5. Data Analysis5.1 Photographic MethodA stop motion film analyzer provides a convenient method of analyzing the results.Picture image size

19、should be set to some easy ratio with the real scales, such as 1:1. Then the tire profile istraced and the maximum tire chain dynamic profile laid in per Figure 1. It is then easy to determine if any of thechain profiles penetrate the maximum permissible profile by overlaying the tracing on the scre

20、en and steppingthe film slowly to examine each frame.5.2 Rigid Foam MethodThe rigid foam can be traced on paper and compared with a tracing of the base tiretested under the same conditions. Measurement should be made as soon as possible after foam is sculpted toinsure accuracy. (Foam may have dimens

21、ional instability.)6. ClassificationA target profile is constructed according to Figure 1. (Note: Maximum permissible profilesare presented in table on Figure 1.) Traction devices may be labeled “SAE Class _” if they meet thefollowing profile requirements at 70 km/h in a straight path.SAE Class STra

22、ction devices that do not penetrate Profile S.SAE Class UTraction devices that do not penetrate Profile U.SAE Class WTraction devices that do not meet the requirements of other classes.PREPARED BY THE SAE HIGHWAY TIRE FORUM COMMITTEESAE J1232 Reaffirmed SEP2000RationaleThis Document has not changed

23、other than to put it into the new SAE Technical Standards BoardFormat. References added as Section 2. All other section numbers have changed accordingly.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThe purpose of this SAE Recommended Practice is to set up a guide as to body,

24、 frame, andwheelhouse clearances required to accommodate tire traction devices (e.g., tire chains), and to providea means of classifying these devices according to their maximum profile. In addition, it enables thevehicle manufacturer to specify the proper traction devices for each vehicle.This repo

25、rt is intended to apply to passenger cars and light trucks up to 4535 kg (10 001 lb) GVW. Thisrecommended practice is not to be construed as approving traction device operation at conditionsexceeding manufacturers specifications, although short periods of such operations may be required fortest purposes.Reference SectionThere are no referenced publications specified herein.Developed by the SAE Highway Tire Forum Committee