SAE J45 pdf download

SAE J45 pdf download.Brake System Test Procedure-Snowmobiles.
1. This SAE Recommended Practice establishes a uniform procedure for the level surface testing of hand-operated brake systems On recreational noncompetitive snowmobiles.
1.1 Purpose—This procedure offers a method of testing snowmobiles on turf. Turf is preferred over snow because test repeatability is more easily obtained. In addition, tests shall be conducted under winter conditions to ensure that the braking systems remain operative and that the vehicle has no undue tendency to lose stability, overturn, or swerve out of a test lane 1.2 m (4 if) wider than the vehicle when the brakes are applied. The purpose of the document Is to establish brake system capabilities with regard to deceleration or stopping distance versus applied brake lever force, as affected by vehicle speed, brake temperature, and usage.
2. References
2.1 Related Publications—The following publications are provided for information purposes only and are not a required part of this document.
2.1.1 SAE Pi.mucATIoNs—Available froni SAE. 400 Commonwealth Drive, Warrendale, PA 15096-0001.
SAE J44—Service Brake System Performance Requlrenients—Snown’iobiles
SAE J 1 282—Snowmobile Brake Control Systems
2 1.2 SSCC Pueuc4 oN—Available from Snowmobile Safety and Certification Committee, 271 Woodland Road, East Lansing, Ml 48823.
SSCC 52—Snowmobile Brake Control Systems (Part of SSCC 11—Safety Standards for Snowmobile Product Certification)
3. Definitions
3.1 Brake Lever Force—A steady force applied in a direction normal to the handle grip in the plane of rotation of the hand brake lever at a distance no more than 25.4 mm (1 in) from the end of the control lever. Refer to 5.3.3.
3.2 Deceleration— Average rate of change of vehicle speed during stopping time, Numerically equal to the initial vehicle speed divided by the stopping time. Does not denote instantaneous deceleration at some time during brake application.
5.3 Test Conditions
5.3.1 TEST SURFACE—Tests shall be conducted on a substantially level (not to exceed f 1% grade), dry turf. The turi shall not exceed 76 mm (3 in) in height. The coefficient of sliding Inction between the test surface and the loaded vehicle with its track locked should be established to be within the range of 0.55 to 0.75. When repeated testing results In vIsible deterioration of the test surface, testing should be moved to a new, unused area.
5.3.2 AMBIENT Am TREATMENI—Ambient air temperature for all tests shall be between —7 and 27 °C (20 and
80F).
5.3.3 BRAKE LEVER FoRcE—The brake force shall be applied in a manner equivalent to that shown in Figure 1. The effective brake lever force shall be applied at a point no more than 25.4 mm (1 in) Irom the end of the control lever m a direction normal to the hand grip and in the plane of rotation of the control lever.
TEST SPEED—Vehicles shall be tested at the specified speed for each test. If the specified speed cannot be obtained, the test speed shall be the greatest achievable speed evenly divisible by 8 km/ti (5 mph). (For example: if 61 km/h (38 mph) is the maximum speed achievable, the test speed for the 64 km/h (40 mph) requirement would become 56 km/h (35 mph).) If the maximum achievable speed is less than 8 km/h, the test speed shall be 5 km/h (3 mph).
5.4 Test Observations
5.4.1 During all phases of testing, any unusual performance such as grab, noise, or track skid is to be noted and recorded. Also note and record any uncontrollable braking action causing the vehicle to lose stability. overturn, or swerve out of a test lane 1.2 m (4 fI) wider than the width of the vehicle.
5.4.2 Using stopping distance or stopping time as the test methods, deceleration shall be determined by Equations 3 and 4.