Due to frequent road traffic incidents, test vehicles fitted with measuring equipment were not allowed on roads in Japan until now.
To increase safety, Japan’s Ministry of Land, Infrastructure, Transport and Tourism has introduced the Japan Light Alloy Wheel (JWL) standard. Authorization for operation in road traffic can only be obtained by meeting the requirements of the standard.
After extensive testing, Kistler’s RoaDyn S635 wheel force transducer has become the only wheel force transducer to obtain JWL certification.
To comply with the JWL standard, the wheel force transducer had to undergo three extensive tests to ensure it meets the need for fatigue strength, mass and moment of inertia. The electronics and telemetry also underwent EMC testing.
A rotating bending test was also carried out, involving simulation of the rotary forces and moments to which the wheel is subjected during driving. For this purpose, a clamping device on the inner rim flange was used to clamp the entire wheel force transducer (comprising the load cells, structural elements and aluminum rim) rigidly onto the test machine.
The transducer was then exposed to a rotary bending moment over the wheel mounting surface. Then, after 100,000 cycles, a rolling test was carried out for 500,000 cycles on a test rig. In the final 13° impact test, the wheel disk was placed on the mounting plate, fixed and inclined by 13°. A free-falling weight was dropped onto the edge of the rim flange, and the wheel was examined for cracks, deformations and air leaks.
After each of the three tests, a dye penetrant inspection (DPI) was carried out to check for cracks.
August 2, 2017
