MESSUNGEN VON KRAFTEN AN GELENKTEN, NICHT ANGETRIEBENEN REIFEN (MEASUREMENTS OF FORCES ON STEERED, TOWED WHEELS)

摘要

A test rig consisting of a rigid frame with a steerable wheel mounted at the back of an off-road vehicle (Unimog) is described. The wheel and the axle are fixed with a spherical bearing on the frame. At drift angles from 0° to 30° the towing forces in travel direction are measured by a force transducer in a pulling rope, the lateral force by two membranes and also a force transducer. The tire load is varied by adding weights from 1000 to 8000 N. With two different front axle tractor tires with a profile of a rolling and driven wheel, rolling resistance and side force are measured at different drift angles and wheel loads. Results are presented for experiments on asphalt road, dirt road respectively field path, meadows, gravel, tilled and plowed field. Analytical curves for mean side force and rolling resistance coefficients on different ground configurations are given. The measurements allow the designer of off-road vehicles to determine the necessary front axle loads for satisfactory steering behavior on tractors operating with eccentric traction. Also the drift angle of vehicles driving on a slope in direction of contour line can be determined. At last the results are useful for simulation of driving behavior of terrain vehicles on the computer.