INFLUENCE OF TYRE TREAD ON STEERING FORCES WITH NON DRIVEN TYRES ON HARD SURFACE

摘要

The paper shows the results of measurements about sideforce and rolling resistance of non driven tyres on hard surface of asphalt. There have been made experiments with 4 implement tyres 12,5/80-18 with different profile, a tractor front tyre 7.50-18 and a terra tyre 38×20.00-16 with the same diameter but greater width. The measured lateral forces have maximun values with a drift angle near 12 to 16 grades. For small loads the lateral force coefficient increased more in relation to drift angle, but decreased more with greater angles than for big loads. Tyres without tread profile have greater sideforce-coefficient S/W than tyres with high profile. The maximum sideforce-coefficients are 80% on tyres with-out profile and 50% on tyres with high profile. The terra tyre type gives great values of sideforces also on hard surface. The rolling resistance in relation to the slip angle is nearly the same for different treads. It increases nearly linearly from 1% to 3% on a straight line course to 30% on a drift angle of 30 degrees.