INFLUENCE OF VERTICAL LOAD ON BRAKING FORCE AND TYRE ADHESION COEFFICIENT OF VEHICLE WHEEL

Abstract

Influence of vertical load on the adhesion coefficient of automobile wheel in the braking mode on the basis of experimental researches is analyzed. Research results of different authors concerning the degree of the influence of various factors on the adhesion coefficient are presented. It is known that the fundamental basis of vehicle active safety is its braking properties, and the nature of braking depends on the interaction of motorcar tires with road surfaces. Such interaction in the theory of a car is usually described by the adhesion coefficient, which can be implemented both in the longitudinal and transverse directions relative to the rotation area of the vehicle wheels. Experimental researches on rolling car wheel of locking border have demonstrated that a high change of filling speed of the brake chamber does not contribute to increasing the braking efficiency and consequently, the work of the modulator in the mode of intensive filling of brake chamber makes no sense. Vice versa, as experimental researches have demonstrated, the reduction of filling rate of the brake chamber increases the efficiency of braking, although at the initial moment of time, due to the low braking torque, the efficiency is slightly underestimated. Considering the inconsistency of the adhesion coefficient in automotive practice will allow modeling dynamics of vehicle inhibition with automatic regulation systems at a higher level and with greater reliability. Increasing the vehicle mass leads to a decrease in the coupling properties of its tires and consequently to reduce the amount of deceleration, reducing its mass, vice versa increases the coupling properties between the tire and support surface, which positively affects the performance of the vehicle braking (its slowing increases).