Теоретичні дослідження силової взаємодії тривісного автомобіля зі стендом з одиночними роликами

Abstract

The article discusses the issues of modeling conditions for obtaining diagnostic information about complex objects. Checking the braking and traction properties of three-axle trucks on a roller stand is considered as an example. As shown by many studies, in particular, which were carried out at the Department of Technical Operation and Service of Automobiles of the KhNADU (HADI), inertial stands provide more reliable information about the technical condition of the car. Such stands allow you to reproduce the real speed and thermal conditions of the brakes. To improve the accuracy of diagnosing a car on a roller stand, it is necessary to have an idea of the nature of the interaction of the car's wheels with the rollers. The study of the rolling of the wheels of a three-axle car bogie on the stand rollers was carried out at the Department of Technical Operation of Cars, KhNADU. However, all these studies were carried out on biaxial stands, where each bogie wheel rests on a pair of rollers. In order to exclude wheel slippage, partial braking is recommended, that is, a mode when partial force on the pedals (or pressure) is created in the system and, as a result, incomplete braking force develops in the braking mechanisms (or deceleration reaches some partial value from the full one). It is necessary to analyze the possibility of implementing full brake test modes on a roller stand by improving the layout and geometrical scheme of the stand. A power model of the system of interaction between a car and a stand has been developed, taking into account the design features of the stand and the design features of the suspension of a three-axle car. The power model of this system includes the equations of equilibrium of the body and two axles, as well as the equations of motion for the rollers and wheels of the car. Based on the results of the analysis of the acting forces in the "car-stand" system, the coefficients of the use of the load q during the brake tests of a three-axle car were determined, and the longitudinal stability of the car was also analyzed. The obtained research results allowed to improve the theory of interaction of the wheels of three-axle vehicles with single rollers of the diagnostic stand.