The substantiation of the selection of diameter rollers of inertial brake stand

Abstract

As you know, the brake test bench with the inertia test allows you to perform a qualitative check of the car's service braking system. For an inertial bench, compactness, low metal content and simplicity are important factors. The fulfillment of these requirements is ensured by the following design parameters of the stand: the layout of the rollers, the coefficient of adhesion of the tire and the roller, the value of the reduced inertial mass of the stand. In order to test the functionality of the roller stand, an experiment was carried out in real working braking regimes. To solve this problem, sets of interchangeable rollers having different diameters were manufactured. The procedure for determining the maximum braking force was to measure the maximum deceleration on these rollers. To increase the accuracy of the measurements, the actual moments of inertia of the interchangeable rollers were determined by the experimental calculating method of bifilar suspension. Based on the results of the experiment with interchangeable rollers, a plot was constructed of the dependence of the load utilization factor on the relative diameter of the roller. The obtained experimental results on the whole confirm the assumptions about the expediency of reducing the diameter of the rollers. Rolls made of silumin alloy showed good values of load utilization factor. This is due to a higher coefficient of adhesion of rubber with aluminum. However, the disadvantage of such rollers is a soft surface, which quickly wears out an abrasive in the tire tread. It should be noted that the use of rollers of smaller diameter gives a significant gain in metal consumption at the same required inertial mass of the rotating parts of the stand. The limitation here is the possible maximum rotational speed of the drive shaft to achieve the re-quired test speed.