Influence of operating factors on the efficiency of the vehicle brake system

Abstract

The main system responsible for the safety of the car is its braking system. The efficiency of the braking system is assessed by several parameters, the main of which is the maximum braking force, which is generated in the braking mechanisms, usually it is disc or drum types of brakes. The analysis of peculiarities of designs of existing types of brakes of cars is carried out, advantages and disadvantages of each of them, characteristics of application and maintenance are substantiated. The main factors that have a significant impact on the efficiency of the car's brake system have been identified. It was carried out the research of the influence of the main operational factors on the efficiency of the car's brake system: the pressure in the car's tires, contamination, and friction pairs of the brake mechanisms. The method of conducting experimental test lane and road researches of influence of the chosen factors on indicators of braking efficiency of the car is developed. Test lane experimental studies were performed using the Bosch BSA 4340 brake test equipment, graphs of changes in the braking efficiency of each of the car's wheels based on the researches were built, depending first on the change in tire pressure, then on the presence of rust, grit, and grime and level of wear of mechanisms. The quantity of the maximum braking force of the car depending on three quantities of pressure in tires of wheels was identified: the pressure recommended by the factory of 0,18 MPa, the lowered and increased pressures 0.15 and 0.25 MPa respectively. The influence of motor oil caught in the brake mechanism or treatment with special pastes on the value of the maximum braking force is also determined. The influence of the state of the brake discs and pads on the braking efficiency of the car was also investigated, the braking indicators were measured before and after the replacement of the brake disc and pads. On the basis of the conducted test line and road researches, conclusions are made and practical recommendations on prevention of reduction of brake efficiency of the car in the conditions of operation are offered.