DETERMINATION OF THE DISC BRAKE FRICTION MOMENT (FUNCTIONAL CALCULATION)

Abstract

The safety of a wheeled vehicle movement (vehicle, tractor, motorcycle, etc.) depends on the braking system, the main components of which are brake mechanisms. In modern wheeled vehicle brake systems both disc and drum brakes are used, depending on the purpose and the operating conditions. As most of the passenger vehicles and motorcycles are operated in good road conditions and the production of which is many times greater than of all other machines they are generally equipped with disc brakes on all wheels. Keeping in mind that the vehicle has 4 wheels, and the motorcycle has 2 wheels, with its front wheel equipped with two disc brakes, it should be concluded that the disc brake is the most mass mechanism of a modern wheeled vehicle. Designing a disk brake with the required properties is impossible without considering the conditions of its operation. Since it is the main mechanism of the braking system and one of the systems that provides traffic safety, its correct functional calculation is of great social and national economic importance. In the existing methods for calculating disc brakes, it is believed that the specific pressure in the places of contact between the disc and the lining of the pads is constant. But the carried out study of operational wear of friction linings (disk brake lining pads, pads of the clutch single-disk and dual-disks) have theoretically proven that the assumption of a constant pressure on the area of friction lining is wrong. The formula obtained on this assumption (p = const) is unreasonably complex, though it is widely used in the literature and in the auto industry. It is proposed to perform a functional calculation of the disk brake according to an extremely simple formula obtained from the kinematics of the shoe during braking, which assumes that p ≠ const and it is confirmed by operational wear and experiment.