Self-energizing vehicle brake system with control arrangement for eliminating brake pad friction fluctuation affects

Abstract

A hydraulic brake system for braking a vehicle wheel includes a hydraulic fluid source, a pump connected to the hydraulic fluid source for pumping hydraulic fluid based on operation of an operating member of the vehicle and a connecting arrangement having one end connected to the pump. A wheel cylinder which is adapted to be mounted adjacent a brake disk of a vehicle wheel includes a brake pad element for being urged against the brake disk upon the application of a hydraulic fluid pressure to impart a braking force to the brake disk. The brake pad element is movable with the brake disk when the brake disk element is urged against the brake disk. In addition, a movable pressure increasing element is positioned adjacent the brake pad element and is movable away from the brake pad element as a result of the brake pad element moving with the brake disk. As a result, an increase in pressure in the wheel cylinder arises in a relatively rapid manner to compensate for compliant characteristics in the braking system and thereby result in a brake system having an improved reaction time. The pump is computer controller so that the hydraulic fluid pressure in the wheel cylinder is maintained at a target level regardless of fluctuations in the brake pad friction coefficient. This eliminates the affects associated with brake pad friction fluctuations to thereby provide a substantially constant brake force.

Dependencies are inferred from the claim text.