Hydraulic servo brakes with ABS control - has variable flow restriction to modulate inlet side of servo pump to reduce brake pedal vibrations.

摘要

The ABS system has a pressure modulation valve (10) between a master brake cylinder (9) and wheel brakes (4), and a second pressure modulation valve (11) which vents brake pressure into a reservoir (1). The reservoir feeds a servo pump (2) via a variable flow restriction (3) which operates in relation to a filled volume of the reservoir. The flow restriction comprises a tapered shaft attached to a piston (8) operating against a return spring (12). The shaft slides in and out of an outlet duct (6) and closes it completely when the reservoir is empty. The venting duct from the wheel brakes to the reservoir leads directly to the reservoir. ADVANTAGE - Reduces vibrations to brake pedal, no separate control valve required.