Anti-skid braking control system for use on motor vehicle

Abstract

An anti-skid braking control system for use on a motor vehicle having first and second wheels includes first and second wheel cylinders for braking the first and second wheels, respectively, with a braking medium pressure transmitted from a master cylinder, first and second solenoid-operated valves disposed in pipes interconnecting the master cylinder and the first and second wheel cylinders, respectively, for selectively providing communication between the master cylinder and the first and second wheel cylinders through the pipes, and first and second pumps connected to the pipes, respectively, for delivering a braking medium from portions of the pipes downstream of the valves to portions of the pipes upstream of the valves. The first and second pumps comprise a common housing, a common plunger slidably disposed in the common housing and reciprocally movable therein, and first and second pressure varying chambers defined by the plunger independently of each other and having respective volumes variable in response to reciprocating movement of the common plunger, the first and second pressure varying chambers having inlet ports, respectively, connected directly to the downstream portions of the pipes. When the anti-skid braking control system operates in an anti-skid braking control mode, the common plunger is reciprocally moved to enable the first and the second pumps to reduce the braking medium pressures in the first and second wheel cylinders independently of each other.