Patent ID: 6464307
Filing Date: 2002-10-15
Classification: B60T

Abstract:
An automotive hydraulic pressure brake system comprising a master cylinder for producing hydraulic pressure corresponding to a force applied to a brake pedal, a reservoir, wheel cylinders, a pump having a suction port connected to said reservoir through a first fluid line and an outlet port connected to said wheel cylinders through a second fluid line, an electric power source for supplying electric power to said pump, an on-off valve provided in a third fluid line connecting said master cylinder to said wheel cylinders, said second fluid line being connected to said third fluid line at a first point between said on-off valve and said wheel cylinders, a bypass line branching from said third fluid line at a second point between said master cylinder and said on-off valve and joining said second fluid line at a third point, a check valve or a relief valve provided in said bypass line for allowing only a fluid flow from said master cylinder toward said wheel cylinders, a shut-off valve provided in said bypass line in series with said check valve or relief valve, and an electronic control unit for keeping said on-off valve closed while said electric power source is functioning normally at least while the brake pedal is being depressed; and wherein said bypass line forms a fluid connection between said master cylinder and said wheel cylinders without passing through said pump.