Patent ID: 6264287
Filing Date: 2001-07-24
Classification: B60T

Abstract:
A hydraulic brake apparatus for a vehicle comprising:wheel brakes for applying a braking force to road wheels of the vehicle in response to hydraulic pressure supplied to the wheel brakes;a reservoir for storing brake fluid;a master cylinder for pressurizing the brake fluid supplied from the reservoir in response to operation of a brake pedal and for discharging the pressurized brake fluid from the master cylinder;a hydraulic pump for pressurizing the brake fluid supplied from the reservoir through the master cylinder and for discharging the pressurized brake fluid from the hydraulic pump;a hydraulic passage for supplying the pressurized brake fluid from the master cylinder to a suction side of the hydraulic pump;a valve positioned in the hydraulic passage for opening and closing the hydraulic passage; anda passage area adjusting device disposed in the hydraulic passage, said passage area adjusting device including a cylinder in which is positioned a piston, said cylinder communicating with an outlet, said piston being provided with a first bore portion and a second bore portion having a smaller cross-sectional area than the first bore portion, said piston being normally urged towards a first position in which brake fluid flows to the outlet by way of the first bore portion and being movable to a second position by hydraulic pressure in the hydraulic passage in which brake fluid flows to the outlet by way of the second bore portion to suppress transmission of hydraulic pulsation generated in the suction side of the hydraulic pump to the master cylinder when the brake pedal is depressed.