Patent ID: 8807667

Claim:
A hydraulic brake system comprising: a master cylinder forming a braking hydraulic pressure according to an operation of a brake pedal; wheel brakes provided in front and rear wheels of a vehicle to receive the braking hydraulic pressure of the master cylinder and exert a braking force; a first hydraulic circuit controlling an oil pressure transmission by connecting a first port of the master cylinder and two wheel brakes; a second hydraulic circuit controlling an oil pressure transmission by connecting a second port of the master cylinder and remaining two wheel brakes; a hydraulic block communicating main passages of the first and second hydraulic circuits with each other, the hydraulic block being provided with a communication passage having one side opened, such that the first and second hydraulic circuits pass through the communication passage; a pump mounted on one side of each of the main passages, with reference to the hydraulic block, to discharge oil through the hydraulic block toward the wheel brake or the master cylinder; an orifice mounted on each of the other side of the main passages, with reference to the hydraulic block; and a damper assembly including: a housing coupled to the inner periphery of the communication passage and mutually communicating with the main passages; a cap sealing the opened side of the communication passage and mounted on the hydraulic block; a piston embedded into the housing and reciprocating in the communication passage; a spring mounted on each end of the piston to elastically support the piston between the cap and the closed side of the communication passage; and a guide mounted on the inside of the cap on the closed side of the communication passage to restrict an operating displacement of the piston or reduce noise caused by shock, wherein the damper assembly further includes a plurality of communication holes that penetrate perpendicular to a reciprocating direction of the piston and connected to the first and second hydraulic circuits, and a hollow, that is a recessed space at each end of the piston in a longitudinal direction of the damper assembly in the housing, in which each spring is disposed to support each end of the piston, and communicating with the first and second hydraulic circuits and having a variable depth to restrict the operating displacement of the piston.