Patent ID: 8534772

Claim:
A hydraulic brake system, comprising: a master cylinder forming a braking hydraulic pressure according to an operation of a brake pedal; wheel brakes disposed 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 of the wheel brakes; a second hydraulic circuit controlling an oil pressure transmission by connecting a second port of the master cylinder and remaining two of the wheel brakes; a hydraulic block communicating main passages of the first and second hydraulic circuits with each other, the hydraulic block having a communication passage having one side opened, such that the first and second hydraulic circuits pass through the communication passage; a pump disposed on one side of each of the main passages, with reference to the hydraulic block, to discharge oil through the hydraulic block to the wheel brake side or the master cylinder side; an orifice disposed on each of the other side of the main passages, with reference to the hydraulic block; and a damper member, including: a piston embedded into the hydraulic block and reciprocating in the communication passage, the piston having stepped portions on both ends thereof such that a diameter of the stepped portions is smaller than a diameter of a central portion of the piston; a cap sealing the opened side of the communication passage and disposed on the hydraulic block, the cap having an opening towards the communication passage; and a spring disposed on each of the stepped portions to be received in the opening of the cap such that the piston is elastically supported between the cap and the closed side of the communication passage.