| 摘要 |
PROBLEM TO BE SOLVED: To provide a hydraulic brake system so easy in terms of design and inexpensive in cost by reducing any force to be added to a control valve element of a pressure regulating valve means to the utmost, in regard to this hydraulic brake system which imparts the brake fluid pressure regulated by the pressure regulating valve means, to a power room at the rear of a master cylinder piston and assists the drive of a brake operating member. SOLUTION: In front of a master cylinder piston 10, a control piston 21 interlocking with this piston is set up and a pressure room R2 is also formed, while a power room R1 is formed at the rear as well. Output brake fluid pressure in an auxiliary fluid pressure source 40 is regulated to the specified pressure according to a movement of the control piston 21 attending upon the operation of a brake pedal 2, imparting it to the power room R1, and drive of this brake pedal 2 is assisted. In addition, a valve sear member 33 is set up in front of the control piston 21, and a control valve element 32 is set up so as to partition off a regulator room R3 in a space with the control piston 21 after being seated, thereby constituting a pressure regulating valve means. Moreover, any operation of the control valve element 32 is regulated by an elastic member 36 according to the brake fluid pressure regulated by this pressure regulating valve means. |
