To increase the pressure of a wheel cylinder while reducing a load on the wheel cylinder without causing the increase of size and the increase of the number of components.
A hydraulic pressure control valve 8 for increasing the pressure of a master cylinder to feed it to the wheel cylinder is formed side by side with a pump. The hydraulic pressure control valve 8 is composed of an inner piston 22 formed in a cylinder 24 communicating with the master cylinder and the wheel cylinder, a first spring 26 for energizing the inner piston 22 toward the master cylinder, a poppet valve 32 formed on the wheel cylinder side, and an outer piston 23 formed on the circumferential side of the inner piston 22. The outer piston 23 is moved toward the master cylinder by a predetermined wheel cylinder pressure, the inner piston 22 is pressed toward the master cylinder through the first spring 26 to be weakened its closing state to the poppet valve 32, and the increase of the wheel cylinder pressure is weakened.
AMARI YASUHIKO
WATANABE SHUZO
