To avoid stagnation of gas in a hydraulic pressure circuit in a brake hydraulic pressure control device with a pump.
Brake liquid pumped up from a reservoir 30 through an intake passage 76 by the pump 70 and stored in an accumulator 72 is supplied to a brake cylinder 14, and brake cylinder pressure is controlled by opening/closing control of pressure increasing/reducing solenoid valves 42, 44. A pressure reducing valve 110 provided in a return passage 100 for returning the brake liquid of the brake cylinder 14 to the reservoir 30 is opened in a state that hydraulic pressure in a pressure reducing solenoid valve 44 side exceeds a set valve opening pressure and is higher than that in an intake passage 76 side, and allows a flow of the brake liquid from the pressure reducing solenoid valve 44 to the intake passage 76. The pressure reducing valve 110 is closed in a closed state of the pressure reducing solenoid valve 44, and transmission of intake negative pressure to the pressure reducing solenoid valve 44 is cut off at the time of operation of the pump. Leaving of bubbles generated due to reduction of pressure of the brake liquid when the pressure reducing solenoid valve 44 is opened, is avoided. A damper is provided in the return passage 100, and generation of the intake negative pressure may be suppressed.
YAMABUKI FUMIYASU
YAMAZAKI TAKESHI
MIYAZAKI TETSUYA
Mitsutoshi Sato