| 摘要 |
PURPOSE:To improve fuel cost and durability of a seal material for a hydraulic circuit by contriving to make the hydraulic pressure adjusting property of a regulator valve to exhibit each specific value respectively depending upon whether the hydraulic pressure of a master cylinder is zero, or the same is raised to the first and the second settled pressure. CONSTITUTION:The above-mentioned unit is provided with a brake hydraulic pressure controlling piston 25 which controls a brake hydraulic pressure by a master cylinder 12, a cut valve 26, an actuator 23 which includes a power hydraulic pressure in and out valve 27 and a bypath valve 28, and a regulator valve 22 which controls the power hydraulic pressure obtained by a hydraulic pump 20 to the value corresponding to the hydraulic pressure of the master cylinder 12. In this case, in the regulator valve 22, the first valve 49, the second valve 50 and the piston 51 are provided on the same axis in its body 48, and the first variable throttle 49a/is provided on the left edge of the valve body 49, and the second variable throttle 50a is provided between the right edge of a valve body 50 and a flat face 49b of the valve 49. The valve body 49 is energized leftward by the brake hydraulic pressure and the balve body 50 is energized rightward by a spring 54. |
