| 摘要 |
PURPOSE:To ensure satisfactory braking force by applying output liquid pressure to one system of wheel cylinders from a master cylinder and to the other system of wheel cylinders directly from a hydraulic booster. CONSTITUTION:When a hydraulic booster 20 is let normally function by power hydraulic pressure from a liquid pressure source 40, its output hydraulic pressure is applied directly to wheel cylinders 53a, 54a of one set of wheels 53, 54, and a master cylinder 10 is boosted to drive by a hydraulic booster 20, whereby its brake hydraulic pressure is applied to wheel cylinders 51a, 52a of the other set of wheels 51, 52. When the boost function of the hydraulic booster 20 becomes insufficient, a booster 8 is operated to increase the brake hydraulic pressure of the master cylinder 10. When the output hydraulic pressure of the hydraulic booster 20 or the master cylinder 10 exceeds a designated pressure due to the operation of the brake pedal 2, the booster 8 is not operated. Thus, satisfactory braking force can be ensured. |
