| 摘要 |
PURPOSE:To provide a hydraulic booster where the output jumping is generated against the input of an input member. CONSTITUTION:An opening/closing valve 172 is open when the power pressure is smaller than the set value, and a sealed fluid chamber 152 is communicated with a reservoir, enabling a slight step-in of a brake pedal 72. When the power pressure exceeds the set value, the opening/closing valve 172 is closed, and when the power pressure becomes higher and further exceeds the valve-opening pressure of a non-return valve 160, the non-return valve 160 is opened, and the hydraulic pressure which is lower than the power pressure by the amount equal to the valve-opening pressure of the non-return valve 160 is introduced to the sealed hydraulic chamber 152, and the reaction force is started to be applied to a reaction piston 68. Then, a certain hydraulic pressure is already generated to the wheel cylinder, obtaining the output jumping characteristic. Thus, a high wheel cylinder pressure is obtained by a small pedal operating force in the beginning of the braking operation, improving the brake working feeling in the initial condition. |
