| 摘要 |
PURPOSE:To prevent the excessively pressing down of a brake pedal at the time of antilock control by forming a small diameter land on the side of the first pressure chamber of the second piston and a large diameter land on the side of its second pressure chamber, and the second supplied liquid chamber in the large diameter land. CONSTITUTION:Power hydraulic pressure is input in a hydraulic booster 20, and regulated according to the movement of a brake pedal 2 to be output into the second supplied liquid chamber 17. In this case, even when the second piston 15 is subjected to energizing force to make it move in an opposite direction, it is kept at its initial position, namely the hydraulic pressure due to a difference in cross-sectional area between the large and small diameter lands 15g, 15h of the second piston 15 is maintained as the energizing force toward the first piston 11. A piston stroke can therefore be shortened, and moreover the excessively pressing down of the brake pedal 2 at the time of antilock control can be prevented by only additionally providing suction and exhaust valves. |
