| 摘要 |
<p>PURPOSE:To reduce the pedal stroke and a treading force therefor by a method wherein a discharging quantity of fluid with respect to a moving amount of a piston is increased at an initial stage of a brake operation and the same is decreased at a later stage thereof. CONSTITUTION:Pistons 7, 9 are moved to the left and pressures in respective chambers begin to increase due to a brake operation. In this case, a pressure increase of the chamber 10 is larger than that of the chamber 11, therefore, liquid in the chamber 10 is flowed into the chamber 11 and is fed into a hydraulic pressure actuator through a withdrawal port 28. When the hydraulic pressure in the chamber 10 reaches a predetermined value, a piston 34 is moved to the right against a spring 38 and the liquid in the chamber 10 is fed into a chamber 35 through a hole 36. Accordingly, the pressure in the chamber 10 is not increased so much even though the piston 7 is moved to the left continuously while only the pressure in the chamber 11 is increased. When the brake is released, the pistons 7, 9 begin to return and the liquid in the chamber 35 returns to the chamber 10, however, the liquid corresponding to a quantity which has flowed into the chamber 11 is short, by that amount, therefore, the pressure of the chamber 10 becomes negative. A valve 25 is opened due to this negative pressure and the liquid is supplemented into the chamber 10.</p> |
