| 摘要 |
PURPOSE:To raise the speed reduction ratio by forming the cylinder bore and pressure receipt piston of each of the two systems in such a way as stepped, and by making the cross areas of each pressure receipt piston and a balance piston in a certain specific relation. CONSTITUTION:Cylinder bores 71, 72 of the two systems are formed by minor dia. parts 101, 102 and major dia. parts 111, 112, respectively. The minor parts are to slide with the minor dia. parts 131, 132 of a pair of pressure receipt pistons 121, 122, while said major dia. parts with the major dia. parts 141, 142 of these pressure receipt pistons. If the cross areas of the major and minor dia. parts are represented by S1 and S2, respectively, and the cross area of the ends of a balance piston 22 by S2, they shall be related as S1>S2>S3, S2+S3>=S1. If the pressure has attained a specific level at the time of braking, the pressure receipt pistons will move to close valves 331, 332. When the pressure is rising, opening the valves 331, 332 is delayed because of the mentioned cross area difference S1-S2. Accordingly the pressure rise of rear wheel brake will become mild to provide a high speed reduction ratio. |
