| 摘要 |
PURPOSE:To improve the extent of brake feeling by making a control piston, with a stepped piston, have a cylinder whose inside is partitioned off into a chamber receiving the hydraulic pressure of power liquid, a hydraulic generating chamber and a chamber absorbing a brake fluid from a master cylinder, in the captioned device for an automobile. CONSTITUTION:A control piston is partitioned off into three chambers A to C in a cylinder body 4 by means of a stepped piston 43. In this constitution, the A chamber is interconnected to a master cylinder via a port 4b, absorbing a brake fluid. The B chamber is interconnected to a normally-closed type solenoid valve via a port 4b and also to a power hydraulic pressure source via a normally-opened type hold valve respectively, operating the stepped piston 43 with this hydraulic pressure. The C chamber forms a storage chamber of a spring 44, while a D chamber is connected to an antilock controller via a port, 4c, and it intensifies the hydraulic pressure with movements of the stepped piston 43, thereby generating braking pressure. In this connection, respective sectional areas A1, A2 and A3 of these chambers A, B and C should be set to A1<A3<A2. |
