| 摘要 |
PURPOSE:To enable a good feeling to be always generated of a pedal by constituting a device providing a booster, driven by a pressure of brake fluid from a master cylinder, in a brake pipe and returning the pressure of brake fluid, used in said booster, directly to a reservoir. CONSTITUTION:In the case of a fluid pressure brake using a two-channel cross piping, two sets of boosters 2 are connected in parallel for a master cylinder 1. Each booster 2 has a control valve 20 closing a communication hole 16 in a stepped piston 15, when it is pressed to the downstream side by a pressure of brake fluid, and a check valve 30 opened in accordance with the displacement of the stepped piston 15 when this communication hole 16 is closed. When the check valve 30 is opened, a high pressure fluid supplying circuit 6 communicates with an adjusting chamber 24, moving a booster control piston 34 feeding the boosted brake fluid to a wheel cylinder 5. A return flow can be performed of brake fluid in a chamber 36 of a booster control cylinder 33 to a reservoir 10 by a passage 25. |
