Hydraulic brake apparatus for a vehicle

摘要

The present invention is directed to a hydraulic brake apparatus for applying braking force to each wheel of a vehicle in response to depression of a brake pedal. A master piston is received in a cylinder body to define a pressure chamber ahead of the master piston and a power chamber behind it. An auxiliary pressure source is provided for pressurizing the brake fluid in a reservoir to discharge power pressure. A control piston is slidably disposed in the cylinder body ahead of the master piston to be movable in response to movement thereof, so that a regulator chamber is defined ahead of the control piston, and a rear end thereof is exposed to the pressure chamber. A first passage is adapted to communicate the auxiliary pressure source with the power chamber, and a second passage is adapted to communicate the power chamber with the reservoir through the regulator chamber. A pressure increase valve device is disposed in the first passage to open or close the first passage in response to movement of the control piston. And, a pressure decrease valve device is disposed in the second passage to open or close the second passage in response to movement of the control piston. Preferably, a one way valve is disposed in the first passage, and a pressure restriction device may be disposed in the second passage.