Aisin Seiki Kabushiki Kaisha

Kyousuke Hata

Michiharu Nishii

Satoshi Ishida

Masaki Oishi

Genji Mizuno

Hideki Yamamoto

Hideo Mizukoshi

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.

Hydraulic brake apparatus for a vehicle

The invention is directed to a hydraulic booster for use in a hydraulic braking system of an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir and a master cylinder for generating a hydraulic braking pressure in response to movement of an input rod. The hydraulic booster has a housing defining therein a boost chamber, a power piston received in the boost chamber for transmitting a boost force to the master cylinder, and a pressure control valve which introduces the hydraulic power pressure from the power source and controls it in response to the movement of the input rod. The pressure control valve includes a cylinder defining therein a bore and a spool received in the bore. The spool has an axial hole and at least two radial holes facing each other and communicating with the axial hole. And, a tubular member is disposed in the axial hole of the spool to prevent the interference of the hydraulic power pressures introduced into the axial hole through the radial holes facing each other, whereby an uncomfortable noise caused by the interference is effectively prevented.

Hydraulic booster with noise reducing tubular member disposed in spool

A hydraulic braking system capable of reducing the brake pedal stroke is provided by adding to the basic hydraulic braking system. The adding system is able to selectively execute the reduction of brake pedal stroke and, at the same time, capable of selectively adding anti-lock function and anti-slip function by including the changeover valves or opening and closing valves to the system. An auxiliary hydraulic pressure generator having a power hydraulic pressure source and regulator is interposed in the hydraulic conduit of at least one circuit, and an outlet port of the regulator is communicated to the wheel cylinders for connecting to the hydraulic conduit of the circuit. Brake pedal stroke can be reduced by inclusion of other conduit arrangements for adding the auxiliary hydraulic pressure generator and, at the same time, the changeover valve, anti-lock control changeover valve, and normally closed valve are selectively releasably added or mounted to the system, so that a brake system having short brake pedal stroke and sporty feeling can be obtained by low cost system ensuring desired braking operation. Additionally, anti-slip control for preventing the slipping of driving wheels can be added.

Growing community of inventors

Kariya, Japan

Kyousuke Hata