Abstract: A vehicle hydraulic brake apparatus includes a brake member, a master cylinder generating brake hydraulic pressure, and a master piston movable in response to operation of the brake member. A closed chamber is defined by the master piston and a power piston is disposed behind the master piston. A power chamber is defined by the power piston rearwardly of the power piston. An auxiliary hydraulic pressure source generates power hydraulic pressure and a pressure regulating device regulates the output power hydraulic pressure and feeds it to the power chamber. A reaction force member is disposed in a front end portion of the power piston and is exposed towards the closed chamber. A retaining device maintains the reaction force member exposed towards the closed chamber, with the rearward reaction force of the master piston being transmitted to a front end portion of the power piston while bypassing the reaction force member.

Abstract: A vehicle hydraulic brake apparatus includes a brake member, a master cylinder generating a brake hydraulic pressure by increasing the pressure of brake fluid in a reservoir, a master piston moved forward in response to operation of the brake member, a closed chamber defined behind the master piston, a power piston disposed behind the master piston, and a power chamber defined behind the power piston. An auxiliary hydraulic pressure source generates power hydraulic pressure and a pressure regulating device connects the auxiliary hydraulic pressure source with the reservoir. The power hydraulic pressure is regulated to a predetermined hydraulic pressure and is fed to the power chamber. A normally-open type valve connects the closed chamber and the power chamber, and is closable upon operation of the brake member. The closed chamber is connected to the reservoir via the normally-open type valve, the power chamber and the pressure regulating device.

Abstract: A hydraulic brake device for a vehicle includes a master cylinder having a master piston and an auxiliary piston for assisting the actuation of the master piston. The vehicle hydraulic brake device also includes a first valve mechanism for hydraulically closing a first pressure transmitting chamber when the actuation of the master piston is assisted by an assisting device, a second valve mechanism for hydraulically closing a second pressure transmitting chamber after the pressure in the first pressure transmitting chamber reaches a predetermined value, and for hydraulically connecting the second pressure transmitting chamber with the first pressure transmitting chamber when the master piston is not actuated by the assisting device.

Abstract: A hydraulic brake device for a vehicle includes an auxiliary piston having an effective cross-sectional area larger than that of a master piston, and a pressure transmitting chamber provided between the large diameter portion and the master piston. The auxiliary piston is operatively associated with the assisting operation of an assisting device. A valve mechanism hydraulically closes the pressure transmitting chamber when the actuation of the master piston is assisted by the assisting device through the auxiliary piston and establishes hydraulic communication between the pressure transmitting chamber and a reservoir of the master cylinder when the master piston is not actuated by the assisting device.

Abstract: A hydraulic pressure brake apparatus which smoothly adds the assistance force of a hydraulic pressure booster to a master cylinder piston after the assistance limitation by a negative pressure booster includes a negative pressure booster that assists a master cylinder piston, a hydraulic pressure booster that assists the master cylinder piston by outputting the hydraulic pressure of a hydraulic pressure pump after the assistance limitation of the negative pressure booster, and a valve mechanism that controls the assistance by the hydraulic pressure booster. A single reaction member in the form of a reaction force rubber disc is provided between the master cylinder piston and the hydraulic pressure booster to transmit the reaction force to a brake pedal via the reaction force rubber disc.

Abstract: The present invention is directed to a hydraulic brake apparatus, which includes wheel brake cylinders, and a master cylinder for advancing a master piston in response to operation of a brake pedal. A power chamber is formed behind the master piston. A reaction piston is disposed, with the front end thereof exposed in the power chamber, so as to transmit a reaction force produced by the pressure in the power chamber to the brake pedal. A power source is provided for pressurizing brake fluid stored in a reservoir to supply power pressure to the power chamber. A solenoid valve is provided for opening and closing a return passage which connects the power chamber to the reservoir, thereby to return the brake fluid thereto. A detection device is provided for detecting the amount of operation of the brake pedal. The solenoid valve is controlled in response to the amount of operation detected by the detection device to reduce the amount of the brake fluid in the power chamber.

Abstract: A brake fluid pressure generating device includes a master cylinder piston slidably disposed in a cylinder body, a pressure chamber and a power chamber formed in the cylinder body, a master cylinder that generates a master cylinder fluid pressure in response to operation of a brake pedal, a supplemental fluid generator that generates a power fluid pressure, a fluid regulator that regulates the power fluid pressure to a regulator fluid pressure in response to operation of the brake pedal, a pressure increase valve that controls communication between the supplemental fluid generator and the power chamber, and a pressure release valve that controls communication between the power chamber and a reservoir tank.

Abstract: To provide an improved braking feeling in a hydraulic brake apparatus, the apparatus includes a pressure source, and a regulator for regulating pressure in the pressure source to a regulated pressure corresponding to the operation force of the brake pedal to supply the regulated pressure to a power chamber during operation of the brake pedal. The regulator includes a pressure increasing valve which establishes and interrupts a fluid communication between the pressure source and the power chamber and a pressure decreasing valve which establishes and interrupts a fluid communication between the power chamber and a reservoir. The apparatus also includes a booster having a power piston operated by the regulated pressure in the power chamber, and a master cylinder associated with at least one wheel brake and interlocked with the booster. A valve member applies the pressure in the pressure source to the power chamber irrespective of operation of the brake pedal.

Abstract: A vehicle hydraulic brake control system includes a wheel brake for applying a hydraulic braking force to a wheel in response to a hydraulic pressure supplied to the wheel brake, a reservoir is which is stored brake fluid under the atmospheric pressure, a main hydraulic pressure source fluidly connected to the reservoir for generating a high hydraulic pressure in response to a force applied to an operating member of the vehicle, and an auxiliary hydraulic pressure source fluidly connected to the reservoir for generating another high hydraulic pressure. A control valve is fluidly connected to the main hydraulic pressure source, the auxiliary hydraulic pressure source, the wheel brake, and the reservoir for establishing a supply and drain of brake fluid under pressure to the wheel brake from either the main hydraulic pressure source or the auxiliary hydraulic pressure source.

Abstract: 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. An auxiliary pressure source is provided for pressurizing the brake fluid in the reservoir to discharge power pressure. A control piston is slidably disposed in a cylinder body ahead of a 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 a pressure chamber. A pressure increase valve is provided for communicating the regulator chamber with the auxiliary pressure source or cutting off the communication in response to movement of the control piston. A pressure decrease valve is provided for communicating the regulator chamber with the reservoir or cutting off the communication in response to movement of the control piston.

Abstract: A vehicle brake control device includes a wheel cylinder mounted on a wheel of a vehicle, a master cylinder which generates a brake fluid pressure according to the amount of operation of the brake pedal and supplies the brake fluid pressure to the wheel cylinder, a pump which draws brake fluid out of a reservoir for generating a brake fluid pressure, and an accumulator which stores the brake fluid pressure generated by the pump. A change-over valve is disposed between the master cylinder and the wheel cylinder to disconnect the wheel cylinder from the master cylinder during its non-operational condition and to connect the wheel cylinder to the master cylinder during its operational condition A fluid conduit connects the accumulator to the wheel cylinder during the non-operational condition of the change-over valve, and a regulator is disposed on the fluid conduit to regulate the fluid pressure in the accumulator according to the amount of brake pedal operation.

Abstract: An auxiliary hydraulic pressure source device for use with an antilock brake system in a vehicle includes an accumulator that can be reduced in size without deteriorating the performance of the vehicle brakes. The auxiliary hydraulic pressure source device also includes a hydraulic pump for delivering brake fluid into a high-pressure brake fluid output line. A first one-way valve connects this output line with the accumulator only when the hydraulic pressure inside the output line exceeds the hydraulic pressure inside the accumulator by more than a given value .DELTA.P. A second one-way valve connects the accumulator with the output line only when the hydraulic pressure inside the output line is lower than the hydraulic pressure inside the accumulator.

Abstract: 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.

Abstract: 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. An auxiliary pressure source is provided for pressurizing the brake fluid in the reservoir to discharge power pressure. A control piston is slidably disposed in a cylinder body ahead of a 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 a pressure chamber. A first pressure receiving device is operatively connected with the control piston for applying thereto first counter brake pressure having a first pressure characteristic, with the power pressure received from the auxiliary pressure source, against the hydraulic brake pressure generated in the pressure chamber and applied to the control piston.

Abstract: The invention is directed to a hydraulic brake apparatus which includes a master cylinder having a cylinder body and a master piston slidably disposed therein for defining a pressure chamber ahead of the master piston and a power chamber behind the master piston. A control piston is slidably disposed in the cylinder body ahead of the master piston to define the pressure chamber behind the control piston, and adapted to be moved in response to movement of the master piston. An auxiliary pressure source is provided for pressurizing brake fluid to generate a power pressure, and a valve assembly is communicated with the auxiliary pressure source to regulate the power pressure into a regulated pressure in response to movement of the control piston. The valve assembly is adapted to supply the regulated pressure into the power chamber to assist the operation of a brake pedal.

Abstract: The invention is directed to a hydraulic brake apparatus which includes a master cylinder having a cylinder body and a master piston slidably disposed therein for defining a pressure chamber ahead of the master cylinder and a power chamber behind the master piston. A control piston is slidably disposed in the cylinder body ahead of the master piston to define the pressure chamber behind the control piston, and adapted to be moved in response to movement of the master piston. An auxiliary pressure source is provided for pressurizing brake fluid to generate a power pressure. A valve assembly having a regulator chamber defined ahead of the control piston is communicated with the auxiliary pressure source to regulate the power pressure into a regulated pressure in response to movement of the control piston, and adapted to supply the regulated pressure into the power chamber to assist the operation of the manually operated member.

Abstract: The invention is directed to a hydraulic brake apparatus which includes a master cylinder having a cylinder body and a master piston slidably disposed therein for defining a pressure chamber ahead of the master piston and a power chamber behind the master piston. A control piston is slidably disposed in the cylinder body ahead of the master piston for defining the pressure chamber behind the control piston. The control piston is moved in response to movement of the master piston. An auxiliary pressure source is provided for pressurizing brake fluid to generate a power pressure. A valve assembly is communicated with the auxiliary pressure source to regulate the power pressure into a regulated pressure in response to movement of the control piston, and adapted to supply the regulated pressure into the power chamber to assist the operation of a brake pedal.

Abstract: The invention is directed to a hydraulic brake apparatus which includes a master cylinder having a cylinder body and a master piston slidably disposed therein for defining a pressure chamber ahead of the master piston and a power chamber behind the master piston. The master piston includes a first piston connected to a brake pedal and a second piston slidably disposed relative to the first piston. The rear ends of the first piston and second piston are exposed to the power chamber, and the front ends of the first piston and second piston are exposed to the pressure chamber. An engaging member is provided for engaging the second piston with the first piston upon forward movement of the second piston. A control piston is slidably disposed in the cylinder body ahead of the master piston to define the pressure chamber behind the control piston.

Abstract: The invention is directed to a brake pressure control system which includes a brake pedal, a wheel brake operatively mounted on a wheel, and a pressure generator which generates a first brake pressure of a first pressure characteristic according to a stroke of the brake pedal, and which generates a second brake pressure of a second pressure characteristic according to the stroke of the brake pedal. The pressure generator is adapted to generate the second brake pressure to be higher than the first brake pressure, with a smaller stroke of the brake pedal than the stroke of the brake pedal for generating the first brake pressure. The system further includes a detector for detecting an emergency brake operation of the brake pedal, and a pressure selecting device which selects one of the first brake pressure and the second brake pressure to be supplied into the wheel brake.

Abstract: A pressure control apparatus includes a first brake pressure control valve for controlling communication between a first wheel brake for applying a braking force to an driving wheel of a vehicle and a pressure generating chamber of a master cylinder and for controlling communication between the first wheel brake and a low back pressure reservoir, and a second brake pressure control valve for controlling communication between a second wheel brake for applying a braking force to a non-driving wheel of the vehicle and the pressure generating chamber and for controlling communication between the second wheel brake and the low back pressure reservoir. A pump draws brake fluid from the reservoir into the first wheel brake and into the second wheel brake through the second control valve.