Abstract: An auxiliary vehicle hydraulic pressure source device includes a hydraulic pressure pump pressurizing and discharging fluid, an accumulator accumulating fluid pressurized and discharged by the hydraulic pressure pump, a hydraulic pressure detector continuously detecting the accumulator hydraulic pressure, and a controller controlling operation of the hydraulic pressure pump based on a comparison of the detection result of the hydraulic pressure detector with a predetermined target pressure.

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 brake apparatus for a vehicle includes a supplementary hydraulic pressure source outputting a pressurized output hydraulic pressure and an electronic control apparatus that controls a hydraulic pump in the supplementary hydraulic pressure source. The electronic control apparatus judges whether the hydraulic pump satisfies a predetermined operating condition based on the output hydraulic pressure of the supplementary hydraulic pressure source or not. The electronic control apparatus compares the output hydraulic pressure with a minimum standard hydraulic pressure, detects a drop in the output hydraulic pressure when the output hydraulic pressure is less than a standard hydraulic pressure and determines that the hydraulic pump does not satisfy the predetermined operating condition.

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 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 hydraulic pressure assisting device includes a power piston slidably accommodated in a housing, an input member movable relative to the power piston in response to operation of a brake member, and an auxiliary hydraulic pressure source that increases brake fluid in a reservoir to a predetermined pressure and outputs power hydraulic pressure. A pressure modulator connected to the auxiliary hydraulic pressure source and the reservoir modulates power hydraulic pressure outputted from the auxiliary hydraulic pressure source to a predetermined pressure corresponding to movement of the input member relative to the power piston and supplies modulated power hydraulic pressure to a power chamber in the power piston. A cylindrical elastic member has one end portion connected to the input member or power piston and another end portion connected to the housing, with a space being defined in the elastic member connected to the pressure modulator and the reservoir.

Abstract: A hydraulic brake apparatus is provided for increasing a braking force with a brake feeling similar to that during a normal brake operation, even if a brake pedal is operated during an automatic brake operation. A valve device having a spool is placed in a power piston and is transferred between first and second positions depending on the operation of the brake pedal. At the first position, a power chamber is at atmospheric pressure level, while at the second position a fluid communication is established between the power chamber and an auxiliary hydraulic pressure source. The spool is driven independent of the operation of the brake pedal. When a hydraulic pressure is applied to the spool, the valve device is switched to the second position, urging the power piston to advance, without transmitting the resultant force to the brake operation member. The driving device, when applied with no hydraulic pressure, retains the valve device at the first position.

Abstract: A hydraulic pressure brake device for a vehicle includes a first piston outputting brake pressure generated in a first pressure chamber and a second piston having a larger diameter than that of the first piston and provided rearward of the first piston and forming a second pressure chamber having a larger diameter than that of the first pressure chamber. The hydraulic pressure brake device further includes a valve device closing the second pressure chamber hydraulically when actuation of the first piston and the second piston is assisted by the assisting device and establishing hydraulic communication between the second pressure chamber and the reservoir when the assisting is not carried out. The first pressure chamber is connected with wheel cylinders provided on front wheels through a first hydraulic pressure system and the second pressure chamber is connected with wheel cylinders provided on rear wheels through a second hydraulic pressure system.

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 piston, an auxiliary piston having first and second pistons, and an assisting device for assisting actuation of the master piston through the auxiliary piston. The brake pressure increase gradient in the assisting operation of the assisting device after the assisting output force of the assisting device reaches a maximum value is the same as the brake pressure increase gradient in the assisting operation of the assisting device before the assisting output force of the assisting device reaches the maximum value because the second piston of the auxiliary piston includes a large diameter portion possessing a diameter that is the same as the diameter of the master piston.

Abstract: A hydraulic pressure brake device is provided with a vacuum boosting device performing a boosting operation and a hydraulic boosting device performing a hydraulic boosting operation. The hydraulic pressure brake device includes a valve device that prohibits the hydraulic boosting operation for the master cylinder piston by the hydraulic boosting device until the vacuum boosting device reaches its boosting limit and allows the hydraulic boosting operation for the master cylinder piston by the hydraulic boosting device when the vacuum boosting device exceeds its boosting limit. A detecting sensor detects the operational condition of the vacuum boosting device and/or the operational condition of the brake pedal. Based on the detected output by the detecting sensor, a pump device for supplying the boosting pressure by the hydraulic boosting device is controlled to be driven.

Abstract: An auxiliary vehicle hydraulic pressure source device includes a hydraulic pressure pump pressurizing and discharging fluid, an accumulator accumulating fluid pressurized and discharged by the hydraulic pressure pump, a hydraulic pressure detector continuously detecting the accumulator hydraulic pressure, and a controller controlling operation of the hydraulic pressure pump based on a comparison of the detection result of the hydraulic pressure detector with a predetermined target pressure.

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 hydraulic pressure assisting device includes a power piston slidably accommodated in a housing, an input member movable relative to the power piston in response to operation of a brake member, and an auxiliary hydraulic pressure source that increases brake fluid in a reservoir to a predetermined pressure and outputs power hydraulic pressure. A pressure modulator connected to the auxiliary hydraulic pressure source and the reservoir modulates power hydraulic pressure outputted from the auxiliary hydraulic pressure source to a predetermined pressure corresponding to movement of the input member relative a to the power piston and supplies modulated power hydraulic pressure to a power chamber in the power piston. A cylindrical elastic member has one end portion connected to the input member or power piston and another end portion connected to the housing, with a space being defined in the elastic member connected to the pressure modulator and the reservoir.

Abstract: A vehicle hydraulic brake system includes a hydraulic pressure generator which pressurizes brake fluid supplied from a reservoir to apply brake pressure to a wheel cylinder in response to operation of a brake member, an auxiliary hydraulic pressure source having an accumulator and a hydraulic pump that pressurizes brake fluid supplied from the reservoir to a predetermined level for generating power hydraulic pressure, and an output hydraulic pressure detector for continuously detecting an output hydraulic pressure of the accumulator. A vehicle condition detector continuously detects an operating condition of the vehicle and a driving condition setting device sets a driving condition of the hydraulic pump based on the detected operating condition of the vehicle. A driving control device controls the hydraulic pump based on the driving condition of the hydraulic pump set by the driving condition setting device and the output hydraulic pressure of the accumulator.

Abstract: A hydraulic brake apparatus is provided for increasing a braking force with a brake feeling similar to that during a normal brake operation, even if a brake pedal is operated during an automatic brake operation. A valve device having a spool is placed in a power piston and is transferred between first and second positions depending on the operation of the brake pedal. At the first position, a power chamber is at atmospheric pressure level, while at the second position a fluid communication is established between the power chamber and an auxiliary hydraulic pressure source. The spool is driven independent of the operation of the brake pedal. When a hydraulic pressure is applied to the spool, the valve device is switched to the second position, urging the power piston to advance, without transmitting the resultant force to the brake operation member. The driving device, when applied with no hydraulic pressure, retains the valve device at the first position.

Abstract: A hydraulic pressure brake device for a vehicle includes a first piston outputting brake pressure generated in a first pressure chamber and a second piston having a larger diameter than that of the first piston and provided rearward of the first piston and forming a second pressure chamber having a larger diameter than that of the first pressure chamber. The hydraulic pressure brake device further includes a valve device closing the second pressure chamber hydraulically when actuation of the first piston and the second piston is assisted by the assisting device and establishing hydraulic communication between the second pressure chamber and the reservoir when the assisting is not carried out. The first pressure chamber is connected with wheel cylinders provided on front wheels through a first hydraulic pressure system and the second pressure chamber is connected with wheel cylinders provided on rear wheels through a second hydraulic pressure system.

Abstract: A hydraulic brake apparatus for a vehicle includes a supplementary hydraulic pressure source outputting a pressurized output hydraulic pressure and an electronic control apparatus that controls a hydraulic pump in the supplementary hydraulic pressure source. The electronic control apparatus judges whether the hydraulic pump satisfies a predetermined operating condition based on the output hydraulic pressure of the supplementary hydraulic pressure source or not. The electronic control apparatus compares the output hydraulic pressure with a minimum standard hydraulic pressure, detects a drop in the output hydraulic pressure when the output hydraulic pressure is less than a standard hydraulic pressure and determines that the hydraulic pump does not satisfy the predetermined operating condition.

Abstract: A hydraulic brake device for a vehicle includes a master piston, an auxiliary piston having first and second pistons, and an assisting device for assisting actuation of the master piston through the auxiliary piston. The brake pressure increase gradient in the assisting operation of the assisting device after the assisting output force of the assisting device reaches a maximum value is the same as the brake pressure increase gradient in the assisting operation of the assisting device before the assisting output force of the assisting device reaches the maximum value because the second piston of the auxiliary piston includes a large diameter portion possessing a diameter that is the same as the diameter of the master piston.