Aisin Seiki Kabushiki Kaisha

Masaki Oishi

Michiharu Nishii

Satoshi Ishida

Takashi Kurokawa

Hideki Yamamoto

Tadashi Terazawa

Hirofumi Nitta

Kenichi Suzuki

Kyousuke Hata

A vehicle brake apparatus comprises brake operation detecting device for detecting an operation of a brake operating member, a fluid pressure type booster which boosts the operating force applied to the brake operating member, a pressure detecting device for detecting a pressure supplied to the fluid pressure type booster, and an electric motor control device. A recirculating type hydraulic pressure modulator is disposed in a hydraulic pressure conduit between a master cylinder and a wheel brake cylinder. The electric motor control device drives an electric motor for activating a recirculating pump in response to the brake operation detected by the brake operation detecting device and the pressure detected by the pressure detecting means so that the pressure in the wheel brake cylinder is modulated.

Brake apparatus for a vehicle

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. The controller includes a pressure difference calculator calculating the pressure difference between the detection result of the hydraulic pressure detector and the predetermined target pressure, a pressure change calculator calculating a pressure change of the accumulator hydraulic pressure per unit time based on the detection result of the hydraulic pressure detector, and an adjusting device adjusting operation of fluid accumulated in the accumulator by operation of the hydraulic pressure pump based on the pressure difference and the pressure change.

Auxiliary hydraulic pressure source device for a vehicle

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.

Hydraulic brake apparatus for a vehicle

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.

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.

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.

Hydraulic brake for a vehicle

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.

Hydraulic pressure assisting device provided for a hydraulic brake apparatus for a vehicle

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.

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.

Hydraulic pressure brake device for vehicles

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.

Hydraulic brake apparatus

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. As a result, even if the brake pedal is operated during the automatic pressurization, with the power pressure supplied by the power source, the brake fluid in the power chamber is reduced by controlling the solenoid valve to be opened and closed, to obtain a sufficient stroke of the brake pedal, so that an adequate brake feeling can be obtained.

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. A valve operating force generating member controls the pressure increase valve and the pressure release valve, a first repulsion force generating member is controlled in response to the regulator fluid pressure and a second repulsion force generating member is controlled in response to the master cylinder fluid pressure. This invention generates a larger magnitude of regulator pressure under the condition that the master cylinder is in a disabled condition.

Brake fluid pressure generating device for a vehicle

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. The valve member includes a first valve establishing and interrupting a fluid communication between the power chamber and the pressure decreasing valve and a second valve establishing and interrupting a fluid communication between the power chamber and the pressure source.

Hydraulic pressure brake apparatus

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. A fluid flow control device is provided in a passage connecting the auxiliary pressure source to a control valve to adjust the hydraulic pressure from the auxiliary pressure source to the control valve in two steps. When hydraulic pressure is supplied from the auxiliary pressure source to the wheel brake via the control valve, an increase rate of the hydraulic pressure in the wheel brake can be made quickly or slowly without operating the control valve on high cycles.

Hydraulic brake control system for use in a vehicle

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. A resilient member is disposed in the cylinder body for defining a counter-force chamber into which pressure is fed from one of the pressure chamber, auxiliary pressure source and power chamber. The resilient member is adapted to activate the pressure increase and decrease valves to move in a direction opposite to a direction thereof moved by the control piston. A pressure control valve is controlled in response to driving and/or braking conditions of the vehicle to vary the pressure in the counter-force chamber continuously thereby to be regulated into a predetermined pressure.

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Toyota, Japan

Masaki Oishi