Toyota Jidosha Kabushiki Kaisha

Advics Co., Ltd.

Masayasu Ohkubo

Fumiaki Kawahata

Hiroshi Nakaoka

Yoshito Tanaka

Akira Sakai

Kiyoharu Nakamura

Masaki Nanahara

Tsuyoshi Yamasaki

Takayuki Yamamoto

Kei Sato

Tetsuya Miyazaki

Masaaki Komazawa

Akihiro Otomo

Hirohiko Morikawa

Akihiro Ohtomo

Masashi Ito

Amane Shimura

Takahiro Okano

Yasuji Mizutani

Shinichi Soejima

Masaki Ninoyu

Tsukasa Fukasawa

Takeshi Ishida

Kentaro Oya

Kazunori Nimura

Kazutaka Noro

Seiji Yogo

Kazuyoshi Sakazaki

An electric brake device for a vehicle, including: a rotation body that rotates with a wheel; a friction member; and an actuator including (a) a piston configured to come into engagement with the friction member, (b) two electric motors each as a drive source, and (c) a motion converting mechanism configured to convert a rotating motion of each of the two electric motors into an advancing and retracting movement of the piston, the actuator being configured such that the piston is advanced to push the friction member against the rotation body so as to generate a braking force and the piston is retracted to move the friction member away from the rotation body so as to cancel the braking force.

Vehicle electric brake device

An electric brake device installed on a vehicle, including: a rotary body to rotate with a wheel; a friction member to be pushed onto the rotary body; an actuator including an electric motor as a drive source to cause the friction member to be pushed onto the rotary body; and a controller to control a braking force generated by the electric brake device by controlling a supply current supplied to the electric motor, wherein the controller determines, by mutually different methods, a plurality of target supply current components each of which is a component of a target supply current as a target of the supply current, determines the target supply current by adding up the target supply current components, and changes contribution degrees of the respective target supply current components in the determination of the target supply current in accordance with a characteristic of the braking force to be generated.

Electric brake device

A vehicle brake system, wherein an electric brake device is configured such that a clearance exists between a friction member and a rotary body when no braking force request is made, and wherein a controller is configured to: execute, for a hydraulic brake device, from a time point of generation of the request, a braking-force-request-dependent control for generating a hydraulic braking force in accordance with a degree of the request; and execute, for the electric brake device, (a) a clearance removing control for removing the clearance, which is executed from the time point of generation of the request till a time point when the degree increases up to a threshold degree, and (b) a braking-force-request-dependent control for generating an electric braking force in accordance with the degree of the request, the control being executed after the time point when the degree becomes equal to the threshold degree.

Vehicle brake system

A vehicle electric brake device configured such that, when no braking force request is made, a piston of an actuator of the electric brake device is retracted to a set backward position so as to allow a clearance to exist between a friction member and a rotary body of the device, wherein a controller of the device is configured to execute, for the actuator, a clearance removing control in which the piston is advanced at a first speed and subsequently advanced such that a piston advancing speed is reduced from the first speed to a second speed, so as to remove the clearance, the clearance removing control being executed when the braking force request is generated, and a braking-force-request-dependent control in which a braking force in accordance with a degree of the braking force request is generated, the braking-force-request-dependent control being executed after execution of the clearance removing control.

An electric brake device includes: an electric brake being configured such that a shaft is moved forward by diving of an electric motor, and the forward movement of the shaft brings the electric brake into an acting state in which brake friction members are pushed against a brake rotary body so as to suppress rotation of a wheel; and a motor controller being configured to control the electric motor, wherein through a rotation speed control on the electric motor, after the shaft reaches a set position before the electric brake comes into the acting state, the motor controller controls a forward speed of the shaft to be smaller than that before the shaft reaches the set position.

A method for detecting fluid leakage from a pressure-decrease valve in a hydraulic brake system having an ABS device including: a shutoff valve for shutting off supply of a working fluid from a fluid-pressure supply source to a brake device provided for a wheel; the pressure-decrease valve for discharging the working fluid from the brake device; a reservoir for storing the working fluid discharged from the pressure-decrease valve; and a return pump for returning the working fluid stored in the reservoir to a portion between the shutoff valve and the fluid-pressure supply source, the method including the steps of: activating the return pump in a state in which the hydraulic brake system is not in ABS operation, and detecting the fluid leakage from the pressure-decrease valve based on a variation in a pressure of the working fluid in the fluid-pressure supply source caused when the return pump is activated.

Method for detecting fluid leakage

A brake ECU brings master cut valves into an open state and brings holding valves into a closed state, thereby controlling a master cylinder and wheel cylinders to communicate to each other when a magnitude of a hydraulic pressure detected by an accumulator pressure sensor has decreased to a value less than a predetermined value set in advance. On the other hand, the ECU maintains holding valves in an open state, and controls an accumulator and the wheel cylinders to communicate to each other via linear control valves. Then, the ECU determines in which brake system a failure occurs out of a brake system for a front right wheel, a brake system for a front left wheel, and brake systems for rear right and left wheels based on changes in hydraulic pressure detected by a sensor, a master cylinder pressure sensor, and a control pressure sensor.

Vehicle brake device

A first ECU estimates whether the operation of a second actuator has been started, based on the variation of the hydraulic pressure with respect to the flow rate of hydraulic fluid outputted from a first actuator. Even in a case where the operation information of the second actuator is not received, the first ECU sets the control mode to a simultaneous operation mode, when it is estimated that the operation of the second actuator has been started. In the simultaneous operation mode, a controlled parameter of linear control valves on assumption that the second actuator is operating is set up, and a stop instruction of regenerative braking is transmitted to a hybrid ECU.

Brake apparatus

A brake ECU uses a control pressure acquired from a control pressure sensor to determine whether a valve closing operation abnormality or a valve opening operation abnormality occurs in one of a pressure increasing linear control valve and an adjusted flow rate cut valve in a state where a hydraulic pressure is supplied from an accumulator. The brake ECU controls, if the brake ECU determines that an abnormality occurs, respectively the control valve and the cut valve to change to an open state or a closed state, and identifies, based on a change in the control pressure acquired from the control pressure sensor, in which of the control valve and the cut valve the valve opening operation abnormality or the valve closing operation abnormality occurs. The brake ECU can use, after a valve in which the valve opening operation abnormality or the valve closing operation abnormality occurs is identified, a valve in which the abnormality does not occur to carry out brake control.

An electromagnetic linear valve includes a housing including a core closing an opening at one end portion of the body portion, and a separation portion separating an interior into a first liquid chamber located in a core side and a second liquid chamber; a plunger disposed in the first liquid chamber so as to move along the axis in a state in which one end thereof faces to the core and the other end can sit on a hole; an elastic member applying a force to move the plunger away from the core; and a coil generating magnetic field to move the plunger toward the core. A recess is formed in a section of an inner circumferential portion of the body portion which intersects with an end face of the core in the first direction.

Electromagnetic linear valve

A hydraulic brake system includes: a hydraulic pressure source provided for a vehicle, and including a hydraulic-pressure generating device and a reservoir; a plurality of hydraulic brakes provided for respective wheels of the vehicle, and configured to restrain rotations of the respective wheels; and a control valve device including at least one hydraulic-pressure control valve group disposed between the hydraulic-pressure generating device and at least one of brake cylinders of the hydraulic brakes and/or between the reservoir and the at least one of the brake cylinders. Each of the at least one hydraulic-pressure control valve group includes (a) at least one ON/OFF control valve and (b) at least one linear control valve that are disposed in parallel with each other.

Hydraulic brake system

A brake control apparatus has first and second wheel cylinders; a master cylinder unit; first and second systems; a separation valve; a pressure control mechanism that controls the working fluid pressure transferred to at least one of the first and second wheel cylinders independently of the brake operation, and a brake ECU. The brake ECU generates a differential pressure across the separation valve by operating the pressure control mechanism when there is no brake operation while a running drive source of a vehicle is stopped to determine whether the separation valve has a leakage abnormality.

Brake control apparatus and control method thereof

A brake control system includes at least one wheel cylinder that receives the work fluid to apply a braking force to a corresponding vehicle wheel, a wheel cylinder pressure control system that controls the control pressure applied to the at least one wheel cylinder by controlling the supply of the work fluid thereto, a first abnormality determination unit that determines whether an abnormality in the wheel cylinder pressure control system based on an initial response characteristic of the control pressure after a braking request within a predetermined abnormality determination time, and a second abnormality determination unit that determines whether the abnormality in the wheel cylinder pressure system is present based on a comparison between the control pressure and a reference pressure based on which the determination is made with respect to the abnormality within a predetermined second abnormality determination time that is set to expire before expiration of the first abnormality determination time.

Brake control system and brake control method

The invention provides a brake control apparatus that improves the controllability of a vehicle in the control for restraining slip of the wheels. The brake control apparatus includes: wheel cylinders that apply braking force individually to wheels by supplying a working fluid; retention valves that are provided respectively upstream of the wheel cylinders and that are opened and closed so as to restrain slip of the wheels; a common control valve provided upstream of the retention valves to supply the working fluid to the wheel cylinders; and a control portion that controls the common control valve by different control laws to restrain fluctuations in pressure on a primary side of the retention valves caused by fluctuations in a capacity to which the working fluid from the common control valve is supplied, by opening or closing of the retention valves.

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Okazaki, Japan

Masayasu Ohkubo