Toyota Jidosha Kabushiki Kaisha

Advics Co., Ltd.

Nippondenso Co., Ltd.

Kiyoyuki Uchida

Yusuke Kamiya

Masaaki Komazawa

Akira Sakai

Yoshio Masuda

Tatsuo Sugitani

Hiroaki Niino

Yasuji Mizutani

Masaki Maruyama

Akitaka Nishio

Yoshifumi Yagi

Kenji Ito

Takahiro Okano

Takashi Kondo

Masaki Ninoyu

Naoto Kushi

Hiroshi Ueno

Hideo Inoue

Kazutaka Noro

Masaaki Uechi

Yasunori Sakata

Hiroshi Igata

Takashi Kurokawa

Yoshinori Kadowaki

Takayoshi Nakatomi

Yosuke Yamasoe

Michio Akiyoshi

Satoshi Ishida

Kazuya Maki

Kazunori Sakai

Yoshiaki Tsuchiya

Akira Fukushima

Nobuhiko Makino

Masayuki Usami

Hiroshi Nakaoka

Hideyuki Aizawa

Tatsushi Kobayashi

Masayuki Soga

Kiyohito Takeuchi

Yuichi Tanaka

Hirohito Nishikata

Yosuke Kuki

Yoshimitsu Ozeki

Showichi Miyago

A hydraulic brake system, including: a brake operation member; a brake device; a master cylinder; a communication switching valve; a low-pressure-source shut-off valve; a high-pressure source; a regulator; a pressure adjuster; and a controller, wherein, when a pressurizing state of the master cylinder is switched from a first pressurizing state to a second pressurizing state after initiation of an operation on the brake operation member, the controller executes a pressurizing-state switching control in which switching of a state of the low-pressure-source shut-off valve from an open state to a closed state and switching of a state of the communication switching valve from a closed state to an open state are carried out after a pressure-regulating state of the regulator has been switched from a first pressure-regulating state to a second pressure-regulating state by controlling the pressure adjuster to increase a second pilot pressure while the first pressurizing state is maintained.

Hydraulic brake system

Vibrations of a hydraulic pressure in an upstream portion due to operations of a slip control device during anti-lock control are transmitted to a control pressure chamber via a pressurizing piston of a master cylinder and a control piston of a regulator. During anti-lock control, in contrast, a pressure-increase linear valve and a pressure-reduction linear valve are opened, allowing change in volume of the control pressure chamber, resulting in reduction in stiffness. This reduction suppresses vibrations of a hydraulic pressure in the control pressure chamber, resulting in suppression of vibrations of a hydraulic pressure in a front pressure chamber. As a result, it is possible to reduce the lowering in control accuracy for a hydraulic pressure in a brake cylinder in anti-lock control using the hydraulic pressure in the front pressure chamber, which can well avoid a long braking distance.

Hydraulic braking system

The braking device for a vehicle includes a judging portion which judges whether the input piston and the output piston are in contact with or separated from each other and a control portion which outputs the control signal to the pilot pressure generating device so that the hydraulic pressure detected by the hydraulic pressure detecting device becomes a target value corresponding to a vehicle state, when judged that the input piston is not in contact with the output piston and outputs another control signal to the pilot pressure generating device, by which the pilot pressure becomes higher than the pilot pressure generated under a same vehicle state to a vehicle state in a case that the control signal is outputted when the judging portion judges that the input piston is not in contact with the output piston, when judged that the input piston is in contact with the output piston.

Braking device for vehicle

The brake device for a vehicle generates two master pressures by controlling one single servo pressure to accurately control braking force. The pressure increasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon increasing the servo pressure and the second pressure increasing characteristic obtained from the servo pressure and the second master pressure. The pressure decreasing characteristic is set based on the first pressure increasing characteristic obtained from the relationship between the servo pressure and the first master pressure upon decreasing the servo pressure and the second pressure decreasing characteristic obtained from the servo pressure and the second master pressure. Thus, the total braking force of the brake device is the sum of a braking force generated by the first master pressure and a braking force generated by the second master piston.

Brake device for vehicle

A hydraulic-pressure control device includes a regulator including a housing, a control piston in the housing, an input chamber at a rear of the piston, and an output chamber in front of the piston; and an input-hydraulic-pressure control device which controls hydraulic pressure in the input chamber to move the piston forward or backward to raise or reduce hydraulic pressure in the output chamber. The input-hydraulic-pressure control device includes a moving-direction control unit which, when a difference obtained by subtracting an actual hydraulic pressure in the output chamber from a target hydraulic pressure in the output chamber is less than a pressurization-side set value, controls the hydraulic pressure in the input chamber to move the piston backward; and when the difference is greater than a reduction-side set value, controls the hydraulic pressure in the input chamber to move the piston forward.

Hydraulic-pressure control device and hydraulic braking system

The vehicular brake device according to the present invention is provided with a first flow passage connecting a first electromagnetic valve and a wheel cylinder, a second flow passage connecting a reservoir portion capable of storing brake fluid and the first flow passage and a second electromagnetic valve disposed in the second flow passage. A pressure differential generating portion generates a predetermined pressure differential by moving a master piston by a drive pressure generating portion after an execution of an advancement control to advance the master piston so that the stroke position of the master piston is within an advanced side area. A second electromagnetic valve control portion places the second electromagnetic valve in an open state for a period including at least a portion of the period of time in an execution period of the advancement control.

Vehicular brake device

The braking control device for controlling a master cylinder device includes a housing, an output piston, an input piston, a separation chamber opening and closing portion, and a driving hydraulic pressure generating portion, and is provided with an operation control for controlling the master cylinder device in an operation force operating state (regulator mode) in which the output piston is driven by operation force on a brake operation member and in a driving hydraulic pressure operating state (linear mode) in which the output piston is driven by driving hydraulic pressure from the driving hydraulic pressure generating portion; a brake operation judgment portion for judging the presence or absence of a brake operation and the probability thereof and a state transition limiter for limiting at least one of state transitions between the operating states when the presence of the brake operation and possibility thereof is determined.

Braking control device

In a hydraulic brake system including a cylinder device that includes a front chamber and a rear chamber located on front and rear sides of a pressurizing piston, respectively, presence or absence of liquid leakage from a brake line is detected based on a hydraulic pressure in the rear chamber. Where a state in which a subtraction value obtained by subtracting an actual rear hydraulic pressure from a target rear hydraulic pressure is larger than a first malfunction determination threshold value has continued for a time not shorter than a first malfunction determination time, and then an increase of the actual rear hydraulic pressure at a rate not lower than a set rate has caused the subtraction value to become smaller than a return determination threshold value, it is determined that the pressurizing piston has been bottomed due to liquid leakage from the front chamber.

Hydraulic-pressure producing device and hydraulic brake system

A hydraulic brake system includes: a master cylinder including a pressurizing piston; a brake cylinder for a hydraulic brake operable by a hydraulic pressure in a front pressure chamber defined in front of the pressurizing piston; and a rear-hydraulic pressure controller connected to a rear chamber defined at a rear of the pressurizing piston. The rear-hydraulic pressure controller controls a hydraulic pressure in the rear chamber and includes: a regulator, operable by at least one of the hydraulic pressure in the front pressure chamber and a control pressure controlled electrically, for supplying an output hydraulic pressure to the rear chamber; and a master-pressure-operating-state detector configured to, when the output hydraulic pressure is greater than a threshold value, detect that the regulator is in a master-pressure operating state in which the regulator is operated by at least the hydraulic pressure in the front pressure chamber.

Hydraulic brake system and hydraulic pressure controller

The vehicle brake system includes a cylinder, an output piston disposed in the cylinder, an input piston disposed in the cylinder but separating from the output piston and defining a separation chamber therebetween, a brake pedal connected to the input piston, a reaction force generating device for generating an elastic reaction force, a separation lock valve for controlling the communication between the separation chamber and the reaction force generating device, a fade state judging portion to judge whether the friction brake device is in a fade state or not and a friction braking force control portion for changing the mode to the fade state when the fade state judging portion judged that the friction brake device is in the fade state, wherein a desired friction braking force can be assured even under the brake fade state.

Vehicle brake system

A vehicle brake device is provided with a master cylinder, a master piston slidably arranged in the master cylinder, an input piston slidably arranged in the master cylinder to be separated from the master piston and defining a separation chamber, an input piston moving amount detecting section for detecting the moving amount of the input piston, a master piston moving amount calculating section for calculating the moving amount of the master piston based on the moving amount of the input piston, and a contact inferring section for inferring the contact of the input piston with the master piston based on the moving amount of the input piston and the moving amount of the master piston.

Vehicle brake device

The brake control device applied to a hydraulic pressure braking force generating device having a driving hydraulic pressure generating device and a pilot hydraulic pressure generating device. The brake control device includes a judging portion which judges whether or not an operating amount of a brake operating member is equal to or less than a predetermined value and a pilot hydraulic pressure control portion which controls the pilot hydraulic pressure generating device to generate a preparatory hydraulic pressure in the pilot hydraulic pressure chamber which is larger than an atmospheric pressure set to a value so that a hydraulic pressure in the wheel cylinder is kept substantially to an atmospheric pressure level when the judging portion judges that the operating amount of the brake operating member is equal to or less than the predetermined value to suppress occurrence of brake dragging during non-braking operation with keeping the braking force responsiveness.

Brake control device

A braking device for a vehicle includes an operating characteristics setting portion for setting an operating characteristic which is a relationship between the input electric power to the electro-magnetic valve and a pressure difference between a master cylinder side and a wheel cylinder side with respect to the electro-magnetic valve, based on the input electric power at the time when the accumulator pressure detected by the accumulator pressure detecting portion first falls to a value equal to or less than a threshold value accumulator pressure by changing the input electric power towards an opening side of the electro-magnetic valve in response to a time lapsed after a predetermined value of the pilot pressure has been generated by the pilot pressure generating portion by first closing the electro-magnetic valve thereby to suppress the manufacturing cost.

When a brake switch is switched from OFF to ON, current is applied to a brake ECU, and a command to switch a master cylinder from a second state to a first state is issued after a lapse of preparation time, so that switching-time change suppression control is performed. A reservoir shutoff valve is closed, and duty control is performed on a communication control valve. The duty ratio is set to 1 when a switching-time control duration expires, and the communication control valve is placed in an open position, to establish the first state. Thus, since the communication control valve is duty-controlled during switching from the second state to the first state, change in the hydraulic pressure of an input chamber is suppressed, and change of the operating feeling is suppressed.

Cylinder device and hydraulic brake system

The vehicle braking control device adapted to a vehicle brake device having an electromagnetic valve which controls the brake fluid flow between the master cylinder and the wheel cylinders in response to the input electric energy. The vehicle braking control device includes a valve opening electric energy obtaining portion which obtains an input electric energy upon opening of the electromagnetic valve as a valve opening electric energy and an operation characteristic setting portion which sets an operation characteristic based on the valve opening electric energy obtained corresponding to the predetermined pressure differential. The opening valve electric energy obtaining portion changes the input electric energy at a valve closing side or a valve opening side with a change amount per unit of time larger than before valve opening in response to an obtaining of the valve opening electric energy.

Vehicle braking control device

Growing community of inventors

Konan, Japan

Kiyoyuki Uchida