Toyota Jidosha Kabushiki Kaisha

Other

Akihiro Otomo

Eiji Nakamura

Fumiaki Kawahata

Kiyoharu Nakamura

Kenji Shirai

Tetsuya Miyazaki

Akira Sakai

Yasunori Yoshino

Kazunori Kagawa

Masayasu Ohkubo

Tsukasa Fukasawa

Masanori Hirose

Takahiro Okano

Junichi Sakamoto

Shinichi Soejima

Satoru Niwa

Hiroshi Toda

Hirohiko Morikawa

Tsuyoshi Yano

Masayuki Sumiyoshi

Masashi Ito

Yoshiaki Kominami

Hideyuki Inoue

Kimihiro Matsuki

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 hydraulic brake unit applies braking force to a plurality of wheels of a vehicle according to the operation of a brake pedal. A pressure increase linear control valve supplies hydraulic fluid from an accumulator to wheel cylinders of disc brake units of the respective wheels. Pressure-sustaining valves are placed in passages that extend from a first passage to the rear wheel cylinders. A pressure-increase response-delay reduction section closes the pressure-sustaining valves for a predetermined period of time after starting the hydraulic pressure control to temporarily limit the inflow of hydraulic fluid into the wheel cylinders that communicate with the first passage. Thus, the amount of the hydraulic fluid that is supplied to the second passage is increased, and it is possible to reduce the hydraulic pressure response delay in the second passage.

Vehicle brake system

A hydraulic brake apparatus for use in a vehicle having wheels and a brake operating member manually operable by a driver, the apparatus including a manual pressure source including (a) a hydraulic booster which boosts an operating source applied by the driver to the brake operating member and produces a first hydraulic pressure corresponding to the boosted operating force, and (b) a master cylinder which produces a second hydraulic pressure corresponding to the boosted operating force as an output of the hydraulic booster; a power pressure source which produces, by utilizing a power, a third hydraulic pressure irrespective of whether the brake operating member is operated; hydraulic brakes which are provided in association with the wheels, respectively, and include respective brake cylinders, and each of which, upon supplying of a hydraulic pressure to a corresponding one of the brake cylinders, applies a hydraulic braking force to a corresponding one of the wheels; a hub portion which is connected to each of the brake cylinders and to which the hydraulic booster, the master cylinder, and the power pressure source are connected in parallel; and a pressure source communication control device which selectively allows at least one of the hydraulic booster, the master cylinder, and the power pressure source to communicate with the hub portion.

Hydraulic brake apparatus

A hydraulic braking pressure control unit including three or more hydraulic pressure control components, and a holder structure which holds those hydraulic pressure control components, wherein the three or more hydraulic pressure control components are selected from electromagnetically operated hydraulic pressure control valves capable of controlling a pressure of a working fluid in a brake cylinder in a braking system, and pressure detecting devices, to detect respective pressures of the fluid used to control the electromagnetically operated hydraulic pressure control valves. The three or more hydraulic pressure control components include three hydraulic pressure control components which are attached to the holder structure such that one of the three hydraulic pressure control components is spaced from the other two hydraulic pressure control components by substantially the same distance.

Hydraulic braking pressure control unit

A brake fluid pressure control device controls brake fluid pressures through control of fluid pressure control valves operated in accordance with control signals from, for example, a computer. Signal lines for supplying control signals to control circuits controlling coils of linear valve devices for some wheels (e.g., front-left and rear-right wheels) are connected to a brake ECU by a connector, and signal lines for supplying control signals to the control circuits controlling coils of linear valve devices for other wheels (e.g., front-right and rear-left wheels) are connected to the brake ECU by a different connector. Thus, even if one of the connectors starts operating abnormally, it is possible to supply control signals via the signal lines connected by the other connector and control linear valve devices for some of the wheels (e.g., a pair of diagonally located wheels).

Brake fluid pressure control device

A braking pressure control apparatus including a first pressure source including a power-operated pressurizing device, a second pressure source operable by a manually operable brake operating member to pressurize a fluid to a pressure higher than a level corresponding to the operating force of the brake operating member, a switching device for selectively placing the braking system in a first state in which a brake cylinder is operated with the fluid pressurized by the first pressure source and a second state in which the brake cylinder is operated with the fluid pressurized by the second pressure source, and a change restricting device operable upon a switching between the first and second states, to restrict a change of the operating state of the brake operating member and a change of the brake cylinder pressure, which change take place due to the switching, or a switching control device for controlling the switching device on the basis of the running condition of a vehicle whose wheel is braked by the braking pressure.

Braking pressure control apparatus capable of switching between two brake operating states using power-operated and manually operated pressure sources, respectively

A braking pressure control apparatus for a hydraulically operated brake, including a first hydraulic system having a first hydraulic pressure source power-operated to pressurize a working fluid and capable of controlling the fluid pressure, for operating the brake, a second hydraulic system having a second hydraulic pressure source operable by an operating force acting on a manually operable brake operating member, to pressurize the working fluid to a pressure higher than a level corresponding to the operating force, for operating the brake, a switching device operable to selectively establish a first state in which the brake is operated with the pressurized fluid delivered from the first hydraulic pressure source, and a second state in which the brake is operated with the pressurized fluid delivered from the second hydraulic pressure source, and a diagnosing device operable to diagnose the second hydraulic system on the basis of the fluid pressure in the second hydraulic system.

Braking pressure control apparatus having device for diagnosing manually operated hydraulic system

In order to prevent a needlessly excessive yaw moment from being applied to the vehicle, thereby improving the running stability of the vehicle when either one of the braking force generation units went wrong, a brake system for vehicles having electric brake units ( ) each provided for each of the wheels to generate a braking force by its actuator ( ) being driven according to the amount of depression of a brake pedal, and a controller ( ) for controlling each of the electric brake units independently of others, is so constructed as to judge if any of the electric brake units went wrong (step ), and when either one of the electric brake units went wrong, to control the electric brake units other than the wrong unit according to the depression amount of the brake pedal so as to accomplish a best available stability of running of the vehicle.

Brake system for vehicles

A hydraulic wheel brake system including a plurality of brakes and a hydraulic brake controller. The brakes includes wheel cylinders corresponding respectively to each wheel. The hydraulic brake controller includes a pump device, and a pump and valve controller. At least one pump included in the pump device is reversible. By controlling the pump and valve controller the pump increases brake fluid pressure in the brake during braking and the brake fluid pressure is reduced through the pump when it is required to be reduced. The hydraulic brake controller has a normal-open solenoid valve between a reservoir and the brake. The normal-open solenoid valve allows the brake fluid to flow when an electric current is not supplied. The hydraulic brake controller has also a normal-close solenoid valve between the reservoir and the brake. The normal-close solenoid valve prevents the brake fluid from flowing when an electric current is not supplied.

Hydraulic wheel brake system

In a brake system of a vehicle in which a pair of wheel cylinders are supplied with a fluid pressure by a fluid circuit having a pair of inlet control valves for selectively connecting the pair of wheel cylinders respectively to an outlet port of a motor-driven pump and a pair of outlet control valves for selectively connecting the pair of wheel cylinders respectively to a fluid reservoir, a brake control device controls the motor driving of the pump and opening/closing of the inlet and outlet control valves, such that a controlled fluid pressure is supplied to the pair of wheel cylinders at least temporarily with the pair of inlet control valves substantially fully opened, while the pair of outlet control valves substantially closed, wherein it is judged if there is a difference between output signals of a pair of wheel cylinder pressure sensors beyond a predetermined threshold value, thereby judging the pair of wheel cylinder pressure sensors to be both operating normally when the difference is not larger than the threshold value.

Brake system for vehicles with routine judgment of normal operation of pressure sensors

A braking system including a brake cylinder, a first hydraulic pressure source having a first pump device for pressurizing a working fluid, a second hydraulic pressure source operable in response to an operation of a brake operating member, to pressurize the fluid to a pressure higher than a value corresponding to an operating force of the brake operating member, and a brake-cylinder-pressure control device operable when the brake cylinder is disconnected from the second hydraulic pressure source, to control the pressure of the fluid pressurized by the first hydraulic pressure source, such that the fluid pressure in the brake cylinder is controlled to a value determined on the basis of the operating force, and wherein an emergency communication device is operated when at least one of the brake-cylinder-pressure control device and the first pump device fails to normally function, to hold the brake cylinder in communication with the second hydraulic pressure source.

Braking system wherein brake cylinder is communicated with pedal-operated pressure source upon failure of pump-operated pressure source

A pump device including a plurality of pumps having respective different operating characteristics, and a pump control device for controlling the plurality of pumps, wherein the pump control device includes a control changing portion operable in response to detection of a failure of at least one of the pumps, for changing a manner of controlling at least one of the other of the pumps such that at least a portion of the operating characteristic of each defective pump is compensated for by the changed manner of controlling each normal pump. The pump device may be used in a hydraulic pressure control system as used for a hydraulically operated braking system for an automotive vehicle.

Pump device wherein detection of failure of one of pumps causes a change in the manner of control of the pump or pumps to compensate for the failure

A power source monitoring apparatus for monitoring a state of a subject power source which consists of at least one of a plurality of electric power sources in an electric system wherein a load device having at least one electrically operated load is electrically connected to the power sources, the monitoring device apparatus a detecting portion which detects a voltage and/or a current of at least one of the load device and the plurality of electric power sources, and a diagnosing device which diagnoses the subject power source for an abnormality on the basis of an output of the detecting portion, while the electric system is placed in a power supply state wherein an electric power is permitted to be supplied from only the subject power source to the load device.

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Toyota, Japan

Akihiro Otomo