Aisin Seiki Kabushiki Kaisha

Other

Satoshi Yokoyama

Masanobu Fukami

Kenji Tozu

Takayuki Itoh

Shinsuke Sakane

Toshihisa Kato

Masaru Kamikado

Hiroshi Toda

Norio Yamazaki

Masahiko Sakabe

Yoshiaki Tsuchiya

Kenji Tanaka

The present invention is directed to an apparatus for determining a state of braking operation of a vehicle. Wheel speed sensors are provided for detecting wheel speeds of a front wheel and a rear wheel. A wheel speed difference is calculated between the wheel speed of the front wheel and the wheel speed of the rear wheel detected by the wheel speed sensors. A braking operation detection device is provided for detecting an operation of a brake pedal. Based upon the calculated wheel speed difference and the operation of the brake pedal detected by the braking operation detection device, it is determined whether the brake pedal was rapidly depressed. In accordance with this result, and in response to the wheel speeds detected by the wheel speed sensors, the braking force applied to the front wheel can be adjusted in a predetermined relationship with the braking force applied to the rear wheel.

Apparatus for determining a state of braking operation

The present invention is directed to a brake control system for a vehicle, which includes a cut-off valve for opening or closing a main passage, which communicates a master cylinder with a wheel brake cylinder, and a pump for discharging the pressurized brake fluid to the wheel brake cylinder, with an outlet of the pump connected to a position between the cut-off valve and the wheel brake cylinder. An inlet valve is provided for opening or closing an auxiliary passage which communicates an inlet of the pump with the master cylinder. And, a controller is adapted to place the cut-off valve in a closed position thereof, place the inlet valve in an open position thereof, and actuate the pump to supply the pressurized brake fluid discharged from the pump into the wheel brake cylinder, when a brake-assist control is to be performed. A detection device such as a pressure sensor is provided for detecting an amount of operation of a brake pedal, so that the controller controls an amount of operation of the pump in response to variation of the amount of operation of the brake pedal detected by the detection device.

Brake control system for a vehicle

A braking force distribution control device for an automotive vehicle is designed to make it possible to initiate a braking force distribution control as rapidly as possible upon rapid braking operation while at the same time being capable of preventing a malfunction of the braking force distribution control even when one of hydraulic pressure lines fails. The braking force distribution control establishes a predetermined relationship between the wheel cylinder pressure of a front wheel and a wheel cylinder pressure of a rear wheel on the basis of a comparison between the wheel speeds of the front and rear wheels. The braking force distribution control is initiated when the decelerations of all the wheels exceed a set value.

Brake force distribution control device for automotive vehicles

The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, a hydraulic pressure pump, and a second valve device for opening or closing an auxiliary passage are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system. At least one of the first and second valve devices is controlled to equalize the slip rates of a pair of wheels, with the wheel brake cylinders operatively mounted thereon and disposed in different hydraulic circuits, and placed at the left side and right side of the vehicle, respectively, when a difference between the slip rates of the wheels placed at the left side and right side exceeds a predetermined value.

The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, which communicates a master cylinder with wheel brake cylinders, a hydraulic pressure pump for supplying the hydraulic pressure to the main passage, and a second valve device for opening or closing an auxiliary passage, which communicates the inlet of the pressure pump with the master cylinder, are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system. In the case where the slip rate of at least one of the front wheels is smaller than the slip rate of at least one of the wheels belonging to a different hydraulic pressure circuit from the hydraulic pressure circuit to which the one of the front wheels belongs, when the brake pedal is being operated, the hydraulic braking pressure discharged from the pressure pump is applied to one of the wheel brake cylinders operatively mounted on at least one of the front wheels, by controlling the second valve device for example.

A brake control apparatus includes a first valve to open and close a main line between a master cylinder and a wheel cylinder, a pump connected between a first valve and the wheel cylinder to supply pressurized brake fluid to the wheel cylinder, an auxiliary line connecting the inlet side of the pump to a master cylinder, a second valve to open and close the auxiliary line, a pressure sensor to detect the output pressure of the master cylinder and an electronic control unit which controls the first valve, the second valve, and the pump based upon the pressure detected by the pressure sensor so that the wheel cylinder receives a higher pressure than that of the master cylinder. The electronic control unit also closes the second valve while the pressure sensor detects the pressure over a certain pressure determined by the road surface condition.

Brake control apparatus

A brake control apparatus includes a first valve for opening and closing a main line, a pump having an inlet port and an outlet port to supply pressurized brake fluid to a point between the main line and the wheel cylinder, an auxiliary line Mfc connecting the inlet port of the pump to a master cylinder, a second valve for opening and closing the auxiliary line, a brake operation sensor for detecting the operation of a brake pedal, and an electronic controller which controls the first valve, the second valve, and the hydraulic pump. The electronic controller judges the need for brake assist control based on the detection by the brake operation sensor and controls the first valve, the second valve and the pump to perform the brake assist control. The electronic control unit also controls the duty ratio for the second valve based on the detection of the brake operation sensor. According to the present invention, the duty ratio is determined based on the detection of the brake operation sensor when the brake assist control is judged to be necessary. The electronic control unit immediately drives the second valve with the determined duty ratio so that the pressure is promptly increased in the wheel cylinder in accordance with the driver's operation of the brake pedal.

Brake control apparatus including duty controlled valve

The present invention is directed to a brake control system for a vehicle, which includes a master cylinder for pressurizing the brake fluid to discharge a master cylinder pressure in response to depression of a brake pedal, a modulator disposed between the master cylinder and a wheel brake cylinder for selecting a pressure control mode out of rapid pressure increase, pulse pressure increase, pulse pressure decrease, rapid pressure decrease and hold modes, a hydraulic pressure pump for discharging the pressurized brake fluid to the wheel brake cylinder through the modulator, and a reservoir for storing the brake fluid drained from the wheel brake cylinder through the modulator. A normally open first switching valve is disposed between the master cylinder and the modulator, and a normally closed second switching valve is disposed between the master cylinder and an inlet of the pressure pump. The first switching valve is placed in its closed position when the braking pressure in the wheel brake cylinder is to be pressurized automatically, while the second switching valve is actuated to communicate the master cylinder with the pressure pump only when the braking pressure in the wheel brake cylinder is being increased by the modulator.

The present invention is directed to a brake control system, which includes a first pressure circuit and a second pressure circuit for communicating a master cylinder with two sets of wheel cylinders, respectively. In each pressure circuit, a modulator is arranged to modulate the braking pressure in each wheel cylinder, a pressure pump is disposed to supply pressurized brake fluid to each wheel cylinder through each modulator, a normally open first valve is arranged to open or close a first passage for communicating the master cylinder with the modulator, and a normally closed second valve is arranged to open or close a second passage for communicating a reservoir directly with the inlet of each pump, or communicating the reservoir with it through the master cylinder. The pressurized brake fluid is supplied to each pressure circuit including the second valve at the inlet of the pump to perform an auxiliary pressurization. In the case where at least the second valve in the first pressure circuit opens the second passage, and the auxiliary pressurization is performed, the communication between the wheel cylinders in the second pressure circuit is blocked, when the brake pedal is not depressed, and the wheel cylinders in the second pressure circuit is communicated with the master cylinder, when the brake pedal is depressed.

A pressure control apparatus is operated to connect a wheel cylinder to a reservoir via a return fluid passage so that brake fluid will be stored in the reservoir to reduce the pressure. In accordance with the operation of a fluid pressure pump, the brake fluid is discharged from the reservoir into the return fluid passage to supply the brake fluid to the wheel cylinder, so that the wheel cylinder pressure is gradually increased. Based on detection of a sharp decrease of the motor load, it is estimated that the reservoir has become empty. Then, brake fluid is taken from a fluid pressure generating apparatus into the wheel cylinder.

Anti-skid control apparatus

The present invention is directed to an anti-skid control system which includes a pressure generator to supply a hydraulic braking pressure into a wheel brake cylinder through an actuator. A return passage is provided for communicating the wheel brake cylinder with the actuator. A pressure pump is disposed in the return passage, and a reservoir is disposed in the return passage at the inlet port's side of the pump. The reservoir stores the brake fluid discharged from the wheel brake cylinder through the actuator to decrease the wheel cylinder pressure. The actuator blocks the communication between the pressure generator and the wheel brake cylinder, and then the pump discharges the brake fluid stored in the reservoir into the return passage thereby to gradually increase the wheel cylinder pressure. A first fluid estimating device estimates a first amount of brake fluid supplied from the pressure generator into a hydraulic circuit disposed downstream of the actuator and including the wheel brake cylinder and the reservoir. And, a fluid supply allowing device allows the actuator to communicate the pressure generator with the wheel brake cylinder, when the first amount of brake fluid is smaller than a first predetermined amount.

Growing community of inventors

Nishio, Japan

Satoshi Yokoyama