Nippondenso Co., Ltd.

Denso Corporation

Hideo Wakata

Kazutoshi Yogo

Yuzo Imoto

Yoshiyuki Hattori

Toshihiro Takei

Takahiro Goshima

Haruhiko Uno

Masuhiro Kondo

Yoshihisa Nomura

Toru Itabashi

Kiyonori Sekiguchi

Masashi Kishimoto

Masahiko Kamiya

Hidemi Ikai

Kenshi Saito

A microcomputer receives a position detection signal from a throttle angle sensor, and produces drive command signals to a drive circuit to control the position of a throttle valve to a target position through a motor. The current supplied to the motor is limited to less than a maximum value in a current variation zone in a normal motor operation range, when the throttle valve cannot be controlled to the target position, that is, when it is locked to the same position. The microcomputer produces a signal to cancel the current limitation to the motor, when it detects from the position detection signal of the throttle angle sensor that the throttle valve undergoes a predetermined change under the current limitation condition.

Motor drive control with low current limitation value

A brake control system for a motor vehicle which is equipped with a running state detector for detecting a running state of the motor vehicle so as to adjust a braking pressure in a wheel-braking cylinder of the motor vehicle in accordance with the detected vehicle running state. The brake control system has a first restriction adjusting valve provided between a hydraulic pressure generating source and the wheel-braking cylinder for adjusting the braking pressure to be supplied from the hydraulic pressure generating source to the wheel-braking cylinder, and a second restriction adjusting valve provided between the wheel-braking cylinder and a reservoir for adjusting a braking liquid to be discharged from the wheel-braking cylinder to the reservoir. Also included in the system is a control unit for outputting control signals to the first and second restriction adjusting valves so as to control the braking pressure in the wheel-braking cylinder in accordance with the detected vehicle running state. This arrangement allows setting of the braking hydraulic pressure increasing and decreasing speeds so as to permit a smooth brake control operation.

Brake control system and restriction adjusting valve for vehicles

In a braking pressure control apparatus for a vehicle, a first valve connected between a hydraulic pressure source and a wheel cylinder serves to permit and inhibit a supply of brake fluid to the wheel cylinder from the hydraulic pressure source. A second valve connected between the wheel cylinder and a reservoir serves to permit and inhibit an escape of the brake fluid from the wheel cylinder toward the reservoir. A control device serves to output control signals to the first and second valves respectively to control the braking pressure in the wheel cylinder in response to a detected running condition of the vehicle. The control device includes a deciding section for deciding whether or not a small variation in the braking pressure in the wheel cylinder should be done on the basis of the detected running condition of the vehicle, and an outputting section for, when the deciding section decides that the small variation in the braking pressure in the wheel cylinder should be done, simultaneously outputting the control signals to the first and second valves to simultaneously execute the supply of the brake fluid to the wheel cylinder and the escape of the brake fluid from the wheel cylinder.

ABS proportional valve capable of remaining open while the wheel

A pressure control valve for use in an automobile braking system includes a spool slidably movable for providing selective fluid communication between a pressure fluid source, a wheel cylinder, and a reservoir. The spool has, or is associated with, a pressure-bearing member responsive to a fluid pressure from the wheel cylinder, for applying a first biasing force to the slidable member to urge the slidable member to a position in which the wheel cylinder and the reservoir communicates with each other. An electromagnetic coil responds to an electric signal for generating an electromagnetic force to urge the slidable member to the above position. The slidable member is normally biased by a spring under a second biasing force, greater than the first biasing force, to urge the slidable member to a position in which the pressure fluid source and the wheel cylinder communicate with each other. The fluid pressure in the wheel cylinder is regulated to cause the sum of the fluid pressure in the wheel cylinder and the electromagnetic force from the electromagnetic coil to counterbalance the second biasing force.

Pressure control valve for continuous pressure control to wheel cylinder

An anti-locking control system for use in a motor vehicle having four wheels, comprising a hydraulic pressure supply system for applying a braking pressure from a master cylinder to two pairs of wheel-braking cylinders for braking the pair of wheels and a pump provided in common for the two pairs of cylinders in the hydraulic pressure supply system to decrease both the braking hydraulic pressures in each pair of wheel-braking cylinders. The hydraulic pressure supply system includes a pair of control valves each of which is arranged to have a first position at which the master cylinder is communicated with each of the pair of wheel-braking cylinders and a suction side of the pump is disconnected to the wheel-braking cylinder and a second position for disconnection to the wheel-braking cylinder and communication with the cylinder. Also provided in the control system an electronic control unit for effecting duty control of the pair of control valves so that the time periods at which the pair of control valves are at the second positions are not overlapped with each other. With this arrangement, although the pressure-decreasing is effected by one pump provided in common for the respective wheel-braking cylinders, it is possible to adequately effect the pressure-decreasing with respect to the lower-pressure side wheel-braking cylinder.

Anti-lock brake control system for use in motor vehicle

An anti-skid control system for use in a motor vehicle includes a two-position type control valve for performing increase and decrease in the braking pressure supplied to a wheel braking cylinder for braking a wheel of the motor vehicle. The control valve is operated in accordance with a signal indicative of a duty ratio from an electronic control unit. The electronic control unit estimates a balanced duty ratio whereby the current braking pressure in the wheel braking cylinder is maintained as it is and determines the duty ratio on the basis of the estimated balanced duty ratio in accordance with the locking state of the wheel.

Anti-skid control system for use in motor vehicle

A brake control system for effectively properly performing a braking hydraulic pressure distribution between a front wheel and a rear wheel or a left wheel and a right wheel of a motor vehicle including a master cylinder for generating a hydraulic pressure in response to depression of a brake pedal thereof and applying the hydraulic pressure through first and second braking passages to first and second wheel braking cylinders. This brake control system has first and second pressure control devices respectively coupled to a braking pressure source for allowing the output hydraulic pressures to be regulated independently of each other under control of a control unit. The output of the first pressure control device is coupled through the first braking passage to the first wheel braking cylinder and the output of the second pressure control device is coupled through the second braking passage to the second wheel braking cylinder. The control unit determines first and second target braking pressures to the first and second wheel braking cylinders on the basis of the hydraulic pressure in the master cylinder. The determined first and second target braking pressures are respectively corrected on the basis of the vehicle acceleration and wheel slip ratios.

Brake control system for controlling a braking force to each wheel of a

When excessive acceleration slip of a driving wheel is detected by wheel speed sensors attached to driving and non-driving wheels, an electronic control unit provides first and second control signals to a change-over valve and a control valve, respectively. The change-over valve operates in accordance with the first control signal to supply hydraulic pressure from a hydraulic pump to control a cut-off valve to thereby cut off communication between a master cylinder and a wheel cylinder. At the same time, hydraulic pressure from the hydraulic pump is fed to the wheel cylinder through the change-over valve and the control valve to brake the driving wheel. The control valve operates in accordance with the second control signal to increase or decrease the pressure in the wheel cylinder thereby adjusting the braking force for the driving wheel.

Vehicular drive control system

A braking system having a pressure modulator which, during normal braking operation, delivers a fluid pressure which is a predetermined multiple of a fluid pressure generated by the master cylinder to a wheel cylinder. The pressure modulator has a solenoid actuator which is energized during braking force proportioning and anti-skid operations to reduce the delivery pressure. In a preferred embodiment, the pressure modulator further includes another solenoid actuator for increasing the delivery pressure during braking force proportioning operation and for delivering fluid pressure during traction control operation.

Braking system with power brake, braking force proportioning, anti-skid,

In a wheel slip prevention control system for preventing the slippage of the driven wheel occuring when a vehicle is accelerated, a reference speed is derived from the non-driven wheel speed and the driven wheel speed is corrected by a correction value obtained as a function of a driven wheel acceleration value and a non-driven wheel acceleration value. The throttle valve is controlled with speed corresponding to the slipping condition of the driven wheel, i.e., with a control speed derived as a function of the reference speed and the corrected driven wheel speed, so that the slippage is quickly and effectively prevented.

Slipping prevention control for vehicle

A fuel injection control apparatus includes a booster apparatus, in which a cylinder chamber is divided into first and second fluid chambers by a piston. The operative area of the piston facing the first fluid chamber is sufficiently greater than that facing the second fluid chamber. Pressurized fuel is supplied to the first fluid chamber through a first check valve. The fluid is delivered from a second fluid chamber to a fuel injection valve via a second check valve. A fluid passage is formed between the first and second fluid chambers. A third check valve is set in the fluid passage, whereby the fuel is allowed to flow only from the first fluid chamber toward the second fluid chamber. The booster piston is located by means of a first piezoelectric device which includes a plurality of piezoelectric elements stacked in layers. When high voltage is applied to the first piezoelectric device to extend it, the piston is moved toward the first fluid chamber. High-voltage power from a second piezoelectric device, which faces the inside of an engine cylinder, is supplied to the first piezoelectric device via a backflow-preventing element. The first piezoelectric device is controlled for discharge in response to the injecting timing.

Apparatus for feeding high-pressure fuel into engine cylinder for

A hydraulic control valve may have a first chamber having an input port, to which an input hydraulic pressure is applied and an output port, and a second chamber having a third port to which a hydraulic control pressure is applied. When a hydraulic pressure below a predetermined level is applied to the first port, the same hydraulic pressure is produced at the second port. When a hydraulic pressure above the predetermined level is applied to the first port, the hydraulic pressure is reduced at a fixed ratio, and thereby a hydraulic pressure lower than the hydraulic pressure applied to the first port is produced at the second port. Thus the hydraulic control valve functions as a proportional valve. When a hydraulic control pressure is applied to the third port, the first and second port are disconnected. Thus the hydraulic control valve functions as a cutoff valve.

Hydraulic control valve

An automotive engine throttle control device has a function for effecting traction control for reducing the engine throttle opening upon detection of any slip of driving wheels and a function for effecting an automatic drive control for controlling the vehicle cruising speed in conformity with a command speed. The device has a first lever operatively connected to an accelerator and a second lever operatively connected to the throttle valve. A spring is disposed to resiliently act between the first and second levers. The second lever is actuated by an actuator which operates in response to throttle opening control instructions.

Throttle control device for vehicles

Disclosed herein is a vehicle running control device having a slip preventing function where a throttle opening degree of an engine is decreased upon occurrence of slip on drive wheels at starting and acceleration to prevent slip, and a running speed control function where a vehicle running speed is controlled to a target value. The control device comprises a common drive source for the above-mentioned both functions, a reduction mechanism for generating a drive output reduced discretely by driving the drive source in a predetermined direction and in a reverse direction, and link mechanism for effecting an open/close control of a throttle by the drive output. In the running speed control operation, the open/close control of the throttle is effected through the reduction mechanism and the link mechanism by intermittently controlling a driving operation of the drive source in the predetermined direction. On the other hand, upon occurrence of the slip on the drive wheels, the throttle opening degree is decreased to prevent the slip by intermittently controlling a driving operation of the drive source in the reverse direction through the reduction mechanism and the link mechanism. Further, the link mechanism is provided with a damper mechanism for damping a repulsive force to an acceleration operating section due to forcible decrease in the throttle opening degree in the slip preventing operation.

Vehicle running control system

An antiskid control device including a main line system for a usual braking operation and a subline system for an antiskid control, in which the flow rate of the subline system is smaller than the flow rate of the mainline system. The main piping system is provided with a cut-off valve which opens at a usual braking operation and closes at an antiskid control. The subline system is provided with a first control valve for opening the subline system and a second control valve for opening or closing the subline system at an antiskid control. The second control valve opens the subline system to supply a small quantity of brake oil to the wheel cylinder, and closes the subline system to release the brake oil in the wheel cylinder to the outside thereof.

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Nagoya, Japan

Hideo Wakata