Jidosha Kiki Co., Ltd.

Jishoda Kiki Co., Ltd.

Ichiro Koike

Takeshi Ohe

Hideo Yabe

Yoshio Suzuki

Tadaaki Fujii

Hideo Konishi

The temperature-dependent pressure detection switch according to the present invention comprises a pressure receiving member to receive hydraulic pressure, on which spring force of the predetermined value is permanently applied to the direction reverse to the operating direction of said hydraulic pressure and the spring force is varied according to temperature change, and a switch unit, which is operated by the movement of said pressure receiving member against said spring force when predetermined hydraulic pressure is received. Accordingly, when ambient temperature changes, spring force is changed, and the switchover setting pressure related to the on-off switchover operation of the switch unit can be changed according to temperature change. Namely, the pressure detection switch can be provided with temperature-dependent property. By the hydraulic pressure control system using the temperature-dependent pressure switch according to this invention, it is possible to accumulate the operating fluid in the accumulator in such quantity as necessary for operating hydraulic equipment.

Temperature-dependent pressure switch and pressure control system using

The operating condition of a power steering device for use in a motor car of the type including a steering mechanism driven by a electric actuator is confirmed by supplying test current to the electric actuator before starting the motor car and then detecting the state variation of the power steering device caused by the test current. The electric actuator may comprise a combination of an electric motor and an oil pump driven thereby, or an electric motor directly coupled to a steering mechanism.

Method and apparatus for power steering

An electric power steering apparatus comprises a steering shaft including a torsion bar to join an input shaft on the side of a steering wheel and an output shaft on the side of a steering road wheel so that they can be rotationally displaced relative to each other, and a non-contact type sensor using a Hall effect device provided in association with the input and output shafts to sense a relative rotational displacement based on a torsion of the torsion bar. The electric power steering apparatus further comprises an electric motor provided around a steering gear body within which the steering shaft is disposed and is driven by a signal from the non-contact type sensor to render a steering assistance to an output shafting leading to the steering road wheel. Thus, this can provide a power steering apparatus of simple and inexpensive structure to prevent that the reliability is lowered when used for a long timer or subject to environment changes, thus eliminating the troublesomeness in the adjustment work therefor. Further, this novel apparatus utilizes the sense function of the non-contact type sensor, thereby making it possible to provide a proper and smooth steering assistance effort conforming to running conditions of a vehicle, resulting in high performance of the power steering apparatus.

Electric power steering apparatus

An electrical power steering apparatus includes a vehicle velocity sensor for detecting a vehicle velocity, a steering torque sensor for detecting a steering torque of a steering wheel, comparators for receiving the voltage signal from the steering torque sensor and detecting a steering direction, a motor drive mechanism, a vehicle wheel declination sensor for detecting a declination of a vehicle wheel, a nonsteering state detecting unit including an absolute value converter, a reference voltage generator and a comparator to detect a nonsteering state, and a controller for supplying a current of a magnitude corresponding to the declination of the vehicle wheel to the motor so as to decrease the declination during the nonsteering state.

Electrical power steering apparatus

A steering apparatus for a vehicle steers both front and rear wheels and has an electric power steering unit for steering the rear wheels with a rotational force of a motor and a controller for generating a rear wheel steering signal in response to a vehicle speed and a front wheel steering angle. The controller includes a plurality of pattern memories for storing rear wheel steering angles, one of which is read out in response to a detected front wheel steering angle in accordance with ratios of rear wheel steering angles to front wheel steering angles. The ratios are predetermined or given as a function of vehicle speeds.

Steering apparatus for vehicle

Power steering control apparatus utilizing an oil pump comprises a car speed sensor producing a car speed signal, a steering sensor producing a steering signal, a mean car speed calculating circuit, a mean steering quantity calculating circuit, a car speed calculating circuit, pattern memory means storing a plurality of number of revolution characteristics of the oil pump corresponding to different patterns, a selector selecting one of the number of revolution characteristics in accordance with the mean steering quantity and the mean car speed, circuit means for deriving out a number of revolution signal of the oil pump corresponding to the car speed, and control means controlling rotation of the oil pump in accordance with the derived out revolution signal of the oil pump.

Method and apparatus for controlling power steering

A method and device for controlling a power steering apparatus for performing power steering by controlling a rotational speed of a motor-driven oil pump, wherein an alarm signal is generated when the power steering apparatus is overloaded, and a current is not supplied to a motor for a predetermined period of time when the power steering apparatus is overloaded.

Method and device for controlling power steering apparatus

A flow control valve is provided which is interposed between the discharge port of an oil pump and a hydraulic device for supplying a necessary amount of hydraulic oil to the hydraulic device, as such oil is discharged by the oil pump. The flow control valve includes a spool valve which is slidably fitted in a valve bore for reciprocatory displacement therein, thus opening or closing a return path for the oil which leads to a tank. A land on the spool valve is formed with an edge of a diameter which is slightly less than the internal diameter of the valve bore, thereby defining a variable orifice between the edge and an adjacent edge of the opening of the return path.

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Higashimatsuyama, Japan

Ichiro Koike