Jidosha Kiki Co., Ltd.

Sadao Takeshima

Takeshi Ohe

Hideo Yabe

Katsumi Higashi

Kunio Okada

Tomoyuki Ishii

Shuichirow Tashiro

An electronic controller of the invention judges whether the pedaling speed exceeds a threshold and a pedal pressure exceeds a threshold based on detected signals from a stroke sensor and a pressure sensor. When the electronic controller judges that the pedaling speed exceeds the threshold and the pedal pressure exceeds the threshold, comparators output signals to actuate a switch. Thus, a braking force for emergency braking is outputted.

Emergency brake system sensing pedal speed and pressure

In a method of controlling an electric power steering apparatus by controlling a drive force of a steering force assisting electric motor when a vehicle speed is lower than a predetermined speed and controlling a braking force of the electric motor when the vehicle speed exceeds the predetermined speed, a steering wheel forward or reverse turning state is determined in accordance with a change in steering torque when the vehicle speed exceeds the predetermined state. The braking force of the electric motor is controlled only when the steering wheel reverse turning state is detected.

Method of controlling electric power steering apparatus

A control device for a power steering apparatus includes a vehicle speed signal generator, a steering angle signal generating circuit, a first pattern memory, a second pattern memory, and a drive circuit. The vehicle speed signal generating circuit generates a vehicle speed signal corresponding to an actual vehicle speed. The steering angle signal generator detects a steering angle and generates a steering angle signal. The first pattern memory generates a power steering signal determined in correspondence with the vehicle speed signal. The second pattern memory generates a correction signal determined in correspondence with the vehicle speed signal and the steering angle signal representing a steering angle with respect to a neutral position of a steering wheel. The drive circuit outputs a correction result by correcting the power steering signal by the correction signal.

Control device for power steering apparatus

A load current control device operates so as to control the magnitude of a current delivered to a load by varying a duty factor. With this control device, a fundamental value is determined on the basis of an instruction of an input signal, and a reference duty factor and a reference current value are determined on the basis of the fundamental value. The control device further operates to correct the reference duty factor on the basis of a difference between the magnitude of a current actually flowing in the load and the reference current value to turn on and off a power supplied in accordance with the corrected duty factor, therby to control the magnitude of the load current. In addition, when the above-said difference is out of a predetermined range, this load current control device outputs a signal indicative of abnormal condition.

Load current control device

In a control device for a power steering apparatus of which steering force is controlled on the basis of a control signal produced in accordance with a vehicle speed signal, the control device comprises means which outputs an engine rotation speed signal corresponding to an engine rotation speed, change relaxation means for relaxing changes in the engine rotation speed signal, and a switchover circuit which outputs an output signal of the change relaxation means instead of the vehicle speed signal when the vehicle speed signal is lost. Accordingly, even if a vehicle speed sensor is out of order for any reason, the power steering is carried out by the engine rotation speed signal, resulting small change of the steering force. Thus, this can protect the vehicle driver from dangerous conditions.

A method and device for controlling a power steering device wherein a flow control valve unit is arranged between an oil pump and a power steering unit, the flow control valve unit being controlled to supply oil to the power steering unit at a flow rate corresponding to a vehicle speed, has the steps of determining whether or not the flow rate of oil supplied to the power steering unit corresponds to a value required in accordance with current steering conditions, and increasing the flow rate to a value so as to correspond to the steering conditions when the flow rate does not correspond to the current steering conditions.

Method and device for controlling power steering device

A control device for a power steering apparatus for controlling a torque applied to the power steering apparatus in accordance with a travel condition. A travel condition determining unit generates a travel condition signal in accordance with an average steering angle value and an average velocity value. A load determining unit generates a load signal in accordance with a sensed load condition. A correction signal generating unit generates a correction signal in accordance with the travel condition signal and the load signal. A memory stores a single reference control characteristic for the power steering apparatus. A correcting unit corrects the reference control characteristics in accordance with the correction signal to provide optimal power steering control.

Power steering control apparatus utilizing on 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 mean lateral acceleration calculating circuit calculating a mean lateral acceleration based on the mean car speed and the mean steering quantity, a car speed calculating circuit, pattern memory means storing a plurality of number of revolutions characteristics of the oil pump corresponding to different patterns, a selector selecting one of the number of revolutions characteristics in accordance with the mean lateral acceleration and the mean car speed, circuit means for deriving out a number of revolutions 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 number of revolutions signal of the oil pump.

Method and apparatus for controlling power steering

In a power steering apparatus for use in a motor car of the type including a control device for controlling a motor driven oil pump in accordance with the output of a sensors which detects the running condition of the motor car driven by an engine, there is provided a control system which stops the oil pump while the engine is being stopped and also stops the oil pump at the time of starting the engine.

Power steering apparatus

A power steering apparatus wherein an oil pump for actuating the power steering apparatus is controlled by a control device in accordance with an output of a sensor device detecting the running state of a motor car. The control device drives said pump when said sensor device detects that the car speed is lower than a predetermined value but stops said pump when said sensor device detects that said car is standstill while the steering wheel of the motor car is not operated.

In a flow quantity control valve of the type comprising a rod shaped valve moved toward and away from an orifice formed in a fluid passage for controlling flow quantity of an operating fluid supplied to a power steering device of a motor car, for example, and drive means for reciprocating the rod shaped valve with respect to the orifice, there is provided an annular permanent magnet loosely encircling the rod shaped valve and located close to the orifice for attracting and removing magnetic particles contained in the operating fluid where the drive means is constituted by a solenoid coil and a plunger, current supplied to the solenoid coil is adjusted in proportion to a running speed of a motor car.

Flow quantity control valves

In a solenoid actuated device for controlling the oil supplied to a power steering unit of a motor car, a driving circuit is provided to pass current through the solenoid. The driving circuit comprises a comparator supplied with an analogue control signal proportional to the running speed of the motor car, a power amplifier including an output transistor which supplies exciting current to the solenoid coil in response to the output of the comparator. A positive feedback resistor is connected between the output of the comparator and the input thereof to which the analogue signal is applied, and a negative feedback resistor is connected between the output of the power amplifier another input of the comparator thereby ON-OFF controlling the output transistor to pass pulse current through the solenoid coil.

Driving circuits of solenoid actuated devices

In an electro-mechanical converter of the type wherein a plunger contained in a cylinder is moved in the axial direction thereof by passing a control signal through a solenoid coil wound about the cylinder, the diameter of the plunger is made sufficiently smaller than the inner diameter of the cylinder such that the plunger can move without causing undue friction. The plunger is supported by ball bearings to be movable with respect to the cylinder. To control a power steering unit of a motor car a control valve is actuated by the plunger for controlling the amount or pressure of the operating oil supplied to the power steering unit, in which case the control signal is made to be proportional to the speed of the motor car.

Electro-mechanical converters and control apparatus for power steering

An electrical energy stored in a capacitor is discharged to the solenoid of a solenoid pump through a thyristor as the latter is controlled to conduct, thereby producing a reciprocating movement of the piston of the pump. The value of the drive current passing through the solenoid is detected by a detection circuit, and a signal which depends on the magnitude of the drive current is applied to the trigger circuit of the thyristor. The period of oscillation of the trigger circuit which controls the conduction of the thyristor is controlled by the signal, whereby a uniform drive energy per unit time to the solenoid pump is assured.

Drive circuit for solenoid pump

A drive circuit for a solenoid pump comprises a series combination of a pump solenoid and a capacitor connected through a rectifier circuit with an a.c. source. The solenoid is shunted by another rectifier poled to pass a charging current to the capacitor. A thyristor is connected across the series combination, and is triggered into conduction, whereupon it short-circuits the series combination to permit a discharge of the capacitor through the solenoid and to prevent a current flow from the source to the capacitor, thus allowing a uniform control of the energy discharged by the capacitor. A trigger circuit for the thyristor comprises a relaxation oscillator including a programmable unijunction transistor, the conduction of which is controlled inversely to fluctuations in the source voltage.

Growing community of inventors

Higashimatsuyama, Japan

Sadao Takeshima