Aisin Seiki Kabushiki Kaisha

Nippon Petrochemicals Company, Limited

Akio Hashimoto

Tomio Yasuda

Hiroshi Naito

Naoji Sakakibara

Noboru Murakami

Hiroshi Nakashima

Yukihisa Oda

Takehiko Fushimi

Shuuetsu Suzuki

Sadahiro Nishimura

Rikio Kuroda

Shuichi Takemoto

Michitaka Terada

Tomino Yasuda

Tubular article method for injection molding thereof

During plural rotations of the the first potentiometer as a result of the operation of a steering wheel, though a specific position of the first potentiometer corresponds to plural rotation angles or rotation numbers of the steering wheel, the correct, real or current rotational angle or rotational number of the steering wheel can be obtained by knowing a one-to-one correspondence between a specific position of the second potentiometer and the reduced rotational angle of the steering wheel.

Sensor for detecting steering angle

An electric power steering system includes a steering torque detecting device for detecting a steering torque applied between an input shaft connected to a steering wheel and an output shaft connected to a steering gear in response to an elastic deformation of an elastic member connecting the input shaft with the output shaft, an electric motor whose rotation is controlled by a control signal from a control device in response to a detecting signal from the steering torque detecting device, and a clutch device interposed between the electric motor and the output shaft and controlling an intermittent transmission of the rotation of the electric motor to the output shaft in response to the elastic deformation of the elastic member. Thereby, it is possible to improve the safety performance, the reliability and the steering wheel feeling of an electric power steering system.

Electric power steering system

A torque detecting device, which is typically used for detecting a steering torque in a motor vehicle, includes a mechanism for converting the torque applied to an input shaft to an axial force between the input shaft and an output shaft. A slider is fitted about the output shaft movably axially along the output shaft and rotatably about its own axis with the output shaft. The axial movement of the slider is electrically detected. An elastic body is provided for returning the input shaft to its neutral position. The converting mechanism has a pin extending through the input shaft at right angles thereto and having two ends projecting therefrom. A pair of slits each having a pair of ends are formed in the output shaft. Each of the ends of the pin is located in one of the slits engageably with either end thereof. A bearing is secured to one end of the pin. A spiral groove is formed in the slider and one end of the pin extends into the groove to dispose the bearing therein.

Torque detecting device

An electric power steering device for vehicles comprises an electric motor connected to a steering shaft and serving as a servomotor for producing assisting steering power. Torque sensors are adapted to sense steering torque on the steering shaft. A vehicle speed detecting means is adapted to detect the actual vehicle speed. A controller is adapted to control the state of energization of the electric motor such that the output torque of the motor is changed in accordance with the change in the steering torque on the steering shaft and that the energization of the motor is stopped when the actual vehicle speed is increased beyond a predetermined threshold speed which is adjustable by a vehicle speed setting means such as a variable resistor.

Electric power steering device

A power steering system uses an electric motor to produce an auxiliary torque which is added to the torque applied to the steering wheel of vehicle by the driver. The system includes first detecting mechanism for detecting the rotating direction and rotating torque value applied to a steering shaft by a driver and producing a steering torque signal for responding to the steering torque applied to the driver, control circuit connected to the first detecting mechanism for controlling the energization of an electric motor according to the steering torque signal, coupling mechanism for coupling the motor to the steering shaft, releasing mechanism for releasing the connection between the motor and the coupling mechanism, converting mechanism for converting a part of rotating force of the motor into axial thrust force and installed in the coupling mechanism, said detecting mechanism for detecting the direction of the axial thrust force, and comparing circuit for comparing the output responding to the rotating direction of steering shaft in the first detecting mechanism with the output in the second detecting mechanism and generating a driving signal for driving the releasing means when the compared result is different from a preset condition. This permits the driver to rotate the steering shaft freely without a load of the motor when the motor is locked.

Motor driven power steering system

A torque detector is provided, which functions in such a manner that as torque is applied between an input shaft and an output shaft, an angular displacement is produced between the input shaft and the output shaft, this angular displacement is converted into an axial displacement by means of a torque-axial displacement converting mechanism to bend a cantilever fixed between a housing and the torque-axial displacement converting mechanism, by means of a strain gage attached to the cantilever the deformation of the cantilever is converted into a change of electric resistance, and by causing a current to flow through the strain gage the torque applied between the input shaft and the output shaft is converted into a voltage.

Torque detector

Improved electric power steering equipment includes an electric motor as a driving device therefor wherein wetness detecting means is adapted to minimize reduction in the torque necessary for the steering operation to thereby improve the steering feeling of a driver. The wetness detecting means detects the degree of wetness of a vehicle or a road surface adjacent to the vehicle. The equipment according to the present invention also includes a control means for driving the electric motor in response to the steering torque detected by a torque detecting means and the degree of wetness detected by the wetness detecting means. Thus, wetness on a road is directly or indirectly detected by the wetness detecting means and based on the detecting results thereof, additional torque necessary for the steering operation is controlled, and therefore a driver can drive a vehicle with a relatively constant steering feeling at all times, regardless of various running states of the vehicle.

Electric power steering equipment

A power transmission device of a motor-driven power steering system is provided which comprises a driving gear mounted on the outside of a shaft transmitting a force given from a steering wheel to a steering mechanism and rotatable about the shaft, a first connecting member including at least one gear for coupling the driving gear and a driving shaft of an electric motor, a second connecting member coupled to one out of the shaft and the driving gear, and a buffering member having elasticity coupled to the other out of the shaft and the driving gear and to the second connecting member. Preferably, the second connecting member has a cylindrical portion secured on the outside of the shaft and projections, and the driving gear has holes for receiving the buffering member and the projections.

Power transmission device of motor-driven power steering

An improved electric power steering system is disclosed. The system includes an electric motor as a driving device. Input system torque, motor current flow and motor temperature are detected and used to control the motor to prevent premature failure of the system due to elevated temperatures in the vehicle engine compartment.

Motor-driven power steering system

A power steering system makes use of an electric motor to produce an auxiliary torque added to the torque which is applied to the steering wheel of a vehicle by the driver. The system includes a motor driver for driving the motor and a motor braking circuit for braking the motor. When the torque manually applied to the steering shaft of the vehicle is greater than a predetermined reference torque, an electronic control apparatus causes the motor driver to energize the motor according to the difference between these two torques. When the former torque is less than the reference torque, the control apparatus causes the motor braking circuit to brake the motor. In this way, the torque that the driver of the vehicle must apply to steer the vehicle is maintained equal to the reference torque, irrespective of the vehicle velocity. The reference torque is set by means of a variable-resistor.

A power steering system uses an electric motor to produce an auxiliary torque which is added to the torque applied to the steering wheel of a vehicle by the driver. The torque applied by the driver is detected by sensors. The system includes a control apparatus to control the operation of the motor according to the output signal from the sensors. The system further includes a closed electrical loop for feeding a signal corresponding to the output from the motor back to the input side of the loop. A variable-resistor is placed so that the amplification factor of an amplifier included in the loop can be changed by the resistor. The knob attached to the variable-resistor is disposed on the dashboard of the vehicle such that it can be reached by the driver's hand. This permits the driver to change the servo ratio, i.e., the ratio of the output torque of the power steering system to the input torque applied by the driver, while the vehicle is in motion.

The steering power transmitting equipment of the present invention comprises a steering gear mechanism having a steering wheel, an upper steering shaft, lower steering shaft and steering gear box, the steering gear mechanism having a torque sensor fixed on the upper steering shaft, a bracket disconnectably fixed to the steering gear box, an electric motor supported on the bracket, a driven gear which is driven by the electric motor and fixed coaxially to the lower steering shaft and an electric controller. The electric controller controls the rotating speed and rotating direction of the electric motor corresponding to the torque and the torque direction inputted by the torque sensor. The power steering gear mechanism is easily mounted on or demounted from standard manual steering equipment without requiring any large scale remodelling of the steering equipment.

Steering power transmitting equipment

A power steering system makes use of a direct-current servomotor to produce an auxiliary torque added to the torque which is applied to the steering wheel of a vehicle by the driver. The system includes an electronic apparatus, which receives a signal indicating the velocity of the vehicle, divides the whole range of the vehicle velocity into at least three ranges, and determines under which of these ranges the present velocity falls. In the lowest range, the control apparatus energizes the motor to produce such an auxiliary torque. In the middle range, the apparatus de-energizes the motor and so no auxiliary torque is generated. In the highest range, the apparatus connects a load such as a resistor with the coil in the motor to brake the rotation of the steering wheel.

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Kawasaki, Japan

Akio Hashimoto