Abstract: An electric power steering device having a clutch 25 for connecting and disconnecting the motor 14 to and from the steering shaft is disclosed, the control circuit of which comprises, in addition to a microcomputer 3, an additional analog direction determiner circuit 17, and a first and a second logical circuit. The first logical circuit consists of a pair of AND gates 20A, 20B generates a final right or left direction signal supplied to the motor driver circuit. The second logical circuit consists of a pair of exclusive OR gates 21A, 21B and an AND gate 22 and supplies a deenergization signal to the clutch driver when the directions determined by the microcomputer and the analog direction determiner circuit disagree.

Abstract: An electric power steering apparatus for an automotive vehicle has an interrupter which cuts off the power to a drive motor when a dangerous situation is detected. In one form of the invention, the interrupter cuts off power to the drive motor when a ground fault sensor detects a ground fault of a motor driver and there is disagreement between a directional drive signal to the drive motor and the direction of torque applied to the steering wheel by the driver. In another form of the invention, the interrupter circuit cuts off power when the vehicle speed exceeds a prescribed level and the torque applied to the steering wheel exceeds a prescribed level for a certain length of time. In a third form of the invention, the interrupter cuts off power when the motor current exceeds a prescribed level and disagreement of directional signals is detected.

Abstract: A motor-driven power assisted steering control apparatus includes a steering torque sensor 1, a motor 14 connected to a steering shaft via a clutch to exert an auxiliary steering force, and circuitry for controlling the motor in correspondence to an output from the steering torque sensing means. A torque neutral point detector 23 detects the neutral point of the steering torques, and first and second level detecting circuits 27, 29 detect when the motor current exceeds first and higher second levels, respectively. When the motor current exceeds the first level with the steering torque value at other than the neutral point, the clutch current is reduced to cause slippage, and when the motor current exceeds the second level with the steering torque value at other than the neutral point, the clutch current is interrupted to thereby stop the motor.

Abstract: A motor-driven power steering system equipped with a control unit (9) which controls the turn of a DC motor (13) as an auxiliary steering force on the basis of a steering torque signal from a steering torque sensor (2) that detects the rotational force of a steering wheel (1) and on the basis of a vehicle-speed signal from a vehicle-speed sensor (10), and which turns an electromagnetic clutch (16) on or off in order to effectively or ineffectively control the rotational force of the DC motor (13) as the auxiliary steering force. Further provided is a fail-safe relay (91) having a normally open contact (91b) on a line for supplying power to the electromagnetic clutch (16). Under an abnormal condition such as breakage in the power source wiring, the electromagnetic clutch (16) is shut off because of no energization of the fail-safe relay (91), and no auxiliary steering force is applied by the DC motor (13).

Abstract: In order to perform a vehicle speed control in a motor driven type power steering control device, a speed change point detection sensor is provided and an assist is added or removed according to a speed change point signal therefrom. Therefore, a construction of an input circuit and a control program become simple and a simple control unit can be used. Further, by inputting a speed change point other than those at which the assist is added, it is possible to easily determine a breakage of an input line for speed change point, resulting in a highly safe power steering.

Abstract: An electric motor assisted power steering device for an automobile is disclosed which comprises a dupicate torque direction determination system. The power steering device comprises, in addition to a microcomputer for determining the amount and direction of the auxiliary torque which is to be provided by the electric motor, an analog direction determiner circuit for determining the direction of the auxiliary torque. The torque sensor outputs a voltage which is substantially in linear relationship with the steering torque applied by the operator. The direction determiner circuit includes: a first comparator which outputs a right direction signal when this output voltage of the torque sensor exceeds a first reference level; and a second comparator which outputs a left direction signal when the output voltage of the torque sensor is below a second reference level which is lower than the first level.

Abstract: An electric rear wheel steering apparatus provided with an electromagnetic clutch 12 between a motor 11 for driving rear wheels 9 and a worm reduction gear 12 having a reversion efficiency of zero or lower, and a control unit 20 adapted to cut off an electric current flowing to the motor 11 and disengage the electromagnetic clutch 12 when an abnormal operation other than predetermined operation is ascertained. When an abnormal operation is detected, the rear wheel steering gear is fixed in the actual position by a control operation of the control unit 20, so that the rear wheels are prevented from becoming uncontrollable.

Abstract: A motor-driven type power assisted steering control apparatus has a torque sensor which is provided with first and second displacement-electric signal converting units and a control unit which is adapted to break a motor current and to interrupt application of a voltage to an electromagnetic clutch as soon as abnormality in the torque sensor is detected on the basis of the electric signals of the first and second displacement-electric signal converting units.

Abstract: A steering torque detecting device includes a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit including slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.

Abstract: A motor-driven type power steering control device includes a control unit. When the control unit detects that power elements are short-circuited or in an open state, the control unit cuts off a current supplied from the power elements to a motor and a voltage applied to an electromagnetic clutch. By modifying a control program for the control unit, it is possible to attain the measures for preventing that burning of a wiring or a battery from dying upon short-circuiting of the power elements and the measures for preventing that only one side of a steering wheel becomes light to steer upon breakage of the power elements.

Abstract: A motor-driven power steering system for a vehicle capable of changing into a non-power assisted manual steering mode by means of a control unit when a speed sensor detects that the vehicle speed has exceeded a prescribed level. When the speed sensor has failed and/or wiring connecting the speed sensor to the control unit is broken, the control unit detects such sensor failure or wiring breaks and operates to change the steering system into a non-power assisted manual steering mode, thereby improving safety in high-speed driving of the vehicle.

Abstract: A steering torque detecting device comprises a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit comprising slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.

Abstract: A motor-driven power steering system for a vehicle having a motor operatively connected to the steerable road wheels of the vehicle and a clutch arrangement interposed therebetween for selectively establishing and interrupting the transmission of power-assisting force from the motor to the road wheels in accordance with vehicle speed and operator-induced steering torque resulting form the steering force exerted on the steering wheel. The current to be supplied to the motor for controlling the running operation thereof is gradually decreased to reduce the power-assisting force transmitted from the motor to the steerable road wheels as the vehicle speed increases before the clutch is switched off and gradually increased to increase the power-assisting forces as the vehicle speed decreases after the clutch is switched on so as to provide a smooth transition from power steering to manual steering or vice versa without causing any abrupt change in the steering torque.

Abstract: A method for depositing solder onto aluminum metal material comprises steps of:(a) activating the surface of aluminum metal;(b) substituting zinc for the surface of aluminum as activated;(c) forming a nickel coating film over the surface of the zinc-substituted layer on the aluminum metal material by the non-electrode plating; and(d) attaching soldering material onto the nickel coating film surface.

Abstract: Prevention of damage to motor and power elements and a steering of a steering wheel during a lock condition of a mechanical system are enabled by distinguishing a lock of the motor and the lock of the mechanical system from a steering of the steering wheel around steering wheel lock positions and by removing a motor current and disengaging an electromagnetic clutch based on the distinction. When the steering wheel is operated around the steering wheel lock positions, a feeling of physical disorder of steering is minimized by reducing the motor current to zero within a predetermined time period.

Abstract: A steering torque detecting device includes a steering shaft consisting of an input shaft and an output shaft, a torsion bar provided between the input shaft and the output shaft, a torque detecting unit for converting a quantity of torsion produced in the torsion bar into an electric output, an electricity collecting unit including slip rings and brushes which takes the electric output and supplies an electric power from an outer power source, bearings for supporting the input and output shaft on the same axial line, and a housing supporting the bearings, a printed wiring board in a circular plate form which is provided at its one surface with a resistance layer and an output electrode radially spaced apart from the resistance layer, the resistance layer and the output electrode constituting a potentiometer, and a slider having a portion extending in the radial direction of the circular printed wiring board so as to have contacting areas with a small width to the resistance layer and the output electrode.

Abstract: A motor-driven power steering system for a vehicle capable of preventing abrupt change in the steering motion or torque an operator even when the battery has been suddenly depleted or excessively discharged during travel of the vehicle, thereby avoiding any possible panic resulting from sudden loss of power assist.

Abstract: Output signals from first and second speed sensors are inputted in a control unit to measure a car speed on the basis of the signals. When the measured value is higher than a predetermined value, control unit determines that one of the speed sensors is abnormal, whereby a motor current to be fed to a d.c. motor is interrupted and a voltage applied to a magnetic clutch is removed.

Abstract: A motor-driven power steering system for a vehicle capable of preventing a motor-related element such as a motor itself, power elements for controlling power supply to the motor or the like from being damage due to an abnormal temperature rise or overheating thereof, thereby substantially avoiding or reducing resultant unsureness or instability in the operator's steering feeling upon change in steering mode as well as improving safety in steering operation. The motor is operatively connected with a steering rack and energizable by a power source for power assisting the steering motion caused by the operator through a steering wheel. A temperature sensor detects the temperature of the motor-related element. An electromagnetic switching clutch is interposed between the motor and the steering rack for selectively establishing and interrupting the transmission of power assisting force from the motor to the steering rack in accordance with the travelling speed of the vehicle.

Abstract: A motor-driven power steering system for front and rear road wheels which is capable of preventing uncontrolled steering resulting from abnormal movement of the rear road wheels in case of a failure in various sensors and/or an electric motor or breakage in the wiring, and enabling vehicle to continuously travel in a safe manner by means of front wheel steering alone after occurrence of such troubles.