Abstract: In an electric power steering apparatus, in which an electric motor for assisting the steering torque is adapted to be driven by PWM wave, and the duty of the PWM wave is adapted to be under the feedback control in time series by detecting the driving current of the motor, when the direction of the target current in this time for the feedback control is different from that of the former time, or when the detected driving current in the motor is zero, the former target voltage of the motor for the feedback control is forcibly set to the voltage value decided in reference to the minimum duty of the PWM wave for driving the motor.

Abstract: In an electric power steering apparatus, a signal processing circuit for a torque sensor for detecting a steering torque and a control circuit for controlling the driving of a steering assisting electric motor on the basis of the result of the signal processing by the signal processing circuit are formed on the same common circuit board. The common circuit board is mounted inside a housing accommodating the torque sensor, a housing accommodating a steering shaft, or a housing accommodating a steering gear.

Abstract: A speed reduction device for steering devices comprises a first rotary shaft supported by a housing and rotatable by an external force, a second rotary shaft axially movably fitted to the first rotary shaft and nonrotatable relative thereto, a movable member attached to the housing axially movably but nonrotatably and fitted to the second rotary shaft axially movably and rotatably relative thereto, a first ball screw connecting the second rotary shaft to the housing, and a second ball screw connecting the movable member to the second rotary shaft.

Abstract: The electric power steering apparatus of the invention is provided with a rotary detector for detecting a rotational position of a motor, a torque sensor for detecting a steering torque, and when the steering torque is within a dead zone, by increasing flow current to a motor for assisting steering force correspondingly to increase of a steering angle decided on the basis of the rotational position of the motor, the steering assisting force corresponding to the steering angle can be gained at the time of returning the steering wheel steered by mostly using by the steering torque being in the dead zone, and the proper steering assisting force can also be gained by making flow quantity corresponding to the steering angle to be minimum within a predetermined speed range and by increasing it at lower or higher speed than the predetermined speed range when the steering wheel is returned during a time of running at a low speed (such as a time of slowing down).

Abstract: An electric power steering apparatus of the invention is provided with a rotary detector for detecting a rotational position of a motor, a vehicle speed sensor for detecting a vehicle speed, a torque sensor for detecting a steering torque, a calculating means for calculating angular velocity of aforesaid motor on the basis of aforesaid rotational position, and a target angular velocity setting means, wherein flow quantity of electric current to a motor for assisting steering force is made larger, when the steering torque is within a dead zone, correspondingly to the increase of the deviation on the basis of the deviation between the target angular velocity and the calculated angular velocity, thereby stabilized steering feeling in the vicinity of the steering angle middle point at the time of returning the steering wheel steered by mostly using the steering torque being in the dead zone.

Abstract: A torque sensor which includes two cylinders fixed to two shafts connected with each other through a torsion bar. The magnetic coupling state of the two cylinders is made variable corresponding to relative rotations of the two shafts. The magnetic coupling state thereof is detected by a coil impedance, which is indicative of a torque acting on the shafts. The two cylinders form at the opposite end edges thereof teeth provided with cutouts disposed circumferentially of the cylinders and are opposite to each other at portions of about half a width of each tooth. The two shafts are regulated by rotation so as to not put the teeth of the cylinders completely opposite or non-opposite to each other.

Abstract: A steering angle middle point detecting apparatus of the invention is provided with a vehicle speed sensor for detecting vehicle speed, a torque sensor for detecting at regular intervals steering torque to be added to a steering wheel, a steering position detecting means for detecting a steering position of a steering mechanism, a means for comparing a steering torque set value previously set corresponding to the vehicle speed with the steering torque detected by the torque sensor, and a steering angle middle point calculating means for calculating a middle point of a steering angle by using the steering position of the steering mechanism detected by the steering position detecting means when the steering torque is smaller than the steering torque set value, which judges that the vehicle goes straight when the detected steering torque is smaller than the steering torque set value corresponding to the vehicle speed, and judges the steering position at that time to be the middle point of the steering angle.

Abstract: A torque sensor which includes two cylinders fixed to two shafts connected with each other through a torsion bar. The magnetic coupling state of the two cylinders is made variable corresponding to relative rotations of the two shafts. The magnetic coupling state thereof is detected, which is indicative of a torque acting on the shafts. The two cylinders form at the opposite end edges thereof teeth provided with cutouts disposed circumferentially of the cylinders and are opposite to each other at portions of about half a width of each tooth. The two shafts are regulated by rotation so as to not put the teeth of the cylinders completely opposite or non-opposite to each other. This enlarges a rate of change in the magnetic coupling state, detecting the torque with high sensitivity, and reducing a lateral difference in the output.

Abstract: A power steering system having an electric motor and including an input shaft fixed to a steering wheel, an output shaft coupled to the motor via a reduction gear, and a torsion bar provided between the input and output shafts, the output shaft being rotatable by the resultant of a manual torque for rotating the wheel and the torque of the motor. The system comprises a sensor for detecting the relative angular displacement between the input shaft and the output shaft, and a microcomputer having stored therein the relationship between the relative angular displacement and the motor current target value for determining the direction of rotation of the motor and a motor current target value from the output of the sensor to produce outputs.

Abstract: In a device for detecting an abnormal condition in a stepping motor, a second phase coil is provided which is in the relation of mutual induction with a first phase coil of the stepping motor to be tested for an abnormal condition, and the application and non-application of the supply voltage to the first phase coil under test is compared with the variation of the terminal voltage of the second phase coil, to detect the breaking of the first phase coil.

Abstract: A method is disclosed for generating a steering angle signal for a motor vehicle by processing a signal produced by a steering angle sensor to eliminate erroneous steering angle signal values caused by a floating state of a potentiometer included in the sensor to output the steering angle signal value corresponding to the rotational angle of a rotatable steering handle shaft where the erroneous signal values occur at specific angular positions of the handle shaft where the potentiometer is in the floating state.

Abstract: A power steering control device in an electronically controlled power steering system in which the degree of opening of an orifice in a liquid pressure circuit is controlled to adjust the steering power assist includes a driver for controlling an actuator for the orifice, a memory for storing, in the form of a table, values set in accordance with a combination of external factors affecting the adjustment of the steering power and orifice opening-degree control data corresponding to the combined values of actual external factors, a detector for detecting the concrete values of the external factors, and an access means for reading an orifice opening-degree control signal from the corresponding memory region in the memory.

Abstract: Apparatus for controlling a steering force of a handle in an automobile having a power steering system in which a driving shaft of an auxiliary fluid pump for obtaining pressure oil for a hydraulic reaction chamber of the power steering system is made common to a driving shaft of a fluid pump for the power steering system to increase a quantity of discharge and oil pressure of the auxiliary pump. Oil pressure with respect to the hydraulic reaction chamber is controlled by the speed and steering angle of the automobile to obtain a proper steering force.

Abstract: A system comprising a read-only memory storing output data relating to the stitching movement of the needle for a plurality of stitch patterns or to the feeding movement of the feed dog for the stitch patterns and order instructing data specifying the order in which the output data is to be read out, the output data and order instructing data being stored in the memory as divided into bight relating data and feed relating data, and an address unit including a bight register and a feed register. Based on the data read out from the memory with each advancement of the stitching and feeding timings alternately given in timed relation to the machine main shaft, the register stores the address data for the data to be read out with the next same stitching or feeding timing. When forming a stitch pattern such as a symmetric pattern which requires the use of data codes representing the same amount of movement, the same stored data is repeatedly read out according to the order instructing data.

Abstract: A pattern generating system for use in electronic sewing machines. Output-oriented data relating to the amount of bight or feed for a stitch pattern and order instruction-oriented data relating to the order in which the output-oriented data is read out are stored in a static memory (ROM) separately in such a manner as to distinguish between the data relating to bight and the data relating to feed. The data relating to the address at which the respective head data on stitch patterns is stored is stored at specified addresses in the static memory addressed by selection instructions corresponding to the stitch patterns given as by a pattern selecting button unit. The static memory is connected to a microcomputer which performs a control operation such that it indexes the static memory, analyzes order instruction-oriented data and updates addresses or gives the output-oriented data to a drive unit which controls the amount and direction of bight and feed.

Abstract: A speed control apparatus for use with an electric sewing machine having a motor drive control device for controlling the drive of the motor. The apparatus comprises a sensing device which can be optionally touched by the operator of the sewing machine, and a sensing signal generating circuit adapted to generate a signal in response to an electric change which is caused when the human body touches the sensing device, the arrangement being such that in response to the operator of the sewing machine touching the sensing device, the sensing signal generating circuit gives a predetermined signal to the motor drive control device, thereby stopping the drive of the motor.