Abstract: A method of producing a rack is proposed, which comprises aligning a first bar piece, an intermediate piece and a second bar piece in order along a common axis; carrying out a first process in which the first and second bar pieces are stationarily held while showing a predetermined intersection angle between the first rack teeth on the first bar piece and the second rack teeth on the second bar piece; and carrying out a second process in which each of the first and second bar pieces and the intermediate piece are brought into contact with each other at mutually facing ends and subjected to a relative rotation therebetween for a friction welding thereby to join the first bar piece, the intermediate piece and the second bar piece together by the friction welding.

Abstract: An integral power steering apparatus includes a hydraulic actuator having a piston separating pressure chambers for steering assistance and a limiter valve to be opened by movement of the piston to fluidly connect the pressure chambers. The limiter valve includes an adjuster for adjusting a press-fit position of a spring pin press fit in a plunger. The adjuster includes a movable adjusting member formed with an abutting surface to abut against the plunger to limit rearward plunger movement when the movable adjusting member is at a first adjuster position, and a regulating member to hold the movable adjusting member at the first adjuster position at the time of adjustment, and to enable the movable adjusting member to move to a second adjuster position after adjustment.

Abstract: A power steering apparatus including a steering shaft, a sensor coil disposed on an outer circumferential side of the steering shaft and detecting a change in impedance value to determine an amount of relative rotation of an input shaft and an output shaft of the steering shaft, a steering housing including a first housing and a second housing, a sensor substrate disposed on the first housing, a neutral point regulating circuit on the sensor substrate which includes a resistor connected to the sensor coil and variably regulates a resistance value of the resistor so as to regulate the impedance value at a neutral point at which the amount of relative rotation of the input shaft and the output shaft is zero, and an electric motor which is driven and controlled in accordance with an output signal of the sensor coil regulated by the neutral point regulating circuit.

Abstract: Electric power steering system has steering mechanism; input and output shaft side rotation angle sensors detecting rotation angles of input and output shafts; operation circuit calculating command current for an electric motor; rotation direction judging circuit judging whether rotation directions of the input and output shafts are identical; advanced-phase judging circuit judging which phase of input and output shaft side rotation angle signals (S1, S2) is advanced; normal/reverse input judging circuit judging that (i) when both rotation directions are identical and S1 is advanced, input is normal input and (ii) when both rotation directions are identical and S2 is advanced, input is reverse input; and command current correcting circuit. The command current correcting circuit corrects the command current so that when the normal input is judged, torque in the same direction as input shaft rotation direction generated by the electric motor is greater than a case of reverse input judgment.

Abstract: A power steering system having a housing having first and second housing sections, a steering shaft rotatably housed in the housing, a sensor coil, a coil bobbin having a coil holding part and a flange part and housed in the first housing section, a first held section provided at the flange part, a sensor board housed in the housing, a second held section provided at the sensor board, first and second riveting portions provided at the first housing section, and an electric motor. The first riveting portion fixes the coil bobbin to the first housing section by melting and deforming the first riveting portion with the first held section touching the first riveting portion. The second riveting portion fixes the sensor board to the first housing section by melting and deforming the second riveting portion with the second held section touching the second riveting portion.

Abstract: In a power steering system and a control apparatus for the power steering system, an abnormality detection process section (27) installed in a second ECU, the second ECU, the second ECU having a multi-core microcomputer in which a plurality of processor cores are mounted within a single processor package, to detect an abnormality of a first angle calculation process section of a first ECU, the first ECU having a single core microcomputer in which a single processor core is mounted within another single processor package and the first angle calculation process section a first angle calculation process section (21) installed in the first ECU to calculate rotation angles of the input axle and output axle on a basis of sinusoidal wave signals and cosine wave signals derived from a steering angle sensor and a torque sensor.

Abstract: In a power steering system, a torque sensor obtains first and second rotation angles, and a steering angle sensor obtains third and fourth rotation angles. A controller includes a first absolute rotation angle calculation section, a second absolute rotation angle calculation section, and an abnormality detection section. The first absolute rotation angle calculation section calculates a first absolute rotation angle as a first estimate of an absolute rotation angle of a steering wheel based on the first and third rotation angles. The second absolute rotation angle calculation section calculates a second absolute rotation angle as a second estimate of the absolute rotation angle of the steering wheel based on the third and fourth rotation angles. The abnormality detection section detects an abnormality by comparison between the first absolute rotation angle and the second absolute rotation angle.

Abstract: In order to provide a solenoid valve or solenoid that allows easy and accurate wire winding for an electric annular coil employed therein, a simple shape is possessed by the electric annular coil with inner and outer cylindrical surfaces that entirely extend in parallel with an axis of the electric annular coil and a sleeve for axially sliding therein an armature together with a plunger is shaped to have a larger diameter portion that is put between a smaller diameter portion of a front core and the inner cylindrical surface of the electric coil, a smaller diameter portion that is put between the armature and a rear core integral with a solenoid housing and a sloped annular intermediate portion that extends between the larger and smaller diameter portions.

Abstract: A variable displacement pump includes: a discharge opening formed at a position to confront a discharge region; a back pressure introduction groove formed on the suction region side; and a discharge side thin wall portion which is formed in the second housing, which has a recessed shape opened to the outside, which is disposed on the discharge region side, which is overlapped with the rotor in the radial direction, and which includes a smallest thickness portion having a smallest wall thickness of thicknesses each of which is an axial length between a bottom surface of the recessed shape and an axially inner side surface of the second housing, the smallest wall thickness being a smallest wall thickness of axial thicknesses of the second housing.

Abstract: An electric power steering device includes a rack bar; a pinion shaft meshing with the rack bar; a worm wheel provided on the pinion shaft; a worm shaft meshing with the worm wheel; an electric motor provided on the worm shaft; a first housing accommodating at least a part of the rack bar and the pinion shaft and includes a first bolt boss formed with a through-hole; a second housing; and a bolt. The second housing includes a worm-wheel accommodating portion accommodating the worm wheel, and a second bolt boss provided to have a shorter distance to the first housing than that of the worm-wheel accommodating portion, and formed with a female-threaded portion. The second bolt boss is opposed to the first bolt boss to cause the female-threaded portion to be continuous with the through-hole of the first bolt boss. The bolt fastens the first housing to the second housing.

Abstract: Electric power steering system has steering mechanism; input and output shaft side rotation angle sensors detecting rotation angles of input and output shafts; operation circuit calculating command current for an electric motor; rotation direction judging circuit judging whether rotation directions of the input and output shafts are identical; advanced-phase judging circuit judging which phase of input and output shaft side rotation angle signals (S1, S2) is advanced; normal/reverse input judging circuit judging that (i) when both rotation directions are identical and S1 is advanced, input is normal input and (ii) when both rotation directions are identical and S2 is advanced, input is reverse input; and command current correcting circuit. The command current correcting circuit corrects the command current so that when the normal input is judged, torque in the same direction as input shaft rotation direction generated by the electric motor is greater than a case of reverse input judgment.

Abstract: A variable displacement vane pump including a relief valve which includes a valve bore, a spherical valve element in the valve bore, a valve seat fixed onto one axial side of the valve bore and having a through hole and an annular seat surface on which the valve element is seated when the relief valve is in a closed position, a coil spring disposed on the other axial side of the valve bore, and a valve element retainer disposed between the valve element and the coil spring, wherein the seat surface is configured such that when the relief valve is in the closed position, a center of the valve element is located offset from a central axis of one winding seating portion of the coil spring which is disposed on an opposite side of the seat surface, in a radial direction of the valve bore.

Abstract: A power steering system has: a steering shaft; a pinion shaft; a torque sensor; a rack housing communicating with inside of the sensor housing; a rack shaft provided in the rack housing; a motor housing communicating with inside of the rack housing; an electric motor provided in the motor housing; an ECU housing communicating with inside of the motor housing; a motor control unit housed in the ECU housing; and a respiration valve provided at any of the sensor housing, the rack housing and the motor housing and located at an upper side with respect to an upper end of the ECU housing in vehicle-mounted state. The respiration valve has function by which air passes through each house and between inside and outside of the ECU housing so as to absorb change of expansion/contraction of the air in the ECU housing while suppressing entry of water from the outside.

Abstract: Disclosed is a power steering system comprising: a control valve disposed in the steering mechanism to selectably supply a working liquid supplied from a first pump or a second pump to a pair of pressure chambers of a power cylinder providing a steering force for at least one steered wheel in accordance with a rotational steering operation of a steering wheel; a first switching valve disposed between the first pump and the control valve to switch a communication and an interruption of the working liquid between the first pump and the control valve; and a second switching valve disposed between the second pump and the control valve to switch the communication and the interruption of the working liquid between the second pump and the control valve, a communication state and an interruption state being selectably formed in the second switching valve when the first switching valve is in the communication state.