Abstract: There is provided a drive control method for a motor including multiple sets of coils and drive circuits in an electric power steering system. In order to reduce computational load when sensorless control is executed, an electrical angle estimator includes an ?-axis voltage component adder and a ?-axis voltage component adder that add together voltage vectors of a first coil and a second coil expressed in a two-phase fixed coordinate system, an ?-axis current component adder and a ?-axis current component adder that add together current vectors of the first coil and the second coil expressed in a two-phase fixed coordinate system, and an induced voltage computing unit that computes an induced voltage based on an added voltage vector and an added current vector.

Abstract: In a state in which the energization in the first direction is possible between the motor and the drive circuit and the motor is not rotating at high speed, when the phase induced voltage value of the specific phase that is the target of determination is continuously equal to or smaller than the abnormality determination threshold, the abnormality detecting unit determines that an open malfunction has occurred in the relay FET of the specific phase.

Abstract: An output section of one detection coil of a first resolver and an output section of one detection coil of a second resolver are connected by a first inter-coil resistor element, and an output section of the other detection coil of the first resolver and an output section of the other detection coil of the second resolver are connected by a second inter-coil resistor element. A sin wave signal for excitation is supplied to one of first and second excitation coils, and a cos wave signal for excitation having the same frequency as that of the sin wave signal for excitation and having a phase delay of 90° in relation to the sin wave signal for excitation is supplied to the other of the first and second excitation coils. By virtue of this configuration, the rotational angles of the two resolvers can be calculated even when one of detection lines is broken.

Abstract: A first excitation AC signal (V1=A1·sin(?t)) is supplied to a first excitation coil of a first resolver via a first excitation line, and a second excitation AC signal (V2=?A2·sin(?t)) is supplied to a second excitation coil of a second resolver via a second excitation line. Within a resolver unit, a first excitation line and a second excitation line are connected via an electric resistance element. By virtue of this configuration, torque can be detected even when any of a ground line, a first excitation line, and a second excitation line of a wire harness is broken.

Abstract: When a steering torque sensor fails, a time delay setting section calculates delayed lateral acceleration by delaying lateral acceleration. A lateral acceleration upper limit restricting section calculates restricted lateral acceleration by restricting the upper limit of the lateral acceleration by the delayed lateral acceleration. An assist torque calculation section calculates a target assist torque on the basis of the restricted lateral acceleration such that the target assist torque increases with the restricted lateral acceleration. Thus, it is possible to properly delay steering assist in relation to detection of the lateral acceleration, whereby slippage of a vehicle due to excessive turning of a steering wheel is suppressed.

Abstract: When a current sensor fails, instead of a normal-time motor control section, an abnormal-time motor control section drives and controls a motor. The abnormal-time motor control section detects a timing at which motor current becomes zero in a state in which all the switching devices are turned off. Every time the motor current becomes zero, the abnormal-time motor control section sets an ON time corresponding to steering torque, and turns on the switching devices corresponding to the direction of the steering torque for the ON time. With this operation, an average current corresponding to the steering torque flows through the motor, whereby deterioration of the followability of steering assist is suppressed.

Abstract: An output section of one detection coil of a first resolver and an output section of one detection coil of a second resolver are connected by a first inter-coil resistor element, and an output section of the other detection coil of the first resolver and an output section of the other detection coil of the second resolver are connected by a second inter-coil resistor element. A sin wave signal for excitation is supplied to one of first and second excitation coils, and a cos wave signal for excitation having the same frequency as that of the sin wave signal for excitation and having a phase delay of 90° in relation to the sin wave signal for excitation is supplied to the other of the first and second excitation coils. By virtue of this configuration, the rotational angles of the two resolvers can be calculated even when one of detection lines is broken.

Abstract: A first excitation AC signal (V1=A1·sin(?t)) is supplied to a first excitation coil of a first resolver via a first excitation line, and a second excitation AC signal (V2=?A2·sin(?t)) is supplied to a second excitation coil of a second resolver via a second excitation line. Within a resolver unit, a first excitation line and a second excitation linea are connected via an electric resistance element. By virtue of this configuration, torque can be detected even when any of a ground line, a first excitation line, and a second excitation line of a wire harness is broken.

Abstract: An electric power steering device for a vehicle includes an estimation mechanism estimating if there is a possibility that a backward electric current flows in a booster circuit toward a vehicle battery device, and a boosting controller stopping the boosting operation of the booster circuit to prevent a backward electric current from flowing in the booster circuit when it is estimated that there is a possibility that a backward electric current flows by the estimation mechanism. The estimation mechanism estimates that there is a possibility that a backward electric current flows in the booster circuit when the steering condition of a steering wheel is a returning condition or a steering-held condition. Otherwise, the estimation mechanism estimates if a backward electric current flows on the basis of input and output voltages of the booster circuit and information on the switching of a first boosting switching element. Thereby, overheat of the booster circuit can be prevented.

Abstract: A feedforward control section computes, on the basis of a target current absolute value, a voltage limit value of a motor drive circuit, and a rotational speed ?r of a motor, a phase angle of a voltage vector which represents the output voltage of the motor drive circuit by a d-q coordinate system, the phase angle being a phase angle in relation to the d-axis of the d-q coordinate system. A feedback control section computes a phase angle based on a deviation between the target current absolute value and the actual current absolute value. A PWM control signal generation section outputs PWM control signals such that the motor drive circuit outputs a three-phase drive voltage whose electrical angle is advanced by a phase angle. Thus, in the case where a large reverse input is applied to a steering mechanism, the motor is caused to generate a large torque to thereby prevent the steering wheel from being rotated.

Abstract: An electrical power supply unit for vehicle comprises: a Main Power Supply 100, a Voltage Converter 40 for converting the output voltage of the Main Power Supply 100 to supply electrical power to a Motor Drive Circuit 30, a Subsidiary Power Supply 50 to be charged by the Voltage Converter 40 and to aid the electrical power supply for the Motor Drive Circuit 30 with its stored electrical power, and an Electrical Power Supply Control Unit 62 to control the converted voltage of the Voltage Converter 40. The Electrical Power Supply Control Unit 62 controls the converted voltage of the Voltage Converter 40 based on the Voltage Converter Temperature Tb and the Subsidiary Power Supply Temperature Ts so that the heat generation condition of the Voltage Converter 40 and the heat generation condition of the Subsidiary Power Supply 50 are balanced.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole layer including a magnetic pole extending along a layer, a coil layer configured to adjoin the magnetic pole layer and including a plurality of conductor patterns constituting a part of a coil wound around the magnetic pole and a resin which fills up a gap between the conductor patterns, a heater layer configured to adjoin the coil layer and including a heater extending in the heater layer via an area along a coil-forming region in which the conductor patterns in the coil layer are formed and an area along a no-coil region off the coil-forming region, and a transition-reluctant portion in that part of the no-coil region which adjoins the heater and having a glass transition temperature higher than that of the resin or not having any glass transition temperature.

Abstract: According to an embodiment, a head stack assembly includes an arm including a swaged seat surface with swaged hole, a load beam supporting a head, and a baseplate secured to a proximal end portion of the load beam, including an annular protrusion secured to the swaged hole of the arm by swaging, and secured to the swaged seat surface. The arm includes a distal end portion located on a longitudinal end side of the arm with respect to the center of the swaged hole and being less rigid than the other portion of the arm around the swaged hole.

Abstract: An electric power steering device for a vehicle includes an estimation mechanism estimating if there is a possibility that a backward electric current flows in a booster circuit toward a vehicle battery device, and a boosting controller stopping the boosting operation of the booster circuit to prevent a backward electric current from flowing in the booster circuit when it is estimated that there is a possibility that a backward electric current flows by the estimation mechanism. The estimation mechanism estimates that there is a possibility that a backward electric current flows in the booster circuit when the steering condition of a steering wheel is a returning condition or a steering-held condition. Otherwise, the estimation mechanism estimates if a backward electric current flows on the basis of input and output voltages of the booster circuit and information on the switching of a first boosting switching element. Thereby, overheat of the booster circuit can be prevented.

Abstract: The present invention provides a numerical analysis model data generating program, method, and system for generating numerical analysis model data, which is used for numerical analysis, on the basis of three-dimensional shape data of a structure that is an object of analysis. Three-dimensional shape data defining the structure is inputted. Holes included in the inputted three-dimensional shape data are extracted, and the size of each of the holes is calculated. If the size of a given hole is smaller than a predetermined size, the hole is filled. Thus, numerical analysis model data is generated. According to the present invention, when the numerical analysis model data is generated, a relatively small amount of analysis model data can be generated without adversely affecting the accuracy in numerical analysis.

Abstract: A steering-force transmitting apparatus including: (a) an operating-member- side shaft; (b) a turning-device-side shaft offset from the operating-member- side shaft; and (c) a rotation transmitting mechanism having (c-1) an engaging portion provided in one of the two shafts and (c-2) a guide passage provided in the other of the two shafts such that the guide passage is held in engagement with the engaging portion. The rotation transmitting mechanism is configured to change a rotational phase difference between the two shafts while causing one of the two shafts to be rotated by rotation of the other of the two shafts. An axially end portion of a main body portion of one of the two shafts and an axially end portion of the other of the two shafts overlap with each other in the axial direction.

Abstract: An electrical power supply unit for vehicle comprises: a Main Power Supply 100, a Voltage Converter 40 for converting the output voltage of the Main Power Supply 100 to supply electrical power to a Motor Drive Circuit 30, a Subsidiary Power Supply 50 to be charged by the Voltage Converter 40 and to aid the electrical power supply for the Motor Drive Circuit 30 with its stored electrical power, and an Electrical Power Supply Control Unit 62 to control the converted voltage of the Voltage Converter 40. The Electrical Power Supply Control Unit 62 controls the converted voltage of the Voltage Converter 40 based on the Voltage Converter Temperature Tb and the Subsidiary Power Supply Temperature Ts so that the heat generation condition of the Voltage Converter 40 and the heat generation condition of the Subsidiary Power Supply 50 are balanced.

Abstract: According to one embodiment, a head gimbal assembly includes: base plate body; flexure; through hole passing through the base plate body; cylindrical base that upstands from the front surface of the base plate body, and has a first inner diameter; a cylindrical flange that continues to the base around the through hole and has a second inner diameter smaller than the first inner diameter; and inner wall surface that is defined by the flange and extends along a cylindrical surface formed by a generating line parallel to a central axis of the through hole. A ratio of a thickness T of the flange defined along a virtual plane orthogonal to the central axis of the through hole to a length L of the inner wall surface defined in a direction parallel to the central axis of the through hole is set to 1.5 or less.

Abstract: According to one embodiment, a magnetic head includes a magnetic pole layer including a magnetic pole extending along a layer, a coil layer configured to adjoin the magnetic pole layer and including a plurality of conductor patterns constituting a part of a coil wound around the magnetic pole and a resin which fills up a gap between the conductor patterns, a heater layer configured to adjoin the coil layer and including a heater extending in the heater layer via an area along a coil-forming region in which the conductor patterns in the coil layer are formed and an area along a no-coil region off the coil-forming region, and a transition-reluctant portion in that part of the no-coil region which adjoins the heater and having a glass transition temperature higher than that of the resin or not having any glass transition temperature.

Abstract: According to one embodiment, a magnetic head includes: a coil configured to be supplied with current; a main magnetic pole configured to be disposed along one surface of the coil and extend in a direction orthogonal to a floating surface from the floating surface; at least one auxiliary magnetic pole configured to be disposed along other surface of the coil and parallel to the main magnetic pole; a connecting portion configured to be linked with the coil and connect the main magnetic pole and the auxiliary magnetic pole; and a radiating layer configured to be disposed between the coil and the auxiliary magnetic pole and have larger thermal conductivity than the auxiliary magnetic pole.