Patent application number | Description | Published |
20090128081 | ELECTRIC STEERING SYSTEM - An electric steering system is provided with: a steering torque detection unit which detects a steering torque acting on the shaft; a brushless motor which includes a rotor and a stator having multi-phase stator coils, and generates an assisting torque for assisting the steering torque; a current supply switching unit which drives the brushless motor; a rotary angle estimation unit which outputs an estimated rotary angle; a determination unit which determines whether or not the estimated rotary angle is appropriate by comparison with a direction of the steering torque; and a steering control unit which drives the brushless motor in accordance with the estimated rotary angle determined to be appropriate by the determination unit to control generation of the assisting torque. | 05-21-2009 |
20090266179 | MAGNETOSTRICTIVE TORQUE SENSOR AND ELECTRIC POWER STEERING APPARATUS - A magnetostrictive torque sensor includes first and second magnetostrictive films mounted on a pinion shaft and having different magnetic anisotropic properties, a first detecting coil disposed in facing relation to the first magnetostrictive film, a second detecting coil disposed in facing relation to the second magnetostrictive film, a transistor, and a detector for detecting a torque applied to the pinion shaft based on a first detected signal representative of a potential at the junction between the first detecting coil and the second detecting coil. | 10-29-2009 |
20090314573 | Magnetostrictive Torque Sensor and Electric Steering System - A magnetostrictive torque sensor comprising: a magnetostrictive film provided on a ferromagnetic shaft; a bias magnetization device which applies a bias magnetic field to the shaft to magnetize the shaft; and a detection device which detects a change in magnetism of the magnetostrictive film, wherein: a torque acting on the shaft calculated based on the detection results of the detection device; and the bias magnetization device applies a bias magnetic field to the shaft at a predetermined timing. | 12-24-2009 |
20100263457 | MAGNETOSTRICTIVE TORQUE SENSOR AND METHOD OF MANUFACTURING SAME - A magnetostrictive torque sensor includes a single magnetostrictive film disposed on a steering shaft, and first and second coils for detecting changes in a magnetic property of the magnetostrictive film. The single magnetostrictive film includes a first anisotropic region and a second anisotropic region, having respective magnetic anisotropies inverse to each other. The first coil is disposed in confronting relation to the first anisotropic region, whereas the second coil is disposed in confronting relation to the second anisotropic region. | 10-21-2010 |
20110035114 | MOTOR CONTROL DEVICE AND ELECTRIC STEERING SYSTEM - A motor control device includes: a rotation angle detection portion that detects a rotation angle of a motor and outputs a rotation angle signal; an abnormal condition detection portion that detects the presence or absence of an abnormal condition of the rotation angle detection portion; a rotation angle estimation portion that estimates the rotation angle of the motor and outputs an estimate rotation angle signal; and a driving control portion that controls driving of the motor on the basis of the rotation angle signal, which is output from the rotation angle detection portion, when the abnormal condition detection portion does not detect an abnormal condition of the rotation angle detection portion, and controls driving of the motor on the basis of the estimate rotation angle signal, which is output from the rotation angle estimation portion, when the abnormal condition detection portion detects an abnormal condition of the rotation angle detection portion. | 02-10-2011 |
20120199414 | ELECTRIC POWER STEERING APPARATUS - An electric power steering apparatus includes a motor control unit for controlling an electric motor operatively connected to a steering shaft. The motor control unit includes a first control unit for controlling a steering torque detected by a torque detecting unit so as to bring the steering torque to zero or to a first predetermined value, and a second control unit for controlling the steering torque detected by the torque detecting unit so as to bring the steering torque to a second predetermined value which is greater than zero or than the first predetermined value, based on an operational quantity detected by an operational-quantity detecting unit or a quantity representative of a vehicle behavior detected by a vehicle-behavior detecting unit. The motor control unit controls the electric motor based on an output signal from the first control unit and an output signal from the second control unit. | 08-09-2012 |
20120232759 | ELECTRIC POWER STEERING DEVICE - An electric power steering device wherein mechanical friction is electrically provided. A steering torque value is detected by a steering torque sensor according to the operation of a steering wheel. An assist current value is calculated by an assist control section on the basis of the steering torque value. A target current value based on the assist current value is determined. For providing friction to the operation of the steering wheel, a friction control section and a friction torque value/current value conversion section generate a corrected steering torque value. A second corrected target current value is created by correcting a first corrected target current value by a friction current value. The corrected steering torque value is obtained by correcting the steering torque value by a friction torque value. The target current value is generated, resulting in a motor being subjected to driving control. | 09-13-2012 |
20120271513 | ELECTRIC POWER STEERING APPARATUS - In the event of a failure of a first electric motor drive signal generator, e.g., the microcomputer, which generates a first electric motor drive signal for performing a feedback control, a second electric motor drive signal generator, e.g., a PWM signal generator, which is made up of discrete circuit components, directly converts a steering torque signal into a second electric motor drive signal. An electric motor, which generates the assistive steering force, is driven by the second electric motor drive signal. | 10-25-2012 |
20120273293 | ELECTRIC POWER STEERING APPARATUS - As a quotient, which is produced when the value of an assistive current for causing an electric motor to generate an assistive torque is divided by the value of a steering torque detected by a steering torque sensor, becomes greater, a greater phase-lag compensation (smaller phase-lead compensation) is performed on the steering torque detected by the steering torque sensor. Within a region in which the steering sensation is reduced, a greater phase-lead compensation is performed. | 11-01-2012 |
20140195122 | ELECTRIC POWER STEERING DEVICE - Provided is an electric power steering device in which the operation feeling is improved without a decrease in commercial value. A phase compensation unit performs a frequency shift on a compensation frequency band compensated by the phase compensation unit. The phase compensation unit performs phase-shift in the compensation frequency band through a frequency shift process, instead of an increase in compensation gain. Therefore, it is possible to minimize occurrences of minute vibrations and abnormal noise in the steering system including the motor that accompany an increase in gain, and to improve the operation feeling and commercial value. | 07-10-2014 |
Patent application number | Description | Published |
20090107756 | Motor rotation angle detection device - A motor rotation angle detection device, comprising a resolver which detects a rotation angle of a motor generating an assist torque for steering road wheels. The resolver includes an annular rotor disposed inside an annular stator with an air gap interposed in between an outer circumferential surface of the rotor and an inner circumferential surface of the stator, so that the stator and the rotor are rotatable relative to each other, wherein a rotor supporting member is connected to a rotary shaft of the motor, and the rotor extends out from an axial end portion of the rotor supporting member so as to surround an outer periphery of the rotary shaft. With the such a motor rotation angle detection device, it is possible to stabilize the magnetic permeability of the rotor, and accordingly to increase an accuracy with which the rotation angle of the motor is detected. | 04-30-2009 |
20090114470 | Electric power steering device - An electric power steering device is configured to transmit an auxiliary torque to a steering unit of front wheels, and includes: an operator; an electric motor configured to generate the auxiliary torque in accordance with at least a steering torque generated by input from the operator; the steering unit of front wheels which includes a pinion shaft; and a rotation terminating mechanism which provides a motion terminating end of the operator, the rotation terminating mechanism being disposed between the operator and the pinion shaft. | 05-07-2009 |
20090218162 | Magnetostrictive torque sensor device, manufacturing method thereof, and vehicle steering apparatus - A magnetostrictive torque sensor device which detects a torque applied to a rotary shaft is provided. The magnetostrictive torque sensor device includes a magnetostrictive portion provided on a surface of the rotary shaft, a coil and a cylindrical back-yoke disposed in outer periphery of the coil. The coil includes a bobbin arranged in outer periphery of the magnetostrictive portion, and a wire wound around the bobbin. A slit is provided on the back-yoke. | 09-03-2009 |
20090288288 | TORQUE SENSOR AND METHOD OF MANUFACTURING THE SAME - The torque sensor includes a plurality of coil units having a substantially cylindrical shape, the coil units including a plurality of detection coils arranged to face a magnetic characteristic change portion formed on a rotary shaft. The coil units include a first coil unit and a second coil unit, and the first coil unit and the second coil unit are disposed in the axial direction of the shaft. The first coil unit and the second coil unit are fixed in an integrally molded resin. Thereby, there is provided a torque sensor having a high productivity and an easy configuration and a method of manufacturing the torque sensor. | 11-26-2009 |
20110231066 | ELECTRIC POWER STEERING APPARATUS AND ELECTRIC MOTOR DRIVING CONTROLLER USED FOR THE APPARATUS - A q-axis target current setting unit generates a q-axis current command value based on a steering input signal from a steering torque sensor and a vehicle speed signal from a vehicle speed sensor. An electric motor generates a predetermined torque based on the q-axis current command value and a q-axis current (a torque current) to which a fed back q-axis real current is added. On the other hand, a d-axis correction current setting unit sets a field weakening current (a d-axis current) in response to a voltage saturation (duty ratio=driving voltage of electric motor/power supply voltage) output from a voltage saturation calculating unit. For this reason, when the voltage saturation becomes high, distortion (harmonics component) in current can be decreased by decreasing the voltage saturation while keeping the torque constant using a predetermined torque current, and a torque ripple can be suppressed. | 09-22-2011 |
20110303480 | ELECTRIC POWER STEERING APPARATUS - In an electric power steering apparatus, an elastic member, disposed between the steering shaft and the housing, configured to be elastically deformed in accordance with rotation or displacement in a vehicle width direction, of the steering shaft. At least two bearings, disposed with a gap in an axial direction of the steering shaft, are configured to support the steering shaft. The elastic member is disposed between the bearings. A supporting member may be disposed between the steering shaft and the elastic member and configured to be displaced by a rotation of a predetermined angle or predetermined distance in accordance with the rotation or a displacement, in the width direction of the vehicle, of the steering shaft with slidable support for the steering shaft. The elastic member is fixed to the supporting member and abuts the housing. | 12-15-2011 |
20120216645 | WORM WHEEL - Provided is a worm wheel that allows the residual stress in the plastic gear forming member thereof to be reduced, and suited for compact design. The worm wheel comprises a metallic core member ( | 08-30-2012 |
20130152703 | MAGNETOSTRICTIVE TORQUE SENSOR AND METHOD OF MANUFACTURING THE SAME - A magnetostrictive torque sensor includes a housing configured to house a magnetostrictive element provided on a rotary shaft, a single coil bobbin and detection coils wound on the coil bobbin. The housing includes a plastic housing body having a generally cylindrical shape and molded integrally with the coil bobbin having the detection coils wound thereon, a metal flange portion disposed on an axial end portion of the generally cylindrical plastic housing body, and a plastic fastener member firmly connecting the metal flange portion to the axial end portion of the plastic housing body. A method of manufacturing such torque sensor is also disclosed. | 06-20-2013 |
Patent application number | Description | Published |
20120233860 | METHOD OF MANUFACTURING MOTORIZED POWER STEERING DEVICE - Disclosed is a method of manufacturing a motorized power steering device wherein auxiliary torque generated by an electric motor ( | 09-20-2012 |
20140326077 | MAGNETOSTRICTIVE TORQUE SENSOR AND ELECTRIC POWER STEERING DEVICE - A magnetostrictive torque sensor includes first to fourth detection coils each wound around a steering axle (a sensor shaft) so as to surround a magnetostrictive film formed on the sensor shaft and a multi-turn winding bias coil that is separated from the first to fourth detection coils and that is wound around the sensor shaft so as to surround the magnetostrictive film. By applying a DC component current to the bias coil, a sufficient bias magnetic field is applied to the magnetostrictive film so that the hysteresis is prevented. | 11-06-2014 |
20140339077 | PLATING DEVICE - Disclosed is a plating device that has a plating tank that retains a plating fluid and carries out magnetic metal plating on a shaft shaped member immersed in the plating fluid as a negative electrode. The plating device is provided with: a plurality of shielding jigs that are fitted to the outer peripheral surface of the shaft shaped member and regulate the part of the shaft shaped member being plated; and a positive electrode provided in the vicinity of the shaft shaped member and having an output part that faces the part being plated. A center position in the axial direction of the shaft shaped member for the part being plated and a center position of the output part are aligned within a prescribed allowable value for the center positions. | 11-20-2014 |
20150144418 | ELECTRIC POWER STEERING APPARATUS - Provided is an electric power steering apparatus capable of performing steering of a steering wheel with a comfortable steering feeling while stabilizing a vehicle behavior even in a vicinity of a steering neutral position. A first electric power steering apparatus includes a steering torque sensor for detecting a steering torque inputted by a driver, a steering angle sensor for detecting a steering angle of a steering wheel, a steering assist motor for applying a steering assist force to the steering wheel, and a drive control unit for performing drive control of the steering assist motor based on the steering torque and the steering angle. The drive control unit performs drive control of the steering assist motor based on the steering angle detected by the steering angle sensor and hysteresis characteristics related to a steering reaction force associated with a change of the steering angle. | 05-28-2015 |