Patents Assigned to NSK Steering Systems Co., Ltd
  • Patent number: 8459077
    Abstract: To form a through hole at one portion of a side wall, of an expanded portion made by plastically deforming one part of a metal tube radially outward, in a portion where the plate thickness gradually changes, a slide tool is withdrawn from inside a punch hole while applying hydraulic pressure to the inside of the side wall. At the instant of commencing withdrawal of the slide tool, the degree of progress in the shearing for the portions of the side wall matching with the two side edges of the punch hole is made different. Then, the timing for moving from shearing to rupture is made to coincide, so that of the side wall, the portions matching with the punch hole, are made reliably into a blank, and are extracted from the side wall.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: June 11, 2013
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd., Sumitomo Metal Industries, Ltd., Sumitomo Pipe & Tube Co., Ltd.
    Inventors: Shoichi Abe, Yasushi Watanabe, Kazumi Shimoii, Atsushi Tomizawa, Mitsutoshi Uchida
  • Patent number: 7641561
    Abstract: A dust cover for a steering shaft includes a bush of low-frictional material, through which a steering shaft penetrates; a plurality of bellows made of rubber, provided in an axial direction of the steering shaft, and arranged between the bush and a panel for sealing the clearance; and an annular seal lip in contact with the outer periphery of the steering shaft.
    Type: Grant
    Filed: January 14, 2005
    Date of Patent: January 5, 2010
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd., Keeper Co., Ltd.
    Inventors: Seiichi Moriyama, Hiroshi Satou, Jun Yamada, Takashi Shiba, Tomohiko Ikenoya, Jun Watanabe
  • Patent number: 7591204
    Abstract: A belt speed reducing apparatus for an electric power steering apparatus includes a drive pulley having a first helical gear, a driven pulley having a second helical gear and a drive belt having a third helical gear in which a relationship of tan ?<? is established between a twist angle ? of the respective helical gears and a friction coefficient ? between the first or the second helical gear and the third helical gear. Further, an electric power steering apparatus for adjusting a backlash between gears of a speed reducing apparatus brought in mesh with each other or adjusting a tension of a belt of a speed reducing apparatus.
    Type: Grant
    Filed: October 8, 2004
    Date of Patent: September 22, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Seiji Ueno, Kazuo Chikaraishi
  • Patent number: 7574294
    Abstract: A control apparatus of an electric power steering apparatus is provided in which a nonlinear element of a motor model of-the electric power steering apparatus is compensated beforehand to linearize the motor model and the back electromotive force of the motor is computed to compensate the back electromotive force for a control loop, and conduct back electromotive force compensation with no lag in order to realize a control apparatus of an electric power steering apparatus with less control error, stable controllability, small motor output torque ripple, good wheel steering feeling, and less motor noise.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: August 11, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: CaoMinh Ta, ChunHao Jiang, Shuji Endo
  • Patent number: 7559405
    Abstract: The present invention provides a controller of an electric power steering device which does not apply an uncomfortable feeling to a operation of steering wheel while securing a fault determination confirming period enough long to prevent an erroneous detection of a torque sensor fault, and can secure a safety operation of steering wheel, even in the case that an output value of a torque sensor detecting a steering torque of a steering wheel becomes abnormal.
    Type: Grant
    Filed: August 26, 2004
    Date of Patent: July 14, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Kazuhiro Kumaido, Yusuke Itakura, Yuho Aoki, Nobuhiro Kubo
  • Patent number: 7548035
    Abstract: The invention relates to a control apparatus of an electric power steering apparatus structured such as to apply a steering assist force generated by a n-phase motor to a steering system of a vehicle, the control apparatus is provided with at least (n?1) numbers of current detecting means for detecting a current Im in each of phases of the motor, a current command value calculating means for outputting a current command value Imref in each of the phases, and n numbers of current control means, and the control apparatus executes a current control of each of the phases by the current control means having the current command value Imref in each of the phases and the current Im in each of the phases as an input.
    Type: Grant
    Filed: November 24, 2004
    Date of Patent: June 16, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Shuji Endo, Yuho Aoki, Hideyuki Kobayashi, CaoMinh Ta
  • Patent number: 7506893
    Abstract: In an impact absorbing type steering column apparatus for a vehicle in which two columns are fitted to each other in such a manner that an upper column, while being moved to the front part of the vehicle with respect to a lower column, absorbs the impact energy at a secondary collision of the vehicle, a bush is fixedly fitted to at least one of the outer peripheral side of the upper column and the inner peripheral side of the lower column in the fitting portion between the two columns.
    Type: Grant
    Filed: April 28, 2004
    Date of Patent: March 24, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Kiyoharu Higashino, Kiyoshi Sadakata
  • Patent number: 7500538
    Abstract: It is an object of the present invention to provide a control unit for an electric power steering apparatus for accurately detecting an abnormality of a steering angle sensor without forming the steering angle sensor as a double system or using an expensive position detection sensor. The object is achieved by calculating a relative steering angle by using inexpensive position detection sensors disposed at a motor of the electric power steering apparatus to output binary values and comparing a change amount of an absolute steering angle detected by the steering angle sensor and a change amount of the calculated relative steering angle with each other to thereby detect the abnormality of the steering angle sensor.
    Type: Grant
    Filed: April 15, 2005
    Date of Patent: March 10, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Takeshi Hara, Shuji Endo
  • Patent number: 7499780
    Abstract: A control apparatus of an electric power steering apparatus is provided in which a nonlinear element of a motor model of-the electric power steering apparatus is compensated beforehand to linearize the motor model and the back electromotive force of the motor is computed to compensate the back electromotive force for a control loop, and conduct back electromotive force compensation with no lag in order to realize a control apparatus of an electric power steering apparatus with less control error, stable controllability, small motor output torque ripple, good wheel steering feeling, and less motor noise.
    Type: Grant
    Filed: May 14, 2004
    Date of Patent: March 3, 2009
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: CaoMinh Ta, ChunHao Jiang, Shuji Endo
  • Patent number: 7464571
    Abstract: According to the hydroforming method by the invention, when slots with the aspect ratio of 3 or more are pierced onto the bulge-formed portion made by the hydroforming, even the piercing can be carried out within a series of processing steps in the hydroforming, thereby eliminating the piercing operation by means of the cumbersome machining process such as milling and ensuring an excellent slot configuration. Thus, the hydroformed parts by the invention are best suited for the automobile parts etc. where various piercing operations are required, and the mold used for the hydroforming method by the invention can be widely employed for processing the automobile parts etc., whereby the invention can be applied for processing the parts in automobiles and industrial machineries as well.
    Type: Grant
    Filed: August 18, 2006
    Date of Patent: December 16, 2008
    Assignees: Sumito Metal Industries, Ltd., NSK Ltd., NSK Steering Systems Co., Ltd., Sumitomo Pipe & Tube Co., Ltd.
    Inventor: Mitsutoshi Uchida
  • Patent number: 7455149
    Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.
    Type: Grant
    Filed: May 10, 2007
    Date of Patent: November 25, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Toru Segawa, Kazuo Chikaraishi
  • Patent number: 7455148
    Abstract: A torsion coil spring 30 applies an elastic force to a worm shaft 29 in a direction towards a worm wheel, via a pre-load pad 70. The pre-load pad 70 restricts displacement in relation to the widthwise direction, by one side face portion of a holder 61 fixed to a gear housing 22. Due to the elastic deformation of the pre-load pad 70 itself based on the elastic force of the torsion coil spring 30, the side face of the pre-load pad 70 is abutted against the one side face portion of the holder 61, so that a gap between the pre-load pad 70 and the one side face portion is minimized. As a result, the occurrence of a teeth fitting noise in the worm reduction gear 16 is suppressed.
    Type: Grant
    Filed: May 10, 2007
    Date of Patent: November 25, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Toru Segawa, Kazuo Chikaraishi
  • Patent number: 7443131
    Abstract: A control device for electric power steering apparatus, in which when torque ripples at the time of the rotation of a motor is reduced by simple arithmetic, smooth and safe assist limitation is performed without deteriorating steering feeling, is provided. For this reason, in the control device for electric power steering apparatus adopting a vector control system for applying an assist force of a motor to a steering system, a phase delay according to an angular velocity is obtained, a corrected electric angle is calculated by adding the phase delay to an electric angle, and generation of a current command value in the vector control is compensated based on the corrected electric angle.
    Type: Grant
    Filed: December 12, 2004
    Date of Patent: October 28, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: CaoMinh Ta, Hideyuki Kobayashi, Shuji Endo
  • Patent number: 7441807
    Abstract: An automotive steering column apparatus has an inner column rotatably supporting a steering shaft, an outer column holding the inner column while rotatably embracing the inner column, a vehicle body side bracket having a vehicle body mount portion which can be mounted on a vehicle body and a pair of left and right facing flat plate portions which extend substantially vertically and disposed in such a manner as to surround the outer column, a clamping mechanism for changing a width of the pair of facing flat plate portions and changing a width of an inner circumferential surface of the outer column in connection with a change in the width of the pair of facing flat portions, and a shear ring mounted on at least either the inner circumferential surface of the outer column or an outer circumferential surface of the inner column. A shear permissive projection is provided on the shear ring.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: October 28, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Shin Yoshimoto, Kiyoharu Higashino, Kiyoshi Sadakata
  • Patent number: 7440829
    Abstract: The present invention provides a steering angle estimating apparatus for vehicle that can accurately determine a steady state at all the steering angles, and can estimate the steering angle as much as possible even in a non-steady state. In the steering angle estimating apparatus for vehicle that has wheel rotational velocity sensors for four wheels, respectively, and estimates the steering angle of the vehicle based on wheel rotational velocities from the wheel rotational velocity sensors, relationships in the wheel rotational velocities between respective combinations of two wheels of the front and rear wheels on right and left sides are compared so that slip of the four wheels is detected.
    Type: Grant
    Filed: September 14, 2004
    Date of Patent: October 21, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventor: Takeshi Hara
  • Patent number: 7438320
    Abstract: A steering column adjustable height and inclination of steering wheel has a singularity of control lever for controlling clamping/unclamping of a telescopic mechanism and a tilting mechanism for the adjustment. An energizing direction inverting mechanism inverts direction of biasing force applied to the lever by an energizing member from clamping direction to unclamping direction halfway through operation of the lever by a driver.
    Type: Grant
    Filed: December 13, 2004
    Date of Patent: October 21, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Kenji Sato, Naoki Sawada, Tetsuya Koike
  • Patent number: 7429216
    Abstract: A vehicular steering apparatus, includes an input shaft for transmitting rotation from a steering wheel, an intermediate shaft including an upper intermediate shaft, a lower intermediate shaft and a buffer coupling for coupling the upper intermediate shaft and the lower intermediate shaft, an output shaft for driving a steering mechanism on a side of a vehicle, and universal joints for respectively coupling the input shaft and the upper intermediate shaft as well as the lower intermediate shaft and the output shaft, in which at least one of the universal joints is a universal ball joint.
    Type: Grant
    Filed: May 11, 2004
    Date of Patent: September 30, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventor: Hiroshi Sekine
  • Patent number: 7423397
    Abstract: An electric power steering device to control a motor based on steering torque generated in a steering shaft and supply an auxiliary steering force conforming to the steering torque to the steering system. The device judges the state wherein the command current value computed based on steering torque and the motor terminal voltage estimated based on a motor rotation number are deemed to be zero and, when the said state is judged, corrects the offset error of a motor current detecting circuit so that the actual motor terminal voltage is equal to zero. It is possible to prevent the auxiliary steering force based on offset error from being supplied to a steering system and eliminate the variation of steering torque.
    Type: Grant
    Filed: October 27, 2005
    Date of Patent: September 9, 2008
    Assignee: NSK Steering Systems Co., Ltd.
    Inventor: Youichi Katahira
  • Patent number: 7416199
    Abstract: There is disclosed a steering apparatus for a vehicle in which a steering power of a steering shaft is assisted by a column-assist type electric power steering apparatus so that the steering power is transmitted to steer the wheels by means of a steering mechanism, in which a telescopic shaft with a male shaft and a female shaft fitted to each other to be mutually unrotatable and slidable is interposed between an output shaft of said column-assist type electric power steering apparatus and an input shaft of the steering mechanism.
    Type: Grant
    Filed: February 5, 2004
    Date of Patent: August 26, 2008
    Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.
    Inventor: Yasuhisa Yamada
  • Patent number: 7412911
    Abstract: A steering column apparatus includes: a stationary column member; a movable column member whose one end is supported on the stationary column member nonrotatably about a center axis and movably along the center axis; a column head disposed on the other end of the movable column member; a wheel shaft supported rotatably on the column head; a column clamp for clamping and unclamping the movable column member with respect to the stationary column member at two or more points which are spaced along the center axis of the movable column member; and a control lever whose operation lever end is positioned in the vicinity of a steering wheel and which is capable of operating the column clamp.
    Type: Grant
    Filed: September 16, 2004
    Date of Patent: August 19, 2008
    Assignees: NSK, Ltd., NSK Steering Systems Co., Ltd.
    Inventors: Masaki Nishioka, Naoki Sawada