Patents by Inventor Kenji Hiramoto

Kenji Hiramoto has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240255693
    Abstract: A plastic optical fiber that has a multilayer structure that includes a core (X), a first cladding (Y), and a second cladding (Z), wherein the core is made of an organic polymer material having a water-absorbing ratio of not less than 0.001% and not more than 0.29% and a total light transmittance of not less than 80% and containing not less than 0.01% by weight and not more than 10% by weight of a plasticizer; a relationship between a refractive index of the core (X) and the refractive index of the first cladding (Y) is defined by inequality: X?Y>0.01, and a relationship between a refractive index of the first cladding (Y) and the refractive index of a second cladding (Z) is defined by inequality: Y?Z>0.05, wherein the plastic optical fiber has high humidity resistance and excellent bending resistance.
    Type: Application
    Filed: June 21, 2021
    Publication date: August 1, 2024
    Inventors: Koki Mitsuno, Satoshi Matsuba, Kenji Hiramoto
  • Patent number: 11955919
    Abstract: An electric motor system includes a battery, an inverter, an electric motor, a zero-phase switching arm and a control unit. The inverter converts DC power output from the battery into three-phase AC power and outputs the three-phase AC power to the electric motor. A rotor of the electric motor rotates by the three-phase AC power output from the inverter. A neural point of the electric motor is connected to the zero-phase switching arm. A zero-phase current flowing through respective windings of the electric motor is adjusted by switching of the zero-phase switching arm. By this means, in the electric motor system, torque is generated at the rotor also using the zero-phase current as well as a three-phase AC current flowing through the respective windings.
    Type: Grant
    Filed: June 21, 2021
    Date of Patent: April 9, 2024
    Assignee: DENSO CORPORATION
    Inventors: Makoto Taniguchi, Kazunari Moriya, Kenji Hiramoto, Hideo Nakai, Yuuko Ohtani, Shinya Urata, Masafumi Namba
  • Patent number: 11751368
    Abstract: The electrically conductive resin composition may contain matrix resin, coke powder, and carbon fiber. The volume mean particle diameter of the coke powder may be not less than 1 ?m and not more than 500 ?m. The content percentage of the coke powder in the electrically conductive resin composition may be not less than 1 wt % and not more than 60 wt %. The aspect ratio of the carbon fiber may be not less than 3 and not more than 1700. The content percentage of the carbon fiber in the electrically conductive resin composition may be not less than 0.5 wt % and not more than 10 wt %.
    Type: Grant
    Filed: February 24, 2021
    Date of Patent: September 5, 2023
    Assignees: NIPPON STEEL CHEMICAL & MATERIAL CO., LTD., MAZDA MOTOR CORPORATION
    Inventors: Toshiaki Miyanaga, Kazuhisa To, Nobuyoshi Kajioka, Junichi Ogawa, Kenji Hiramoto
  • Publication number: 20230079383
    Abstract: A motor system of the present disclosure includes a permanent magnet motor including a stator having N-phase windings and a rotor having a permanent magnet, N being a natural number greater than or equal to three, an inverter that supplies N-phase drive currents for generating a rotating magnetic field to the stator, and a zero-phase current supply unit that supplies a zero-phase current to the N-phase windings of the stator. The motor system applies the zero-phase current to the N-phase windings in response to an inter-terminal voltage of the permanent magnet motor reaching a predetermined value of the inter-terminal voltage.
    Type: Application
    Filed: November 21, 2022
    Publication date: March 16, 2023
    Applicant: DENSO CORPORATION
    Inventors: Makoto TANIGUCHI, Yuuko OHTANI, Shinya URATA, Hideo NAKAI, Kenji HIRAMOTO
  • Patent number: 11606889
    Abstract: Provided is carbon material filler for an electromagnetic shield, which includes a graphitizable carbon material to be mixed into a molding material in order to absorb electromagnetic waves, the carbon material filler for an electromagnetic shield satisfying (1) to (3): (1) A spacing d002 of a 002 plane of the graphitizable carbon material measured through X-ray diffraction measurement (XRD) is at least 0.338 nm. (2) A relative intensity ratio (A/B) value between a peak intensity (A) of a “002 plane” detected when the graphitizable carbon material is measured through X-ray diffraction measurement (XRD) and a higher peak intensity (B) that is selected from a “100 plane” and a “004 plane” is at least 2.5 and less than 27. (3) The filler is in powder form and the average particle diameter D50 is at least 1 ?m and at most 5 mm.
    Type: Grant
    Filed: March 23, 2021
    Date of Patent: March 14, 2023
    Assignee: Mazda Motor Corporation
    Inventors: Toshiaki Miyanaga, Kazuhisa To, Nobuyoshi Kajioka, Junichi Ogawa, Kenji Hiramoto
  • Publication number: 20210313912
    Abstract: An electric motor system includes a battery, an inverter, an electric motor, a zero-phase switching arm and a control unit. The inverter converts DC power output from the battery into three-phase AC power and outputs the three-phase AC power to the electric motor. A rotor of the electric motor rotates by the three-phase AC power output from the inverter. A neural point of the electric motor is connected to the zero-phase switching arm. A zero-phase current flowing through respective windings of the electric motor is adjusted by switching of the zero-phase switching arm. By this means, in the electric motor system, torque is generated at the rotor also using the zero-phase current as well as a three-phase AC current flowing through the respective windings.
    Type: Application
    Filed: June 21, 2021
    Publication date: October 7, 2021
    Applicant: DENSO CORPORATION
    Inventors: Makoto TANIGUCHI, Kazunari MORIYA, Kenji HIRAMOTO, Hideo NAKAI, Yuuko OHTANI, Shinya URATA, Masafumi NAMBA
  • Publication number: 20210307217
    Abstract: The electrically conductive resin composition may contain matrix resin, coke powder, and carbon fiber. The volume mean particle diameter of the coke powder may be not less than 1 ?m and not more than 500 ?m. The content percentage of the coke powder in the electrically conductive resin composition may be not less than 1 wt % and not more than 60 wt %. The aspect ratio of the carbon fiber may be not less than 3 and not more than 1700. The content percentage of the carbon fiber in the electrically conductive resin composition may be not less than 0.5 wt % and not more than 10 wt %.
    Type: Application
    Filed: February 24, 2021
    Publication date: September 30, 2021
    Applicants: Nippon Steel Chemical & Material Co., Ltd., Mazda Motor Corporation
    Inventors: Toshiaki MIYANAGA, Kazuhisa TO, Nobuyoshi KAJIOKA, Junichi OGAWA, Kenji HIRAMOTO
  • Publication number: 20210307222
    Abstract: Provided is carbon material filler for an electromagnetic shield, which includes a graphitizable carbon material to be mixed into a molding material in order to absorb electromagnetic waves, the carbon material filler for an electromagnetic shield satisfying (1) to (3): (1) A spacing d002 of a 002 plane of the graphitizable carbon material measured through X-ray diffraction measurement (XRD) is at least 0.338 nm. (2) A relative intensity ratio (A/B) value between a peak intensity (A) of a “002 plane” detected when the graphitizable carbon material is measured through X-ray diffraction measurement (XRD) and a higher peak intensity (B) that is selected from a “100 plane” and a “004 plane” is at least 2.5 and less than 27. (3) The filler is in powder form and the average particle diameter D50 is at least 1 ?m and at most 5 mm.
    Type: Application
    Filed: March 23, 2021
    Publication date: September 30, 2021
    Applicants: NIPPON STEEL CHEMICAL & MATERIAL CO., LTD., Mazda Motor Corporation
    Inventors: Toshiaki Miyanaga, Kazuhisa To, Nobuyoshi Kajioka, Junichi Ogawa, Kenji Hiramoto
  • Patent number: 9667113
    Abstract: A rotor for a rotating electrical device includes: a rotor coil that is wound on each of the rotor salient poles; a retaining member that is supported by a rotor core; and an outer magnetic member. The retaining member has a beam bridged between the adjacent rotor salient poles and prevents the rotor coil from falling out. The outer magnetic member is provided in an end of the beam.
    Type: Grant
    Filed: August 23, 2013
    Date of Patent: May 30, 2017
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kaoru Kubo, Ryoji Mizutani, Hiroki Kato, Eiji Yamada, Shintaro Chinen, Kenji Hiramoto, Hideo Nakai
  • Patent number: 9577480
    Abstract: A rotor includes a plurality of salient poles, each of which is formed by a plurality of plate members including steel plates that are stacked together, provided extending in a radial direction and around which a coil is wound. The plurality of salient poles has auxiliary salient poles that protrude from the salient poles between two salient poles that are adjacent to one another. The auxiliary salient poles are formed by only a first plate member that is a portion of plate members that forms the salient poles.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: February 21, 2017
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Eiji Yamada, Ryoji Mizutani, Shintaro Chinen, Kenji Hiramoto, Hideo Nakai
  • Patent number: 9124159
    Abstract: A stator that includes stator windings wound around teeth. A rotor includes: a rotor core; rotor windings wound around main salient poles of the rotor; and a diode serving as a magnetic characteristic adjustment portion that causes magnetic characteristics produced on the main salient poles by electromotive forces induced in the rotor windings to differ in the circumferential direction of the rotor. The rotor has auxiliary salient poles that are each protruded from a side surface of each main salient pole in the circumferential direction. In each of rotor slots formed between the main salient poles adjacent to each other in the circumferential direction, the auxiliary salient poles adjacent to each other in the circumferential direction are connected to each other within the rotor slot. In each rotor slot, at least a portion of the rotor windings is disposed radially inside the auxiliary salient poles.
    Type: Grant
    Filed: June 12, 2012
    Date of Patent: September 1, 2015
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Eiji Yamada, Ryoji Mizutani, Shintaro Chinen, Kenji Hiramoto, Hideo Nakai
  • Patent number: 9083276
    Abstract: A stator has multi-phase stator coils that are wound around a stator core by concentrated winding. A rotor has rotor coils that are wound at multiple portions of a rotor core in the circumferential direction and diodes that serve as rectifier unit that is connected to the rotor coils and that varies the magnetic characteristics of the respective rotor coils alternately in the circumferential direction. A rotary electric machine driving system includes a decreasing/increasing pulse superimposing unit that superimposes decreasing pulse current for a pulse-shaped decrease on a q-axis current command for passing currents through the stator coils and that superimposes increasing pulse current for a pulse-shaped increase on a d-axis current command.
    Type: Grant
    Filed: February 14, 2012
    Date of Patent: July 14, 2015
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Eiji Yamada, Ryoji Mizutani, Kenji Hiramoto, Hideo Nakai, Norimoto Minoshima
  • Publication number: 20150194855
    Abstract: A rotor of a rotary electric machine includes a rotor core having a plurality of rotor salient poles disposed on an outer periphery of the rotor core in a circumferential direction of the rotor core, rotor coils wound on the rotor salient poles, and a retainer member provided to close a slot formed between the rotor salient poles. The retainer member includes a leg portion extending radially in the slot between rotor coils wound on two rotor salient poles adjacent to each other in the circumferential direction and fixed to the rotor core, and beam portions extending in the opposite circumferential directions each other from a radially outer end portion of the leg portion and that close an outer periphery of the slot. The leg portion of the retainer member is provided with protrusion portions protruded in circumferential directions to engage with the coil winding that forms the rotor coils.
    Type: Application
    Filed: July 22, 2013
    Publication date: July 9, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kaoru KUBA, Ryoji MIZUTANI, Hiroki KATO, Eiji YAMADA, Shintaro CHINEN, Hideo NAKAI, Kenji HIRAMOTO
  • Publication number: 20150155753
    Abstract: A rotor for a rotating electrical device includes: a rotor coil that is wound on each of the rotor salient poles; a retaining member that is supported by a rotor core; and an outer magnetic member. The retaining member has a beam bridged between the adjacent rotor salient poles and prevents the rotor coil from falling out. The outer magnetic member is provided in an end of the beam.
    Type: Application
    Filed: August 23, 2013
    Publication date: June 4, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kaoru Kubo, Ryoji Mizutani, Hiroki Kato, Eiji Yamada, Shintaro Chinen, Kenji Hiramoto, Hideo Nakai
  • Publication number: 20150155810
    Abstract: A rotary electric machine control system includes a control device that controls a rotary electric machine. When there is a current phase at which a reluctance torque is maximum between a first current phase (?1) of a first current vector (I1) on which current pulses have not been superimposed yet and a second current phase (?2) of a second current vector (I2) obtained by increasing a d-axis current and reducing a q-axis current, the control device sets an intermediate current vector (Im) having an intermediate phase (?m) between the first and second current phases (?1, ?2). The intermediate current vector (Im) is set so as to be larger than an imaginary current vector (Ima) at the intermediate phase (?m) in the case where a vector locus is varied in a straight line from the first current vector (I1) to the second current vector (I2). The current pulses are generated by changing the current vector in order of I1, Im and I2 and returning the current vector in order of Im and I1.
    Type: Application
    Filed: September 24, 2013
    Publication date: June 4, 2015
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Eiji Yamada, Kenji Hiramoto
  • Patent number: 8847455
    Abstract: A plurality of salient poles projecting toward a stator are arranged on a rotor core along the circumferential direction while being spaced apart from each other, and rotor windings are wound around these salient poles. The rotor windings are short-circuited through diodes, respectively; and when currents rectified by the diodes flow through the rotor windings, the salient poles are magnetized to produce a magnet where the magnetic pole is fixed. The width ? of each salient pole in the circumferential direction is smaller than a width corresponding to an electric angle of 180° of the rotor, and the rotor windings are wound around each salient pole by short-pitch winding.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: September 30, 2014
    Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Toyota Jidosha Kabushiki Kaisha, Kabushiki Kaisha Toyota Jidoshokki, Denso Corporation
    Inventors: Kenji Hiramoto, Hideo Nakai, Eiji Yamada, Norimoto Minoshima, Masahiro Seguchi
  • Patent number: 8742710
    Abstract: A rotary electric machine system includes: a stator that has multi-phase stator coils and that generates stator magnetomotive forces based on respective stator currents having different phases supplied to the multi-phase stator coils; a rotor on which rotor coils are wound such that magnetic poles are formed by rotor currents generated in response to the stator magnetomotive forces generated by the stator; a regulating unit that regulates a flow direction of each of the rotor currents to one direction to thereby regulate a polarity of each of the magnetic poles; and a control unit that controls currents supplied to the stator coils on the basis of a target torque. The control unit superimposes a pulse on the stator currents to adjust the ratio of each of the stator currents and each of the rotor currents so as to minimize a copper loss in the stator and the rotor.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: June 3, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Eiji Yamada, Kenji Hiramoto, Hideo Nakai, Norimoto Minoshima
  • Patent number: 8680801
    Abstract: A rotating electrical machine system includes a stator that has stator windings of a plurality of phases, and that generates a stator magnetomotive force in accordance with stator current of different phases, which is supplied to the stator windings of the plurality of phases; a rotor on which rotor windings are wound such that rotor current is generated in accordance with the stator magnetomotive force generated by the stator and a magnetic pole is formed by the rotor current; and a control unit that controls an output torque from the rotor, by controlling the stator current. In a case where a predetermined torque is output from the rotor, the control unit applies a pulse to the stator current so as to increase the stator current and reduce the rotor current, when a temperature of the rotor is high as compared with when the temperature of the rotor is low.
    Type: Grant
    Filed: March 23, 2012
    Date of Patent: March 25, 2014
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Eiji Yamada, Kenji Hiramoto, Hideo Nakai, Norimoto Minoshima
  • Publication number: 20140028160
    Abstract: A stator has a stator core, and stator windings wound around either the stator core or teeth of the stator. A rotor has a rotor core, windings wound around either the rotor core or teeth of the rotor, and magnetic auxiliary poles disposed between the teeth adjacent in a circumferential direction. The rotor further has diodes that are magnetic characteristic adjustment portions that cause the magnetic characteristic that occurs in the teeth by induced electromotive force produced in the rotor windings to vary in the circumferential direction of the rotor core.
    Type: Application
    Filed: April 4, 2012
    Publication date: January 30, 2014
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Eiji Yamada, Ryoji Mizutani, Kenji Hiramoto, Hideo Nakai, Norimoto Minoshima
  • Publication number: 20130334937
    Abstract: A stator has multi-phase stator coils that are wound around a stator core by concentrated winding. A rotor has rotor coils that are wound at multiple portions of a rotor core in the circumferential direction and diodes that serve as rectifier unit that is connected to the rotor coils and that varies the magnetic characteristics of the respective rotor coils alternately in the circumferential direction. A rotary electric machine driving system includes a decreasing pulse superimposing unit that superimposes decreasing pulse current for a pulse-shaped decrease on a q-axis current command for passing currents through the stator coils.
    Type: Application
    Filed: February 14, 2012
    Publication date: December 19, 2013
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Eiji Yamada, Ryoji Mizutani, Kenji Hiramoto, Hideo Nakai, Norimoto Minoshima