Patents by Inventor Naofumi Chiwata

Naofumi Chiwata 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).

  • Patent number: 10996246
    Abstract: A current detection method for a current detection device including magnetism detection elements that detect magnetic flux density and output a voltage signal corresponding to the magnetic flux density is provided. The method includes acquiring measured value data that is obtained as a result of providing magnetic flux density in a detectable range of the magnetism detection elements that indicates the relationship between the magnetic flux density and an output voltage signal from the current detection device. Next, computational processing is performed so as to fit the acquired measured value data to a formula that includes plural factors and indicates the output voltage of the magnetism detection elements, thereby calculating the plural factors, and correcting the output voltage signal from the magnetism detection elements in accordance with the calculated factors so as to be approximately linear with respect to the magnetic flux density.
    Type: Grant
    Filed: October 10, 2014
    Date of Patent: May 4, 2021
    Assignee: HITACHI METALS, LTD.
    Inventors: Naoki Futakuchi, Naofumi Chiwata, Katsuya Akimoto
  • Patent number: 10338105
    Abstract: A current detector includes a half-bridge configuration including first and second magnetic detection elements that are connected in series and disposed such that a magnetization direction of a magnetic pinned layer thereof is opposite to each other, and a bias magnetic field generating means for applying a bias magnetic field to the first and second magnetic detection elements. The bias magnetic field has a substantially same intensity and is formed in a direction substantially orthogonal to the magnetization direction and opposite to each other.
    Type: Grant
    Filed: November 17, 2015
    Date of Patent: July 2, 2019
    Assignee: Hitachi Metals, Ltd.
    Inventors: Naoki Futakuchi, Naofumi Chiwata, Katsuya Akimoto
  • Patent number: 10225967
    Abstract: A noise suppression cable includes an insulated electric wire including an insulator that covers an outer periphery of a conductor wire, and a magnetic tape layer formed by transversely winding a magnetic tape on an outer periphery of the insulated electric wire. A magnetic body constituting the magnetic tape is cut out from a rolled material in such a manner that a width direction of the magnetic tape corresponds to a rolled direction, and the magnetic body has a magnetic property that is different between the width direction and an orthogonal direction to the width direction.
    Type: Grant
    Filed: March 25, 2015
    Date of Patent: March 5, 2019
    Assignee: HITACHI METALS, LTD.
    Inventors: Katsutoshi Nakatani, Kenji Ajima, Yosuke Sumi, Katsuya Akimoto, Naofumi Chiwata, Hiroshi Okikawa, Yasuharu Muto
  • Patent number: 9880206
    Abstract: An electric current sensor includes a plurality of bus bars arranged in parallel, a plurality of magnetic detection elements that are adapted to detect a strength of a magnetic field generated by an electric current flowing through the bus bars and to output a voltage according to the strength of the magnetic field detected, and an arithmetic operation part to arithmetically operate an electric current flowing through the bus bars based on the voltage output from the plurality of magnetic detection elements.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: January 30, 2018
    Assignee: HITACHI METALS, LTD.
    Inventors: Katsuya Akimoto, Hisashi Tate, Naoki Futakuchi, Naofumi Chiwata, Ken Okuyama, Yukio Ikeda, Kazuhisa Takahashi
  • Publication number: 20170307663
    Abstract: A current detection method for a current detection device including magnetism detection elements that detect magnetic flux density and output a voltage signal corresponding to the magnetic flux density is provided. The method includes acquiring measured value data that is obtained as a result of providing magnetic flux density in a detectable range of the magnetism detection elements that indicates the relationship between the magnetic flux density and an output voltage signal from the current detection device. Next, computational processing is performed so as to fit the acquired measured value data to a formula that includes plural factors and indicates the output voltage of the magnetism detection elements, thereby calculating the plural factors, and correcting the output voltage signal from the magnetism detection elements in accordance with the calculated factors so as to be approximately linear with respect to the magnetic flux density.
    Type: Application
    Filed: October 10, 2014
    Publication date: October 26, 2017
    Inventors: Naoki FUTAKUCHI, Naofumi CHIWATA, Katsuya AKIMOTO
  • Patent number: 9734931
    Abstract: It is an objective of the invention to provide a high-power supply cable characterized in that even when mounted in a narrow space where the cable undergoes a repetitive bending motion, any undesirable deformation out of the bending plane is small. There is provided a power-supply cable including: an electric wire including an electrical conductor and a resin sheath covering the electrical conductor, the electric wire having a tendency to generate a curl under a no-load condition, the curl having a curling direction, the curling direction being a normal to the curl, the electric wire having one or more longitudinal ends; a connecting terminal disposed at one of the longitudinal ends of the electric wire; and a curling tendency direction indicator showing the curling direction, the indicator being disposed along a normal line to the curl of the electric wire.
    Type: Grant
    Filed: August 19, 2014
    Date of Patent: August 15, 2017
    Assignee: HITACHI METALS, LTD.
    Inventors: Tomohisa Suzuki, Takeshi Terasaki, Fumihito Oka, Hirotaka Eshima, Naofumi Chiwata
  • Patent number: 9679688
    Abstract: A shield cable includes an insulated electrical cable of a conductor wire sheathed about the circumference by an insulator, and a magnetic tape layer formed by wrapping magnetic tape about the circumference of the insulated electrical cable. The magnetic tape is a magnetic tape shaped by continuously cutting to constant width an elongated sheet comprising a magnetic material. The magnetic tape, on at least the insulated electrical cable-facing surface thereof, has grooves extending in the lengthwise direction, for accommodating at least one of pairs of burrs that are formed at both widthwise edge surfaces during cutting of the elongated sheet.
    Type: Grant
    Filed: February 27, 2014
    Date of Patent: June 13, 2017
    Assignee: Hitachi Metals, Ltd.
    Inventors: Katsuya Akimoto, Naofumi Chiwata, Yosuke Sumi, Katsutoshi Nakatani, Kenji Ajima, Hiroshi Okikawa, Yasuharu Muto
  • Patent number: 9645189
    Abstract: A partial discharge charge amount measuring method includes generating a partial discharge in a sample by applying a voltage from a voltage impressing device connected to the sample, the voltage being higher than a partial discharge inception voltage, continuously measuring and recording terminal voltages of a capacitor connected in series between the sample and a ground at least until a breakdown of the sample occurs by alternately operating at least two data loggers connected to the capacitor at intervals of a predetermined time, calculating an amount of electric charge discharged from the sample and remaining in the capacitor by multiplying a difference in the recorded terminal voltages of the capacitor by a capacitance of the capacitor, and calculating an accumulated discharge amount by accumulating the discharged amount of electric charge at earliest until the breakdown of the sample occurs.
    Type: Grant
    Filed: November 22, 2013
    Date of Patent: May 9, 2017
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yosuke Sumi, Naofumi Chiwata, Hideyuki Kikuchi
  • Patent number: 9557352
    Abstract: A current detection structure includes a plurality of busbars arranged in parallel, and a plurality of magnetic detection elements each provided for corresponding one of the plurality of busbars so as to measure a strength of a magnetic field generated by a current flowing through the corresponding busbar. The plurality of magnetic detection elements are mounted on a single circuit board.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: January 31, 2017
    Assignee: HITACHI METALS, LTD.
    Inventors: Katsuya Akimoto, Hisashi Tate, Naofumi Chiwata, Ken Okuyama, Naoki Futakuchi, Yukio Ikeda, Kazuhisa Takahashi, Shinya Hayashi, Takahiro Futatsumori
  • Publication number: 20170020037
    Abstract: A noise suppression cable includes an insulated electric wire including an insulator that covers an outer periphery of a conductor wire, and a magnetic tape layer formed by transversely winding a magnetic tape on an outer periphery of the insulated electric wire. A magnetic body constituting the magnetic tape is cut out from a rolled material in such a manner that a width direction of the magnetic tape corresponds to a rolled direction, and the magnetic body has a magnetic property that is different between the width direction and an orthogonal direction to the width direction.
    Type: Application
    Filed: March 25, 2015
    Publication date: January 19, 2017
    Inventors: Katsutoshi NAKATANI, Kenji AJIMA, Yosuke SUMI, Katsuya AKIMOTO, Naofumi CHIWATA, Hiroshi OKIKAWA, Yasuharu MUTO
  • Patent number: 9530542
    Abstract: A shielded cable includes an insulated wire including a conductor wire and an insulation formed around the conductor wire, and a shield layer formed around the insulated wire and including a shield wire. The shield wire includes a tubular member including a conductive material and defining a gap therein, and a magnetic powder is filled in the gap.
    Type: Grant
    Filed: February 10, 2015
    Date of Patent: December 27, 2016
    Assignee: HITACHI METALS, LTD.
    Inventors: Katsuya Akimoto, Naofumi Chiwata, Yosuke Sumi, Katsutoshi Nakatani, Kenji Ajima, Hiroshi Okikawa, Yasuharu Muto
  • Patent number: 9513317
    Abstract: A current detection structure includes a busbar to flow a current therethrough, a magnetic detection element to detect a strength of a magnetic field generated by the current flowing through the busbar, and a current detecting portion to determine the current flowing through the busbar based on the magnetic field detected by the magnetic detection element. A through-hole is formed penetrating the busbar such that a current path is formed on both sides of the through-hole. The magnetic detection element is disposed in the through-hole. The current detecting portion determines the current flowing through the busbar based on a strength of a synthetic magnetic field detected by the magnetic detection element. The synthetic magnetic field is produced by combining a magnetic field that is generated by a current flowing through the current path on the both sides of the through-hole.
    Type: Grant
    Filed: January 20, 2015
    Date of Patent: December 6, 2016
    Assignee: Hitachi Metals, Ltd.
    Inventors: Ken Okuyama, Naofumi Chiwata, Katsuya Akimoto, Naoki Futakuchi, Yukio Ikeda, Kazuhisa Takahashi
  • Patent number: 9508468
    Abstract: A noise suppression cable includes an electrical wire, a first magnetic material including a pair of first surfaces formed along an axis direction of the electrical wire and a convex portion projecting from the first surfaces, and a second magnetic material including a pair of second surfaces disposed on a periphery of the electrical wire, the pair of the second surfaces contacting the pair of the first surfaces such that a tubular shape is formed by the first and second magnetic materials. The first magnetic material and the second magnetic material are configured to generate a compression stress in the convex portion of the first magnetic material by receiving an external force so as to reduce a relative permeability of the convex portion.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: November 29, 2016
    Assignee: HITACHI METALS, LTD.
    Inventors: Katsutoshi Nakatani, Yosuke Sumi, Kenji Ajima, Katsuya Akimoto, Naofumi Chiwata, Hiroshi Okikawa, Yasuharu Muto
  • Patent number: 9484128
    Abstract: A noise suppression cable includes an insulated wire, an internal magnetic tape layer including a resin layer and a magnetic material layer formed on one surface of the resin layer, the internal magnetic tape layer being spirally wound on a periphery of the insulated wire in a first direction along a longitudinal direction of the cable so as to allow the magnetic material layer of the internal magnetic tape layer to face outside, and an external magnetic tape layer including a resin layer and a magnetic material layer formed on one surface of the resin layer, the external magnetic tape layer being spirally wound on a periphery of the internal magnetic tape layer in a second direction different from the first direction along the longitudinal direction of the cable so as to allow the magnetic material layer of the external magnetic tape layer to face inside.
    Type: Grant
    Filed: February 13, 2015
    Date of Patent: November 1, 2016
    Assignee: HITACHI METALS, LTD.
    Inventors: Yoshinori Sunaga, Takahiro Sugiyama, Naofumi Chiwata
  • Patent number: 9455071
    Abstract: A noise suppression cable includes a conductor wire, and a magnetic insulation layer on a periphery of the conductor wire. The magnetic insulation layer includes an insulating material and two or more types of magnetic powders that have different frequency characteristics from each other.
    Type: Grant
    Filed: June 5, 2015
    Date of Patent: September 27, 2016
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yosuke Sumi, Naofumi Chiwata, Katsuya Akimoto, Katsutoshi Nakatani, Hiroshi Komuro, Kenji Ajima, Hiroshi Okikawa, Yasuharu Muto
  • Publication number: 20160211060
    Abstract: A shield cable includes an insulated electrical cable of a conductor wire sheathed about the circumference by an insulator, and a magnetic tape layer formed by wrapping magnetic tape about the circumference of the insulated electrical cable. The magnetic tape is a magnetic tape shaped by continuously cutting to constant width an elongated sheet comprising a magnetic material. The magnetic tape, on at least the insulated electrical cable-facing surface thereof, has grooves extending in the lengthwise direction, for accommodating at least one of pairs of burrs that are formed at both widthwise edge surfaces during cutting of the elongated sheet.
    Type: Application
    Filed: February 27, 2014
    Publication date: July 21, 2016
    Inventors: Katsuya AKIMOTO, Naofumi CHIWATA, Yosuke SUMI, Katsutoshi NAKATANI, Kenji AJIMA, Hiroshi OKIKAWA, Yasuharu MUTO
  • Patent number: 9396841
    Abstract: A noise suppression cable includes a plurality of twisted pair wires, an inclusion that includes an insulating material and a magnetic powder and separates the plurality of twisted pair wires, and a sheath that includes an insulating material and covers a periphery of the plurality of twisted pair wires and the inclusion.
    Type: Grant
    Filed: January 27, 2015
    Date of Patent: July 19, 2016
    Assignee: Hitachi Metals, Ltd.
    Inventors: Yosuke Sumi, Naofumi Chiwata, Katsuya Akimoto, Katsutoshi Nakatani, Kenji Ajima, Hiroshi Okikawa, Yasuharu Muto
  • Publication number: 20160146860
    Abstract: A current detector includes a plurality of current paths arranged in parallel, magnetic detection portions that are provided corresponding to the plurality of current paths and have magnetic detection elements for detecting strength of a magnetic field generated by an electric current flowing through each of the current paths, a temperature sensor for detecting a temperature of the magnetic detection portions, correction circuits for correcting an output of the magnetic detection elements based on a result of detection by the temperature sensor, and detection circuits for detecting a magnitude of the electric current flowing through each of the current paths based on the output corrected by the correction circuits. The magnetic detection portions and the temperature sensor are housed, together with a portion of the plurality of current paths, in a molded package. A number of the temperature sensor is less than that of the magnetic detection portions.
    Type: Application
    Filed: November 18, 2015
    Publication date: May 26, 2016
    Applicant: Hitachi Metals, Ltd.
    Inventors: Naoki FUTAKUCHI, Naofumi CHIWATA, Takahiro FUTATSUMORI, Hiroshi SAKAGUCHI
  • Publication number: 20160146859
    Abstract: A current detector includes a half-bridge configuration including first and second magnetic detection elements that are connected in series and disposed such that a magnetization direction of a magnetic pinned layer thereof is opposite to each other, and a bias magnetic field generating means for applying a bias magnetic field to the first and second magnetic detection elements. The bias magnetic field has a substantially same intensity and is formed in a direction substantially orthogonal to the magnetization direction and opposite to each other.
    Type: Application
    Filed: November 17, 2015
    Publication date: May 26, 2016
    Inventors: Naoki FUTAKUCHI, Naofumi CHIWATA, Katsuya AKIMOTO
  • Publication number: 20150357087
    Abstract: A noise suppression cable includes a conductor wire, and a magnetic insulation layer on a periphery of the conductor wire. The magnetic insulation layer includes an insulating material and two or more types of magnetic powders that have different frequency characteristics from each other.
    Type: Application
    Filed: June 5, 2015
    Publication date: December 10, 2015
    Inventors: Yosuke SUMI, Naofumi Chiwata, Katsuya Akimoto, Katsutoshi Nakatani, Hiroshi Komuro, Kenji Ajima, Hiroshi Okikawa, Yasuharu Muto