Patents by Inventor Kenichi Fujikawa

Kenichi Fujikawa 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: 11623276
    Abstract: A method for manufacturing a magnet includes (1) a step of preparing three or more unmagnetized magnet materials of which magnetization easy axes are oriented in predetermined directions, and adhering the unmagnetized magnet materials with each other to make an assembly, and (2) a step of applying a curved pulse magnetic field to the assembly to magnetize the assembly, wherein in the step (2), the unmagnetized magnet materials are magnetized into magnet blocks, and an angle ? (where 0???180 degrees holds) formed by magnetization directions of at least a pair of magnet blocks adjacent to each other is in a range of 30 degrees to 120 degrees.
    Type: Grant
    Filed: May 25, 2018
    Date of Patent: April 11, 2023
    Assignee: NITTO DENKO CORPORATION
    Inventors: Kenichi Fujikawa, Shoichiro Saito, Katsuya Kume, Takashi Yamamoto
  • Publication number: 20220044852
    Abstract: Disclosed is a rare earth-sintered magnet in which a plurality of magnetic material particles are sintered. Surface magnetic flux density has a greatest value of 350 mT to 600 mT, the rare earth-sintered magnet has a thickness of 1.5 mm to 6 mm, a cross section of the rare earth-sintered magnet taken along a thickness direction is non-circular, and the cross section has an area in which axes of easy magnetization of the magnetic material particles has polar anisotropic orientation.
    Type: Application
    Filed: April 5, 2018
    Publication date: February 10, 2022
    Inventors: Kenichi FUJIKAWA, Takashi YAMAMOTO, Shoichiro SAITO, Takashi OZAKI, Katsuya KUME, Yuki HIRANO
  • Patent number: 11239014
    Abstract: Provided are a rare-earth magnet capable of realizing a high magnetic flux amount without using any back yoke, and a linear motor comprising a movable element using the rare-earth permanent magnet. A rare-earth permanent magnet-forming sintered body for forming a permanent magnet is integrally sintered while being formed into a given three-dimensional shape with a lengthwise cross-section having a first surface extending in a length direction thereof, a second surface lying at a distance from the first surface in a thickness direction thereof and extending in the length direction, and an edge surface of each of lengthwise opposite ends thereof. This sintered body is formed such that easy magnetization axes of the magnet material particles included in a central region thereof are oriented in such a manner as to be directed along an arch-shaped path.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: February 1, 2022
    Assignee: NITTO DENKO CORPORATION
    Inventors: Makoto Fujihara, Toshinobu Hoshino, Shoichiro Saito, Kenichi Fujikawa
  • Patent number: 11101707
    Abstract: This invention provides for a rare-earth permanent magnet-forming sintered body obtained by integrally sintering magnet material particles containing a rare-earth substance while shaping the magnet material particles, a rare-earth permanent magnet obtained by magnetizing the sintered body, and a rotary machine in which the permanent magnet is embedded.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: August 24, 2021
    Assignee: NITTO DENKO CORPORATION
    Inventors: Makoto Fujihara, Kenichi Fujikawa, Takashi Yamamoto, Shoichiro Saito
  • Publication number: 20210012934
    Abstract: Provided are: a sintered body that forms a rare-earth magnet and is configured in a manner such that the divergence between the orientation angles of the easy axes of magnetization of magnet material particles and the orientation axis angle of the magnet material particles is kept within a prescribed range in an arbitrary micro-section of a magnet cross-section; and a rare-earth sintered magnet. This sintered body for forming a rare-earth magnet has two or more different regions exhibiting an orientation axis angle of at least 20°, given that the orientation axis angle is defined as the highest-frequency orientation angle among the orientation angles of the easy magnetization axes, relative to a pre-set reference line, of a plurality of magnet material particles in a rectangular section at an arbitrary position in a plane including the thickness direction and the widthwise direction.
    Type: Application
    Filed: September 17, 2020
    Publication date: January 14, 2021
    Inventors: Kenichi FUJIKAWA, Takashi YAMAMOTO, Hirofumi EBE, Makoto FUJIHARA, Eiichi IMOTO, Tomohiro OMURE
  • Patent number: 10867729
    Abstract: Provided is a method for producing a sintered body that forms a rare-earth permanent magnet, has a single sintered structure and an arbitrary shape, and has easy magnetization axis orientations of different directions applied to the magnet material particles in a plurality of arbitrary regions. This method forms a three-dimensional first molded article from a composite material formed by mixing a resin material and magnet material particles containing a rare-earth substance. The first molded article is then subjected to a deforming force and a second molded article is formed in which the orientation direction of the easy magnetization axis of the magnet material particles in at least the one section of the horizontal cross-section is changed to a direction which differs from the orientation direction of the first molded article. The second molded article is heated to a sintering temperature and kept at the temperature for a period of time.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: December 15, 2020
    Assignee: NITTO DENKO CORPORATION
    Inventors: Kenichi Fujikawa, Katsuya Kume, Kazuo Ouchi, Toshinobu Hoshino, Masakazu Morimoto, Hirofumi Ono, Katsuyuki Nakabayashi, Miho Yamaguchi, Hiroshi Matsuo, Toshiaki Okuno, Makoto Fujihara, Eiichi Imoto, Hirofumi Ebe, Tomohiro Omure, Izumi Ozeki, Takashi Yamamoto, Yuki Kato, Tomoya Matsuda, Shoichiro Saito
  • Patent number: 10867732
    Abstract: This invention provides for a rotary electric machine that includes a rotor having a plurality of permanent magnets arranged in the circumferential direction, and in which the leakage of magnetic flux can be suppressed with a simple structure; and a rare-earth permanent magnet-forming sintered compact for forming rare-earth permanent magnets to be used in said rotary electric machine.
    Type: Grant
    Filed: March 24, 2016
    Date of Patent: December 15, 2020
    Assignee: NITTO DENKO CORPORATION
    Inventors: Makoto Fujihara, Kenichi Fujikawa, Shoichiro Saito
  • Publication number: 20200282463
    Abstract: A method for manufacturing a magnet includes (1) a step of preparing three or more unmagnetized magnet materials of which magnetization easy axes are oriented in predetermined directions, and adhering the unmagnetized magnet materials with each other to make an assembly, and (2) a step of applying a curved pulse magnetic field to the assembly to magnetize the assembly, wherein in the step (2), the unmagnetized magnet materials are magnetized into magnet blocks, and an angle ? (where 0???180 degrees holds) formed by magnetization directions of at least a pair of magnet blocks adjacent to each other is in a range of 30 degrees to 120 degrees.
    Type: Application
    Filed: May 25, 2018
    Publication date: September 10, 2020
    Inventors: Kenichi FUJIKAWA, Shoichiro SAITO, Katsuya KUME, Takashi YAMAMOTO
  • Patent number: 10669876
    Abstract: There is provided a seal structure to suppress a leak flow of a working fluid from a gap between a rotating structure and a stationary structure, the rotating structure being configured to rotate in a prescribed direction about an axial center line, the stationary structure facing an outer periphery of the rotating structure in a radial direction with the gap inbetween, wherein the stationary structure has a cavity in which the rotating structure is accommodated, an inner peripheral surface of the cavity is provided with a seal fin that extends toward the axial center line and a plurality of stationary-side recesses arranged along a flow direction of the leak flow, and as compared with a first stationary-side recess disposed on a most upstream side, a second stationary-side recess disposed on an immediately downstream side of the first stationary-side recess is set to have a smaller depth dimension.
    Type: Grant
    Filed: February 24, 2017
    Date of Patent: June 2, 2020
    Assignee: MITSUBISHI HITACHI POWER SYSTEMS, LTD.
    Inventors: Kazuyuki Matsumoto, Kenichi Fujikawa
  • Publication number: 20200161032
    Abstract: The rare-earth sintered magnet has a configuration in which a large number of magnet material particles including a rare-earth substance and each having an axis of easy magnetization have been integrally sintered. The rare-earth sintered magnet is provided with a first surface and a second surface opposing each other in the thickness direction. In a plane in parallel with a width direction and the thickness direction, the magnet material particles are magnetized such that, in a region extending from each of both end portions in the width direction toward the center portion in the width direction, the orientation direction of the easy magnetization axis is gradually changed. A maximum surface magnetic flux density in the first surface and a maximum surface magnetic flux density in the second surface satisfy the relationship (D1/D2)?4.
    Type: Application
    Filed: May 8, 2018
    Publication date: May 21, 2020
    Inventors: Kenichi FUJIKAWA, Takashi YAMAMOTO, Shoichiro SAITO, Takashi OZAKI, Katsuya KUME
  • Patent number: 10629348
    Abstract: The present invention provides a permanent magnet unit in which insulating layers are located at positions where an eddy current can be reduced most effectively. The permanent magnet unit includes at least one insulating layer, and a plurality of permanent magnet pieces located adjacent to each other with the at least one insulating layer in between. The at least one insulating layer is located at positions defined based on a magnitude of an eddy current flowing inside a permanent magnet, corresponding to a change in a magnetic field of the permanent magnet into which a plurality of the permanent magnet pieces are integrally formed without the at least one insulating layer.
    Type: Grant
    Filed: September 16, 2016
    Date of Patent: April 21, 2020
    Assignee: NITTO DENKO CORPORATION
    Inventors: Shoichiro Saito, Makoto Fujihara, Izumi Ozeki, Kenichi Fujikawa
  • Patent number: 10573440
    Abstract: This invention provides for a rare-earth permanent magnet-forming sintered body having an integral sintered structure of magnet material particles containing a rare-earth substance. The integral sintered structure is formed in a three-dimensional shape having: a cross-section with a shape defined by a radially outer-side arc-shaped surface having a first curvature radius, a radially inner-side arc-shaped surface having a second curvature radius less than the first curvature radius and having an arc shape concentric with the outer-side arc-shaped surface; and a first end face and a second end face each of which is a radially-extending face along a virtual radial line extending from a curvature center of the arc shapes; and an axial length extending in a direction perpendicular to the cross-section.
    Type: Grant
    Filed: November 17, 2016
    Date of Patent: February 25, 2020
    Assignee: NITTO DENKO CORPORATION
    Inventors: Makoto Fujihara, Kenichi Fujikawa, Shoichiro Saito
  • Patent number: 10544341
    Abstract: The present invention provides a thermal conductive polymer composition with low probability for mixing of an air bubble in a thermal conductive molded article, which is a thermal conductive polymer composition including thermal conductive inorganic particles having a specific particle size distribution and an electrically insulating polymer.
    Type: Grant
    Filed: December 16, 2014
    Date of Patent: January 28, 2020
    Assignees: NITTO DENKO CORPORATION, NITTO SHINKO CORPORATION
    Inventors: Kenichi Fujikawa, Yoshiharu Hatakeyama, Miho Yamaguchi, Yuji Yamagishi, Akihiro Oohashi
  • Publication number: 20190228888
    Abstract: A method comprises: charging a rare-earth magnet-forming material comprising magnet material particles into a mold, in a state in which an easy magnetization axis of each of the magnet material particles is oriented in one plane; sintering the rare-earth magnet-forming material charged in the mold by heating the rare-earth magnet-forming material to a sintering temperature while applying a given magnitude of pressing force to the rare-earth magnet-forming material, to thereby form a sintered body in which the magnet material particles are integrally sintered; and then subjecting the sintered body to high-temperature heat treatment, under a pressure lower than the pressing force during the sintering and under a maximum achieving temperature which ranges from greater than 900° C. to 1100° C., and whose difference from a maximum achieving temperature during the pressure sintering is within 250° C.
    Type: Application
    Filed: September 25, 2017
    Publication date: July 25, 2019
    Inventors: Kenichi FUJIKAWA, Izumi OZEKI, Takashi YAMAMOTO, Hirofumi EBE, Takuya NOBUTA
  • Publication number: 20190221339
    Abstract: Provided are: a method for manufacturing a sintered body as a base of a sintered magnet and a method for manufacturing a permanent magnet. Specifically, a magnet raw material is pulverized into magnet powder, the magnet powder pulverized and a binder are mixed, thereby to form a compound. The, a formed body, obtained by forming the compound formed, is sintered by heating up the same to a firing temperature in a pressed state at a predetermined heat-up rate, and by keeping the same at the firing temperature. In the sintering step, the pressure value for pressing the formed body is set to: less than 3 MPa from the start of heating up of the formed body to a predetermined timing during heating up of the formed body; and 3 MPa or more after the timing.
    Type: Application
    Filed: September 22, 2017
    Publication date: July 18, 2019
    Inventors: Hirofumi EBE, Izumi OZEKI, Takashi YAMAMOTO, Kenichi FUJIKAWA
  • Publication number: 20190048735
    Abstract: There is provided a seal structure to suppress a leak flow of a working fluid from a gap between a rotating structure and a stationary structure, the rotating structure being configured to rotate in a prescribed direction about an axial center line, the stationary structure facing an outer periphery of the rotating structure in a radial direction with the gap inbetween, wherein the stationary structure has a cavity in which the rotating structure is accommodated, an inner peripheral surface of the cavity is provided with a seal fin that extends toward the axial center line and a plurality of stationary-side recesses arranged along a flow direction of the leak flow, and as compared with a first stationary-side recess disposed on a most upstream side, a second stationary-side recess disposed on an immediately downstream side of the first stationary-side recess is set to have a smaller depth dimension.
    Type: Application
    Filed: February 24, 2017
    Publication date: February 14, 2019
    Applicant: Mitsubishi Hitachi Power Systems, Ltd.
    Inventors: Kazuyuki Matsumoto, Kenichi Fujikawa
  • Publication number: 20180336981
    Abstract: This invention provides for a rare-earth permanent magnet-forming sintered body having an integral sintered structure of magnet material particles containing a rare-earth substance. The integral sintered structure is formed in a three-dimensional shape having: a cross-section with a shape defined by a radially outer-side arc-shaped surface having a first curvature radius, a radially inner-side arc-shaped surface having a second curvature radius less than the first curvature radius and having an arc shape concentric with the outer-side arc-shaped surface; and a first end face and a second end face each of which is a radially-extending face along a virtual radial line extending from a curvature center of the arc shapes; and an axial length extending in a direction perpendicular to the cross-section.
    Type: Application
    Filed: November 17, 2016
    Publication date: November 22, 2018
    Inventors: Makoto FUJIHARA, Kenichi FUJIKAWA, Shoichiro SAITO
  • Publication number: 20180240581
    Abstract: The present invention provides a permanent magnet unit in which insulating layers are located at positions where an eddy current can be reduced most effectively. The permanent magnet unit includes at least one insulating layer, and a plurality of permanent magnet pieces located adjacent to each other with the at least one insulating layer in between. The at least one insulating layer is located at positions defined based on a magnitude of an eddy current flowing inside a permanent magnet, corresponding to a change in a magnetic field of the permanent magnet into which a plurality of the permanent magnet pieces are integrally formed without the at least one insulating layer.
    Type: Application
    Filed: September 16, 2016
    Publication date: August 23, 2018
    Inventors: Shoichiro SAITO, Makoto FUJIHARA, Izumi OZEKI, Kenichi FUJIKAWA
  • Publication number: 20180221951
    Abstract: Provided is a heretofore non-existing, novel rare-earth sintered magnet having both of an extremely low carbon content and an extremely small average particle size of magnet material particles. The sintered body for forming a rare-earth magnet comprises a large number of magnet material particles sintered together, wherein each of the magnet material particles contains a rare-earth substance and has an easy magnetization axis. This sintered body for forming a rare-earth magnet has a carbon content of 500 ppm or less, and the magnet material particles have an average particle size of 2 ?m or less.
    Type: Application
    Filed: July 29, 2016
    Publication date: August 9, 2018
    Applicant: NITTO DENKO CORPORATION
    Inventors: Kenichi FUJIKAWA, Izumi OZEKI, Tomohiro OMURE, Miho YAMAGUCHI, Toshiaki OKUNO, Hiroshi MATSUO
  • Publication number: 20180130581
    Abstract: Provided is a method for producing a sintered body that forms a rare-earth permanent magnet, has a single sintered structure and an arbitrary shape, and has easy magnetization axis orientations of different directions applied to the magnet material particles in a plurality of arbitrary regions. This method forms a three-dimensional first molded article from a composite material formed by mixing a resin material and magnet material particles containing a rare-earth substance. The first molded article is then subjected to a deforming force and a second molded article is formed in which the orientation direction of the easy magnetization axis of the magnet material particles in at least the one section of the horizontal cross-section is changed to a direction which differs from the orientation direction of the first molded article. The second molded article is heated to a sintering temperature and kept at the temperature for a period of time.
    Type: Application
    Filed: March 24, 2016
    Publication date: May 10, 2018
    Inventors: Kenichi FUJIKAWA, Katsuya KUME, Kazuo OUCHI, Toshinobu HOSHINO, Masakazu MORIMOTO, Hirofumi ONO, Katsuyuki NAKABAYASHI, Miho YAMAGUCHI, Hiroshi MATSUO, Toshiaki OKUNO, Makoto FUJIHARA, Eiichi IMOTO, Hirofumi EBE, Tomohiro OMURE, Izumi OZEKI, Takashi YAMAMOTO, Yuki KATO, Tomoya MATSUDA, Shoichiro SAITO