Patents by Inventor Takao Yabumi

Takao Yabumi 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: 9324485
    Abstract: A material for anisotropic magnet, comprising, (1) a Pr-T-B—Ga-based composition containing Pr: 12.5 to 15.0 atomic percent, B: 4.5 to 6.5 atomic percent, Ga: 0.1 to 0.7 atomic percent, and the balance of T and inevitable impurities, wherein T is Fe or obtained by substituting Co for a portion of the Fe; and having, (2) a degree of magnetic alignment of 0.92 or more, wherein the degree of magnetic alignment is defined by remanence (Br)/saturation magnetization (Js); and (3) a crystal grain diameter of 1 ?m or less.
    Type: Grant
    Filed: January 6, 2010
    Date of Patent: April 26, 2016
    Assignee: DAIDO STEEL CO., LTD.
    Inventors: Keiko Hioki, Takao Yabumi, Hayato Hashino
  • Patent number: 9281106
    Abstract: A material for anisotropic magnet, comprising, (1) a Pr-T-B—Ga-based composition containing Pr: 12.5 to 15.0 atomic percent, B: 4.5 to 6.5 atomic percent, Ga: 0.1 to 0.7 atomic percent, and the balance of T and inevitable impurities, wherein T is Fe or obtained by substituting Co for a portion of the Fe; and having, (2) a degree of magnetic alignment of 0.92 or more, wherein the degree of magnetic alignment is defined by remanence (Br)/saturation magnetization (Js); and (3) a crystal grain diameter of 1 ?m or less.
    Type: Grant
    Filed: January 6, 2010
    Date of Patent: March 8, 2016
    Assignee: DAIDO STEEL CO., LTD.
    Inventors: Keiko Hioki, Takao Yabumi, Hayato Hashino
  • Patent number: 8002906
    Abstract: The present invention provides a rare earth magnet, which is formed through at least hot molding, the rare earth magnet containing grains including an R2X14B phase as a main phase, and a grain boundary phase surrounding peripheries of the grains, in which R is at least one element selected from the group consisting of Nd, Pr, Dy, Tb and Ho, and X is Fe or Fe with a part being substituted by Co; in which an element RH is more concentrated in the grain boundary phase than in the grains, in which the element RH is at least one element selected from the group consisting of Dy, Tb and Ho; and the element RH is present with a substantially constant concentration distribution from the surface part of the magnet to the central part of the magnet.
    Type: Grant
    Filed: June 30, 2009
    Date of Patent: August 23, 2011
    Assignee: Daido Tokushuko Kabushiki Kaisha
    Inventors: Shunji Suzuki, Hayato Hashino, Masahiro Hiraoka, Takao Yabumi
  • Patent number: 7800474
    Abstract: The present invention provides a bond magnet for direct current reactor which is to be disposed in a gap formed in a magnetic core of a direct current rector, the bond magnet containing a magnet powder containing a rapidly quenched powder of a rare earth magnet alloy. The present invention also provides a direct current reactor including a magnetic core having a gap and a winding area wound around the magnetic core, in which the bond magnet is disposed in the gap of the magnetic core.
    Type: Grant
    Filed: February 18, 2009
    Date of Patent: September 21, 2010
    Assignees: Daido Tokushuko Kabushiki Kaisha, Kuretake Electro-Steel Co., Ltd.
    Inventors: Takao Yabumi, Koji Tsuru
  • Publication number: 20100172783
    Abstract: A material for anisotropic magnet, comprising, (1) a Pr-T-B—Ga-based composition containing Pr: 12.5 to 15.0 atomic percent, B: 4.5 to 6.5 atomic percent, Ga: 0.1 to 0.7 atomic percent, and the balance of T and inevitable impurities, wherein T is Fe or obtained by substituting Co for a portion of the Fe; and having, (2) a degree of magnetic alignment of 0.92 or more, wherein the degree of magnetic alignment is defined by remanence (Br)/saturation magnetization (Js); and (3) a crystal grain diameter of 1 ?m or less.
    Type: Application
    Filed: January 6, 2010
    Publication date: July 8, 2010
    Applicant: DAIDO STEEL CO., LTD.
    Inventors: Keiko HIOKI, Takao YABUMI, Hayato HASHINO
  • Publication number: 20100003156
    Abstract: The present invention provides a rare earth magnet, which is formed through at least hot molding, the rare earth magnet containing grains including an R2X14B phase as a main phase, and a grain boundary phase surrounding peripheries of the grains, in which R is at least one element selected from the group consisting of Nd, Pr, Dy, Tb and Ho, and X is Fe or Fe with a part being substituted by Co; in which an element RH is more concentrated in the grain boundary phase than in the grains, in which the element RH is at least one element selected from the group consisting of Dy, Tb and Ho; and the element RH is present with a substantially constant concentration distribution from the surface part of the magnet to the central part of the magnet.
    Type: Application
    Filed: June 30, 2009
    Publication date: January 7, 2010
    Applicant: DAIDO TOKUSHUKO KABUSHIKI KAISHA
    Inventors: Shunji SUZUKI, Hayato HASHINO, Masahiro HIRAOKA, Takao YABUMI
  • Publication number: 20090218012
    Abstract: A material for magnetic anisotropic magnet, comprising (1) a Pr-T-B—Ga-based composition containing Pr: 13.0 to 15.0 atomic percent, B: 4.5 to 6.5 atomic percent, Ga: 0.1 to 0.7 atomic percent, and the balance of. T and inevitable impurities, wherein T is obtained by substituting Co for Fe or a portion of Fe, (2) the material for magnetic anisotropic magnet is obtained by rapidly-cooling a molten alloy having the composition, pulverizing the ribbon obtained by the rapid-cooling, cold-forming the alloy powder obtained by the pulverizing, hot-forming the cold-formed body, and performing hot plastic working to the hot-formed body, and (3) the degree of magnetic orientation of the material for magnetic anisotropic magnet, which is defined by remanence (Br)/saturation magnetic flux density (Js), is 0.9 or more.
    Type: Application
    Filed: February 25, 2009
    Publication date: September 3, 2009
    Applicant: DAIDO STEEL CO., LTD
    Inventors: Keiko HIOKI, Takao YABUMI, Hayato HASHINO
  • Publication number: 20090206973
    Abstract: The present invention provides a bond magnet for direct current reactor which is to be disposed in a gap formed in a magnetic core of a direct current rector, the bond magnet containing a magnet powder containing a rapidly quenched powder of a rare earth magnet alloy. The present invention also provides a direct current reactor including a magnetic core having a gap and a winding area wound around the magnetic core, in which the bond magnet is disposed in the gap of the magnetic core.
    Type: Application
    Filed: February 18, 2009
    Publication date: August 20, 2009
    Applicants: DAIDO TOKUSHUKO KABUSHIKI KAISHA, KURUTAKE ELECTRO-STEEL CO., LTD.
    Inventors: Takao Yabumi, Koji Tsuru
  • Publication number: 20090081071
    Abstract: A rare earth permanent magnet alloy with a high coercive force is disclosed. The rare earth permanent magnet alloy comprises: a rare earth-iron-boron type magnetic phase (R2Fe14B type magnetic phase) constituting a parent phase; and a defect structure. The parent phase contains the defect structure. Displacement of magnetic domain wall of the R2Fe14B type magnetic phase is prevented by the defect structure, thereby improving coercive force.
    Type: Application
    Filed: September 9, 2008
    Publication date: March 26, 2009
    Inventors: Hiroshi YAMAMOTO, Tetsurou Tayu, Masashi Ohmura, Keizou Otani, Takao Yabumi, Hayato Hashino