Patents by Inventor Hidefumi Kishimoto

Hidefumi Kishimoto 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: 11087922
    Abstract: A method for producing a rare earth magnet, including preparing a melt of a first alloy having a composition represented by (R1vR2wR3x)yTzBsM1t (wherein R1 is a light rare earth element, R2 is an intermediate rare earth element, R3 is a heavy rare earth element, T is an iron group element, and M1 is an impurity element, etc.), cooling the melt of the first alloy at a rate of from 100 to 102 K/sec to obtain a first alloy ingot, pulverizing the first alloy ingot to obtain a first alloy powder having a particle diameter of 1 to 20 ?m, preparing a melt of a second alloy having a composition represented by (R4pR5q)100-uM2u (wherein R4 is a light rare earth element, R5 is an intermediate or heavy rare earth element, M2 is an alloy element, etc.), and putting the first alloy powder into contact with the melt of the second alloy.
    Type: Grant
    Filed: April 13, 2018
    Date of Patent: August 10, 2021
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Noritsugu Sakuma, Masao Yano, Hidefumi Kishimoto, Tetsuya Shoji
  • Patent number: 11078561
    Abstract: There are provided a soft magnetic material having a high saturation magnetization and a low coercive force and excellent in thermal endurance, and a method for producing the same. The present disclosure relates to a soft magnetic material represented by the following composition formula: Fe100-x-yBxNiy, wherein x satisfies 10?x?16 in at %, and y satisfies 0<y?4 in at %, having a coercive force of 20 A/m or less, and having a coercive force characteristic decrease rate after a thermal endurance test {[(coercive force after thermal endurance test?coercive force before thermal endurance test)/coercive force before thermal endurance test]×100 (%)} of 20% or less, wherein the thermal endurance test is carried out by allowing the soft magnetic material to stand in a constant temperature oven at 170° C. in the air for 100 h, and a method for producing the same.
    Type: Grant
    Filed: May 21, 2019
    Date of Patent: August 3, 2021
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kiyotaka Onodera, Hidefumi Kishimoto
  • Patent number: 10910987
    Abstract: To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced. A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is Tc1 K, and the Curie temperature of another is Tc2 K, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at Ts K that is (Tc1?100) K or higher and lower than Tc2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature Ts K or Tc1 K, whichever is lower.
    Type: Grant
    Filed: July 2, 2019
    Date of Patent: February 2, 2021
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu Sakuma, Masao Yano, Masaaki Ito, Tetsuya Shoji, Hidefumi Kishimoto, Akira Kato
  • Patent number: 10892076
    Abstract: A rare earth magnet includes a main phase, a grain boundary phase present around the main phase and an intermediate phase interposed between the main phase and the grain boundary phase, and has an overall composition that is represented by the formula ((Ce(1-x)Lax)(1-y)R1y)pT(100-p-q-r)BqM1r?(R21-zM2z)s (where, R1 and R2 are rare earth elements other than Ce and La, T is at least one selected from among Fe, Ni, and Co, M1 is an element having a small amount that does not influence magnetic characteristics, and M2 is an alloy element for which a melting point of R21-zM2z is lower than a melting point of R2). A total concentration of Ce and La is higher in the main phase than in the intermediate phase, and a concentration of R2 is higher in the intermediate phase than in the main phase.
    Type: Grant
    Filed: December 5, 2017
    Date of Patent: January 12, 2021
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Noritsugu Sakuma, Tetsuya Shoji, Hidefumi Kishimoto, Masao Yano
  • Patent number: 10748684
    Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.
    Type: Grant
    Filed: August 6, 2019
    Date of Patent: August 18, 2020
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Masao Yano, Hidefumi Kishimoto, Noritsugu Sakuma, Tetsuya Shoji, Akira Manabe
  • Publication number: 20200036322
    Abstract: To provide a motor control method ensuring that dragging loss at the time of high rotation can be reduced. A motor control method, wherein a composite permanent magnet has a core part and a shell part, the Curie temperature of one of the core part and the shell part is Tc1 K, and the Curie temperature of another is Tc2 K, and wherein when the magnitude of the reluctance torque is equal to or greater than the magnitude of the magnet torque, the temperature of the composite permanent magnet is set at Ts K that is (Tc1?100) K or higher and lower than Tc2 K and when the magnitude of the reluctance torque is less than the magnitude of the magnetic torque, the temperature of the composite permanent magnet is set at lower than the temperature Ts K or Tc1 K, whichever is lower.
    Type: Application
    Filed: July 2, 2019
    Publication date: January 30, 2020
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu SAKUMA, Masao YANO, Masaaki ITO, Tetsuya SHOJI, Hidefumi KISHIMOTO, Akira KATO
  • Publication number: 20190368019
    Abstract: There are provided a soft magnetic material having a high saturation magnetization and a low coercive force and excellent in thermal endurance, and a method for producing the same. The present disclosure relates to a soft magnetic material represented by the following composition formula: Fe100-x-yBxNiy, wherein x satisfies 10?x?16 in at %, and y satisfies 0<y?4 in at %, having a coercive force of 20 A/m or less, and having a coercive force characteristic decrease rate after a thermal endurance test {[(coercive force after thermal endurance test?coercive force before thermal endurance test)/coercive force before thermal endurance test]×100 (%)} of 20% or less, wherein the thermal endurance test is carried out by allowing the soft magnetic material to stand in a constant temperature oven at 170° C. in the air for 100 h, and a method for producing the same.
    Type: Application
    Filed: May 21, 2019
    Publication date: December 5, 2019
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kiyotaka ONODERA, Hidefumi KISHIMOTO
  • Publication number: 20190362870
    Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.
    Type: Application
    Filed: August 6, 2019
    Publication date: November 28, 2019
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Masao YANO, Hidefumi KISHIMOTO, Noritsugu SAKUMA, Tetsuya SHOJI, Akira MANABE
  • Patent number: 10468165
    Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.
    Type: Grant
    Filed: June 5, 2014
    Date of Patent: November 5, 2019
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Masao Yano, Hidefumi Kishimoto, Noritsugu Sakuma, Tetsuya Shoji, Akira Manabe
  • Patent number: 10464132
    Abstract: A method for producing a raw material powder of a permanent magnet, includes: preparing a material powder of a permanent magnet, measuring magnetic characteristics of the material powder, and judging the quality of the material powder as the raw material powder based on a preliminarily determined relation between magnetic characteristics and the structure of the material powder. A method for producing a permanent magnet includes integrating material powders judged as good in the step of judging the quality as raw material powders by the method for producing a raw material powder of a permanent magnet. A method for inspecting a permanent magnet material powder includes transmitting a magnetic field to a material powder of a permanent magnet, receiving the magnetic field from the material powder, and measuring a magnetic field difference between the transmitted magnetic field and the received magnetic field as magnetic characteristics of the material powder.
    Type: Grant
    Filed: May 24, 2013
    Date of Patent: November 5, 2019
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto, Mikiya Nozaki, Masao Yano, Tetsuya Shoji, Akira Manabe
  • Patent number: 10424426
    Abstract: To provide a rare earth magnet ensuring excellent magnetic anisotropy while reducing the amount of Nd, etc., and a manufacturing method thereof. A rare earth magnet comprising a crystal grain having an overall composition of (R2(1-x)R1x)yFe100-y-w-z-vCowBzTMv (wherein R2 is at least one of Nd, Pr, Dy and Tb, R1 is an alloy of at least one or two or more of Ce, La, Gd, Y and Sc, TM is at least one of Ga, Al, Cu, Au, Ag, Zn, In and Mn, 0<x<1, y=12 to 20, z=5.6 to 6.5, w=0 to 8, and v=0 to 2), wherein the average grain size of the crystal grain is 1,000 nm or less, the crystal grain consists of a core and an outer shell, the core has a composition of R1 that is richer than R2, and the outer shell has a composition of R2 that is richer than R1.
    Type: Grant
    Filed: June 5, 2014
    Date of Patent: September 24, 2019
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Masao Yano, Hidefumi Kishimoto, Noritsugu Sakuma, Tetsuya Shoji, Akira Manabe
  • Patent number: 10351935
    Abstract: Provided is a magnetic compound represented by the formula (R(1-x)Zrx)a(Fe(1-y)Coy)bTcMdAe (wherein R represents one or more rare earth elements, T represents one or more elements selected from the group consisting of Ti, V, Mo, and W, M represents one or more elements selected from the group consisting of unavoidable impurity elements, Al, Cr, Cu, Ga, Ag, and Au, A represents one or more elements selected from the group consisting of N, C, H, and P, 0?x?0.5, 0?y?0.6, 4?a?20, b=100?a?c?d, 0<c<7, 0?d?1, and 1?e?18), in which a main phase of the magnetic compound includes a ThMn12 type crystal structure, and a volume percentage of an ?-(Fe,Co) phase is 20% or lower.
    Type: Grant
    Filed: September 3, 2015
    Date of Patent: July 16, 2019
    Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Noritsugu Sakuma, Akira Kato, Kota Washio, Hidefumi Kishimoto, Masao Yano, Akira Manabe, Masaaki Ito, Shunji Suzuki, Kurima Kobayashi
  • Publication number: 20180308633
    Abstract: A method for producing a rare earth magnet, including preparing a melt of a first alloy having a composition represented by (R1vR2wR3x)yTzBsM1t (wherein R1 is a light rare earth element, R2 is an intermediate rare earth element, R3 is a heavy rare earth element, T is an iron group element, and M1 is an impurity element, etc.), cooling the melt of the first alloy at a rate of from 100 to 102 K/sec to obtain a first alloy ingot, pulverizing the first alloy ingot to obtain a first alloy powder having a particle diameter of 1 to 20 ?m, preparing a melt of a second alloy having a composition represented by (R4pR5q)100-uM2u (wherein R4 is a light rare earth element, R5 is an intermediate or heavy rare earth element, M2 is an alloy element, etc.), and putting the first alloy powder into contact with the melt of the second alloy.
    Type: Application
    Filed: April 13, 2018
    Publication date: October 25, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Patent number: 10090090
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Grant
    Filed: October 16, 2017
    Date of Patent: October 2, 2018
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Publication number: 20180182516
    Abstract: To provide an R—Fe—B-based rare earth magnet where R is mainly Ce, ensuring that even when a rare earth element R1 except for Ce is very small in amount or is not present, the coercive force can be enhanced. A rare earth magnet wherein the rare earth magnet has a total composition represented by the formula: CepR1qT(100-p-q-r-s)BrM1s (wherein R1 is a rare earth element except for Ce, T is one or more members selected from Fe, Ni and Co, M1 is one or more members selected from Ti, Ga, Zn, Si, Al, Nb, Zr, Mn, V, W, Ta, Ge, Cu, Cr, Hf, Mo, P, C, Mg, Hg, Ag, and Au, and an unavoidable impurity, and p, q, r, and s are 11.80?p?12.90, 0?q?3.00, 5.00?r?20.00, and 0?s?3.00), and wherein the rear earth magnet comprises a magnetic phase and a (Ce,R1)-rich phase present around the magnetic phase.
    Type: Application
    Filed: December 19, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Publication number: 20180182519
    Abstract: A rare earth magnet includes a main phase, a grain boundary phase present around the main phase and an intermediate phase interposed between the main phase and the grain boundary phase, and has an overall composition that is represented by the formula ((Ce(1-x)Lax)(1-y)R1y)pT(100-p-q-r)BqM1r.(R21-zM2z)s (where, R1 and R2 are rare earth elements other than Ce and La, T is at least one selected from among Fe, Ni, and Co, M1 is an element having a small amount that does not influence magnetic characteristics, and M2 is an alloy element for which a melting point of R21-zM2z is lower than a melting point of R2). A total concentration of Ce and La is higher in the main phase than in the intermediate phase, and a concentration of R2 is higher in the intermediate phase than in the main phase.
    Type: Application
    Filed: December 5, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki Ito, Noritsugu Sakuma, Tetsuya Shoji, Hidefumi Kishimoto, Masao Yano
  • Publication number: 20180182515
    Abstract: A rare earth magnet comprising a main phase, a grain boundary phase present around the main phase, and an intermediate phase sandwiched between the main phase and the grain boundary phase, and having a total composition of the rare earth magnet represented by the formula: CepR1qT(100-p-q-r-s)BrM1s.(R21-xM2x)t R1 and R2 are a rare earth element except for Ce, T is one or more members selected from Fe, Ni, and Co, M1 is a minor element, and M2 is an alloy element that makes, the melting point of R21-xM2x to be lower than the melting point of R2 the concentration of Ce is higher in the main phase than in the intermediate phase, and the concentration of R2 is higher in the intermediate phase than in the main phase, and a production method thereof.
    Type: Application
    Filed: December 19, 2017
    Publication date: June 28, 2018
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaaki ITO, Noritsugu SAKUMA, Masao YANO, Hidefumi KISHIMOTO, Tetsuya SHOJI
  • Publication number: 20180040404
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Application
    Filed: October 16, 2017
    Publication date: February 8, 2018
    Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi KISHIMOTO, Noritsugu SAKUMA, Masao YANO, Weibin CUI, Yukiko TAKAHASHI, Kazuhiro HONO
  • Patent number: 9818520
    Abstract: The invention provides a nanocomposite magnet, which has achieved high coercive force and high residual magnetization. The magnet is a non-ferromagnetic phase that is intercalated between a hard magnetic phase with a rare-earth magnet composition and a soft magnetic phase, wherein the non-ferromagnetic phase reacts with neither the hard nor soft magnetic phase. A hard magnetic phase contains Nd2Fe14B, a soft magnetic phase contains Fe or Fe2Co, and a non-ferromagnetic phase contains Ta. The thickness of the non-ferromagnetic phase containing Ta is 5 nm or less, and the thickness of the soft magnetic phase containing Fe or Fe2Co is 20 nm or less. Nd, or Pr, or an alloy of Nd and any one of Cu, Ag, Al, Ga, and Pr, or an alloy of Pr and any one of Cu, Ag, Al, and Ga is diffused into a grain boundary phase of the hard magnetic phase of Nd2Fe14B.
    Type: Grant
    Filed: December 27, 2012
    Date of Patent: November 14, 2017
    Assignees: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE FOR MATERIALS SCIENCE
    Inventors: Hidefumi Kishimoto, Noritsugu Sakuma, Masao Yano, Weibin Cui, Yukiko Takahashi, Kazuhiro Hono
  • Patent number: 9761358
    Abstract: A method for producing a nanocrystalline rare earth magnet having a grain and a grain boundary phase includes: quenching a melt of a rare earth magnet composition to form a quenched thin ribbon having a nanocrystalline structure; sintering the quenched thin ribbon to obtain a sintered body; heat treating the sintered body at a temperature which is higher than a lowest temperature in a first temperature range where the grain boundary phase diffuses or flows, and which is lower than a lowest temperature in a second temperature range where the grain becomes coarse; and quenching the heat treated sintered body to 200° C. or less at a cooling speed of 50° C./min or more.
    Type: Grant
    Filed: August 22, 2012
    Date of Patent: September 12, 2017
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Noritsugu Sakuma, Hidefumi Kishimoto