Patents by Inventor Hironobu KUMAOKA

Hironobu KUMAOKA 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: 11887761
    Abstract: A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and P (phosphorous), and a P concentrated area existing closer to a surface side than the internal area and having a higher P concentration than in the internal area.
    Type: Grant
    Filed: February 15, 2022
    Date of Patent: January 30, 2024
    Assignee: TDK CORPORATION
    Inventors: Hironobu Kumaoka, Kazuhiro Yoshidome, Hiroyuki Matsumoto, Akito Hasegawa
  • Patent number: 11881338
    Abstract: A soft magnetic alloy comprising an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, a SB concentrated area existing closer to the surface side than the Co concentrated area and having a higher concentration of at least one element selected from Si and B than in the internal area, and a Fe concentrated area including Fe existing closer to the surface side than the SB concentrated area; wherein a crystalized area ratio of the SB concentrated area represented by SSBcry/SSB and a crystalized area ratio of the Fe concentrated area represented by SFecry/SFe, satisfy a relation of (SSBcry/SSB)<(SFecry/SFe).
    Type: Grant
    Filed: February 15, 2022
    Date of Patent: January 23, 2024
    Assignee: TDK CORPORATION
    Inventors: Hironobu Kumaoka, Kazuhiro Yoshidome, Akito Hasegawa, Satoko Mori
  • Patent number: 11791077
    Abstract: A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, and a SB concentrated area existing closer to the surface side than the Co concentrated area and having a higher concentration of at least one element selected from Si and B than in the internal area.
    Type: Grant
    Filed: February 15, 2022
    Date of Patent: October 17, 2023
    Assignee: TDK CORPORATION
    Inventors: Hironobu Kumaoka, Kazuhiro Yoshidome, Akito Hasegawa, Satoko Mori
  • Publication number: 20220380875
    Abstract: A soft magnetic alloy and the like which simultaneously satisfy a high saturation magnetic flux density Bs and a high corrosion resistance. A soft magnetic alloy includes Mn and a component expressed by a compositional formula of ((Fe(1?(?+?))Co?Ni?)1??X1?)(1?(a+b+c+d+e))BaPbSicCdCre (atomic ratio). X1 is one or more selected from Ti, Zr, Hf, Nb, Ta, Mo, W, Al, Ga, Ag, Zn, S, Ca, Mg, V, Sn, As, Sb, Bi, N, O, Au, Cu, rare earth elements, and platinum group elements. Further, a to e and ? to ? are within predetermined ranges. Mn amount f (at %) is within a range of 0.002?f<3.0. The soft magnetic alloy satisfies a corrosion potential of ?630 mV or more and ?50 mV or less and a corrosion current density of 0.3 ?A/cm2 or more and 45 ?A/cm2 or less.
    Type: Application
    Filed: May 13, 2021
    Publication date: December 1, 2022
    Applicant: TDK CORPORATION
    Inventors: Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO, Akito HASEGAWA, Hironobu KUMAOKA
  • Publication number: 20220328223
    Abstract: A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, and a Co concentration degree of the Co concentrated area is larger than 1.2.
    Type: Application
    Filed: March 17, 2022
    Publication date: October 13, 2022
    Applicant: TDK CORPORATION
    Inventors: Hironobu KUMAOKA, Kazuhiro YOSHIDOME, Akito HASEGAWA, Satoko MORI
  • Publication number: 20220328222
    Abstract: A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, and a SB concentrated area existing closer to the surface side than the Co concentrated area and having a higher concentration of at least one element selected from Si and B than in the internal area.
    Type: Application
    Filed: February 15, 2022
    Publication date: October 13, 2022
    Applicant: TDK CORPORATION
    Inventors: Hironobu KUMAOKA, Kazuhiro YOSHIDOME, Akito HASEGAWA, Satoko MORI
  • Publication number: 20220319748
    Abstract: A soft magnetic alloy including an internal area having a soft magnetic type alloy composition including Fe and P (phosphorous), and a P concentrated area existing closer to a surface side than the internal area and having a higher P concentration than in the internal area.
    Type: Application
    Filed: February 15, 2022
    Publication date: October 6, 2022
    Applicant: TDK CORPORATION
    Inventors: Hironobu KUMAOKA, Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO, Akito HASEGAWA
  • Publication number: 20220319749
    Abstract: A soft magnetic alloy comprising an internal area having a soft magnetic type alloy composition including Fe and Co, a Co concentrated area existing closer to a surface side than the internal area and having a higher Co concentration than in the internal area, a SB concentrated area existing closer to the surface side than the Co concentrated area and having a higher concentration of at least one element selected from Si and B than in the internal area, and a Fe concentrated area including Fe existing closer to the surface side than the SB concentrated area; wherein a crystalized area ratio of the SB concentrated area represented by SSBcry/SSB and a crystalized area ratio of the Fe concentrated area represented by SFecry/SFe, satisfy a relation of (SSBcry/SSB)<(SFecry/SFe).
    Type: Application
    Filed: February 15, 2022
    Publication date: October 6, 2022
    Applicant: TDK CORPORATION
    Inventors: Hironobu KUMAOKA, Kazuhiro YOSHIDOME, Akito HASEGAWA, Satoko MORI
  • Patent number: 11427896
    Abstract: A soft magnetic alloy thin strip which has high saturation magnetic flux density and low coercivity, which enables a core with high space factor and high saturation magnetic flux density. A soft magnetic alloy thin strip including a main component that has a composition formula (Fe(1?(?+?))X1?X2?)(1?(a+b+c+d+e+f))MaBbPcSidCeSf. In the formula, X1, X2 and M are selected from a specific element group; 0?a?0.140, 0.020?b?0.200, 0?c?0.150, 0?d?0.090, 0?e?0.030, 0?f?0.030, ??0, ??0, and 0??+??0.50; and at least one of a, c and d is larger than 0. The strip has a structure that is composed of an Fe-based nanocrystal; and the surface roughness of a release surface satisfies 0.85?Rae/Rac?1.25 (wherein Rac is the average of arithmetic mean roughnesses in the central portion, and Rae is the average in the edge portion).
    Type: Grant
    Filed: December 3, 2018
    Date of Patent: August 30, 2022
    Assignee: TDK CORPORATION
    Inventors: Akito Hasegawa, Hironobu Kumaoka, Kazuhiro Yoshidome, Hiroyuki Matsumoto, Kenji Horino, Isao Nakahata
  • Publication number: 20220208423
    Abstract: A soft magnetic alloy powder which is a soft magnetic alloy powder having a low coercivity, and with which it is possible to obtain a green compact magnetic core having a high magnetic permeability. A soft magnetic alloy powder including a composition formula (Fe(1?(?+?))X1 ?X2 ?) (1?(a+b+c+d+e+f)) MaBbPcSidCeSf. XI is one or more elements selected from the group consisting of Co and Ni, X2 is one or more elements selected from the group consisting or Al, Mn, Ag, Zn, Sn, As, Sb, Cu, Cr, Bi, N, O and rare earth elements, and M is one or more elements selected from the group consisting of Nb, Hf, Zr, Ta, Mo, W, Ti and V. The amount of each component contained is within a specified range. The amorphous rate X (%) is at least 85%.
    Type: Application
    Filed: April 22, 2020
    Publication date: June 30, 2022
    Applicant: TDK CORPORATION
    Inventors: Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO, Akito HASEGAWA, Hironobu KUMAOKA
  • Publication number: 20210230720
    Abstract: A soft magnetic alloy powder has a specific composition in which a Co content is large. A soft magnetic alloy powder has a glass transition point Tg and a melting point Tm, 900° C.?Tm?1200° C. is satisfied, or when coercivity when applying a pressure XP to a soft magnetic alloy powder is set as YH, and a straight line obtained by linearly approximating a relationship between XP and YH by a method of least squares is set as YH=kXP+1, k (unit: Oe/MPa) satisfies 0?k?0.00100.
    Type: Application
    Filed: December 11, 2020
    Publication date: July 29, 2021
    Applicant: TDK CORPORATION
    Inventors: Yoshiki KAJIURA, Akito HASEGAWA, Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO, Hironobu KUMAOKA
  • Publication number: 20210098162
    Abstract: Provided is a soft magnetic alloy including a Fe-based nanocrystal and metallic glass. A differential scanning calorimetry curve of the soft magnetic alloy has a glass transition point Tg, a temperature rising rate of the soft magnetic alloy in measurement of the differential scanning calorimetry curve is 40 K/minute, and a temperature Tp of a maximum exothermic peak in the differential scanning calorimetry curve is higher than the Tg.
    Type: Application
    Filed: September 22, 2020
    Publication date: April 1, 2021
    Applicant: TDK Corporation
    Inventors: Hironobu KUMAOKA, Akito HASEGAWA, Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO
  • Publication number: 20200362442
    Abstract: A soft magnetic alloy thin strip which has high saturation magnetic flux density and low coercivity, which enables a core with high space factor and high saturation magnetic flux density. A soft magnetic alloy thin strip including a main component that has a composition formula (Fe(1?(?+?))X1?X2?)(1?(a+b+c+d+e+f))MaBbPcSidCeSf. In the formula, X1, X2 and M are selected from a specific element group; 0?a?0.140, 0.020?b?0.200, 0?c?0.150, 0?d?0.090, 0?e?0.030, 0?f?0.030, ??0, ??0, and 0??+??0.50; and at least one of a, c and d is larger than 0. The strip has a structure that is composed of an Fe-based nanocrystal; and the surface roughness of a release surface satisfies 0.85?Rae/Rac?1.25 (wherein Rac is the average of arithmetic mean roughnesses in the central portion, and Rae is the average in the edge portion).
    Type: Application
    Filed: December 3, 2018
    Publication date: November 19, 2020
    Applicant: TDK CORPORATION
    Inventors: Akito HASEGAWA, Hironobu KUMAOKA, Kazuhiro YOSHIDOME, Hiroyuki MATSUMOTO, Kenji HORINO, Isao NAKAHATA
  • Publication number: 20200312499
    Abstract: A soft magnetic alloy contains Fe as a main element and has an amorphous phase. On a differential scanning calorimetry curve of the soft magnetic alloy, a glass transition temperature Tg is found in a range from 350° C. to 600° C. and three or more exothermic peaks are found in a range from 350° C. to 850° C.
    Type: Application
    Filed: March 25, 2020
    Publication date: October 1, 2020
    Applicant: TDK CORPORATION
    Inventors: Hironobu KUMAOKA, Akito HASEGAWA, Hiroyuki MATSUMOTO, Kazuhiro YOSHIDOME