Patents by Inventor Matahiro Komuro

Matahiro Komuro 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).

  • Publication number: 20220128135
    Abstract: An object of the present invention is to provide a ball screw having a structure in which a screw shaft and a nut satisfy required performance and having improved durability, a method for manufacturing the ball screw, a power steering device, and a method for manufacturing the power steering device. A ball screw according to the present invention includes: a nut made of a steel substrate having an inner peripheral surface on which a female screw is formed; a screw shaft that is combined with the nut and is made of a steel substrate having an outer peripheral surface on which a male screw facing the female screw is formed; and a plurality of balls arranged between the female screw and the male screw. A surface of the nut in contact with the ball and a surface of the screw shaft in contact with the ball each have carburized layers. A carbon concentration in the carburized layer of the nut is higher than a carbon concentration in the carburized layer of the screw shaft.
    Type: Application
    Filed: March 3, 2020
    Publication date: April 28, 2022
    Applicant: Hitachi Astemo, Ltd.
    Inventors: Matahiro KOMURO, Hisamitsu HATOU, Kotaro SHIINO, Koji NUMAKURA, Shintaro TSUJIMI
  • Publication number: 20220042157
    Abstract: A soft magnetic material that is sheet-shaped or foil-shaped and has a high saturation magnetic flux density, contains iron, carbon, and nitrogen, and includes a martensite containing carbon and nitrogen, and ?-Fe, wherein the ?-Fe includes a nitrogen-containing phase. The soft magnetic material is produced by steps of heating an iron-based material that is sheet-shaped or foil-shaped, carburizing the iron-based material with a carburizing gas, dispersing a granular carbide in ?-Fe in the iron-based material at a temperature equal to or lower than a eutectoid temperature, transforming the ?-Fe into ?-Fe at a temperature higher than the eutectoid temperature, diffusing nitrogen into the ?-Fe using a nitrogen supply gas to form ?-Fe—N—C, and rapidly heating and then rapidly cooling the ?-Fe—N—C to transform the ?-Fe—N—C into a martensite. The result is a thermally stable soft magnetic material having a saturation magnetic flux density higher than that of pure iron.
    Type: Application
    Filed: September 11, 2019
    Publication date: February 10, 2022
    Inventors: Matahiro KOMURO, Yuichi SATSU, Hisamitsu HATOU, Seunghwan PARK
  • Publication number: 20210272727
    Abstract: Provided are: a sintered magnet having an improved maximum energy product while maintaining the magnetic coercivity of the magnet; and a production method for such a sintered magnet. The sintered magnet (10a) according to the present invention comprises particles (6) each including: a main phase (2) in which the main component is a compound containing a rare-earth element and iron; and a diffusion layer (1) provided on the surface of the main phase (2). The diffusion layers (1) are characterized by: containing, as a main component, a compound resulting from a solid-solution of carbon and/or nitrogen in said compound of the main phase (2); and having a concentration gradient of carbon and/or nitrogen from the surfaces of the particles (6) toward the interior thereof.
    Type: Application
    Filed: March 8, 2019
    Publication date: September 2, 2021
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi SATSU
  • Publication number: 20190284676
    Abstract: For providing a structural material having improved fatigue strength and abrasion resistance, provided is a structural material containing iron and carbon, including: a first layer formed of pearlite; a second layer formed of a mixed phase of martensite and a carbide; and a third layer formed of a carbide, in order from a center to a surface of the structural material. The carbide of the third layer is represented by MC (where M is one element among Ti, V, Nb, Mo, Ta, and W), and the structural material has a concentration gradient in which an M element concentration is decreased from the surface to the center of the structural material.
    Type: Application
    Filed: October 25, 2017
    Publication date: September 19, 2019
    Applicant: HITACHI, LTD.
    Inventors: Matahiro KOMURO, Hisamitsu HATOU, Kazuya NONOMURA
  • Patent number: 10240225
    Abstract: Disclosed herein is a technique to reduce the residual stress of a steel material while improving the mechanical property and the corrosion resistance of the material. A steel material is provided that includes a plurality of ferrite crystal grains, and a laminar iron-rich phase formed at unidirectionally occurring grain boundaries of all grain boundaries of the ferrite crystal grains. A material processing method is provided that includes: heating a steel material that contains a plurality of ferrite crystal grains; applying a magnetic field to a heated portion while heating the steel material; applying an electric field to the heated portion in a direction that crosses the direction of the applied magnetic field while heating the steel material; and measuring a displacement occurring in the steel material under the magnetic field and the electric field.
    Type: Grant
    Filed: September 17, 2015
    Date of Patent: March 26, 2019
    Assignee: HITACHI, LTD.
    Inventors: Matahiro Komuro, Masafumi Noujima, Naoya Okizaki
  • Patent number: 9373432
    Abstract: The purpose of the present invention is to provide an alcoholic solvent, in which FeCo-based particles becoming a soft magnet are improved, for enhancing properties of a magnetic material using no heavy rare earth elements, and is to provide a sintered magnet produced by using it.
    Type: Grant
    Filed: November 15, 2012
    Date of Patent: June 21, 2016
    Assignee: Hitachi Chemical Company, Ltd.
    Inventors: Nobuo Abe, Yuichi Satsu, Matahiro Komuro, Takayuki Kanda
  • Publication number: 20160083821
    Abstract: Disclosed herein is a technique to reduce the residual stress of a steel material while improving the mechanical property and the corrosion resistance of the material. A steel material is provided that includes a plurality of ferrite crystal grains, and a laminar iron-rich phase formed at unidirectionally occurring grain boundaries of all grain boundaries of the ferrite crystal grains. A material processing method is provided that includes: heating a steel material that contains a plurality of ferrite crystal grains; applying a magnetic field to a heated portion while heating the steel material; applying an electric field to the heated portion in a direction that crosses the direction of the applied magnetic field while heating the steel material; and measuring a displacement occurring in the steel material under the magnetic field and the electric field.
    Type: Application
    Filed: September 17, 2015
    Publication date: March 24, 2016
    Applicant: HITACHI, LTD.
    Inventors: Matahiro KOMURO, Masafumi NOUJIMA, Naoya OKIZAKI
  • Patent number: 9129731
    Abstract: Disclosed is a sintered magnet which is a rare-earth magnet using a less amount of a rare-earth element but having a higher maximum energy product and a higher coercivity. The sintered magnet includes a NdFeB crystal; and an FeCo crystal adjacent to the NdFeB crystal through the medium of a grain boundary. The FeCo crystal includes a core and a periphery and has a cobalt concentration decreasing from the core to the periphery. The FeCo crystal has a difference in cobalt concentration of 2 atomic percent or more between the core and the periphery. In the NdFeB crystal, cobalt and a heavy rare-earth element are unevenly distributed and enriched in the vicinity of the grain boundary.
    Type: Grant
    Filed: August 13, 2012
    Date of Patent: September 8, 2015
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Isao Kitagawa, Akira Sugawara
  • Publication number: 20150170809
    Abstract: The purpose of the present invention is to improve the magnetic characteristics of a sintered magnet without any additional heavy rare earth element. A sintered magnet composed of an NdFeB main phase and a grain boundary phase, wherein; the grain boundary phase contains an oxyfluoride; the concentration of fluorine in the oxyfluoride is higher than that of oxygen therein; the concentration of fluorine in the oxyfluoride decreases depthwise from the surface of the sintered magnet toward the center thereof; and the saturation magnetic flux density of the sintered magnet decreases depthwise from the surface of the sintered magnet toward the center thereof.
    Type: Application
    Filed: May 30, 2012
    Publication date: June 18, 2015
    Applicant: HITACHI, LTD.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20150162117
    Abstract: The purpose of the present invention is to improve the magnetic characteristics of a sintered magnet without adding a supplementary heavy rare earth element.
    Type: Application
    Filed: June 13, 2012
    Publication date: June 11, 2015
    Applicant: HITACHI, LTD.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20150071702
    Abstract: The present invention provides a structural body comprising a welded portion of a duplex stainless steel inclusive of an ? phase and a ? phase and an unwelded portion of the duplex stainless steel, wherein an X-ray diffraction intensity for the ? phase is higher in a heat affected zone including the welded portion than in the unwelded portion and becomes a local maximum within the heat affected zone. The present invention provides aA production method for a structural body of a duplex stainless steel, wherein a heat affected zone including a welded portion of the structural body is heat-treated between 600° C. and 800° C. while a magnetic field of 1˜10 T is applied to the heat affected zone.
    Type: Application
    Filed: August 19, 2014
    Publication date: March 12, 2015
    Applicant: HITACHI, LTD.
    Inventors: Matahiro KOMURO, Naoya OKIZAKI, Masafumi NOJIMA
  • Patent number: 8821649
    Abstract: Characteristics of a magnetic material are improved without using a heavy rare earth element as a scarce resource. By incorporating fluorine into a magnetic powder and controlling the crystal orientation in crystal grains, a magnetic material securing magnetic characteristics such as coercive force and residual flux density can be fabricated. As a result, the resource problem with heavy rare earth elements can be solved, and the magnetic material can be applied to magnetic circuits that require a high energy product, including various rotating machines and voice coil motors of hard discs.
    Type: Grant
    Filed: February 17, 2011
    Date of Patent: September 2, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Kanda, Matahiro Komuro, Hiroyuki Suzuki, Yuichi Satsu
  • Patent number: 8764917
    Abstract: A ferromagnetic compound magnet in accordance with the present invention includes a ferromagnetic compound based on a binary alloy containing R—Fe system (R is a 4f transition element or Y) or a ternary allay containing R—Fe-T system (R is a 4f transition element or Y, and T is a 3d transition element except for Fe, or Mo, Nb or W), the ferromagnetic compound being characterized by: atomic percentage of the element R to the element Fe or to the elements Fe and T is 15% or lower; an element F is incorporated into an interstitial position in a crystal lattice of the alloy. The ferromagnetic compound is expressed in a chemical formula of: R2Fe17Fx; R2(Fe,T)17Fx; R3Fe29Fy; R3(Fe,T)29Fy; RFe12Fz; or R(Fe,T)12Fz (0<x?3, 0<y?4, 0<z?1).
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: July 1, 2014
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Suzuki, Matahiro Komuro, Yuichi Satsu, Takao Imagawa
  • Publication number: 20130278104
    Abstract: The present invention makes it possible to increase the residual magnetic flux density and the coercive force of a rare earth magnet; and raise the Curie temperature. In a magnet formed by compressing magnetic particles, the surface of a magnetic particle is covered with a metal fluoride film, the magnetic particle has a crystal structure containing a homo portion formed by bonding adjacent iron atoms and a hetero portion formed by bonding two iron atoms via an atom other than iron, and the distance between the two iron atoms in the hetero portion is different from the distance between the adjacent iron atoms in the homo portion.
    Type: Application
    Filed: June 24, 2013
    Publication date: October 24, 2013
    Inventors: Matahiro KOMURO, Yuichi SATSU, Hiroyuki SUZUKI
  • Publication number: 20130069746
    Abstract: Disclosed is a sintered magnet which is a rare-earth magnet using a less amount of a rare-earth element but having a higher maximum energy product and a higher coercivity. The sintered magnet includes a NdFeB crystal; and an FeCo crystal adjacent to the NdFeB crystal through the medium of a grain boundary. The FeCo crystal includes a core and a periphery and has a cobalt concentration decreasing from the core to the periphery. The FeCo crystal has a difference in cobalt concentration of 2 atomic percent or more between the core and the periphery. In the NdFeB crystal, cobalt and a heavy rare-earth element are unevenly distributed and enriched in the vicinity of the grain boundary.
    Type: Application
    Filed: August 13, 2012
    Publication date: March 21, 2013
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi Satsu, Isao Kitagawa, Akira Sugawara
  • Patent number: 8388769
    Abstract: To mold a high-resistance magnet at low temperature, including room temperature, the magnet includes magnetic powders, metallic powders having a lower hardness than the magnetic powders and a high-resistance layer, wherein the magnetic powders occupy a larger volume than the metallic powders. In particular, the high-resistance layer contains a fluorine compound and is placed between the magnetic powder and the metallic powders.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: March 5, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Takashi Yasuhara
  • Patent number: 8358040
    Abstract: A permanent magnet type electric rotating machine having a high resistance permanent magnet used for the electric rotating machine, the permanent magnet containing a magnetic powder and a fluorine compound, in which the current waveform is controlled for reducing the loss to satisfy a relation: A<C<B and restrict the 7th higher-harmonic component to 20% or less where A is the content for the 5th higher harmonic component, B is the content for the 7th higher harmonic component, and C is the content for the 11th higher harmonic component, assuming the total of contents for the fundamental components of a current supplied to the findings being 100%.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: January 22, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Haruo Koharagi, Yuji Enomoto
  • Patent number: 8350430
    Abstract: An R—Fe—B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 ?m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 ?m to 500 ?m from the magnet surface.
    Type: Grant
    Filed: April 23, 2012
    Date of Patent: January 8, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Matahiro Komuro, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose
  • Patent number: 8303732
    Abstract: A rare earth magnet having a composition represented by RTB wherein R denotes a rare earth element, T a transition metal and B boron, the magnet being composed of magnet powder constituted by crystalline particles. The particles of the magnetic powder have a ratio of a short diameter being 10 ?m or more to a long diameter is 0.5 or less. An element Rm having a magnetic anisotropy higher than that of the rare earth element is contained in the surface and inside of the magnet constituted by the magnet powder in an approximately constant concentration. An oxy-fluoride and carbon are present at boundaries of the particles of the magnet powder.
    Type: Grant
    Filed: January 29, 2010
    Date of Patent: November 6, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Suzuki, Takao Imagawa, Yuichi Satsu, Matahiro Komuro
  • Publication number: 20120205573
    Abstract: An R—Fe—B sintered magnet has a structure including main phase crystal grains and a grain boundary area surrounding the crystal grains. The sintered magnet includes fluorine and a specified metal element selected from elements belonging to Group 2 through Group 16 of periodic table excepting the rare earth element, carbon and boron. The fluorine has a higher concentration in a region closer to a magnet surface than in the center. The specified element also has a higher concentration in the region closer to the surface. The sintered magnet includes oxyfluoride containing carbon, Dy and the metal element in a grain boundary area region at a distance of 1 ?m or greater from the magnet surface, and the carbon has a higher concentration than the concentration of the metal element in a region at a distance of 1 ?m to 500 ?m from the magnet surface.
    Type: Application
    Filed: April 23, 2012
    Publication date: August 16, 2012
    Applicant: Hitachi, Ltd.
    Inventors: Matahiro KOMURO, Yuichi Satsu, Yoshii Morishita, Shigeaki Funyu, Mitsuo Katayose