Patents by Inventor Kohei Muramatsu

Kohei Muramatsu 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: 8398879
    Abstract: A powder mixture, which contains a soft magnetic powder and an insulating powder lubricant in an amount of 0.1% by mass or more relative to the soft magnetic powder, is formed by compacting at a compacting pressure of 800 MPa or less, thereby obtaining a powder compact that has a space factor of the soft magnetic powder of 93% or more. The powder compact can be used as a soft magnetic powdered core. The soft magnetic powdered core has a specific resistance or 10,000 ??cm or more. A powder of a metal soap such as barium stearate or lithium stearate is used as the insulating powder lubricant.
    Type: Grant
    Filed: July 8, 2010
    Date of Patent: March 19, 2013
    Assignee: Hitachi Powdered Metals Co., Ltd.
    Inventors: Kohei Muramatsu, Chio Ishihara, Masaki Yanaka
  • Publication number: 20120119134
    Abstract: A powder mixture, which contains a soft magnetic powder and an insulating powder lubricant in an amount of 0.1% by mass or more relative to the soft magnetic powder, is formed by compacting at a compacting pressure of 800 MPa or less, thereby obtaining a powder compact that has a space factor of the soft magnetic powder of 93% or more. The powder compact can be used as a soft magnetic powdered core. The soft magnetic powdered core has a specific resistance or 10,000 ??cm or more. A powder of a metal soap such as barium stearate or lithium stearate is used as the insulating powder lubricant.
    Type: Application
    Filed: July 8, 2010
    Publication date: May 17, 2012
    Applicant: HITACHI POWDERED METALS CO., LTD
    Inventors: Kohei Muramatsu, Chio Ishihara, Masaki Yanaka
  • Patent number: 8062583
    Abstract: A method for producing a soft magnetic powdered core includes preparing a mixture of a soft magnetic powder and a resin powder, compacting the mixture into a predetermined shape so as to obtain a compact, and heating the compact. The resin powder has a median size of not more than 30 ?m, a maximum particle size of not more than 100 ?m, and a specific surface area of not less than 1.0 m2/cm3, and the additive amount thereof is 0.005 to 2 vol %.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: November 22, 2011
    Assignees: Hitachi Powdered Metals Co., Ltd., Denso Corporation
    Inventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
  • Patent number: 8029626
    Abstract: A method for producing a soft magnetic powdered core comprises a mixing step for forming a raw powder by adding a thermoplastic resin powder to a soft magnetic powder and mixing them, a compacting step for forming a compact by compacting the raw powder into a predetermined shape, a melting and setting step for the resin in which the resin of the compact is melted by heating to at least the melting point of the thermoplastic resin and the melted resin is set by cooling to a room temperature, and a crystallizing step for the resin in which the set resin is heated to not less than the exothermic onset temperature and not more than the endothermic onset temperature, which are measured by DSC analysis of the thermoplastic resin, and is cooled to a room temperature.
    Type: Grant
    Filed: March 17, 2008
    Date of Patent: October 4, 2011
    Assignees: Hitachi Powered Metals Co., Ltd., Denso Corporation
    Inventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
  • Publication number: 20080230737
    Abstract: A method for producing a soft magnetic powdered core comprises a mixing step for forming a raw powder by adding a thermoplastic resin powder to a soft magnetic powder and mixing them, a compacting step for forming a compact by compacting the raw powder into a predetermined shape, a melting and setting step for the resin in which the resin of the compact is melted by heating to at least the melting point of the thermoplastic resin and the melted resin is set by cooling to a room temperature, and a crystallizing step for the resin in which the set resin is heated to not less than the exothermic onset temperature and not more than the endothermic onset temperature, which are measured by DSC analysis of the thermoplastic resin, and is cooled to a room temperature.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 25, 2008
    Applicants: HITACHI POWERED METALS CO., LTD., DENSO CORPORATION
    Inventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu
  • Publication number: 20080232995
    Abstract: A method for producing a soft magnetic powdered core includes preparing a mixture of a soft magnetic powder and a resin powder, compacting the mixture into a predetermined shape so as to obtain a compact, and heating the compact. The resin powder has a median size of not more than 30 ?m, a maximum particle size of not more than 100 ?m, and a specific surface area of not less than 1.0 m2/cm3, and the additive amount thereof is 0.005 to 2 vol %.
    Type: Application
    Filed: March 17, 2008
    Publication date: September 25, 2008
    Applicants: HITACHI POWDERED METALS CO., LTD., DENSO CORPORATION
    Inventors: Chio Ishihara, Kazuo Asaka, Kohei Muramatsu, Tsuyoshi Akao, Hirotake Hamamatsu