Patents by Inventor Yoshihisa Kiyotoki

Yoshihisa Kiyotoki 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: 6889957
    Abstract: In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1, in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 ?m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 ?m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.
    Type: Grant
    Filed: October 16, 2002
    Date of Patent: May 10, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • Patent number: 6886809
    Abstract: In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1, in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 ?m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 ?m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: May 3, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • Publication number: 20040247477
    Abstract: A powder of an alloy containing a compound is enclosed in a cylindrical container, hot isostatic press and/or hot extrusion are applied in that state, and compound is isolated by these workings in order to metallically bond the powders with each other. When the metallic part is inserted into the container or the metallic part has a cylindrical shape, the container is formed of a material which can be the metallic part. Then, machining is applied in order to produce a metallic part having on a surface thereof an alloyed layer containing the dispersed compound particles.
    Type: Application
    Filed: June 2, 2004
    Publication date: December 9, 2004
    Inventors: Mitsuo Chigasaki, Jiro Kuniya, Yoshihisa Kiyotoki, Akira Sakamoto, Satoshi Furusawa
  • Publication number: 20040056231
    Abstract: In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1, in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &mgr;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &mgr;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.
    Type: Application
    Filed: September 25, 2003
    Publication date: March 25, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • Patent number: 6672330
    Abstract: A valve is characterized by excellent corrosion and wear resistance and maintainability due to use of a bonding corrosion and wear proof alloy containing non-continuously distributed eutectic carbide on the sliding portions of various types of apparatuses and valves by diffusion bonding. This serves to improve the maintainability of a thermal and nuclear power plant and to provide a nuclear power plant using recirculating water, which ensures excellent working safety, in particular. The corrosion and wear proof alloy is characterized in that network-formed eutectic carbide in the alloy containing the cast structure base metal and eutectic carbide is formed into(multiple) granules or lumps having a particle size of 30 microns or less so that said eutectic carbide is non-continuously distributed.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: January 6, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Yoshihisa Kiyotoki, Takahiko Kato, Yoshiteru Chiba
  • Publication number: 20030180175
    Abstract: To provide a corrosion-resisting and wear resisting alloy including cobalt, nickel or iron as a base used for a sliding part or a valve seat for a machine, and restraining erosion and corrosion caused by eutectic carbide constituting the alloy in an atmosphere with dissolved oxygen.
    Type: Application
    Filed: March 13, 2003
    Publication date: September 25, 2003
    Applicants: Hitachi, Ltd., Hitachi Kyowa Engineering Co., Ltd.
    Inventors: Yoshihisa Kiyotoki, Yoshiteru Chiba, Shin Kumagai, Yasuhiro Ogawa, Akira Sakamoto, Hiroyuki Shinohara
  • Publication number: 20030147769
    Abstract: To provide a corrosion-resisting and wear resisting alloy including cobalt, nickel or iron as a base used for a sliding part or a valve seat for a machine, and restraining erosion and corrosion caused by eutectic carbide constituting the alloy in an atmosphere with dissolved oxygen.
    Type: Application
    Filed: October 15, 2002
    Publication date: August 7, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Yoshiteru Chiba, Shin Kumagai, Yasuhiro Ogawa, Akira Sakamoto, Hiroyuki Shinohara
  • Publication number: 20030132415
    Abstract: A valve which is cobalt-free excellent in wear resistance and seizure resistance manufactured by forming valve seats for a valve disc and a valve body with a nickel base alloy in which silicide particles or boride particles of small particle size are finely dispersed, and the valve seat is bonded to the valve disc or the valve body by way of an insert material comprising a nickel base alloy of a lower melting point by transient liquid phase diffusion bonding.
    Type: Application
    Filed: November 6, 2002
    Publication date: July 17, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Yoshihisa Kiyotoki, Kikuo Takeshima, Akira Sakamoto, Yoshiteru Chiba
  • Publication number: 20030129075
    Abstract: In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1, in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &mgr;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &mgr;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.
    Type: Application
    Filed: October 16, 2002
    Publication date: July 10, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • Publication number: 20030026379
    Abstract: In the joint construction of cobalt-based alloy, a cobalt-based alloy layer 1, in which granular or massive eutectic carbide 2 disperses, is joined to a metal of a base metal 37 via an insert metal layer 36. For the joint construction of cobalt-based alloy, liquid phase diffusion bonding is performed at a temperature of 1100° C. for a retention time of 1 hour with an insert metal with a thickness of about 40 &mgr;m being interposed between the base metal, which is S45C carbon steel, and a cobalt-based alloy material which has granular or massive eutectic carbide with a grain size not larger than 30 &mgr;m in a matrix of cast structure and contains 1.03 wt % C, 29.73 wt % Cr, 3.86 wt % W, 2.59 wt % Ni, 2.67 wt % Fe, 0.59 wt % Si, and 0.07 wt % Mo, the balance substantially being Co. The cobalt-based alloy layer 1 after bonding contains granular or massive eutectic carbide.
    Type: Application
    Filed: February 27, 2002
    Publication date: February 6, 2003
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • Publication number: 20020064678
    Abstract: To provide a corrosion-resisting and wear resisting alloy including cobalt, nickel or iron as a base used for a sliding part or a valve seat for a machine, and restraining erosion and corrosion caused by eutectic carbide constituting the alloy in an atmosphere with dissolved oxygen.
    Type: Application
    Filed: August 28, 2001
    Publication date: May 30, 2002
    Inventors: Yoshihisa Kiyotoki, Yoshiteru Chiba, Shin Kumagai, Yasuhiro Ogawa, Akira Sakamoto, Hiroyuki Shinohara
  • Publication number: 20010017906
    Abstract: The object of the present invention is to provide a valve characterized by excellent corrosion and wear resistance and maintainability by bonding corrosion and wear proof alloy containing non-continuously distributed eutectic carbide to the sliding portions of various types of apparatuses and valves by diffusion bonding. Another object of the present invention is to improve the maintainability of a thermal and nuclear power plant and to provide a nuclear power plant comprising the recirculating water which ensures excellent working safety, in particular.
    Type: Application
    Filed: February 5, 2001
    Publication date: August 30, 2001
    Inventors: Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Yoshihisa Kiyotoki, Takahiko Kato, Yoshiteru Chiba
  • Patent number: 5156197
    Abstract: A float type liquid level meter is provided having an enhanced resistance against vibration transmitted from outside of the float type liquid level meter. The inventor obtained a finding that an external vibration is amplified with a connecting lever which is composing a part of the float type liquid level meter and a fluctuation of an output signal of the float type liquid level meter is proportional to the vibration of the connecting lever. An enhanced resistance against vibration is achieved by providing a connecting lever having a structure which prevents the connecting lever from generating vibration of a low order mode.
    Type: Grant
    Filed: October 22, 1990
    Date of Patent: October 20, 1992
    Assignee: Hitachi, Ltd.
    Inventor: Yoshihisa Kiyotoki