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).

  • Publication number: 20190193195
    Abstract: The present invention is intended is to improve the corrosion resistance of an overlay used in a nuclear power plant, and to reduce dissolution of cobalt from an overlay. The corrosion and wear resistant overlay is formed along a surface of a base by laser lamination modeling, and is configured from a plurality of metal layers of a Co-base alloy. The thickness of carbide eutectics that precipitate in the metal layers is the largest in the metal layer closest to the base, and is gradually smaller in the metal layers farther away from the base. The intensity of the laser beam applied to form layers by laser lamination modeling is adjusted so that the carbide eutectics that precipitate in at least the outermost metal layer have a controlled size of 10 ?m or less.
    Type: Application
    Filed: December 21, 2018
    Publication date: June 27, 2019
    Inventors: Sei HIRANO, Yoshihisa KIYOTOKI, Hajime MIYATA, Hirotsugu KAWANAKA, Shinji MATSUSHITA, Hiroshi SHIRATORI
  • Patent number: 10260651
    Abstract: A butterfly valve includes a valve body-side valve seat section, a valve box-side valve seat section, and a valve movement mechanism. The valve movement mechanism includes a cam groove, a cam projection, and a reverse key. The valve movement mechanism moves the valve body in an extending direction of the flow passage along with rotation of the valve shaft between a blocking position and an open position. One of the valve body-side valve seat section and the valve box-side valve seat section is formed of a laminated material composed of alternatingly stacked plates made of metal and plates made of expanded graphite.
    Type: Grant
    Filed: December 14, 2015
    Date of Patent: April 16, 2019
    Assignees: Hitachi-GE Nuclear Energy, Ltd., Okano Valve Mfg. Co. Ltd.
    Inventors: Yoshiharu Kawahara, Yoshihisa Kiyotoki, Takayoshi Nakashima, Keisuke Sakemura, Yoshitomo Kanemura, Yukio Imoto
  • Publication number: 20180182500
    Abstract: A high reliable water injection device is provided that injects water into a reactor containment vessel and can reliably shut off cooling water at normal times and quickly and reliably inject water into the reactor containment vessel without the need for external power, in a case of emergency. The water injection device injects water into a reactor containment vessel includes a flow path through which cooling water is supplied; a disk that closes the flow path; a swing arm that is connected to the disk and performs closing and opening of the flow path by the disk; and a weight that is connected to the swing arm via a swing lever, in which the weight is supported by a support member made of a low melting point alloy.
    Type: Application
    Filed: December 22, 2017
    Publication date: June 28, 2018
    Inventors: Daisuke HIRASAWA, Yoshihisa KIYOTOKI, Hisashi SATOU, Keisuke SAKEMURA, Keiji SASAKI, Yuta FUKUDA
  • Patent number: 9916908
    Abstract: A gas supply apparatus of the present invention includes a gas discharge line of a first electromagnetic valve having s a switching valve placed therein, and a second electromagnetic valve placed between the switching valve and a gas supply source. The switching valve switches between a gas discharge from the first electromagnetic valve and a gas supply to the first electromagnetic valve. At the time of a normal operation, the second electromagnetic valve opens a gas discharge line side and closes a switching valve side, and when the power source is lost, the second electromagnetic valve opens the switching valve side and closes the gas discharge line side. In this way, even when the power source is lost, an operating valve can not only be operated remotely but also be operated safely by a remote operator.
    Type: Grant
    Filed: October 30, 2014
    Date of Patent: March 13, 2018
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Ryo Kubota, Kenji Onodera, Yoshihisa Kiyotoki
  • Publication number: 20170370491
    Abstract: Provided is a butterfly valve configured so that the sealing performance of the butterfly valve is ensured even if the butterfly valve is exposed to high-temperature fluid and is installed in a high radiation environment. A butterfly valve has: a valve body-side valve seat section which is formed on the outer periphery of a valve body; a valve box-side valve seat section which is formed on a valve box; and a valve movement mechanism which, as a valve shaft pivots, moves the valve body in the direction of extension of a flow passage, between a blocking position at which the valve body-side valve seat section and the valve box-side valve seat section are in contact with each other to close a flow passage, and an open position at which the valve body-side valve seat section and the valve box-side valve seat section are separated from each other to open the flow passage.
    Type: Application
    Filed: December 14, 2015
    Publication date: December 28, 2017
    Inventors: Yoshiharu KAWAHARA, Yoshihisa KIYOTOKI, Takayoshi NAKASHIMA, Keisuke SAKEMURA, Yoshitomo KANEMURA, Yukio IMOTO
  • Publication number: 20150117585
    Abstract: A gas supply apparatus of the present invention includes: an operating valve that is placed in the middle of a piping for letting at least gas in a plant flow and that operates a valve main body by the gas flowing in the piping; a first electromagnetic valve that is placed in the middle of the piping and that opens or closes a flow of the gas to the operating valve; and a gas supply source that supplies the first electromagnetic valve with the gas. A gas discharge line of the first electromagnetic valve has a switching valve placed therein and has a second electromagnetic valve placed between the switching valve and the gas supply source. The switching valve switches between a gas discharge from the first electromagnetic valve and a gas supply to the first electromagnetic valve. When a power source is lost, the switching valve is switched to connection to the gas supply source so as to supply the first electromagnetic valve with the gas.
    Type: Application
    Filed: October 30, 2014
    Publication date: April 30, 2015
    Inventors: Ryo KUBOTA, Kenji ONODERA, Yoshihisa KIYOTOKI
  • Patent number: 8888069
    Abstract: The invention provides a valve which suppresses a continuous corrosion of a chemical compound phase such as an eutectic carbide or the like in a valve seat, and improves a corrosion resistance, an impact resistance and an erosion resistance of the valve seat. The invention disperses a chemical compound phase such as the eutectic carbide or the like crystallizing in a dendrite gap as a granular shape or a blocky shape which is equal to or less than about 100 ?m, by moving a tool rotating in a crimped state by a load application to a vertical direction to a surface of the valve seat so as to carry out a friction stir processing, and forming a weld metallographic structure of a surface layer portion of the valve seat as a cubic.
    Type: Grant
    Filed: March 30, 2011
    Date of Patent: November 18, 2014
    Assignee: Hitachi-GE Nuclear Energy, Ltd.
    Inventors: Yusaku Maruno, Seunghwan Park, Yoshihisa Kiyotoki, Shin Kumagai
  • Publication number: 20140254738
    Abstract: The present invention is directed to remote operation of an operation valve such as an air operated valve even at the time of power loss. A gas supply apparatus of the present invention includes: an operation valve mounted in some midpoint of a piping for passing at least gas in a plant and operating a valve body by the gas flowing in the piping; an solenoid valve mounted in some midpoint of the piping and allowing/stopping flow of the gas to the operation valve; and a gas supply source for supplying gas to the solenoid valve. A switching valve for switching between exhaust from the solenoid valve and gas supply to the solenoid valve is mounted in an exhaust line of the solenoid valve and, at the time of power loss, the switching valve is switched to connection to the gas supply source for supplying gas to the solenoid valve.
    Type: Application
    Filed: February 19, 2014
    Publication date: September 11, 2014
    Applicant: HITACHI-GE NUCLEAR ENERGY, LTD.
    Inventors: Ryo KUBOTA, Kenji ONODERA, Yoshihisa KIYOTOKI
  • Publication number: 20110278490
    Abstract: The invention provides a valve which suppresses a continuous corrosion of a chemical compound phase such as an eutectic carbide or the like in a valve seat, and improves a corrosion resistance, an impact resistance and an erosion resistance of the valve seat. The invention disperses a chemical compound phase such as the eutectic carbide or the like crystallizing in a dendrite gap as a granular shape or a blocky shape which is equal to or less than about 100 ?m, by moving a tool rotating in a crimped state by a load application to a vertical direction to a surface of the valve seat so as to carry out a friction stir processing, and forming a weld metallographic structure of a surface layer portion of the valve seat as a cubic.
    Type: Application
    Filed: March 30, 2011
    Publication date: November 17, 2011
    Inventors: Yusaku Maruno, Seunghwan Park, Yoshihisa Kiyotoki, Shin Kumagai
  • Patent number: 7584668
    Abstract: A monitoring system for valve device according to the present invention comprises a semiconductor single crystalline substrate including a bridged circuit and the bridged circuit comprising impurity-diffused resistors. The semiconductor single crystalline substrate is mounted to any of a valve device's valve stem, valve yoke, drive shaft, or elastic body disposed at the end of the drive shaft. Thrust and torque of the valve device are measured by the semiconductor single crystalline substrate and then the measured values are used for monitoring the valve device.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: September 8, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Ohta, Hiromi Shimazu, Yohei Tanno, Yoshihisa Kiyotoki, Kenji Onodera, Kenji Araki
  • Publication number: 20080034882
    Abstract: A monitoring system for valve device according to the present invention comprises a semiconductor single crystalline substrate including a bridged circuit and the bridged circuit comprising impurity-diffused resistors. The semiconductor single crystalline substrate is mounted to any of a valve device's valve stem, valve yoke, drive shaft, or elastic body disposed at the end of the drive shaft. Thrust and torque of the valve device are measured by the semiconductor single crystalline substrate and then the measured values are used for monitoring the valve device.
    Type: Application
    Filed: August 7, 2007
    Publication date: February 14, 2008
    Inventors: Hiroyuki Ohta, Hiromi Shimazu, Yohei Tanno, Yoshihisa Kiyotoki, Kenji Onodera, Kenji Araki
  • Publication number: 20070081916
    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. The metallic parts having on a surface thereof an alloyed layer containing dispersed compound particles can be produced without using a joining method such as welding.
    Type: Application
    Filed: December 8, 2006
    Publication date: April 12, 2007
    Inventors: Mitsuo Chigasaki, Jiro Kuniya, Yoshihisa Kiyotoki, Akira Sakamoto, Satoshi Furusawa
  • Patent number: 6959916
    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: Grant
    Filed: November 6, 2002
    Date of Patent: November 1, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Yoshihisa Kiyotoki, Kikuo Takeshima, Akira Sakamoto, Yoshiteru Chiba
  • Patent number: 6896978
    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: February 27, 2002
    Date of Patent: May 24, 2005
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihisa Kiyotoki, Mitsuo Chigasaki, Shizuo Matsushita, Jiro Kuniya, Takahiko Kato, Yoshiteru Chiba
  • 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