Patents by Inventor Sadato Shimizu
Sadato Shimizu 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: 6639962Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.Type: GrantFiled: January 15, 2002Date of Patent: October 28, 2003Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd., Hitachi Ibaraki Business Engineering Co., Ltd.Inventors: Kunio Enomoto, Katsuhiko Hirano, Eisaku Hayashi, Ren Morinaka, Sadato Shimizu, Satoshi Kanno, Shigeru Tanaka, Tetsuya Ishikawa
-
Patent number: 6519991Abstract: A water jet peening apparatus which can carry out an efficient peening work on a large-diameter cylindrical structure by injecting a jet stream which contains air bubbles caused by cavitation at a low angle of incidence is provided. The apparatus is comprised of a nozzle which introduces a high pressure water and injects a water jet stream containing air bubbles caused by cavitation at the cylindrical structure disposed in water, wherein the angle of injection of the jet stream is smaller than 45 degrees relative to a tangent of the cylindrical structure.Type: GrantFiled: April 24, 2002Date of Patent: February 18, 2003Assignees: Hitachi, Ltd., Hitachi Kiso Co., Ltd., Hitachi Ibaraki Business Engineering Co., Ltd., Hitachi Engineering Co., Ltd.Inventors: Katsuhiko Hirano, Kunio Enomoto, Eisaku Hayashi, Sadato Shimizu, Ren Morinaka, Tetsuya Ishikawa, Shigeru Tanaka, Noboru Chiba
-
Publication number: 20020159558Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.Type: ApplicationFiled: January 15, 2002Publication date: October 31, 2002Inventors: Kunio Enomoto, Katsuhiko Hirano, Eisaku Hayashi, Ren Morinaka, Sadato Shimizu, Satoshi Kanno, Shigeru Tanaka, Tetsuya Ishikawa
-
Publication number: 20020116970Abstract: A water jet peening apparatus which can carry out an efficient peening work on a large-diameter cylindrical structure by injecting a jet stream which contains air bubbles caused by cavitation at a low angle of incidence is provided. The apparatus is comprised of a nozzle which introduces a high pressure water and injects a water jet stream containing air bubbles caused by cavitation at the cylindrical structure disposed in water, wherein the angle of injection of the jet stream is smaller than 45 degrees relative to a tangent of the cylindrical structure.Type: ApplicationFiled: April 24, 2002Publication date: August 29, 2002Applicant: Hitachi, Ltd.Inventors: Katsuhiko Hirano, Kunio Enomoto, Eisaku Hayashi, Sadato Shimizu, Ren Morinaka, Tetsuya Ishikawa, Shigeru Tanaka, Noboru Chiba
-
Patent number: 6425276Abstract: A water jet peening apparatus which can carry out an efficient peening work on a large-diameter cylindrical structure by injecting a jet stream which contains air bubbles caused by cavitation at a low angle of incidence is provided. The apparatus is comprised of a nozzle which introduces a high pressure water and injects a water jet stream containing air bubbles caused by cavitation at the cylindrical structure disposed in water, wherein the angle of injection of the jet stream is smaller than 45 degrees relative to a tangent of the cylindrical structure.Type: GrantFiled: January 21, 2000Date of Patent: July 30, 2002Assignees: Hitachi, Ltd., Hitachi Kiso Co., Ltd., Hitachi Ibaraki Business Engineering Co., Ltd., Hitachi Engineering Co., Ltd.Inventors: Katsuhiko Hirano, Kunio Enomoto, Eisaku Hayashi, Sadato Shimizu, Ren Morinaka, Tetsuya Ishikawa, Shigeru Tanaka, Noboru Chiba
-
Patent number: 6345083Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.Type: GrantFiled: August 12, 1999Date of Patent: February 5, 2002Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd., Hitachi Ibaraki Business Engineering Co., Ltd.Inventors: Kunio Enomoto, Katsuhiko Hirano, Eisaku Hayashi, Ren Morinaka, Sadato Shimizu, Satoshi Kanno, Shigeru Tanaka, Tetsuya Ishikawa
-
Patent number: 6341151Abstract: A preventive maintenance method and apparatus for a structural member in a reactor pressure vessel according to the present invention reduce a tensile residual stress on a surface of the structural member by impinging a water jet from a nozzle onto a plane surface of a deflector to thereby change direction of flow of the water jet, and impinging the water jet after being deflected onto the surface of the structural member. This method and apparatus are applicable to a narrow space portion, and can improve a residual stress on the surface of the structural member and can also prevent damage such as stress corrosion cracking.Type: GrantFiled: August 29, 2000Date of Patent: January 22, 2002Assignees: Hitachi, Ltd., Hitachi Engineering Co., Ltd., Hitachi Ibaraki Business Engineering Co., Ltd.Inventors: Kunio Enomoto, Katsuhiko Hirano, Eisaku Hayashi, Ren Morinaka, Sadato Shimizu, Satoshi Kanno, Shigeru Tanaka, Tetsuya Ishikawa
-
Patent number: 6240155Abstract: A method of performing maintenance on a structural member inside a reactor pressure vessel includes lowering an annular guide rail having a second lug until the guide rail rests on an upper flange of a core shroud provided inside the reactor pressure vessel, detachably mounting the second lug of the guide rail to a first lug mounted on the core shroud, positioning a discharging nozzle at a position at which compressive remaining stress is added to a surface of the core shroud by moving the discharging nozzle in a radial direction and an axial direction of the core shroud by a discharging nozzle moving apparatus mounted on a turnable revolving on the guide rail and discharging water to add compressive remaining stress to a surface of the core shroud from the discharging nozzle.Type: GrantFiled: August 4, 1999Date of Patent: May 29, 2001Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki KaishaInventors: Koichi Kurosawa, Eisaku Hayashi, Sadato Shimizu, Minoru Ootaka, Fujio Yoshikubo, Ren Morinaka, Masayuki Nishino, Noboru Chiba, Kunio Enomoto, Kazunori Sato
-
Patent number: 6058153Abstract: A preventive maintenance apparatus for structural members inside a nuclear reactor pressure vessel includes a ring-shaped guide rail having a plurality of lugs which is placed on an upper flange of a core shroud provided inside a reactor pressure vessel. At least some of lugs separately engage with a plurality of guide rods provided on an inner surface of the reactor pressure vessel. A turntable is rotated on the guide rail. A first discharging nozzle moving apparatus placed on the turntable moves a first discharging nozzle for adding compressive remaining stress to an outer surface of the core shroud in a radial direction of the core shroud and in an axial direction of the core shroud. A second discharging nozzle moving apparatus placed on the turntable moves a second discharging nozzle for adding compressive remaining stress to an inner surface of the core shroud in a radial direction of the core shroud and in an axial direction of the core shroud.Type: GrantFiled: February 20, 1998Date of Patent: May 2, 2000Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki KaishaInventors: Koichi Kurosawa, Eisaku Hayashi, Sadato Shimizu, Minoru Ootaka, Fujio Yoshikubo, Ren Morinaka, Masayuki Nishino, Noboru Chiba, Kunio Enomoto, Kazunori Sato
-
Patent number: 5897062Abstract: A fluid jet nozzle has a water chamber accommodating therein pressurized fluid, an orifice communicating with the water chamber and contracting the fluid from the water chamber, a throat communicating with the orifice and through which the fluid from the orifice passes, a multiplication chamber communicating with the throat and receiving the fluid from the throat for multiplying cavitation, and a diffusion chamber receiving the fluid from the multiplication chamber for diffusing the fluid.Type: GrantFiled: October 18, 1996Date of Patent: April 27, 1999Assignees: Hitachi, Ltd., Babcock-Hitachi Kabushiki KaisyaInventors: Kunio Enomoto, Katsuhiko Hirano, Masahiro Otaka, Kazuo Amano, Eisaku Hayashi, Sadato Shimizu, Ren Morinaka, Kazunori Sato
-
Patent number: 5537037Abstract: A nondestructive inspecting apparatus is arranged to have an exciting magnet for applying an ac magnetic field to a sample and a SQUID for converting change of a magnetic characteristic of the sample occurring when the ac magnetic field is applied to the sample into an electric signal. The exciting magnet is a cancelled coil assembly composed of plural coils having respective polarities.Type: GrantFiled: March 15, 1994Date of Patent: July 16, 1996Assignee: Hitachi, Ltd.Inventors: Masahiro Otaka, Sadato Shimizu, Kazuo Takaku, Shinji Sakata