Patents by Inventor Seiji Furusako

Seiji Furusako 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: 10099311
    Abstract: A spot welding method is a method of performing spot welding to obtain a spot welded joint, the method including a spot welding with two-stage welding, setting a ratio (I2/I1) of a current I2 of a second welding process to a current I1 of a first welding process to from 0.5 to 0.8, setting a time tc of a cooling process within a range of from 0.8×tmin to 2.5×tmin wherein tmin is calculated using the equation (0.2×H2) according to a sheet thickness H of the steel sheets, setting an welding time t2 of a second welding process within a range of from 0.7×tmin to 2.5×tmin, and setting a pressure from the cooling process onward to greater than a pressure until the first welding process.
    Type: Grant
    Filed: April 16, 2014
    Date of Patent: October 16, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji Furusako, Fuminori Watanabe, Yasunobu Miyazaki, Tohru Okada, Tasuku Zeniya, Koichi Sato
  • Patent number: 10081071
    Abstract: In an arc spot welded joint manufacturing method in which two steel sheets configured by high strength steel having a component carbon content of 0.07% by mass or greater are overlapped, and the sheets are lap welded together in a spot pattern. The method includes a first welding pass in which a second steel sheet on the lower side is melted up to a back face side, and first weld metal is formed including a first reinforcement portion, and a second welding pass in which a second weld metal including a second reinforcement portion is formed over the first weld metal, such that the heights of the first reinforcement portion or the second reinforcement portion is formed at t/5 or greater with respect to the sheet thickness t of the steel sheets, and the average weld bead diameter is formed at from 3t to 10t.
    Type: Grant
    Filed: July 30, 2014
    Date of Patent: September 25, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji Furusako, Shinji Kodama, Yasunobu Miyazaki, Hatsuhiko Oikawa
  • Patent number: 10081073
    Abstract: In a spot welded joint according to an aspect of the present invention, with respect to a rectangular planar region of 100 ?m×100 ?m which is perpendicular to a sheet surface of the plurality of the steel sheets and which centers around an inner point spaced away by 100 ?m in a direction parallel with the sheet surface from an edge of a nugget, in a case of measuring a P concentration at a pitch of 1 ?m to obtain measured values of the P concentration at 100×100 of measurement points, and in a case of repetitively calculating an average value of the measured values of the P concentration at 20 of the measurement points which are adjacent to each other and which are arranged in a row in the direction parallel with the sheet surface among the 100×100 of the measurement points while shifting each one point to obtain 81×100 of the average values, the number of the average values which are more than two times an average P concentration is 0 to 100.
    Type: Grant
    Filed: April 25, 2013
    Date of Patent: September 25, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Fuminori Watanabe, Tomohito Tanaka, Seiji Furusako, Yasunobu Miyazaki, Hideki Hamatani, Hatsuhiko Oikawa
  • Publication number: 20180236589
    Abstract: A lap welding method of a steel sheet includes spot welding in a state in which the flange portion of a second steel sheet member having the flange portion and a standing wall portion is overlapped with the first steel sheet member, thereby forming a nugget between a first steel sheet member and a flange portion; and, after the spot welding, laser welding a region between an R stop of the standing wall portion and the nugget, thereby forming a weld bead, and, in the weld bead, a length dimension is equal to or longer than a diameter of the nugget, and a width dimension is 0.5 to 3.0 mm.
    Type: Application
    Filed: September 16, 2016
    Publication date: August 23, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Tohru OKADA, Koichi SATO, Yasunobu MIYAZAKI
  • Patent number: 10040145
    Abstract: When two high-strength steel sheets (1A, 1B) whose sheet thickness ratio={the sum of sheet thicknesses of the steel sheets}/{the sheet thickness of the thinner steel sheet (when they have the same thickness, the sheet thickness per one sheet)} is within a range of not less than 2 nor more than 5 and which both have tensile strength of not less than 780 MPa nor more than 1850 MPa are stacked to be subjected to resistance spot welding, a first welding step being pre-welding with a pressurizing force P1 kN and a welding current I1 kA and a second welding step being main welding with a pressurizing force P2 kN and a welding current I2 kA are performed, the pressurizing forces P1, P2 are set to a fixed pressurizing force P=P1=P2 all through the first welding step and the second welding step and are set within a range expressed by {0.5?P?3.
    Type: Grant
    Filed: September 24, 2012
    Date of Patent: August 7, 2018
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji Furusako, Hatsuhiko Oikawa, Yasunobu Miyazaki
  • Publication number: 20180185902
    Abstract: Provided is a mechanical joining apparatus enabling stable riveting when joining metal sheets even when the sheets are large in deformation resistance, the apparatus comprising a punch and die, blank holder and power device, wherein the punch and die are arranged facing each other, the holder is configured by an electrode material able to push against and electrically heat the sheets by one end of the holder, the punch is comprised of a material able to drive in a rivet, the die is comprised of an electrode material able to support and electrically heat the sheets, and the power device is configured to start supply of current through the holder and die so as to raise the temperature of the sheets at the same time as the start of driving in of the rivet and to continue to supply current until the end of driving in of the rivet.
    Type: Application
    Filed: July 1, 2016
    Publication date: July 5, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Tohru OKADA, Yasunobu MIYAZAKI, Fuminori WATANABE, Yoshiaki NAKAZAWA
  • Publication number: 20180185903
    Abstract: Provided is a mechanical joining apparatus enabling reduction of breakage of the area around a rivet of a joint obtained by riveting, the apparatus comprising a punch and die, blank holder, first power device, second power device and cooling device, wherein the first power device is configured to start supply of current through the holder and die so as to raise the temperature of the sheets before the punch drives in the rivet, the second power device is configured to start supply of current through the punch and die so as to supply current through and heat treat the rivet after the punch drives in the rivet, and the cooling device is connected to the punch and is configured to cool the rivet after the rivet is heat treated.
    Type: Application
    Filed: July 1, 2016
    Publication date: July 5, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Tohru OKADA, Yasunobu MIYAZAKI, Fuminori WATANABE, Yoshiaki NAKAZAWA
  • Publication number: 20180079026
    Abstract: A spot welding method able to simply prevent liquid metal embrittlement cracks in spot welding of plated steel sheets, comprising, before spot welding, removing the plating at least in a zone including the inside of a circle centered at a scheduled location where the center of the nugget is formed and having an outer circumference of the inside of the outer edge of a weld affected zone or a zone at the mated surfaces of the steel sheets to be welded at the inside of a circle sharing a center of a scheduled location becoming the center of the nugget formed at the mated surfaces of the steel sheets and having an outer circumference of the inside of the outer edge of a weld affected zone
    Type: Application
    Filed: March 30, 2016
    Publication date: March 22, 2018
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Yasunobu MIYAZAKI, Fuminori WATANABE, Chisato WAKABAYASHI, Kunio HAYASHI, Hiroyuki KAWATA, Seiji FURUSAKO, Sho MATSUI
  • Publication number: 20170348798
    Abstract: There is provided a power supply device that supplies an output current to an electric processing device which performs electric processing on workpieces. The device includes: a first power supply; a magnetic energy recovery switch that receives a current supplied from the first power supply, and converts the received current into the output current; and a control unit that controls the magnetic energy recovery switch such that an electric current frequency of the output current includes a first electric current frequency and a second electric current frequency which are different from each other within a one-time electric processing time using the electric processing device.
    Type: Application
    Filed: December 11, 2015
    Publication date: December 7, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Fuminori WATANABE, Kazuhiko FUKUTANI, Seiji FURUSAKO, Chisato WAKABAYASHI, Tohru OKADA
  • Publication number: 20170297151
    Abstract: An arc spot welding method able to give a predetermined weld bead diameter or excess metal height in a back surface weld bead of arc spot welding and able to give a welded joint excellent in both strengths of TSS and CTS and a welding apparatus for working the same are provided. A steel sheet containing carbon in 0.2 mass % or more and having a sheet thickness “t” and at least one steel sheet containing carbon in 0.
    Type: Application
    Filed: October 6, 2015
    Publication date: October 19, 2017
    Applicant: Nippon Steel & Sumitomo Metal Corporation
    Inventors: Shinji KODAMA, Seiji FURUSAKO, Yasunobu MIYAZAKI
  • Patent number: 9649725
    Abstract: At a plurality of welding positions in an overlap portion of a plurality of members including a high-tensile steel sheet whose carbon content is 0.07 weight % or more, first beads (31 to 36) in a closed loop shape or a closed loop-like shape and second beads (41 to 46) in a closed loop shape or a closed loop-like shape on inner sides of the first bead (31 to 36) are formed by remote laser welding for joining. At this time, there are a procedure for successively forming the plural first beads (31 to 36) and a procedure for successively forming the plural second beads (41 to 46) for the plural formed first beads (31 to 36), and in both of the cases, the beads are each formed at a position except the closest welding position among the plural welding positions. Consequently, it is possible to enhance strength of a weld zone and to suppress welding deformation.
    Type: Grant
    Filed: October 12, 2011
    Date of Patent: May 16, 2017
    Assignee: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji Furusako, Yasunobu Miyazaki, Yasuaki Naito
  • Publication number: 20170080515
    Abstract: The spot welding method of the present invention has steps of preliminary conduction, first conduction, second conduction, and third conduction: Preliminary conduction: Conduction method aimed at improving closeness of contact surfaces of steel sheets and reducing sheet gaps by gradually increasing the welding current (for example, upslope conduction). If rapidly applying current, current would be locally carried and that part would melt resulting in expulsion, so this is a conduction method gradually running current (for example upslope conduction) to avoid local heating. First conduction: Conduction method running a constant welding current and using the heat generated by the electrical contact resistance between steel sheets to cause the formation of a nugget when preliminary conduction results in close contact surfaces between the steel sheets.
    Type: Application
    Filed: May 1, 2015
    Publication date: March 23, 2017
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Yasunobu MIYAZAKI, Hitomi NISHIBATA, Yasuo TAKAHASHI
  • Publication number: 20160271721
    Abstract: A spot welding electrode of a donut-shaped electrode wherein even when a welded member of a steel sheet is slanted with respect a plane perpendicular to an axis of the spot welding electrode, a cross tensile strength (CTS) of the spot welded joint can be improved. The donut shape spot welding electrode according to the present invention has an electrode tip and an electrode support. The electrode tip contacts the electrode support to be able to move. Due to this, it is possible to strikingly raise the ability of the donut-shaped electrode to track a steel sheet and make the entire surface of the donut shape contact-and-conduction part contact the steel sheet, so it is possible to secure a high CTS value even if the steel sheet is slanted.
    Type: Application
    Filed: December 5, 2014
    Publication date: September 22, 2016
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Fuminori WATANABE, Tohru OKADA, Seiji FURUSAKO
  • Publication number: 20160158865
    Abstract: In an arc spot welded joint manufacturing method in which two steel sheets configured by high strength steel having a component carbon content of 0.07% by mass or greater are overlapped, and the sheets are lap welded together in a spot pattern. The method includes a first welding pass in which a second steel sheet on the lower side is melted up to a back face side, and first weld metal is formed including a first reinforcement portion, and a second welding pass in which a second weld metal including a second reinforcement portion is formed over the first weld metal, such that the heights of the first reinforcement portion or the second reinforcement portion is formed at t/5 or greater with respect to the sheet thickness t of the steel sheets, and the average weld bead diameter is formed at from 3t to 10t.
    Type: Application
    Filed: July 30, 2014
    Publication date: June 9, 2016
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Shinji KODAMA, Yasunobu MIYAZAKI, Hatsuhiko OIKAWA
  • Publication number: 20160082543
    Abstract: By obtaining a spot-welded joint being a spot-welded joint formed by overlapping a plurality of pieces of steel plates (1A, 1B) and performing spot welding on the steel plates, including a high-strength steel plate whose tensile strength is 750 (MPa) to 2500 (MPa), being at least one piece of steel plate out of the plurality of pieces of steel plates, in which a carbon equivalent Ceq of the high-strength steel plate is 0.20 mass % to 0.55 mass %, and ten or more of iron-based carbides in each of which a length of a longest portion is 0.1 (?m) or more exist in a square region 103 within a heat-affected zone 4 of a cross section that passes through a center of a welding mark, and is cut along a plate thickness direction of the steel plates (1A, 1B), a cross tensile strength of the spot-welded joint to be formed is improved.
    Type: Application
    Filed: June 2, 2014
    Publication date: March 24, 2016
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Chisato WAKABAYASHI, Fuminori WATANABE, Seiji FURUSAKO, Yasunobu MIYAZAKI, Hiroyuki KAWATA, Tohru OKADA, Hideki HAMATANI
  • Publication number: 20160067814
    Abstract: A spot welding method is a method of performing spot welding to obtain a spot welded joint, the method including a spot welding with two-stage welding, setting a ratio (I2/I1) of a current I2 of a second welding process to a current I1 of a first welding process to from 0.5 to 0.8, setting a time tc of a cooling process within a range of from 0.8×tmin to 2.5×tmin wherein tmin is calculated using the equation (0.2×H2) according to a sheet thickness H of the steel sheets, setting an welding time t2 of a second welding process within a range of from 0.7×tmin to 2.5×tmin, and setting a pressure from the cooling process onward to greater than a pressure until the first welding process.
    Type: Application
    Filed: April 16, 2014
    Publication date: March 10, 2016
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji FURUSAKO, Fuminori WATANABE, Yasunobu MIYAZAKI, Tohru OKADA, Tasuku ZENIYA, Koichi SATO
  • Publication number: 20150174690
    Abstract: When two high-strength steel sheets (1A, 1B) whose sheet thickness ratio={the sum of sheet thicknesses of the steel sheets}/{the sheet thickness of the thinner steel sheet (when they have the same thickness, the sheet thickness per one sheet)} is within a range of not less than 2 nor more than 5 and which both have tensile strength of not less than 780 MPa nor more than 1850 MPa are stacked to be subjected to resistance spot welding, a first welding step being pre-welding with a pressurizing force P1 kN and a welding current I1 kA and a second welding step being main welding with a pressurizing force P2 kN and a welding current I2 kA are performed, the pressurizing forces P1, P2 are set to a fixed pressurizing force P=P1=P2 all through the first welding step and the second welding step and are set within a range expressed by {0.5?P?3.
    Type: Application
    Filed: September 24, 2012
    Publication date: June 25, 2015
    Applicant: NIPPON STEEL & SUMITOMO METAL CORPORATION
    Inventors: Seiji Furusako, Hatsuhiko Oikawa, Yasunobu Miyazaki
  • Publication number: 20150104243
    Abstract: In a spot welded joint according to an aspect of the present invention, with respect to a rectangular planar region of 100 ?m×100 ?m which is perpendicular to a sheet surface of the plurality of the steel sheets and which centers around an inner point spaced away by 100 ?m in a direction parallel with the sheet surface from an edge of a nugget, in a case of measuring a P concentration at a pitch of 1 ?m to obtain measured values of the P concentration at 100×100 of measurement points, and in a case of repetitively calculating an average value of the measured values of the P concentration at 20 of the measurement points which are adjacent to each other and which are arranged in a row in the direction parallel with the sheet surface among the 100×100 of the measurement points while shifting each one point to obtain 81×100 of the average values, the number of the average values which are more than two times an average P concentration is 0 to 100.
    Type: Application
    Filed: April 25, 2013
    Publication date: April 16, 2015
    Inventors: Fuminori Watanabe, Tomohito Tanaka, Seiji Furusako, Yasunobu Miyazaki, Hideki Hamatani, Hatsuhiko Oikawa
  • Publication number: 20130168371
    Abstract: At a plurality of welding positions in an overlap portion of a plurality of members including a high-tensile steel sheet whose carbon content is 0.07 weight % or more, first beads (31 to 36) in a closed loop shape or a closed loop-like shape and second beads (41 to 46) in a closed loop shape or a closed loop-like shape on inner sides of the first bead (31 to 36) are formed by remote laser welding for joining. At this time, there are a procedure for successively forming the plural first beads (31 to 36) and a procedure for successively forming the plural second beads (41 to 46) for the plural formed first beads (31 to 36), and in both of the cases, the beads are each formed at a position except the closest welding position among the plural welding positions. Consequently, it is possible to enhance strength of a weld zone and to suppress welding deformation.
    Type: Application
    Filed: October 12, 2011
    Publication date: July 4, 2013
    Inventors: Seiji Furusako, Yasunobu Miyazaki, Yasuaki Naito
  • Patent number: 8123286
    Abstract: A vehicle side section structure that is capable of a required stiffness and enables a reduction in weight of a roof side section is provided. A roof side rail that structures a vehicle side section structure is provided with: a roof outer panel that has length in a vehicle front-rear direction and is opened inward of the vehicle, and has a pair of upper and lower flanges; and a roof side frame member that is joined to the pair of upper and lower flanges of the roof outer panel at a pair of upper and lower flanges. The roof side frame member has, between the upper and lower flanges, an outward protruding portion that is protruded in a vehicle outward direction and an inward protruding portion 46 that is protruded in a vehicle inward direction, and in a sectional view cut orthogonally to the length direction, a length of a top wall of the outward protruding portion is longer than a length of a top wall of the inward protruding portion.
    Type: Grant
    Filed: December 1, 2008
    Date of Patent: February 28, 2012
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Seiji Furusako, Hideo Takeda