Patents by Inventor Koki Nakada
Koki Nakada 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).
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Patent number: 11969813Abstract: A spot welding method includes a heating step of energizing an electrode in pressure contact with an Al alloy member to heat and melt a join part by resistance heating and a cooling step of cooling the join part after the heating step in a state in which the electrode is in pressure contact with the Al alloy member. The alloy is a wrought alloy of Mg: 0.2 to 1.2 mass %, Si: 0.4 to 1.5%, and Cu: 1.1% or less or a casting alloy of Si: 7 to 11% and Mg: 0.1 to 0.4% with respect to 100% as a whole. The cooling step includes a first cooling process performed with a reduced amount of input energy to the join part as compared with the heating step and a second cooling process performed after the first cooling process at a higher cooling rate than that in the first cooling process.Type: GrantFiled: February 25, 2021Date of Patent: April 30, 2024Assignees: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hideaki Matsuoka, Takanori Nakagaki, Kyosuke Izuno, Koki Nakada, Manabu Ooga
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Patent number: 11772186Abstract: A novel spot welding method for steel sheets and an aluminum alloy sheet, includes stacked sheet materials from a pair of opposing electrodes to join the sheet materials by resistance heating. The pair of opposing electrodes are in pressure contact with both outer surfaces of the sheet sets. The sheet sets include at least a first and second steel sheet, and an aluminum alloy sheet stacked in this order. A first energization step forms a molten pool between facing surfaces of the first and second steel sheets without melting the aluminum alloy sheet. A second energization step causes a melting reaction between facing surfaces of the second steel sheet and the aluminum alloy sheet. The first and second steel sheets are joined via a first nugget. The second steel sheet and the aluminum alloy sheet are joined via a second nugget including an intermetallic compound generated by the melting reaction.Type: GrantFiled: July 12, 2021Date of Patent: October 3, 2023Assignees: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hideaki Matsuoka, Takashi Asada, Tatsuyuki Amago, Kyosuke Izuno, Koki Nakada, Tomohiko Sekiguchi, Shuhei Ogura
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Patent number: 11660705Abstract: A laser welding method is provided to ensure a sufficient joining strength between metal plates by increasing the area of a joining region while preventing “burn through” of a molten metal. In the laser welding method by applying a laser beam to a surface of multiple metal plates superimposed on each other, a scanning locus with the laser beam is sequentially shifted from an inner circular scanning locus to an outer one in a predetermined joining region on the metal plates, and an emission interval is provided to temporally stop the metal-plate-surface irradiation when the scanning locus is shifted. Thus, every time the scanning locus is shifted, the molten metal due to the previous irradiation is cooled and increases its viscosity. Accordingly, the “burn through” is prevented regardless of increase of the area of the joining region, which results in a sufficient joining strength between the metal plates.Type: GrantFiled: April 24, 2019Date of Patent: May 30, 2023Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Koki Nakada, Toru Hioki, Atsushi Kawakita, Shuhei Ogura, Takashi Goto
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Patent number: 11511371Abstract: In a laser welding method, generation of relatively large blow holes in a welding part is prevented while decrease in productivity is reduced. The laser welding method for lap welding, using a laser beam LB, of a plurality of metal plates and including an aluminum alloy cast plate includes: a melting path of scanning and irradiating circularly a superimposed part of the aluminum alloy plate and the aluminum alloy cast plate with a first laser beam LB1 to form a molten pool of the molten aluminum alloy plate and the molten aluminum alloy cast plate; and a stirring path of scanning and irradiating circularly the molten pool with a second laser beam LB2 having a scanning speed V2 faster than a scanning speed V1 of the first laser beam LB1 to stir the molten pool.Type: GrantFiled: May 30, 2019Date of Patent: November 29, 2022Assignee: TOYOTA JTDOSHA KABUSHIKI KAISHAInventors: Toru Hioki, Shuhei Ogura, Atsushi Kawakita, Koki Nakada, Takashi Goto, Ryosuke Kawai
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Publication number: 20220314358Abstract: A resistance spot welding method includes the steps of: removing at least part of oil on a surface of a welding target material by energization between a pair of electrodes; and after the oil removal step, forming a nugget in an overlapped portion of the welding target material by energization between the pair of electrodes.Type: ApplicationFiled: March 11, 2022Publication date: October 6, 2022Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Koki NAKADA, Kyosuke Izuno
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Publication number: 20220111464Abstract: A novel spot welding method for steel sheets and an aluminum alloy sheet, includes stacked sheet materials from a pair of opposing electrodes to join the sheet materials by resistance heating. The pair of opposing electrodes are in pressure contact with both outer surfaces of the sheet sets. The sheet sets include at least a first and second steel sheet, and an aluminum alloy sheet stacked in this order. A first energization step forms a molten pool between facing surfaces of the first and second steel sheets without melting the aluminum alloy sheet. A second energization step causes a melting reaction between facing surfaces of the second steel sheet and the aluminum alloy sheet. The first and second steel sheets are joined via a first nugget. The second steel sheet and the aluminum alloy sheet are joined via a second nugget including an intermetallic compound generated by the melting reaction.Type: ApplicationFiled: July 12, 2021Publication date: April 14, 2022Applicants: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hideaki MATSUOKA, Takashi ASADA, Tatsuyuki AMAGO, Kyosuke IZUNO, Koki NAKADA, Tomohiko SEKIGUCHI, Shuhei OGURA
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Publication number: 20210268597Abstract: A spot welding method includes a heating step of energizing an electrode in pressure contact with an Al alloy member to heat and melt a join part by resistance heating and a cooling step of cooling the join part after the heating step in a state in which the electrode is in pressure contact with the Al alloy member. The alloy is a wrought alloy of Mg: 0.2 to 1.2 mass %, Si: 0.4 to 1.5%, and Cu: 1.1% or less or a casting alloy of Si: 7 to 11% and Mg: 0.1 to 0.4% with respect to 100% as a whole. The cooling step includes a first cooling process performed with a reduced amount of input energy to the join part as compared with the heating step and a second cooling process performed after the first cooling process at a higher cooling rate than that in the first cooling process.Type: ApplicationFiled: February 25, 2021Publication date: September 2, 2021Applicants: KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHO, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Hideaki MATSUOKA, Takanori NAKAGAKI, Kyosuke IZUNO, Koki NAKADA, Manabu OOGA
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Publication number: 20190366479Abstract: In a laser welding method, generation of relatively large blow holes in a welding part is prevented while decrease in productivity is reduced. The laser welding method for lap welding, using a laser beam LB, of a plurality of metal plates and including an aluminum alloy cast plate includes: a melting path of scanning and irradiating circularly a superimposed part of the aluminum alloy plate and the aluminum alloy cast plate with a first laser beam LB1 to form a molten pool of the molten aluminum alloy plate and the molten aluminum alloy cast plate; and a stirring path of scanning and irradiating circularly the molten pool with a second laser beam LB2 having a scanning speed V2 faster than a scanning speed V1 of the first laser beam LB1 to stir the molten pool.Type: ApplicationFiled: May 30, 2019Publication date: December 5, 2019Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Toru HIOKI, Shuhei OGURA, Atsushi KAWAKITA, Koki NAKADA, Takashi GOTO, Ryosuke KAWAI
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Publication number: 20190329361Abstract: A laser welding method is provided to ensure a sufficient joining strength between metal plates by increasing the area of a joining region while preventing “burn through” of a molten metal. In the laser welding method by applying a laser beam to a surface of multiple metal plates superimposed on each other, a scanning locus with the laser beam is sequentially shifted from an inner circular scanning locus to an outer one in a predetermined joining region on the metal plates, and an emission interval is provided to temporally stop the metal-plate-surface irradiation when the scanning locus is shifted. Thus, every time the scanning locus is shifted, the molten metal due to the previous irradiation is cooled and increases its viscosity. Accordingly, the “burn through” is prevented regardless of increase of the area of the joining region, which results in a sufficient joining strength between the metal plates.Type: ApplicationFiled: April 24, 2019Publication date: October 31, 2019Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Koki Nakada, Toru Hioki, Atsushi Kawakita, Shuhei Ogura, Takashi Goto