Patents by Inventor Kenichi Kumagai
Kenichi Kumagai 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: 8288928Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 tincm or less.Type: GrantFiled: September 23, 2010Date of Patent: October 16, 2012Assignees: NGK Spark Plug Co., Ltd., Sumitomo Electric Industries, Ltd.Inventors: Kenichi Kumagai, Teruyuki Kondo, Kozo Amano, Kazuo Yamazaki, Yoshihiro Nakai, Masatada Numano
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Publication number: 20110012500Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 tincm or less.Type: ApplicationFiled: September 23, 2010Publication date: January 20, 2011Applicants: NGK SPARK PLUG CO., LTD., SUMITOMO ELECTRIC INDUSTRIES, LTD.Inventors: Kenichi KUMAGAI, Teruyuki KONDO, Kozo AMANO, Kazuo YAMAZAKI, Yoshihiro NAKAI, Masatada NUMANO
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Patent number: 7825571Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 ??cm or less.Type: GrantFiled: January 30, 2006Date of Patent: November 2, 2010Assignees: NGK Spark Plug Co., Ltd., Sumitomo Electric Industries, Ltd.Inventors: Kenichi Kumagai, Teruyuki Kondo, Kozo Amano, Kazuo Yamazaki, Yoshihiro Nakai, Masatada Numano
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Patent number: 7804232Abstract: To provide a spark plug in which separation of a tip can be prevented and enough wear resistance can be obtained without increasing the content of nickel in the tip portion, and a use method of the spark plug. In a spark plug (100) including an outside electrode (10) including an electrode body portion (11) and a tip (12) bonded to the electrode body portion (11), and a center electrode (20), and the tip (12) is opposed to the front end portion of the center electrode (20) through a spark discharge gap (G), the electrode body portion (11) is made of a nickel alloy containing 13 to 18% by mass of Cr, 0.03 to 0.08% by mass of C, 1 to 3.5% by mass of Mo, 0 to 0.8% by mass of Si, Al, Mn and Ti, and 68% by mass or more of Ni, and the tip (12) is made of a platinum alloy containing 0 to 4% by mass of Ni.Type: GrantFiled: January 27, 2005Date of Patent: September 28, 2010Assignee: NGK Spark Plug Co., Ltd.Inventors: Kenichi Kumagai, Wataru Matsutani, Kenji Kobayashi
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Patent number: 7741763Abstract: A spark plug including a center electrode; an insulator; a metal shell; a ground electrode; and an annular packing, all as defined herein, wherein the packing has a hardness greater than or equal to a hardness of the stepped portion of the metal shell or has a Vickers hardness of not less than 300 Hv. Preferably, a difference between the hardness of the packing and the hardness of the stepped portion of the metal shell is from 120 Hv to 160 Hv, and the packing has a Vickers hardness of not more than 500 Hv.Type: GrantFiled: August 28, 2007Date of Patent: June 22, 2010Assignee: NGK Spark Plug Co., Ltd.Inventors: Kenichi Kumagai, Koji Mizoguchi
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Publication number: 20080278053Abstract: To provide a spark plug in which separation of a tip can be prevented and enough wear resistance can be obtained without increasing the content of nickel in the tip portion, and a use method of the spark plug. In a spark plug (100) including an outside electrode (10) including an electrode body portion (11) and a tip (12) bonded to the electrode body portion (11), and a center electrode (20), and the tip (12) is opposed to the front end portion of the center electrode (20) through a spark discharge gap (G), the electrode body portion (11) is made of a nickel alloy containing 13 to 18% by mass of Cr, 0.03 to 0.08% by mass of C, 1 to 3.5% by mass of Mo, 0 to 0.8% by mass of Si, Al, Mn and Ti, and 68% by mass or more of Ni, and the tip (12) is made of a platinum alloy containing 0 to 4% by mass of Ni.Type: ApplicationFiled: January 27, 2005Publication date: November 13, 2008Inventors: Kenichi Kumagai, Wataru Matsutani, Kenji Kobayashi
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Publication number: 20080054778Abstract: A spark plug including a center electrode; an insulator; a metal shell; a ground electrode; and an annular packing, all as defined herein, wherein the packing has a hardness greater than or equal to a hardness of the stepped portion of the metal shell or has a Vickers hardness of not less than 300 Hv. Preferably, a difference between the hardness of the packing and the hardness of the stepped portion of the metal shell is from 120 Hv to 160 Hv, and the packing has a Vickers hardness of not more than 500 Hv.Type: ApplicationFiled: August 28, 2007Publication date: March 6, 2008Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kenichi KUMAGAI, Koji MIZOGUCHI
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Publication number: 20060170320Abstract: A spark plug comprising: a cylindrical metal shell; a cylindrical insulator provided in an inner hole of said metal shell; a center electrode provided in a leading end side inner hole of said insulator; and a ground electrode having one end bonded to a leading end side of said metal shell and having another end face forming a spark discharge gap with said center electrode, wherein said ground electrode comprises an electrode material containing from 0.5 to 1.5 wt. % of Si, from 0.5 to 1.5 wt. % of Al, from 0.02 to 1.0 wt. % of at least one of Ti, V, Zr, Nb and Hf, from 0.03 to 0.09 wt. % of C and 95.5 wt. % or more of Ni, and having a specific resistance at 20° C. of 25 ??cm or less.Type: ApplicationFiled: January 30, 2006Publication date: August 3, 2006Inventors: Kenichi Kumagai, Teruyuki Kondo, Kozo Amano, Kazuo Yamazaki, Yoshihiro Nakai, Masatada Numano
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Patent number: 6759795Abstract: A spark plug having a tubular metallic shell (1), an insulator (2) fitted into the metallic shell (1), a center electrode (3) provided in the insulator (2), and a ground electrode (4), one end of the ground electrode (4) being joined to the metallic shell (1) by means of welding or a like process, and a spark discharge gap (g) being formed between the other end portion of the ground electrode (4) and the center electrode (3), the spark plug being further characterized in that: the ground electrode (4) has an electrode base metal (4a), a Cu-based heat transfer acceleration element (4c) embedded in the electrode base metal (4a) and formed predominantly from Cu, and a noble metal chip (32) welded to the electrode base metal (4a) at a position facing the spark discharge gap (g); and the electrode base metal (4a) is an Ni alloy containing Cr in an amount of 14%-17% by mass, Mo in an amount of 0.8%-3.5% by mass, and Ni in an amount of 68%-85.2% by mass.Type: GrantFiled: February 26, 2003Date of Patent: July 6, 2004Assignee: NGK Spark Plug Co., Ltd.Inventors: Kenichi Kumagai, Makoto Yamaguchi, Hiroaki Kuki
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Publication number: 20040080252Abstract: A spark plug for use in an internal combustion engine includes a tubular insulator having an axial hole extending therethrough; a center electrode fitted into the axial hole and having a distal end portion protruding from a distal end of the insulator; and a ground electrode arranged such that at least a portion of spark discharge generated between the ground electrode and the distal end portion of the center electrode includes creeping discharge along the surface of the distal end portion of the insulator. The distal end portion of the center electrode contains Ni as a primary component in an amount of 80 wt % or more and Fe and Cr as secondary components in a total amount of 2.5 wt % to 10.0 wt % and further contains Al as a secondary component in an amount of 0.2 wt % to 0.8 wt %.Type: ApplicationFiled: September 23, 2003Publication date: April 29, 2004Applicant: NGK Spark Plug Co., Ltd.Inventors: Satoko Ito, Kenji Kobayashi, Kenichi Kumagai, Wataru Matsutani, Yoshihiro Matsubara
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Publication number: 20030178925Abstract: A spark plug having a tubular metallic shell (1), an insulator (2) fitted into the metallic shell (1), a center electrode (3) provided in the insulator (2), and a ground electrode (4), one end of the ground electrode (4) being joined to the metallic shell (1) by means of welding or a like process, and a spark discharge gap (g) being formed between the other end portion of the ground electrode (4) and the center electrode (3), the spark plug being further characterized in that: the ground electrode (4) has an electrode base metal (4a), a Cu-based heat transfer acceleration element (4c) embedded in the electrode base metal (4a) and formed predominantly from Cu, and a noble metal chip (32) welded to the electrode base metal (4a) at a position facing the spark discharge gap (g); and the electrode base metal (4a) is an Ni alloy containing Cr in an amount of 14%-17% by mass, Mo in an amount of 0.8%-3.5% by mass, and Ni in an amount of 68%-85.2% by mass.Type: ApplicationFiled: February 26, 2003Publication date: September 25, 2003Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kenichi Kumagai, Makoto Yamaguchi, Hiroaki Kuki
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Patent number: 6603244Abstract: A spark plug includes: a central electrode; an insulator surrounding the central electrode radially; a metallic shell surrounding the insulator radially; and a ground electrode having a first end connected to the metallic shell and a second end defining a side face. The ground electrode is so bent that the side face of the second end faces the central electrode. The ground electrode contains: a nickel in a range from 58% to 71% by weight, a chromium in a range from 21% to 25% by weight, an iron in a range from 7% to 20% by weight, and an aluminum in a range from 1% to 2% by weight. The ground electrode has a Vickers hardness in a range from Hv 140 to Hv 220 through a Vickers hardness test specified in Japanese Industrial Standard Z2244. A load 9.8 N is applied to the ground electrode in the hardness test.Type: GrantFiled: February 26, 2002Date of Patent: August 5, 2003Assignee: NGK Spark Plug Co., Ltd.Inventors: Yoshihisa Sugiyama, Tomoharu Suzuki, Kenichi Kumagai
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Publication number: 20020158559Abstract: A spark plug includes: a central electrode; an insulator surrounding the central electrode radially; a metallic shell surrounding the insulator radially; and a ground electrode having a first end connected to the metallic shell and a second end defining a side face. The ground electrode is so bent that the side face of the second end faces the central electrode. The ground electrode contains: a nickel in a range from 58% to 71% by weight, a chromium in a range from 21% to 25% by weight, an iron in a range from 7% to 20% by weight, and an aluminum in a range from 1% to 2% by weight. The ground electrode has a Vickers hardness in a range from Hv 140 to Hv 220 through a Vickers hardness test specified in Japanese Industrial Standard Z2244. A load 9.8 N is applied to the ground electrode in the hardness test.Type: ApplicationFiled: February 26, 2002Publication date: October 31, 2002Applicant: NGK SPARK PLUG CO., LTD.Inventors: Yoshihisa Sugiyama, Tomoharu Suzuki, Kenichi Kumagai
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Patent number: 4911883Abstract: Stainless steels possessing a superior cold workability and hot workability, which are yet economical. The stainless steels comprise not more than 0.04% carbon, not more than 0.60% silicon, 2.2-3.8% manganese, 2.5-4.0% copper, 6-8% nickel, 17-19% chromium, and the remainder being iron together with impurities. And, not more than 0.002% sulfur is decreased to provide stainless steels which possess superior corrosion resistance, and not more than 0.010% nitrogen are decreased in the stainless steels as required.Type: GrantFiled: July 8, 1988Date of Patent: March 27, 1990Assignee: Aichi Steel Work, Ltd.Inventors: Kenichi Kumagai, Yoshinobu Honkura, Toru Matsuo, Kouji Murata