Patents by Inventor Kuniharu Tanaka
Kuniharu Tanaka 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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Publication number: 20180375298Abstract: The present invention allows reduction in high frequency noise of a spark plug. A Fe-containing oxide layer is formed on the surface of a beneath-flange rod-shaped portion, of a metal terminal of the spark plug, between a terminal flange portion and an upper end of a metal shell. The surface area of the Fe-containing oxide layer is not less than 10% of the surface area of the beneath-flange rod-shaped portion.Type: ApplicationFiled: September 19, 2016Publication date: December 27, 2018Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kuniharu TANAKA, Toshitaka HONDA, Hirokazu KURONO, Hironori UEGAKI
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Publication number: 20180358784Abstract: A spark plug has an insulator, a rod-shaped electrode member disposed in an axial hole of the insulator, and a cylindrical magnetic member disposed on an outer circumference of the electrode member within the axial hole. The insulator includes a large inner diameter region, a middle inner diameter region located frontward of the large inner diameter region and having an inner diameter smaller than that of the large inner diameter region, and a small inner diameter region located frontward of the middle inner diameter region and having an inner diameter smaller than that of the middle inner diameter region. The electrode member is retained on a step portion of the insulator between the middle inner diameter region and the small inner diameter region. The magnetic member is positioned in the axial hole at a location within the large inner diameter region.Type: ApplicationFiled: June 6, 2018Publication date: December 13, 2018Applicant: NGK SPARK PLUG CO., LTD.Inventors: Hironori UEGAKI, Shoma TSUMAGARI, Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kuniharu TANAKA
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Patent number: 10153622Abstract: A spark plug has an insulator, a rod-shaped electrode member disposed in an axial hole of the insulator, and a cylindrical magnetic member disposed on an outer circumference of the electrode member within the axial hole. The insulator includes a large inner diameter region, a middle inner diameter region located frontward of the large inner diameter region and having an inner diameter smaller than that of the large inner diameter region, and a small inner diameter region located frontward of the middle inner diameter region and having an inner diameter smaller than that of the middle inner diameter region. The electrode member is retained on a step portion of the insulator between the middle inner diameter region and the small inner diameter region. The magnetic member is positioned in the axial hole at a location within the large inner diameter region.Type: GrantFiled: June 6, 2018Date of Patent: December 11, 2018Assignee: NGK SPARK PLUG CO., LTD.Inventors: Hironori Uegaki, Shoma Tsumagari, Kazuhiro Kurosawa, Katsuya Takaoka, Kuniharu Tanaka
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Patent number: 10090646Abstract: Disclosed is a spark plug capable of suppressing high-frequency noise by improving the material of an electrical connection part between a center electrode and a metal terminal within an axial hole of an insulator. A spark plug has an electrical connection part arranged in an axial hole of an insulator to establish electrical connection between a center electrode and a metal terminal. The electrical connection part includes a conductor having a first crystal phase formed of a Fe-containing oxide and a second crystal phase formed of a conductive metal oxide of perovskite crystal structure.Type: GrantFiled: June 2, 2015Date of Patent: October 2, 2018Assignee: NGK SPARK PLUG CO., LTD.Inventors: Katsuya Takaoka, Kazuhiro Kurosawa, Kuniharu Tanaka, Hisashi Kozuka, Toshitaka Honda, Hirokazu Kurono, Haruki Yoshida, Hironori Uegaki
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Publication number: 20180166861Abstract: A connection structure between a center electrode and a metal terminal of a spark plug having a composite part that contains a plurality of secondary particles each formed of a plurality of primary particles of iron-containing oxide as a magnetic substance, and a conductive material coating the plurality of secondary particles. The iron-containing oxide includes at least one of an oxide represented by M1+AOFe2?AO3 (where ?0.5?A?0.5; and M is at least one kind of element selected from the group consisting of Mn, Fe, Co, Ni, Cu, Mg, Zn and Ca) and an oxide represented by Q3Fe5O12 (where Q is at least one kind of element selected from the group consisting of Y, Lu, Yb, Tm, Er, Ho, Dy, Tb, Gd and Sm). In cross section, an average particle size of the primary particles is 0.5 ?m to 100 ?m, an average particle size of the secondary particles is 0.5 mm to 2.0 mm, and a porosity of the inside of the secondary particles is 5% or lower.Type: ApplicationFiled: May 25, 2016Publication date: June 14, 2018Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kuniharu TANAKA, Toshitaka HONDA, Hirokazu KURONO, Hironori UEGAKI
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Patent number: 9997894Abstract: A spark plug includes a cylindrical metallic shell having a ground electrode at a forward end of the cylindrical metallic shell, a cylindrical insulator held in the metallic shell, a center electrode disposed in the insulator, a resistor element disposed in the insulator and having a forward end located rearward of a rear end of the center electrode, a forward-end-side electrically conductive seal layer disposed in the insulator to be located between the center electrode and the resistor element, and a rear-end-side electrically conductive seal layer disposed in the insulator to be located rearward of the resistor element. The forward end of the resistor element is located forward of the rear end of the metallic shell, and the rear end of the resistor element is located rearward of the rear end of the metallic shell.Type: GrantFiled: March 22, 2017Date of Patent: June 12, 2018Assignee: NGK SPARK PLUG CO., LTD.Inventors: Hironori Uegaki, Kazuhiro Kurosawa, Katsuya Takaoka, Kuniharu Tanaka
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Patent number: 9912125Abstract: A spark plug includes an insulator, a center electrode, a metallic shell, and a ground electrode. The insulator contains not less than 90.0 mass % and not greater than 98.1 mass % of Al2O3 with respect to a total mass of elements, as reduced to oxides, contained in the insulator, and has a porosity not greater than 5%. Assuming that a porosity of the insulator after a heat treatment is B, a difference (B?A) of the porosities before and after the heat treatment is not greater than 3.5%. In the heat treatment, the insulator is placed in a furnace, and a temperature in the furnace is increased from a room temperature to 1400° C. at a temperature increase rate of 7° C./min and is held at 1400° C. for 30 minutes, and thereafter, the temperature is decreased from 1400° C. to 400° C. at a temperature decrease rate of 10° C. or less per 5 minutes and is decreased to the room temperature.Type: GrantFiled: September 22, 2016Date of Patent: March 6, 2018Assignee: NGK SPARK PLUG CO., LTD.Inventors: Haruki Yoshida, Jumpei Isasa, Toshitaka Honda, Yutaka Yokoyama, Kuniharu Tanaka, Nobuyoshi Araki, Toshiki Kon
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Publication number: 20180048126Abstract: An alumina-based sintered body includes 92 mass % to 96 mass % of Al in terms of an oxide, and at least three elements selected from Group II elements, one of the at least three elements being 1.90 mass % or more of Ba in terms of an oxide. The alumina-based sintered body includes the following phases in a grain boundary phase present between alumina crystal grains: a first crystal phase containing Si and at least one of the Group II elements, and a second crystal phase containing Al and at least one of the Group II elements. In X-ray diffraction of the alumina-based sintered body, the maximum relative intensity of the first crystal phase and the maximum relative intensity of the second crystal phase are both 2 or above relative to the maximum diffraction intensity of the alumina crystal.Type: ApplicationFiled: August 4, 2017Publication date: February 15, 2018Applicant: NGK Spark Plug Co., LTD.Inventors: Yutaka YOKOYAMA, Kuniharu TANAKA, Nobuyoshi ARAKI, Hirokazu KURONO, Toshimasa SAJI, Yusuke NOMURA, Jumpei ISASA
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Publication number: 20170353013Abstract: A spark plug having an insulator with a leg portion whose outer circumferential surface has an arithmetic mean roughness Ra of 0.5 ?m or less. The leg portion has a first section, a second section, and a third section. The first section has an outer diameter that decreases toward the forward end of the first section. The second section is located forward of and adjacent to the first section and its outer diameter decreases toward the forward end of the second section. The outer circumferential surface of the second section is located inward of a first straight line passing through the base and forward ends of the outer circumferential surface of the first section. The third section is located forward of and adjacent to the second section. The outer diameter of the third section is equal to or less than a forward end outer diameter Ds of the second section over the entire third section.Type: ApplicationFiled: May 30, 2017Publication date: December 7, 2017Applicant: NGK SPARK PLUG CO., LTD.Inventors: Haruki YOSHIDA, Kuniharu TANAKA, Yutaka YOKOYAMA, Shun KONDO, Hirokazu KURONO, Toshimasa SAJI
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Publication number: 20170326765Abstract: An employed rear mold is comprised of a plurality of mold pieces. The plurality of mold pieces include a first mold piece which forms a first partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface, and a second mold piece which is located axially forward of the first mold piece and forms a second partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface. Releasing the molded body includes starting to move the first mold piece rearward in relation to a rear molded portion, and, subsequently to starting to move the first mold piece, starting to move the second mold piece rearward in relation to the rear molded portion, thereby disassembling the rear mold into the plurality of mold pieces.Type: ApplicationFiled: September 23, 2015Publication date: November 16, 2017Applicant: NGK Spark Plug Co., Ltd.Inventors: Hirokazu Kurono, Hironori Uegaki, Toshitaka Honda, Hiroyuki Hazama, Kuniharu Tanaka, Hiroyuki Kawaji
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Publication number: 20170288374Abstract: A spark plug includes a cylindrical metallic shell having a ground electrode at a forward end of the cylindrical metallic shell, a cylindrical insulator held in the metallic shell, a center electrode disposed in the insulator, a resistor element disposed in the insulator and having a forward end located rearward of a rear end of the center electrode, a forward-end-side electrically conductive seal layer disposed in the insulator to be located between the center electrode and the resistor element, and a rear-end-side electrically conductive seal layer disposed in the insulator to be located rearward of the resistor element. The forward end of the resistor element is located forward of the rear end of the metallic shell, and the rear end of the resistor element is located rearward of the rear end of the metallic shell.Type: ApplicationFiled: March 22, 2017Publication date: October 5, 2017Applicant: NGK SPARK PLUG CO., LTD.Inventors: Hironori UEGAKI, Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kuniharu TANAKA
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Patent number: 9755404Abstract: A spark plug includes an insulator made of an alumina sintered body containing Al2O3 as a principal component and additional components including; an Si component, a Ba component, an Mg component, a Ca component, an Sr component, and a rare earth element component. When the additional components are expressed as oxides including RSiO2, RBaO, RMgO, RCaO, RSrO, and RRE2O3, contents (mass %) of the sub-component satisfy expressions (1) to (6) as follows: (1) 1.0?RSiO2?5.0; (2) 0.5?RBaO?5.0; (3) 0?RMgO?0.18; (4) 0?RMgO/RBaO?0.36; (5) 0.3?(RMgO+RCaO+RSrO)?1.8; and (6) 0?RRE2O3?0.1.Type: GrantFiled: September 14, 2016Date of Patent: September 5, 2017Assignee: NGK SPARK PLUG CO., LTD.Inventors: Jumpei Isasa, Haruki Yoshida, Yutaka Yokoyama, Kuniharu Tanaka, Nobuyoshi Araki, Toshiki Kon
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Publication number: 20170214219Abstract: Disclosed is a spark plug capable of suppressing high-frequency noise by improving the material of an electrical connection part between a center electrode and a metal terminal within an axial hole of an insulator. A spark plug has an electrical connection part arranged in an axial hole of an insulator to establish electrical connection between a center electrode and a metal terminal. The electrical connection part includes a conductor having a first crystal phase formed of a Fe-containing oxide and a second crystal phase formed of a conductive metal oxide of perovskite crystal structure.Type: ApplicationFiled: June 2, 2015Publication date: July 27, 2017Applicant: NGK SPARK PLUG CO., LTD.Inventors: Katsuya TAKAOKA, Kazuhiro KUROSAWA, Kuniharu TANAKA, Hisashi KOZUKA, Toshitaka HONDA, Hirokazu KURONO, Haruki YOSHIDA, Hironori UEGAKI
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Patent number: 9653888Abstract: A spark plug including an insulator containing not less than 92 mass % and not greater than 96 mass % of Al component in terms of oxide, wherein the insulator is formed from an alumina sintered body comprising alumina crystal and a grain boundary phase present between crystal grains of the alumina crystal. Assuming that mass contents of an Si component, an Mg component, a Ba component, and a Ca component in terms of oxide are represented by MSiO2, MMgO, MBaO, and MCaO, respectively, and a sum of MSiO2, MMgO, MBaO, and MCaO is represented by Mt, the grain boundary phase contains these components so as to satisfy conditions (1) to (4) as follows: (1) 0.17?MSiO2/Mt?0.47; (2) 0.005?MMgO/Mt?0.07; (3) 0.29?MBaO/Mt?0.77; (4) 0.03?MCaO/Mt?0.19.Type: GrantFiled: September 22, 2016Date of Patent: May 16, 2017Assignee: NGK SPARK PLUG CO., LTD.Inventors: Yutaka Yokoyama, Kuniharu Tanaka, Katsuya Takaoka, Shun Kondo, Nobuyoshi Araki, Toshiki Kon, Haruki Yoshida, Jumpei Isasa, Hirokazu Kurono, Hironori Uegaki, Toshimasa Saji, Yusuke Nomura
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Publication number: 20170093132Abstract: A spark plug includes an insulator made of an alumina sintered body containing Al2O3 as a principal component and additional components including; an Si component, a Ba component, an Mg component, a Ca component, an Sr component, and a rare earth element component. When the additional components are expressed as oxides including RSiO2, RBaO, RMgO, RCaO, RSrO, and RRE2O3, contents (mass %) of the sub-component satisfy expressions (1) to (6) as follows: (1) 1.0?RSiO2?5.0; (2) 0.5?RBaO?5.0; (3) 0?RMgO?0.18; (4) 0?RMgO/RBaO?0.36; (5) 0.3?(RMgO+RCaO+RSiO)?1.8; and (6) 0?RRE2O3?0.1.Type: ApplicationFiled: September 14, 2016Publication date: March 30, 2017Applicant: NGK Spark Plug Co., LTD.Inventors: Jumpei ISASA, Haruki YOSHIDA, Yutaka YOKOYAMA, Kuniharu TANAKA, Nobuyoshi ARAKI, Toshiki KON
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Publication number: 20170093133Abstract: A spark plug includes an insulator, a center electrode, a metallic shell, and a ground electrode. The insulator contains not less than 90.0 mass % and not greater than 98.1 mass % of Al2O3 with respect to a total mass of elements, as reduced to oxides, contained in the insulator, and has a porosity not greater than 5%. Assuming that a porosity of the insulator after a heat treatment is B, a difference (B?A) of the porosities before and after the heat treatment is not greater than 3.5%. In the heat treatment, the insulator is placed in a furnace, and a temperature in the furnace is increased from a room temperature to 1400° C. at a temperature increase rate of 7° C./min and is held at 1400° C. for 30 minutes, and thereafter, the temperature is decreased from 1400° C. to 400° C. at a temperature decrease rate of 10° C. or less per 5 minutes and is decreased to the room temperature.Type: ApplicationFiled: September 22, 2016Publication date: March 30, 2017Inventors: Haruki YOSHIDA, Jumpei ISASA, Toshitaka HONDA, Yutaka YOKOYAMA, Kuniharu TANAKA, Nobuyoshi ARAKI, Toshiki KON
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Publication number: 20170093134Abstract: A spark plug including an insulator containing not less than 92 mass % and not greater than 96 mass % of Al component in terms of oxide, wherein the insulator is formed from an alumina sintered body comprising alumina crystal and a grain boundary phase present between crystal grains of the alumina crystal. Assuming that mass contents of an Si component, an Mg component, a Ba component, and a Ca component in terms of oxide are represented by MSiO2, MMgO, MBaO, and MCaO, respectively, and a sum of MSiO2, MMgO, MBaO, and MCaO is represented by Mt, the grain boundary phase contains these components so as to satisfy conditions (1) to (4) as follows: (1) 0.17?MSiO2/Mt?0.47; (2) 0.005?MMgO/Mt?0.07; (3) 0.29?MBaO/Mt?0.77; (4) 0.03?MCaO/Mt?0.19.Type: ApplicationFiled: September 22, 2016Publication date: March 30, 2017Applicant: NGK SPARK PLUG CO., LTD.Inventors: Yutaka YOKOYAMA, Kuniharu TANAKA, Katsuya TAKAOKA, Shun KONDO, Nobuyoshi ARAKI, Toshiki KON, Haruki YOSHIDA, Jumpei ISASA, Hirokazu KURONO, Hironori UEGAKI, Toshimasa SAJI, Yusuke NOMURA
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Patent number: 9595814Abstract: A connection portion connecting a center electrode and a terminal metal fixture together in a through hole of the insulator includes a resistor and a magnetic substance structure including a magnetic substance and a conductor and being disposed on a leading end side or a rear end side of the resistor while being positioned away from the resistor. The connection portion further includes a first conductive sealing portion, a second conductive sealing portion and a third conductive sealing portion. The first conductive sealing portion is disposed on a leading end side of a first member and is in contact therewith. The second conductive sealing portion is disposed between the first member and a second member and is in contact with the first and second members. The third conductive sealing portion is disposed on a rear end side of the second member and is in contact therewith.Type: GrantFiled: December 25, 2014Date of Patent: March 14, 2017Assignee: NGK SPARK PLUG CO., LTD.Inventors: Takashi Kasashima, Katsuya Takaoka, Kazuhiro Kurosawa, Kuniharu Tanaka, Toshitaka Honda, Hirokazu Kurono, Haruki Yoshida, Hironori Uegaki
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Patent number: 9590395Abstract: A connection portion connecting a center electrode and a terminal metal fixture together in a through hole of the insulator includes a resistor and a magnetic substance structure including a magnetic substance and a conductor. The connection portion further includes a first conductive sealing portion, a second conductive sealing portion and a third conductive sealing portion. The first conductive sealing portion is disposed on a leading end side of a first member and is in contact therewith. The second conductive sealing portion is disposed between the first member and a second member and is in contact with the first member and the second member. The third conductive sealing portion is disposed on a rear end side of the second member and is in contact therewith.Type: GrantFiled: December 25, 2014Date of Patent: March 7, 2017Assignee: NGK SPARK PLUG CO., LTD.Inventors: Katsuya Takaoka, Kazuhiro Kurosawa, Kuniharu Tanaka, Toshitaka Honda, Hirokazu Kurono, Haruki Yoshida, Hironori Uegaki
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Publication number: 20160329687Abstract: A connection portion connecting a center electrode and a terminal metal fixture together in a through hole of the insulator includes a resistor and a magnetic substance structure including a magnetic substance and a conductor and being disposed on a leading end side or a rear end side of the resistor while being positioned away from the resistor. The connection portion further includes a first conductive sealing portion, a second conductive sealing portion and a third conductive sealing portion. The first conductive sealing portion is disposed on a leading end side of a first member and is in contact therewith. The second conductive sealing portion is disposed between the first member and a second member and is in contact with the first and second members. The third conductive sealing portion is disposed on a rear end side of the second member and is in contact therewith.Type: ApplicationFiled: December 25, 2014Publication date: November 10, 2016Applicant: NGK SPARK PLUG CO., LTD.Inventors: Takashi KASASHIMA, Katsuya TAKAOKA, Kazuhiro KUROSAWA, Kuniharu TANAKA, Toshitaka HONDA, Hirokazu KURONO, Haruki YOSHIDA, Hironori UEGAKI