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).
-
Publication number: 20220088806Abstract: A kitchen knife (1) includes a blade (3). The blade (3) is formed of a material having a density of 12.9 g/cc or more and a Young's modulus of 345 GPa or more.Type: ApplicationFiled: July 2, 2020Publication date: March 24, 2022Inventors: Yusuke KATSU, Kuniharu TANAKA, Takeshi MITSUOKA
-
Patent number: 11183819Abstract: A spark plug according to one embodiment of the present invention includes an insulator formed of an alumina-based sintered body, wherein the insulator contains 90 wt % or more of an aluminum component in terms of oxide, and wherein crystal grains of the insulator has an average grain size of 1.5 mm or smaller and a grain size standard deviation of 1.2 ?m or smaller.Type: GrantFiled: September 18, 2019Date of Patent: November 23, 2021Assignee: NGK SPARK PLUG CO., LTD.Inventors: Yutaka Yokoyama, Nobuyoshi Araki, Kuniharu Tanaka, Haruki Yoshida, Hironori Uegaki, Toshiki Kon, Yusuke Nomura
-
Patent number: 10879675Abstract: 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: GrantFiled: May 30, 2017Date of Patent: December 29, 2020Assignee: NGK SPARK PLUG CO., LTD.Inventors: Haruki Yoshida, Kuniharu Tanaka, Yutaka Yokoyama, Shun Kondo, Hirokazu Kurono, Toshimasa Saji
-
Patent number: 10751923Abstract: 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: GrantFiled: September 23, 2015Date of Patent: August 25, 2020Assignee: NGK Spark Plug Co., Ltd.Inventors: Hirokazu Kurono, Hironori Uegaki, Toshitaka Honda, Hiroyuki Hazama, Kuniharu Tanaka, Hiroyuki Kawaji
-
Publication number: 20200112146Abstract: A spark plug according to one embodiment of the present invention includes an insulator formed of an alumina-based sintered body, wherein the insulator contains 90 wt % or more of an aluminum component in terms of oxide, and wherein crystal grains of the insulator has an average grain size of 1.5 mm or smaller and a grain size standard deviation of 1.2 ?m or smaller.Type: ApplicationFiled: September 18, 2019Publication date: April 9, 2020Applicant: NGK SPARK PLUG CO., LTD.Inventors: Yutaka Yokoyama, Nobuyoshi Araki, Kuniharu Tanaka, Haruki Yoshida, Hironori Uegaki, Toshiki Kon, Yusuke Nomura
-
Patent number: 10586627Abstract: The spark plug includes an insulator made from an alumina-based sintered body, and the insulator contains 90 to 98 wt % of an Al component in oxide equivalent. The insulator contains 1 to 5 wt % of an Si component, 0.1 to 1 wt % of an Mg component, 2 wt % or less of a Ca component, 0.3 to 6 wt % of a Ba component, and 0.11 to 5 wt % of a rare earth component, in oxide equivalent. In analysis using a scanning transmission electron microscope with a probe diameter of an electron beam set at 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, and an alkaline earth metal at the crystal grain boundary is less than a detection limit.Type: GrantFiled: June 22, 2018Date of Patent: March 10, 2020Assignee: NGK SPARK PLUG CO., LTD.Inventors: Haruki Yoshida, Kuniharu Tanaka, Shun Kondo, Yutaka Yokoyama, Yusuke Nomura, Michitaka Yamada
-
Patent number: 10424901Abstract: Provided is a spark plug capable of ensuring fouling resistance with a simple configuration. An insulator includes a step portion formed on an outer circumferential surface thereof. A center electrode is arranged in an axial hole of the insulator. A cylindrical metal shell having a shelf portion formed on an inner circumferential surface thereof is arranged radially outside the insulator. The insulator further includes a front end portion located frontward of the step portion. An outer circumferential surface of the front end portion has an arithmetic average roughness of 0.5 ?m or smaller in a circumferential direction. A recess is formed with a depth of 3 to 20 ?m in at least part of an end surface and the outer circumferential surface of the front end portion so as to extend from the front toward the rear.Type: GrantFiled: May 25, 2017Date of Patent: September 24, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Jumpei Isasa, Seiji Nakano, Hirokazu Kurono, Kuniharu Tanaka, Yutaka Yokoyama, Haruki Yoshida, Shun Kondo
-
Patent number: 10348061Abstract: The spark plug includes an insulator formed of an alumina-based sintered body, and the insulator contains Si, Ba, and a rare earth element. In an analysis of the insulator by using a scanning transmission electron microscope having an electron-probe diameter of 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, a content of an alkaline earth metal is less than a detection limit at the crystal grain boundary, and a diffraction spot is present in an electron diffraction pattern of a portion where Ba is detected.Type: GrantFiled: June 26, 2018Date of Patent: July 9, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Hideto Yamada, Haruki Yoshida, Kuniharu Tanaka, Michitaka Yamada, Yusuke Nomura
-
Patent number: 10340667Abstract: A spark plug having a resistor disposed between a metal terminal and a center electrode so as to be electrically connected to the metal terminal and the center electrode, wherein the resistor is in contact with an inner circumferential surface of the insulator. On a cross section taken along the axial line so as to include the axial line, in a case where a plurality of points are plotted at predetermined intervals in a direction of the axial line so as to be present on a partial boundary line, within an arbitrary range in the direction of the axial line, of a boundary line between the insulator and the resistor, and a regression line is drawn by a least-squares method with use of the plurality of points, an average value of distances in a direction perpendicular to the regression line between the regression line and the partial boundary line is 0.1 to 0.3 ?m.Type: GrantFiled: October 10, 2018Date of Patent: July 2, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Toshinori Takeichi, Kuniharu Tanaka, Hirokazu Kurono, Haruki Yoshida, Hironori Uegaki
-
Patent number: 10305260Abstract: Disclosed is a spark plug including: an insulator having an axial hole formed along an axis of the spark plug; a center electrode disposed in a front end side of the axial hole; and a metal shell fixed around an outer circumference of the insulator, with a front end portion of the insulator protruding frontward from a front end of the metal shell. The front end portion of the insulator consists only of a first section and a second section located adjacent to and frontward of the first section and having an inner diameter larger than that of the first section. The second section has a chamfered area formed on an inner circumferential surface thereof so as to continue to a front end of the insulator.Type: GrantFiled: July 12, 2018Date of Patent: May 28, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Haruki Yoshida, Kuniharu Tanaka, Toshinori Takeichi, Michitaka Yamada, Yusuke Nomura
-
Publication number: 20190131776Abstract: Provided is a spark plug capable of ensuring fouling resistance with a simple configuration. An insulator includes a step portion formed on an outer circumferential surface thereof. A center electrode is arranged in an axial hole of the insulator. A cylindrical metal shell having a shelf portion formed on an inner circumferential surface thereof is arranged radially outside the insulator. The insulator further includes a front end portion located frontward of the step portion. An outer circumferential surface of the front end portion has an arithmetic average roughness of 0.5 ?m or smaller in a circumferential direction. A recess is formed with a depth of 3 to 20 ?m in at least part of an end surface and the outer circumferential surface of the front end portion so as to extend from the front toward the rear.Type: ApplicationFiled: May 25, 2017Publication date: May 2, 2019Applicant: NGK SPARK PLUG CO., LTD.Inventors: Jumpei ISASA, Seiji NAKANO, Hirokazu KURONO, Kuniharu TANAKA, Yutaka YOKOYAMA, Haruki YOSHIDA, Shun KONDO
-
Patent number: 10277012Abstract: A spark plug having a connection portion disposed between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor which is a wire helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member which is in contact with the magnetic substance, the conductor, and an inner peripheral surface of the insulator, is disposed between the magnetic substance and the conductor, and the inner peripheral surface of the insulator, and has lower electrical conductivity than the conductor. The conductor is made of one or more of an oxide conductor, carbon, and a carbon compound.Type: GrantFiled: August 21, 2018Date of Patent: April 30, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro Kurosawa, Katsuya Takaoka, Kota Yokoyama, Kuniharu Tanaka, Hirokazu Kurono, Hironori Uegaki
-
Patent number: 10270228Abstract: A spark plug having a connection portion disposed in the axial hole and between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member disposed between the magnetic substance and the conductor, and an inner peripheral surface of the insulator and having lower electrical conductivity than the conductor. The conductor includes a base and a conductive layer disposed on an outer periphery of the base and having higher electrical conductivity than the base, and the conductive layer has a thickness of larger than 0.1 ?m and equal to or smaller than 25 ?m.Type: GrantFiled: August 21, 2018Date of Patent: April 23, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro Kurosawa, Katsuya Takaoka, Kota Yokoyama, Kuniharu Tanaka, Hirokazu Kurono, Hironori Uegaki
-
Publication number: 20190115729Abstract: A spark plug having a resistor disposed between a metal terminal and a center electrode so as to be electrically connected to the metal terminal and the center electrode, wherein the resistor is in contact with an inner circumferential surface of the insulator. On a cross section taken along the axial line so as to include the axial line, in a case where a plurality of points are plotted at predetermined intervals in a direction of the axial line so as to be present on a partial boundary line, within an arbitrary range in the direction of the axial line, of a boundary line between the insulator and the resistor, and a regression line is drawn by a least-squares method with use of the plurality of points, an average value of distances in a direction perpendicular to the regression line between the regression line and the partial boundary line is 0.1 to 0.3 ?m.Type: ApplicationFiled: October 10, 2018Publication date: April 18, 2019Applicant: NGK SPARK PLUG CO., LTD.Inventors: Toshinori TAKEICHI, Kuniharu TANAKA, Hirokazu KURONO, Haruki YOSHIDA, Hironori UEGAKI
-
Publication number: 20190067914Abstract: A spark plug having a connection portion disposed between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor which is a wire helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member which is in contact with the magnetic substance, the conductor, and an inner peripheral surface of the insulator, is disposed between the magnetic substance and the conductor, and the inner peripheral surface of the insulator, and has lower electrical conductivity than the conductor. The conductor is made of one or more of an oxide conductor, carbon, and a carbon compound.Type: ApplicationFiled: August 21, 2018Publication date: February 28, 2019Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kota YOKOYAMA, Kuniharu TANAKA, Hirokazu KURONO, Hironori UEGAKI
-
Publication number: 20190067915Abstract: A spark plug having a connection portion disposed in the axial hole and between a metal terminal and a center electrode. The connection portion includes: a magnetic substance formed from a Fe-containing oxide; a conductor helically disposed on an outer periphery of the magnetic substance and electrically connected to the metal terminal and the center electrode; and an intermediate member disposed between the magnetic substance and the conductor, and an inner peripheral surface of the insulator and having lower electrical conductivity than the conductor. The conductor includes a base and a conductive layer disposed on an outer periphery of the base and having higher electrical conductivity than the base, and the conductive layer has a thickness of larger than 0.1 ?m and equal to or smaller than 25 ?m.Type: ApplicationFiled: August 21, 2018Publication date: February 28, 2019Applicant: NGK SPARK PLUG CO., LTD.Inventors: Kazuhiro KUROSAWA, Katsuya TAKAOKA, Kota YOKOYAMA, Kuniharu TANAKA, Hirokazu KURONO, Hironori UEGAKI
-
Patent number: 10193311Abstract: 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: GrantFiled: August 4, 2017Date of Patent: January 29, 2019Assignee: NGK SPARK PLUG CO., LTD.Inventors: Yutaka Yokoyama, Kuniharu Tanaka, Nobuyoshi Araki, Hirokazu Kurono, Toshimasa Saji, Yusuke Nomura, Jumpei Isasa
-
Publication number: 20190020181Abstract: Disclosed is a spark plug including: an insulator having an axial hole formed along an axis of the spark plug; a center electrode disposed in a front end side of the axial hole; and a metal shell fixed around an outer circumference of the insulator, with a front end portion of the insulator protruding frontward from a front end of the metal shell. The front end portion of the insulator consists only of a first section and a second section located adjacent to and frontward of the first section and having an inner diameter larger than that of the first section. The second section has a chamfered area formed on an inner circumferential surface thereof so as to continue to a front end of the insulator.Type: ApplicationFiled: July 12, 2018Publication date: January 17, 2019Applicant: NGK SPARK PLUG CO., LTD.Inventors: Haruki YOSHIDA, Kuniharu TANAKA, Toshinori TAKEICHI, Michitaka YAMADA, Yusuke NOMURA
-
Publication number: 20180375299Abstract: The spark plug includes an insulator formed of an alumina-based sintered body, and the insulator contains Si, B a, and a rare earth element. In an analysis of the insulator by using a scanning transmission electron microscope having an electron-probe diameter of 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, a content of an alkaline earth metal is less than a detection limit at the crystal grain boundary, and a diffraction spot is present in an electron diffraction pattern of a portion where Ba is detected.Type: ApplicationFiled: June 26, 2018Publication date: December 27, 2018Applicant: NGK SPARK PLUG CO., LTD.Inventors: Hideto YAMADA, Haruki YOSHIDA, Kuniharu TANAKA, Michitaka YAMADA, Yusuke NOMURA
-
Publication number: 20180374601Abstract: The spark plug includes an insulator made from an alumina-based sintered body, and the insulator contains 90 to 98 wt % of an Al component in oxide equivalent. The insulator contains 1 to 5 wt % of an Si component, 0.1 to 1 wt % of an Mg component, 2 wt % or less of a Ca component, 0.3 to 6 wt % of a Ba component, and 0.11 to 5 wt % of a rare earth component, in oxide equivalent. In analysis using a scanning transmission electron microscope with a probe diameter of an electron beam set at 1 nm, Si and a rare earth element are detected at a crystal grain boundary having a thickness of 15 nm or less, and an alkaline earth metal at the crystal grain boundary is less than a detection limit.Type: ApplicationFiled: June 22, 2018Publication date: December 27, 2018Inventors: Haruki YOSHIDA, Kuniharu TANAKA, Shun KONDO, Yutaka YOKOYAMA, Yusuke NOMURA, Michitaka YAMADA