Patents by Inventor Naomichi Miyashita

Naomichi Miyashita 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: 9190812
    Abstract: A spark plug having a metallic shell extending along an axis (CL1) and a solid annular gasket. The metallic shell has an externally threaded portion and a seat portion, and the gasket has an inside diameter smaller than the thread diameter of the externally threaded portion and is provided between the externally threaded portion and the seat portion. The forward end surface of the gasket has an inclined portion which inclines rearward with respect to the direction of the axis (CL1) from the radially outer side toward the raidally inner side. The thickness of the gasket along the axis (CL1) is 2.0 mm or less; the distance along the axis (CL1) between the outermost circumferential edge and the innermost circumferential edge of inclined portion is 0.02 mm to 0.12 mm; and the Vickers hardness of the gasket is 60 Hv or more.
    Type: Grant
    Filed: April 9, 2012
    Date of Patent: November 17, 2015
    Assignee: NGK SPARK PLUG CO., LTD.
    Inventors: Naomichi Miyashita, Yuuichi Nakano
  • Patent number: 9010765
    Abstract: A gasket for use around a thread neck of an automotive component, the gasket dimensioned to prevent the gasket from falling off of the thread neck and to prevent a male screw portion from biting into the gasket.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: April 21, 2015
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Naomichi Miyashita, Mamoru Musasa
  • Patent number: 8766521
    Abstract: In process of threadably fitting a metal shell having a surface formed with an Ni plated layer into a mounting hole, in a state where a gasket made of stainless steel is uncompressed while being interposed between a protrusion part and an opening periphery, a surface of the gasket is out of contact with another surface thereof. When the gasket is viewed on a cross section in a direction of an axial line O, the gasket contacts with the protrusion part at one point of a point X, the gasket contacts with the opening periphery flat one point of a point Y, and the point Y is located outside of the point X in a radial direction. Further, the point Y is located inside of a maximum outer diameter Dz of a seating surface of the protrusion part in the radial direction.
    Type: Grant
    Filed: July 29, 2011
    Date of Patent: July 1, 2014
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Hirotoshi Yoshizaki, Naomichi Miyashita, Mamoru Musasa
  • Patent number: 8664844
    Abstract: An object of the invention is to restrain separation of an electrode tip from a ground electrode or from a center electrode. A spark plug satisfies a condition 0.8?A1/A2?1.9, where, as viewed on a section which contains a center axis (O) of an electrode tip, A1 [Hv] is hardness of the electrode tip as measured outside a circle having a radius of 0.2 mm, with a boundary point (PA) on a surface of the spark plug between a fusion zone and the electrode tip serving as the center of the circle, and A2 [Hv] is hardness of the electrode tip as measured within the circle having a radius of 0.2 mm.
    Type: Grant
    Filed: April 5, 2010
    Date of Patent: March 4, 2014
    Assignee: NGK Spark Plug., Ltd.
    Inventors: Naomichi Miyashita, Mamoru Musasa
  • Patent number: 8664843
    Abstract: A spark plug having an insulator with improved breakage resistance. The spark plug has a cross-section that satisfies the following relationship: 0.6 mm<=L, where “A” represents a connection point between a support portion of the insulator and an insulator trunk portion formed at a front end side with respect to the support portion, where “B” represents a position closer to the outer circumference side among the positions of (a) an innermost position of a contact portion where the support portion and a packing are in contact with each other and (b) an intersection of the support portion and a virtual straight line that is parallel to an axial line of the spark plug and extends from an innermost circumferential end of a stepped portion of a metal shell, and where “L” represents a length of a path from point “A” to point “B” along a surface of the insulator.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: March 4, 2014
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Yuichi Yamada, Hiroaki Kuki, Naomichi Miyashita, Jiro Kyuno
  • Publication number: 20140042894
    Abstract: A spark plug having a metallic shell extending along an axis (CL1) and a solid annular gasket. The metallic shell has an externally threaded portion and a seat portion, and the gasket has an inside diameter smaller than the thread diameter of the externally threaded portion and is provided between the externally threaded portion and the seat portion. The forward end surface of the gasket has an inclined portion which inclines rearward with respect to the direction of the axis (CL1) from the radially outer side toward the raidally inner side. The thickness of the gasket along the axis (CL1) is 2.0 mm or less; the distance along the axis (CL1) between the outermost circumferential edge and the innermost circumferential edge of inclined portion is 0.02 mm to 0.12 mm; and the Vickers hardness of the gasket is 60 Hv or more.
    Type: Application
    Filed: April 9, 2012
    Publication date: February 13, 2014
    Inventors: Naomichi Miyashita, Yuuichi Nakano
  • Patent number: 8624475
    Abstract: Disclosed is a spark plug having an insulator with good breakage resistance. A spark plug 1 contains a ceramic insulator 2, a plate packing 22 and a metal shell 3. The ceramic insulator 2 has, on an outer circumferential surface thereof, a step portion 14, a leg portion 13 and a curved surface portion 31 between the step portion 14 and the leg portion 13. The metal shell 3 has, on an inner circumferential surface thereof, a taper portion 21. The ceramic insulator 2 is fixed in the metal shell 3 with the step portion 14 retained on the taper portion 21 via the plate packing 22. Herein, 50% or more of an inner circumferential edge portion IP of the plate packing 22 is in contact with a part of the ceramic insulator 2 located front of a middle region CP of the curved surface portion 31.
    Type: Grant
    Filed: August 8, 2011
    Date of Patent: January 7, 2014
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Takuya Shimamura, Tomoaki Kato, Jiro Kyuno, Naomichi Miyashita
  • Publication number: 20130169141
    Abstract: In process of threadably fitting a metal shell having a surface formed with an Ni plated layer into a mounting hole, in a state where a gasket made of stainless steel is uncompressed while being interposed between a protrusion part and an opening periphery, a surface of the gasket is out of contact with another surface thereof. When the gasket is viewed on a cross section in a direction of an axial line O, the gasket contacts with the protrusion part at one point of a point X, the gasket contacts with the opening periphery at one point of a point Y, and the point Y is located outside of the point X in a radial direction. Further, the point Y is located inside of a maximum outer diameter Dz of a seating surface of the protrusion part in the radial direction.
    Type: Application
    Filed: July 29, 2011
    Publication date: July 4, 2013
    Inventors: Hirotoshi Yoshizaki, Naomichi Miyashita, Mamoru Musasa
  • Patent number: 8476817
    Abstract: The present invention provides a spark plug which is capable of suppressing a occurrence of crack and separation by determining a structural configuration of a melting portion formed in a junction portion between a discharge portion and a pedestal portion which form an ignition portion that protrudes from a ground electrode. In a profile line shape of a cross section including a center axis P of an ignition portion 80, an exposure surface 88 of a melting portion 83 connects a side surface 82 of a discharge portion 81 and a side surface 85 of a pedestal portion 84. Further, an exterior angle ? formed between an imaginary line Q, which passes through a boundary position X1 between the melting portion 83 and the pedestal portion 84 and a boundary position X2 between the melting portion 83 and the discharge portion 81, and the center axis P at a node C, satisfies 135°???175°.
    Type: Grant
    Filed: January 27, 2010
    Date of Patent: July 2, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Naomichi Miyashita, Mamoru Musasa, Akira Suzuki, Kazuyoshi Torii, Tomoaki Kato
  • Patent number: 8410673
    Abstract: A spark plug having a center electrode and a ground electrode including a ground electrode main body part having an end thereof facing the center electrode and a noble metal tip joined to the ground electrode main body part at a position facing a leading end of the center electrode, a spark discharge gap being formed between the leading end of the center electrode and the noble metal tip, wherein at least a portion of the ground electrode main body part, to which the noble metal tip is joined, is made of an Ni alloy containing 12 to 45 mass % of Cr, 7 mass % or less of Fe, 0.5 to 5 mass % of Al, 0.3 to 5 mass % of Si and 50 mass % or more of the balance, and wherein the joined portion and the noble metal tip are joined by laser welding or electron beam welding.
    Type: Grant
    Filed: September 9, 2009
    Date of Patent: April 2, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Kazuyoshi Torii, Tomoo Tanaka, Akira Suzuki, Mamoru Musasa, Naomichi Miyashita, Osamu Yoshimoto
  • Patent number: 8378560
    Abstract: An ignition part (80) of a ground electrode (30) includes a fused part (85) in which construction materials of a base portion (82) and a noble metal member (81) are fused and mixed by performing laser welding on the two. In the fused part (85), an average ratio P of components originated from the noble metal member (81) at points K1, L1, and M1 is equal to or greater than 80%, and an average ratio Q of components originated from the base portion at points K3, L3, and M3 is equal to or higher than 20%, and P+Q is equal to or higher than 160%. Accordingly, it is possible to obtain joining strength in the parts in the ignition part (80), thereby sufficiently preventing the generation of cracks, separation, and the like due to thermal stress.
    Type: Grant
    Filed: November 14, 2008
    Date of Patent: February 19, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Akira Suzuki, Naomichi Miyashita, Kazuyoshi Torii
  • Publication number: 20130015756
    Abstract: A spark plug having an insulator with improved breakage resistance. The spark plug has a cross-section that satisfies the following relationship: 0.6 mm<=L, where “A” represents a connection point between a support portion of the insulator and an insulator trunk portion formed at a front end side with respect to the support portion, where “B” represents a position closer to the outer circumference side among the positions of (a) an innermost position of a contact portion where the support portion and a packing are in contact with each other and (b) an intersection of the support portion and a virtual straight line that is parallel to an axial line of the spark plug and extends from an innermost circumferential end of a stepped portion of a metal shell, and where “L” represents a length of a path from point “A” to point “B” along a surface of the insulator.
    Type: Application
    Filed: March 28, 2011
    Publication date: January 17, 2013
    Inventors: Yuichi Yamada, Hiroaki Kuki, Naomichi Miyashita, Jiro Kyuno
  • Patent number: 8344604
    Abstract: A precious metal tip on the side of a ground electrode is indirectly joined to the front end portion of the ground electrode via a mounting part interposed therebetween. The mounting part includes a base part and a protruding part. First, in the state where the precious metal tip is in contact with the protruding part, laser welding or the like is performed thereon to form a fused part and obtain a complex, and the base part is joined to a flat surface of the ground electrode by resistance welding. The grain size of grains of the mounting part in the vicinity of the of the fused part is greater than the grain size of the grain size of the grains thereof in the vicinity of the ground electrode, and the grain size of the grains of the flange part of the mounting part is smaller than the grain size of the grains of the protruding part.
    Type: Grant
    Filed: November 13, 2008
    Date of Patent: January 1, 2013
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Kazuyoshi Torii, Naomichi Miyashita, Mamoru Musasa, Akira Suzuki, Tomoo Tanaka, Osamu Yoshimoto
  • Publication number: 20120267995
    Abstract: Disclosed is a spark plug having an insulator with good breakage resistance. A spark plug 1 contains a ceramic insulator 2, a plate packing 22 and a metal shell 3. The ceramic insulator 2 has, on an outer circumferential surface thereof, a step portion 14, a leg portion 13 and a curved surface portion 31 between the step portion 14 and the leg portion 13. The metal shell 3 has, on an inner circumferential surface thereof, a taper portion 21. The ceramic insulator 2 is fixed in the metal shell 3 with the step portion 14 retained on the taper portion 21 via the plate packing 22. Herein, 50% or more of an inner circumferential edge portion IP of the plate packing 22 is in contact with a part of the ceramic insulator 2 located front of a middle region CP of the curved surface portion 31.
    Type: Application
    Filed: August 8, 2011
    Publication date: October 25, 2012
    Inventors: Takuya Shimamura, Tomoaki Kato, Jiro Kyuno, Naomichi Miyashita
  • Patent number: 8294344
    Abstract: A spark member (70) is formed by joining a noble metal member (71) and an intermediate member (75) and is provided in a spark discharge gap between a center electrode and a ground electrode (30). A bottom surface (80) of the intermediate member (75) is resistance-welded to an inner surface (33) of the ground electrode (30), and a weld metal zone (73) is formed in the region of joint therebetween. As viewed on the section of the spark member (70) which contains a centerline (Q), the weld metal zone (73) is reliably formed within the range of the length (D) of a columnar portion (76) as measured along a direction orthogonal to the projecting direction of the spark member (70) and has a length (d) of at least 0.1 times (10% of) the length (D).
    Type: Grant
    Filed: December 25, 2008
    Date of Patent: October 23, 2012
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Kazuyoshi Torii, Akira Suzuki, Naomichi Miyashita, Mamoru Musasa, Kenji Moritani
  • Publication number: 20120062099
    Abstract: An object of the invention is to restrain separation of an electrode tip from a ground electrode or from a center electrode. A spark plug satisfies a condition 0.8?A1/A2?1.9, where, as viewed on a section which contains a center axis (O) of an electrode tip, A1 [Hv] is hardness of the electrode tip as measured outside a circle having a radius of 0.2 mm, with a boundary point (PA) on a surface of the spark plug between a fusion zone and the electrode tip serving as the center of the circle, and A2 [Hv] is hardness of the electrode tip as measured within the circle having a radius of 0.2 mm.
    Type: Application
    Filed: April 5, 2010
    Publication date: March 15, 2012
    Inventors: Naomichi Miyashita, Mamoru Musasa
  • Patent number: 8106572
    Abstract: A spark plug in which an ignition portion of a ground electrode formed through joining of a noble metal chip to the ground electrode has high durability, and a method of manufacturing the spark plug.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: January 31, 2012
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Tomoo Tanaka, Naomichi Miyashita
  • Publication number: 20110294369
    Abstract: The present invention provides a spark plug which is capable of suppressing a occurrence of crack and separation by determining a structural configuration of a melting portion formed in a junction portion between a discharge portion and a pedestal portion which form an ignition portion that protrudes from a ground electrode. In a profile line shape of a cross section including a center axis P of an ignition portion 80, an exposure surface 88 of a melting portion 83 connects a side surface 82 of a discharge portion 81 and a side surface 85 of a pedestal portion 84. Further, an exterior angle ? formed between an imaginary line Q, which passes through a boundary position X1 between the melting portion 83 and the pedestal portion 84 and a boundary position X2 between the melting portion 83 and the discharge portion 81, and the center axis P at a node C, satisfies 135°???175°.
    Type: Application
    Filed: January 27, 2010
    Publication date: December 1, 2011
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Naomichi Miyashita, Mamoru Musasa, Akira Suzuki, Kazuyoshi Torii, Tomoaki Kato
  • Patent number: 8044562
    Abstract: There is provided a spark section (80) of needle-like shape protruding from an inner surface (33) of a ground electrode (30) to define a spark gap between the spark section and an electrode tip on a center electrode. The spark section (80) has a noble metal member (81) and an intermediate member (86) joined to each other. The materials of the noble metal member (81) and the intermediate member (86) are selected in such a manner that the thermal conductivity of the intermediate member (86) is lower than that of the noble metal member (81). This limits heat radiation through the heat radiation passage from the noble metal member (81) through the intermediate member (86) to the ground electrode (30) so as to maintain the noble metal member (81) at a higher temperature than conventional types and reduce a quenching effect of the noble metal member (81) on a flame core generated in the spark gap for improvement in ignition performance.
    Type: Grant
    Filed: November 12, 2008
    Date of Patent: October 25, 2011
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Mamoru Musasa, Naomichi Miyashita, Kazuyoshi Torii
  • Publication number: 20110163653
    Abstract: A spark plug includes a cylindrical metal shell; a cylindrical insulator that is held in the metal shell; a center electrode; and a ground electrode that comprises a ground electrode main body part and a noble metal tip, a spark discharge gap being formed between the leading end of the center electrode and the noble metal tip wherein at least a portion of the ground electrode main body part, to which the noble metal tip is joined, is made of Ni alloy containing 12 to 35 mass % of Cr, 7 mass % or less of Fe, 0.5 to 5 mass % of Al, 0.3 to 5 mass % of Si and 50 mass % or more of the balance, and wherein the joined portion and the noble metal tip are joined by laser welding or electron beam welding.
    Type: Application
    Filed: September 9, 2009
    Publication date: July 7, 2011
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Kazuyoshi Torii, Tomoo Tanaka, Akira Suzuki, Mamoru Musasa, Naomichi Miyashita, Osamu Yoshimoto