Patents by Inventor Tomoaki Kato

Tomoaki Kato 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: 7839065
    Abstract: A plasma jet spark plug and a manufacturing method therefor are disclosed. In a state in which a noble-metal chip having a flange-like outwardly projecting portion is disposed in a communication section of a ground electrode, an electrode base metal of the ground electrode is disposed in a stepped engagement portion of a metallic shell, which retains an insulator therein. While being pressed against a front end portion of the insulator, the noble-metal chip is joined to the electrode base metal, whereby a clearance between the ground electrode (electrode base metal) and the front end portion of the insulator can be closed. Therefore, energy of plasma generated within the cavity does not leak.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: November 23, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Toru Nakamura, Tomoaki Kato
  • Publication number: 20100289398
    Abstract: A spark plug (100) including a center electrode (130) and a ground electrode (140), which is formed by joining a ground electrode chip (143) to a ground electrode base material (141) via an intermediate member (142). A method for producing the spark plug (100) includes providing a projecting portion (142p) on the intermediate member (142), and projection-welding the intermediate member (142) to the ground electrode base material (141) by means of the projecting portion (142p), to thereby join the intermediate member 142 to the ground electrode base material (141). Further, the intermediate member (142) of the spark plug (100) includes a cylindrical columnar portion (142e) which is joined to the ground electrode chip (143), and a flange portion (142d) which is joined to the ground electrode base material (141) and which flange portion (142d) has a diameter greater than that of the cylindrical columnar portion (142e).
    Type: Application
    Filed: July 29, 2010
    Publication date: November 18, 2010
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Tomoaki KATO, Kazuyoshi TORII, Mamoru MUSASA
  • Patent number: 7830580
    Abstract: An optical modulator is provided with a stripe-shaped optical waveguide, which has an upper clad layer, a lower clad layer formed between the upper clad layer and a substrate, and an undoped core layer which is arranged between the upper clad layer and the lower clad layer and has a complex refractive index that changes corresponding to the intensity of an applied electric field, to a signal light propagating inside. On both sides of the stripe-shaped optical waveguide, conductor walls are configured by arranging a pair of parallel blocking flat boards with an insulating wall in between. Thus, the semiconductor optical modulator having a high optical modulation efficiency is provided.
    Type: Grant
    Filed: February 6, 2008
    Date of Patent: November 9, 2010
    Assignee: NEC Corporation
    Inventor: Tomoaki Kato
  • Publication number: 20100275870
    Abstract: A spark plug includes a center electrode extending along an axial line, a ground electrode, and a noble metal tip. A center axis of the noble metal tip is displaced from a center axis of the ground electrode toward a base-end side in the axial line. The ground electrode includes an outer layer and an inner layer, and a distal end of the inner layer is closer to the axial line than a base end of the ground electrode. An overlap area between the inner layer and the noble metal tip occupies a ratio of 25% or more in a projective plane defined by projecting, along the center axis, a plane of the ground electrode viewed from a distal-end face on a cross section of the ground electrode in which a maximum cross-sectional area of the inner layer is achieved, among cross sections orthogonal to the center axis.
    Type: Application
    Filed: December 25, 2008
    Publication date: November 4, 2010
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Hiroyuki Kameda, Katsutoshi Nakayama, Kaori Kishimoto, Tomoaki Kato
  • Publication number: 20100264823
    Abstract: A spark plug with excellent vibration resistance performance and resistor load life-span characteristics, and a reduced diameter which is achieved by strengthening adhesion between a resistor and a conductive glass sealing layer.
    Type: Application
    Filed: March 23, 2009
    Publication date: October 21, 2010
    Inventors: Akira Suzuki, Tomoaki Kato, Tsutomu Shibata, Mamoru Musasa
  • Patent number: 7808250
    Abstract: There is provided a test method for detecting the presence or absence of a defect in a spark plug insulator, including a reference voltage determination process, a test area determination process, a test voltage determination process and a current detection process. In the reference voltage determination process, a reference voltage VF is determined. In the test area and voltage determined processes, test area and voltage are determined so as not to incur a flashover on the basis of a reference insulator of the same material, shape and size as the spark plug insulator when the reference insulator is placed in position between first and second test electrodes. In the current detection step, the test voltage is applied between the first and second test electrodes to detect an electric current between the first and second test electrodes.
    Type: Grant
    Filed: May 30, 2008
    Date of Patent: October 5, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Toshitaka Honda, Hirokazu Kurono, Tomoaki Kato
  • Patent number: 7786657
    Abstract: A spark plug including a ground electrode and a noble metal tip joined to a distal end portion of the noble metal tip. The noble metal tip is joined to the ground electrode via a molten bond in which the noble metal tip and the ground electrode are fused. A protruding length of the noble metal tip is 0.3 mm or more. Regarding the molten bond, relationships 50?S1+S2?120 and ?1>?2 are satisfied for a first molten angle S1°, a second molten angle S2°, a first contact angle ?1° and a second contact angle ?2° as defined herein.
    Type: Grant
    Filed: November 26, 2008
    Date of Patent: August 31, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventor: Tomoaki Kato
  • Patent number: 7772752
    Abstract: A plasma-jet spark plug comprising an insulator and a ground electrode which are disposed apart from each other in an axial direction (O) to prevent a damage of the insulator. The spark plug is capable of reducing an energy loss of the ejected plasma by defining a dimension of a clearance between the insulator and the ground electrode whereby deterioration of the ignitability of the plasma-jet spark plug is prevented.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: August 10, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Toru Nakamura, Tomoaki Kato
  • Publication number: 20100142026
    Abstract: An optical modulator is provided with a stripe-shaped optical waveguide, which has an upper clad layer, a lower clad layer formed between the upper clad layer and a substrate, and an undoped core layer which is arranged between the upper clad layer and the lower clad layer and has a complex refractive index that changes corresponding to the intensity of an applied electric field, to a signal light propagating inside. On the both sides of the stripe-shaped optical waveguide, conductor walls are configured by arranging a pair of parallel blocking flat boards with an insulating wall in between.
    Type: Application
    Filed: February 6, 2008
    Publication date: June 10, 2010
    Applicant: NEC CORPORATION
    Inventor: Tomoaki Kato
  • Publication number: 20100133977
    Abstract: A ground electrode and a metal shell are joined by welding or the like while an entire end face of a base of the ground electrode is brought into contact with a front end constituent face of the metal shell. The ground electrode has an extending portion extending forward in an axial (O) direction of the ground electrode. A front end portion faces a noble metal tip joined to a front end portion of the center electrode through a bending portion and forms a spark discharge gap (G) therebetween. A gap (a clearance) having a sufficient space to accommodate a virtual sphere (Q) with a radius of 1.2 mm is provided so that the virtual sphere (Q) being in contact with an inner face of the bending portion of the ground electrode is neither in contact with a center electrode nor an insulator.
    Type: Application
    Filed: August 6, 2008
    Publication date: June 3, 2010
    Inventor: Tomoaki Kato
  • Publication number: 20100117507
    Abstract: The present invention provides a spark plug that includes a center electrode extending in an axial direction, a ceramic insulator having an axial hole formed in the axial direction to retain the center electrode in a front side of the axial hole and thereby form an assembly unit of the center electrode and the ceramic insulator, a metal shell surrounding an outer circumference of the ceramic insulator to retain therein the assembly unit, and a ground electrode having one end portion joined to a front end face of the metal shell and the other end portion facing the center electrode to define a spark gap therebetween, wherein the spark plug satisfies the following conditions: H?1 mm, Vc?17 mm3 and Ra?1.
    Type: Application
    Filed: September 10, 2008
    Publication date: May 13, 2010
    Inventors: Akira Suzuki, Tomoaki Kato, Mamoru Musasa, Jiro Kyuno
  • Publication number: 20100116794
    Abstract: A method for manufacturing a spark plug is a method for manufacturing the spark plug having an electrode base member and a noble metal tip welded thereto by means of a laser or an electrode base member, a tip base member joined thereto, and a noble metal tip welded to the tip bases material by means of a laser, and the method includes a laser welding process of welding the electrode base member or the tip base member to the noble metal tip by means of a laser and through use of a laser beam whose BBP value assumes 25 mm·mrad (a radius·a half angle) or less at a time point when a laser beam enters a transfer optical system for guiding the laser beam to areas to be welded where laser welding is to be performed.
    Type: Application
    Filed: March 31, 2008
    Publication date: May 13, 2010
    Inventors: Akikazu Taido, Tomoaki Kato
  • Publication number: 20100106384
    Abstract: A vehicle 1 has a torque coupling 8, which is located in a driving power transmission system for transmitting the torque of an engine 2 to front and rear wheels 13f, 13r. The torque coupling 8 changes the torque distribution by adjusting the frictional engaging force of an electromagnetic clutch 16. The vehicle 1 also has a 4WD ECU 21 (CPU), which controls the operation of the torque coupling 8 based on the driving state. The 4WD ECU 21 (CPU) estimates a transfer case oil temperature Tptu. When the transfer case oil temperature Tptu is higher than or equal to a first predetermined transfer case oil temperature KTptu1, the 4WD ECU 21 executes overheat prevention control.
    Type: Application
    Filed: October 22, 2009
    Publication date: April 29, 2010
    Applicant: JTEKT CORPORATION
    Inventors: Masaki MITA, Ryohei Shigeta, Tomoaki Kato
  • Publication number: 20100102728
    Abstract: The cavity of a plasma jet ignition plug is configured in a stepped shape; i.e., composed of a constricted portion and a diameter-increased portion (65). The inner diameter (B) of the constricted portion is made smaller than the inner diameter (A) of the diameter-increased portion. Further, as measured along the direction of the axis O, the length (Y) of the constricted portion is made equal to or greater than the length (X) of the diameter-increased portion. This configuration suppresses a pressure loss produced when the generated plasma expands within the cavity. As a result, the energy of the plasma at the time of jetting is increased, and the igniting performance for an air-fuel mixture can be improved.
    Type: Application
    Filed: June 13, 2008
    Publication date: April 29, 2010
    Inventors: Tomoaki Kato, Toru Nakamura, Yuichi Yamada
  • Publication number: 20100101073
    Abstract: There is provided manufacturing method of a spark plug that includes a center electrode and a ground electrode with a discharge gap left therebetween. At least one of the center electrode and the ground electrode has an electrode body containing a base metal and a noble metal tip welded to the electrode body. The spark plug manufacturing method includes a laser welding step for welding the noble metal tip and the electrode body by placing the noble metal tip at a given position on the electrode body, irradiating a pulsed laser onto the noble metal tip and the electrode body and thereby sequentially forming welding spots corresponding to pulses of the laser in a circumferential direction of the noble metal tip, wherein at least one of the laser pulses is an initially increasing type laser pulse having a laser intensity waveform in which a laser intensity increases with time during a predetermined initial period from a pulse start time.
    Type: Application
    Filed: March 27, 2008
    Publication date: April 29, 2010
    Inventors: Tomoaki Kato, Akikazu Taido, Yuichi Nakano
  • Patent number: 7666047
    Abstract: There is provided a method for producing a spark plug in which welding strength between a noble metal tip and an electrode joined by laser welding can be restrained from becoming weak. A noble metal tip (90) to be joined to a center electrode (2) or ground electrode of a spark plug to form a spark discharge gap is resistance-welded to each electrode containing no noble metal and then laser-welded. In the noble metal tip (90) exposed under a severe environment involving spark discharge, a molten portion (80) formed in such a manner that a portion of the noble metal tip (90) and a portion of the electrode are melted by laser welding and a non-molten portion (95) on the noble metal tip (90) side are apt to be peeled from each other in a boundary surface (83) between the molten portion (80) and the non-molten portion (95).
    Type: Grant
    Filed: November 18, 2004
    Date of Patent: February 23, 2010
    Assignee: NGK Spark Plug Co., Ltd.
    Inventors: Akira Suzuki, Tomoaki Kato, Kazuyoshi Torii, Akikazu Taido
  • Publication number: 20100019644
    Abstract: A spark plug of the present invention is designed as a small-diameter spark plug, which includes: a metal shell having a mounting thread formed with a nominal diameter of M12 or smaller based on JIS standard; a ground electrode consisting a first structural member extending from one end toward the other end thereof and at least one ith structural member (i=2, 3, 4, 5) laminated to cover an outer surface of the first structural member, the length of protrusion of the other end of the ground electrode from a front end face of the metal shell being 4.5 mm or larger, the ground electrode having a bent portion formed between the one end to the other end thereof with a curvature radius of 2.3 mm or smaller; and an electrode tip joined to the other end of the ground electrode at a position facing the front end of the center electrode and having a protrusion length of 0.5 mm or larger and a cross sectional area of 0.20 to 1.13 mm2.
    Type: Application
    Filed: September 10, 2008
    Publication date: January 28, 2010
    Inventors: Reimon Fukuzawa, Tomoaki Kato, Akira Suzuki
  • Publication number: 20090322198
    Abstract: For producing a spark plug that has a high dimensional accuracy in the spark gap, a method is disclosed which comprises (a) preparing a semi-finished spark plug unit (100b) which comprises a center electrode (20) that has a leading end portion (22), a metal shell (50) that holds therein through an insulator (10) the center electrode (20) except the leading end portion (22) and a ground electrode (30) fixed to a leading end of the metal shell (50), (b) bending the ground electrode (30) so that a bent front portion (31) of the ground electrode (30) projects toward the leading end portion (22) of the center electrode (20), (c) putting an electrode tip (95) on a given part of the bent front portion (31) of the ground electrode (30) in such a manner that a front portion of the electrode tip (95) projects from the bent front portion (31) toward the leading end portion (22) of the center electrode (20) and (d) welding the electrode tip (95) to the given part of the bent front portion (31) of the ground electrode (30
    Type: Application
    Filed: June 24, 2009
    Publication date: December 31, 2009
    Applicant: NGK SPARK PLUG CO., LTD.
    Inventors: Hiroyuki KAMEDA, Tomoaki Kato
  • Publication number: 20090267195
    Abstract: A semiconductor device of present invention comprises a layered structure including a cladding layer with a first conductivity, an active layer, and a cladding layer with a second conductivity which are successively grown on a semiconductor substrate of (001) orientation, and an embedding layer covering both side surfaces of the layered structure in a widthwise direction across a longitudinal direction of the layered structure in a plane parallel to a surface of the semiconductor substrate. A portion of side surfaces of the active layer in the widthwise direction lies parallel to at least (010) or (100) surface.
    Type: Application
    Filed: December 19, 2006
    Publication date: October 29, 2009
    Applicant: NEC CORPORATION
    Inventor: Tomoaki Kato
  • Publication number: 20090227169
    Abstract: A manufacturing method for an ignition plug is provided. The method includes: preparing an insulator having a cavity provided at a leading end portion thereof by disposing a leading end of the center electrode more inwards than a leading end of the insulator; building the insulator in an interior of the metal shell such that the leading end of the insulator is situated closer to a rear end side than the leading end of the metal shell; removing at least part of a leading end portion of the metal shell which projects from a leading end face of the insulator; and disposing the ground electrode at the leading end portion of the metal shell and welding the ground electrode and the metal shell together after the removal step.
    Type: Application
    Filed: March 6, 2009
    Publication date: September 10, 2009
    Inventors: Toru Nakamura, Tomoaki Kato, Yuichi Yamada