Patent application number | Description | Published |
20080238281 | PLASMA-JET SPARK PLUG - 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. Clearance having a first clearance dimension “a” is formed between a front end of the insulator and the ground electrode. Since a volume S of a cavity formed at the front end side of the insulator is set to | 10-02-2008 |
20080238282 | METHOD FOR PRODUCING SPARK PLUG AND SPARK PLUG - A spark plug ( | 10-02-2008 |
20080238283 | PLASMA JET SPARK PLUG AND MANUFACTURING METHOD THEREFOR - 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. | 10-02-2008 |
20100019644 | SPARK PLUG - 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 mm | 01-28-2010 |
20100101073 | SPARK PLUG MANUFACTURING METHOD - 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. | 04-29-2010 |
20100102728 | PLASMA JET IGNITION PLUG AND IGNITION DEVICE FOR THE SAME - 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 ( | 04-29-2010 |
20100116794 | METHOD FOR MANUFACTURING SPARK PLUG - 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. | 05-13-2010 |
20100133977 | SPARK PLUG AND MANUFACTURING METHOD THEREOF - 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. | 06-03-2010 |
20100264823 | SPARK PLUG - 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. | 10-21-2010 |
20100275870 | SPARK PLUG FOR INTERNAL COMBUSTION ENGINE - 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. | 11-04-2010 |
20100289398 | METHOD FOR PRODUCING SPARK PLUG AND SPARK PLUG - A spark plug ( | 11-18-2010 |
20110000453 | SPARK PLUG - An isolation portion (P) of an insulator ( | 01-06-2011 |
20110017163 | SPARK PLUG - A spark plug is provided capable of speedily burn off carbon adhered on an insulator. With this spark plug, in order to improve the temperature rise performance of a front end side of an insulator | 01-27-2011 |
20110018422 | SPARK PLUG - When an insulator of a spark plug receives an external force in a bending direction perpendicular to an axis at a rear end side body portion, a position C where the insulator is supported by a crimping portion via a packing acts as a fulcrum, and a stress is applied between the position C and a position B where the insulator is supported by a ledge portion via a packing. When an insulator is designed in which the balance of size and modulus of section is adjusted so that τA which denotes a proof strength against bending between a rear end position A of the insulator and the position C and τB which denotes a proof strength against bending between the position B and the position C satisfy 0.71≦τA/τB≦1.27, cracks can be prevented. | 01-27-2011 |
20110037373 | PLASMA JET SPARK PLUG - A plasma jet spark plug comprising:
| 02-17-2011 |
20110210659 | SPARK PLUG AND MANUFACTURING METHOD THEREFOR - Provided are a spark plug in which the occurrence of spark blowout or the like is restrained for improvement of ignition performance, and a method of manufacturing the spark plug. A ground electrode | 09-01-2011 |
20110215702 | SPARK PLUG - A spark plug having an electrode, an insulator, a metallic shell, a main ground electrode, and at least two auxiliary ground electrodes. | 09-08-2011 |
20120169207 | SPARK PLUG - A spark plug includes a ceramic insulator having an axial bore extending in the direction of an axis (CL | 07-05-2012 |
20120184171 | METHOD FOR MANUFACTURING IGNITION PLUG - A method for manufacturing 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 a center electrode more inwards in an axial hole than a leading end of the insulator; building the insulator in an interior of a metal shell; disposing a ground electrode at a leading end portion of the metal shell; positioning a center of a through hole of the ground electrode and a center of the cavity of the insulator; and welding the ground electrode and the metal shell together after the positioning step. | 07-19-2012 |