Patent application number | Description | Published |
20090134764 | SPARK PLUG FOR INTERNAL COMBUSTION ENGINE AND METHOD FOR PRODUCING THE SPARK PLUG - A spark plug including: a ground electrode including a thick portion provided on a base end side, a thin portion provided on a distal end side, and a stepped portion provided on an inner peripheral surface between the thick portion and the thin portion; a noble metal tip partially embedded in an inner peripheral surface of the thin portion; and a bulge portion provided on the inner peripheral surface of the thin portion between the stepped portion and the noble metal tip. When viewed from a side surface of the ground electrode, a relationship [a protruding height of the noble metal tip from the inner peripheral surface of the thin portion]≧[a protruding height of the bulge portion from the inner peripheral surface of the thin portion]. | 05-28-2009 |
20090140624 | SPARK PLUG INTERNAL COMBUSTION ENGINE AND METHOD FOR PRODUCING THE SPARK PLUG - A spark plug including: a center electrode; a substantially cylindrical insulator; a cylindrical metal shell; a ground electrode having a base end joined to a leading end portion of the metal shell and a distal end bent toward the axis line. The ground electrode includes: a thick portion provided on a base end side, a thin portion provided on a distal end side, and a stepped portion provided on an inner peripheral surface between the thick portion and the thin portion. A noble metal tip is joined to and partially embedded in the inner peripheral surface of the thin portion and disposed to form a gap between the noble metal tip and the leading end portion of the center electrode. | 06-04-2009 |
20120001533 | SPARK PLUG AND ITS MANUFACTURING METHOD - A spark plug includes an insulator, a center electrode, a metal shell, a ground electrode, and a noble metal tip joined to at least one of the two electrodes. The noble metal tip is joined to the electrode via a melt portion formed by using a laser or electron beam from a side surface of the noble metal tip. In a predetermined section, including a central axis of the noble metal tip, ¾ or more of one end face of the noble metal tip is joined to the electrode. When the thickness of the melt portion is taken to be TX (mm), and the length in a direction of irradiation with the laser beam is taken to be LX (mm), TX and LX satisfy 1.5≦LX/TX, and an angle αX or angle αY, formed by two predetermined straight lines, satisfies −15≦αX (αY)≦25. | 01-05-2012 |
20120038263 | SPARK PLUG - A spark plug includes a center electrode extending in an axial direction; an insulator formed externally of the outer circumference of the center electrode; a metallic shell formed externally of the outer circumference of the insulator and having a ledge which supports the insulator; and a ground electrode joined to the metallic shell. The insulator has a support portion which faces the ledge. A “frontward direction” is defined as the direction parallel to the axial direction toward a spark portion formed between the center electrode and the ground electrode. The insulator has a diameter reduction portion whose outside diameter reduces along the frontward direction from the support portion, and a diameter increase portion whose outside diameter increases along the frontward direction from the front end of the diameter reduction portion. This restrains the generation of leak current while maintaining heat resistance of the spark plug. | 02-16-2012 |
20130148254 | IGNITION SYSTEM AND SPARK PLUG - An ignition system having a spark plug, a discharge power supply, and an AC power supply. Voltage from the discharge power supply and AC power from the AC power supply are supplied to a spark discharge gap through an electrode of the spark plug. The AC power from the AC power supply is applied to a spark generated by the voltage from the discharge power supply in the spark discharge gap. | 06-13-2013 |
20130200773 | SPARK PLUG - In a spark plug, a fusion zone where a ground electrode and a noble metal tip are fused together is formed in at least a portion of an interfacial region between the ground electrode and the noble metal tip. When the fusion zone is projected in the axial direction, the projected fusion zone overlaps 70% or more of the area of the noble metal tip. As viewed on a section which passes through the center of gravity of the noble metal tip and is perpendicular to the longitudinal direction of the ground electrode, the relational expression 1.3≦B/A is satisfied, where A is the greatest thickness of the fusion zone along the axial direction, and B is the length from a portion having the greatest thickness of the fusion zone to the inner end of the fusion zone. | 08-08-2013 |
20130214689 | PLASMA IGNITION DEVICE AND PLASMA IGNITION METHOD - A technique of improving the life of a spark plug which generates spark discharge and AC plasma. A plasma ignition device includes a power control section which reduces AC power P after generation of AC plasma in an AC power supply period Sa during which the AC power P is continuously supplied to a spark plug within a maintainable power range Rp within which the AC plasma can be maintained. | 08-22-2013 |
20130233291 | IGNITION DEVICE AND STRUCTURE FOR MOUNTING SAME - An ignition device ( | 09-12-2013 |
20140139098 | SPARK PLUG - A spark plug includes a center electrode, a ground electrode, and a tip joined to the center electrode and forming a spark discharge gap with the ground electrode. The tip is joined to the center electrode via a fusion zone, which has an exposed surface exposed to the external environment. In a section containing an axis and the center of the exposed surface, C−B≧0.02 is satisfied, where C (mm) is the distance on the side surface of the tip between the fusion zone and the distal end of the tip, and B (mm) is the distance between a distal end surface of the tip and a portion of the fusion zone located closer to the axis than the side surface of the tip and located closest in the fusion zone to the distal end surface of the tip. | 05-22-2014 |
20140175967 | SPARK PLUG - A spark plug has a center electrode having an electrode base member and a core material which is disposed in the electrode base member and which predominantly contains copper, and a noble metal tip disposed at a forward end of the center electrode, and a fusion portion formed between the noble metal tip, and the electrode base member and the core material. The fusion portion is in contact with the core material in a cross section which is parallel to the center axis of the center electrode and which passes through the center axis and the fusion portion. The fusion portion contains a component of the noble metal tip, a component of the electrode base member, and a copper component forming the core material. | 06-26-2014 |