Patent application number | Description | Published |
20090127998 | SPARK PLUG - A spark plug including: a center electrode including an electrode base member and a core member; an electrode tip joined to the center electrode via a molten bond; an insulator holding the center electrode; a metal shell holding the insulator; and a ground electrode joined to the metal shell. Relationships d≦2.1 [mm] and −0.09×d+0.3305-21-2009 | |
20100117507 | SPARK PLUG - 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 mm | 05-13-2010 |
20100203791 | METHOD FOR MANUFACTURING SPARK PLUG - A method for manufacturing a spark plug which includes: (a) preparing a metal shell; (b) preparing an insulator; (c) inserting the insulator in an insertion hole of the metal shell; (d) forming an intended crimping portion of the metal shell into a crimping portion; and (e) pressing a lower side portion of the metal shell closer to a position lower than the intended compressive deformation portion, and pressing the crimping portion of the metal shell in an axial direction to compressively deform the intended compressive deformation portion of the metal shell and thus seal a space between a stepped portion of the metal shell and a stepped portion of the insulator, wherein step (e) controls a pressing amount of a press in a constant value from the start of compressive deformation to the end thereof. | 08-12-2010 |
20120146484 | SPARK PLUG FOR INTERNAL COMBUSTION ENGINE AND METHOD OF MANUFACTURING SPARK PLUG - A generation of a stress corrosion cracking is prevented in a middle section. The spark plug | 06-14-2012 |
20120176019 | SPARK PLUG - Problem is to enhance the welding strength when a projecting shape section is resistance-welded to a around electrode. A ground electrode | 07-12-2012 |
20130169141 | SPARK PLUG - 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. | 07-04-2013 |
Patent application number | Description | Published |
20110294369 | SPARK PLUG - 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 | 12-01-2011 |
20120062099 | SPARK PLUG - 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. | 03-15-2012 |
20130038198 | SPARK PLUG FOR INTERNAL COMBUSTION ENGINE AND METHOD OF MANUFACTURING THE SPARK PLUG - A spark plug includes a center electrode, a ground electrode, and a noble metal tip. The noble metal tip is joined to an object member of at least one of two electrodes via a fusion zone. A projected overlap region of the noble metal tip and the fusion zone accounts for 70% or more of a projected region of the noble metal tip. The object member contains at least Si out of Al and Si such that the amount of Si is 0.4% by mass or higher and such that the total amount of Al and Si is 0.5% by mass. Multi-fusion spots exist on the surface of the fusion zone. Segments of a baseline which pass through the respective multi-fusion spots have a total length of a predetermined percentage of the length of the baseline. Joining strength to the noble metal tip can thereby be greatly improved when the member to be joined contains Si. | 02-14-2013 |