发明名称 |
Spark plug |
摘要 |
A spark plug includes an insulator including an axial hole and having an outer periphery with a tapered outer face; a metal shell having a thread portion and a tapered inner face; and a circular packing sandwiched between the tapered outer face of the insulator and the tapered inner face of the metal shell. On at least one cross section including the axis, (A/B)≧3.1, B≧0.25, and (A+B)≦2.0 are satisfied, where A represents a length of (a difference between an effective diameter of the thread portion and an inner diameter at a rear end of the tapered inner face)/2, and B represents a length of (a difference between the inner diameter at the rear end of the tapered inner face and an inner diameter at a front end of the tapered inner face)/2. |
申请公布号 |
US9225150(B2) |
申请公布日期 |
2015.12.29 |
申请号 |
US201314412118 |
申请日期 |
2013.07.16 |
申请人 |
NGK SPARK PLUG CO., LTD. |
发明人 |
Nishida Masahiro;Kato Tomoaki;Ozeki Keiji;Mukouyama Naoyuki;Kobayashi Tsutomu |
分类号 |
F02M57/06;F02P13/00;H01T13/00;H01T13/36;H01B3/12 |
主分类号 |
F02M57/06 |
代理机构 |
Leason Ellis LLP |
代理人 |
Leason Ellis LLP |
主权项 |
1. A spark plug comprising:
a tubular insulator having an axial hole extending in a direction of an axis thereof, the tubular insulator having an outer periphery with a tapered outer face where an outer diameter thereof decreases from a rear end to a front end thereof; a tubular metal shell having a through-hole extending in the axial direction through which the insulator is inserted, the tubular metal shell having a thread portion including an installation thread ridge on an outer periphery of the thread portion and a tapered inner face where an inner diameter thereof decreases from the rear end to the front end on an inner periphery of the thread portion; and a circular packing, which is sandwiched between the tapered outer face of the insulator and the tapered inner face of the metal shell to seal a gap therebetween, wherein: the thread portion has a nominal diameter of not more than 10 mm; and on at least one cross section including the axis, relationships (A/B)≧3.1, B≧0.25, and (A+B)≦2.0 are satisfied, where A represents a length (mm) of (a difference between an effective diameter of the thread portion and an inner diameter at a rear end of the tapered inner face)/2, and B represents a length (mm) of (a difference between the inner diameter at the rear end of the tapered inner face and an inner diameter at a front end of the tapered inner face)/2. |
地址 |
Nagoya JP |