发明名称 |
Spark plug including ground electrode having a protrusion and a hole |
摘要 |
It is an object of the present invention to provide a spark plug that can be produced at low cost and secure compatibility between ignition performance and durability. The spark plug according to the present invention includes a center electrode and a ground electrode having an inner surface facing the center electrode, characterized in that; the ground electrode has a protrusion and a hole; the protrusion protrudes from the inner surface by a protruding length A of 0.4 to 1 mm and has a first straight portion with a projected first straight portion area S1 of 1.5 to 3 mm2; the hole has an opening at an outer surface of the ground electrode, a second straight portion, a bottom portion and a transition portion; the opening is formed in such a manner that the ratio (S2/S1) of a projected opening area S2 of the opening to the projected first straight portion area S1 is not less than 1.2; and the transition portion is in the form of a taper portion.
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申请公布号 |
US8350455(B2) |
申请公布日期 |
2013.01.08 |
申请号 |
US200913120870 |
申请日期 |
2009.10.01 |
申请人 |
NGK SPARK PLUG CO., LTD.;KAMEDA HIROYUKI;KATSURAYA KOHEI |
发明人 |
KAMEDA HIROYUKI;KATSURAYA KOHEI |
分类号 |
H01T13/20 |
主分类号 |
H01T13/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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