发明名称 |
Spark plug for an internal combustion engine |
摘要 |
In a spark plug, a tubular insulator has an axial bore in which a center electrode and a terminal electrode are axially aligned, the terminal electrode having a seal portion fixedly supported by partly filling the axial bore with a glass sealant. The insulator further has a tapered shoulder portion between a diameter-reduced portion and a diameter-increased portion, each provided on the insulator. A metallic shell is placed around the diameter-increased portion of the insulator, a rear end of the metallic shell being caulked against the diameter-reduced portion of the insulator, a space between the metallic shell and the diameter-reduced portion of the insulator being filled with a ceramic powder. An inclination of the tapered shoulder portion of the insulator ranges from 10 to 45 degrees against a plane perpendicular to the terminal electrode. A roulette is formed on an outer surface of the seal portion of the terminal electrode in which the glass sealant is filled. A front end of the seal portion of the terminal electrode is located in the range of +5.0 mm to -1.0 mm from a boundary where the tapered shoulder portion meets the diameter-increased portion of the insulator.
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申请公布号 |
US5760533(A) |
申请公布日期 |
1998.06.02 |
申请号 |
US19960622170 |
申请日期 |
1996.03.27 |
申请人 |
NGK SPARK PLUG CO., LTD. |
发明人 |
SAIKI, YOSHIAKI;ANDO, MINORU;YOSHIDA, MITSUTAKA |
分类号 |
H01T13/20;H01T13/34;H01T13/36;(IPC1-7):H01T13/04 |
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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