Title:
SPARK PLUG
Document Type and Number:
WIPO Patent Application WO/2014/189079
Kind Code:
A1
Abstract:
Provided is a novel technique for improving the durability of a spark plug. The spark plug comprises: a central electrode extending in the axial direction; an insulator having a shaft hole extending in the axial direction with the central electrode inserted into the shaft hole; a main metal fitting disposed around the insulator; a first ground electrode electrically connected to the main metal fitting and forming a first gap in conjunction with the front end surface of the central electrode; and a second ground electrode electrically connected to the main metal fitting, bonded to the main metal fitting, and extending from the main metal fitting to a position facing the lateral surface of the central electrode to form a second annular gap between the lateral surface of the central electrode and the inner peripheral surface of itself. Here, the ratio of the size of the first gap to the size of the second gap is between 0.80 and 1.25.
More Like This:
| JP6948904 | Spark plug for internal combustion engine |
| JPH031473 | SPARK LAMP |
Inventors:
SAKAKURA YASUSHI (JP)
Application Number:
PCT/JP2014/063470
Publication Date:
November 27, 2014
Filing Date:
May 21, 2014
Export Citation:
Assignee:
NGK SPARK PLUG CO (JP)
International Classes:
H01T13/32; H01T13/46
Foreign References:
| JPH08315955A | 1996-11-29 | |||
| JP2003257585A | 2003-09-12 | |||
| JP2003257585A | 2003-09-12 |
Other References:
See also references of EP 3001520A4
Attorney, Agent or Firm:
TOKKYO GYOMUHOJIN OHTORI INTERNATIONAL PATENT FIRM (JP)
Patent business corporation 鳳国際 patent firm (JP)
Patent business corporation 鳳国際 patent firm (JP)
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