HIGH-FREQUENCY PLASMA SPARK PLUG

Title:

HIGH-FREQUENCY PLASMA SPARK PLUG

Document Type and Number:

WIPO Patent Application WO/2013/073487

Kind Code:

A1

Abstract:

A spark plug (1) is equipped with a center electrode (5) which extends in the direction of an axial line (CL1), an insulator (2) having a shaft hole (4) through which the center electrode (5) is inserted, a tip (31) which is bonded to the apical end of the center electrode (5) by a fused section (35), and a ground electrode (27) which forms a gap (33) with the tip (31), said spark plug (1) generating high-frequency plasma in the gap (33) by supplying high-frequency power to the gap (33). The apical end of the tip (31) is positioned frontward beyond the apical end of the insulator (2) in the direction of the axial line (CL1). In addition, at least a portion of the outer surface of the fused section (35) is positioned inside the shaft hole (4), and the distance between the apical opening of the axial hole (4) and the rearmost end of the outer surface of the fused section (35) along the axial line (CL1) is set to 0.1mm or greater. Consequently, the durability of the spark plug (1) for generating high-frequency plasma can be improved by effectively minimizing the wearing of the fused section.

Inventors:

KATSURAYA KOHEI (JP)
NAKAYAMA KATSUTOSHI (JP)

Application Number:

PCT/JP2012/079209

Publication Date:

May 23, 2013

Filing Date:

November 12, 2012

Export Citation:

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Assignee:

NGK SPARK PLUG CO (JP)

International Classes:

H01T13/20; F02P3/01; F02P13/00; H01T13/16

Foreign References:

JP2007250257A	2007-09-27
JP2009008100A	2009-01-15
JP2009008100A	2009-01-15
JP2008123989A	2008-05-29
JP2006236906A	2006-09-07

Other References: