SPARK PLUG FOR INTERNAL COMBUSTION ENGINE

Title:

SPARK PLUG FOR INTERNAL COMBUSTION ENGINE

Document Type and Number:

WIPO Patent Application WO/2010/038611

Kind Code:

A1

Abstract:

A spark plug configured without providing a noble metal tip on a ground electrode, wherein the spark plug has improved ignitability and an extended life and wherein the ground electrode has high strength. A spark plug (1) is provided with a center electrode (5), an insulator (2), a main fitting (3), and a ground electrode (27). A spark is discharged substantially along the axis (CL1) direction in a spark discharge gap (33) formed between the center electrode (5) and the ground electrode (27). The ground electrode has a narrow section (42) having a width which is substantially constant and is less than the outer diameter of a tip surface (5F) of the center electrode (5), and the ground electrode also has a wide section (41) having a width larger than the width of the narrow section (42). When viewed from the tip side in the axis (CL1) direction, the base end of the narrow section (42) is located on the root side of the ground electrode (27) from the tip surface (5F) of the center electrode (5) and the base end of the narrow section (42) is located on the tip side in the axis (CL1) direction from the center of the spark discharge gap (33).

Inventors:

KAMEDA HIROYUKI (JP)

Application Number:

PCT/JP2009/066078

Publication Date:

April 08, 2010

Filing Date:

September 15, 2009

Export Citation:

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Assignee:

NGK SPARK PLUG CO (JP)
KAMEDA HIROYUKI (JP)

International Classes:

H01T13/32; H01T13/20

Foreign References:

JPS535629U	1978-01-19
JP2000252039A	2000-09-14
JPH1154240A	1999-02-26
JPH07135066A	1995-05-23
JP3461637B2	2003-10-27
JP2004087464A	2004-03-18
JP2007250344A	2007-09-27
JP2001307858A	2001-11-02
JP2006236906A	2006-09-07

Other References: