SPARK PLUG FOR INTERNAL COMBUSTION ENGINE - Nippon Special Ceramics Co., Ltd.

Title:

SPARK PLUG FOR INTERNAL COMBUSTION ENGINE

Document Type and Number:

Japanese Patent JP3498252

Kind Code:

B2

Abstract:

PROBLEM TO BE SOLVED: To enhance durability of a spark plug by suppressing the perspiration of noble-metal chips, on the end face of a center electrode for use in a gas engine, and on the discharge surface of an earth electrode preventing formation of bridges that may result in misfires, etc., and reducing discharge voltages.
SOLUTION: A chamfered portion 12 of a predetermined size is formed at the outer periphery 11 of the end of a noble-metal chip 9 on the end face 6 of a center electrode. Thus concentration of spark discharges on the outer periphery 11 of the end of the noble-metal chip 9 is prevented to prevent wear of the noble-metal chip. The prevention of spark discharge concentration leads to the prevention of formation of bridges between spark gaps by suppressing the perspiration of the noble-metal chip that may be caused by local temperature rises, thus making it possible to avoid misfires, etc.

Inventors:

Kazumi Kawamura

Application Number:

JP27072295A

Publication Date:

February 16, 2004

Filing Date:

September 26, 1995

Export Citation:

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