Patent Number: 7,045,939

Title: Spark plug having a welded electrode and the method of producing the same

Abstract: A spark plug used in an automotive internal combustion engine. The spark plug includes a center electrode. An insulator is disposed around the center electrode. A metal main body is disposed around the insulator. A ground electrode has a first end section connected to the metal main body, and a second end section located opposite to the center electrode. Additionally, a tip is formed of an alloy whose main component is Ir. The tip is secured to the ground electrode and serving as a spark consumption-resistant electrode material. The tip has an axis directed to the center electrode. In the spark plug, a molten and solidified section formed of alloy is disposed to fix the tip to the ground electrode. The molten and solidified section includes a surrounding molten and solidified section located surrounding a peripheral surface of a major part of the tip embedded in the ground electrode.

Inventors: Teramura; Hideki (Mie, JP), Musasa; Mamoru (Nagoya, JP), Kondo; Kiyohiro (Aichi, JP)

Assignee: NGK Spark Plug Co., Ltd.

International Classification: H01T 13/20 (20060101); H01T 21/02 (20060101)

Expiration Date: 5/16/02018