Spark plug for an internal combustion engine and process for its manufacture

US6064144A · kind A · utility

Assignee

• BERU Aktiengesellschaft · DE

Inventors

• Harald Knoll · Oberstenfeld, DE
• Erwin Schneck · Öhringen, DE
• Werner Niessner · Steinheim, DE
• Dirk Von Hacht · Bornsteiner Straße, DE
• Heinz Ambacher · Memmingen, DE

Key dates

• Filing date: Feb 12, 1998
• Grant date: May 16, 2000
• Expiry date: Feb 12, 2018

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01T13/467
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

A spark plug, especially one for a gas-fueled internal combustion engine has an electrically conducting spark plug body (1), a central electrode (3) which is located in the spark plug body (1) and which is electrically insulated from and projects away from the spark plug body (1), and a ground electrode (4) which is electrically connected to the spark plug body (1) and is made in the form of an annular electrode. The annular electrode (4) surrounds the front part of central electrode (3) such that an annular ignition gap (ZS) is formed between them. Surfaces of the central electrode (3) and the annular electrode (4) bordering the ignition gap (ZS) are provided with precious metal armorings in the form of sleeves (5, 6,), especially of platinum or a platinum alloy. This yields a spark plug with an extremely long service life. A method for producing this spark plug involves the steps of forming a concentric centering groove in the spark plug body for the ground electrode, forming welding cams on the ground electrode, and inserting the ground electrode with the welding cams into the centering groove of the spark plug body and welding the welding cams to the spark plug body.