Spark plug with electrodes having noble metal inserts

US4771210A · kind A · utility

Assignee

• Beru Ruprecht GmbH & Co. KG · DE

Inventors

• Karl Mohle · Murr, DE
• Herbert Lang · Memmingen, DE

Key dates

• Filing date: Feb 18, 1987
• Grant date: Sep 13, 1988
• Expiry date: Feb 18, 2007

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01T13/39
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

In a spark plug with center electrode and body electrode in which the cylindrical center electrode comprises in its end face a blind bore in which a pin-shaped small-volume noble metal insert is inserted and fixed by upsetting, it is provided that the front region (1a) of the center electrode (1), provided with end-side bore (2) and insert (3) disposed therein, is reduced radially over almost the entire length of the bore (2), the reduced region (1a) having a constant diameter, and that a further pin-shaped small-volume noble metal insert (5) is fixed in a bore (4) formed coaxially with the bore (2) in the body electrode (6). The production of the spark plug can proceed from commercially usual spark plug parts made on conventional production machines; the noble metal insert of the spark plug is securely attached in the center electrode and the body electrode part opposite the noble metal insert has a reduced burnup, thus increasing the life of the spark plug.