Spark plug, has molded part welded to earth electrode, and spacer whose thermal expansion co-efficient differs from thermal expansion co-efficient of earth electrode, which emanates from body, where molded part is made of noble metals

摘要

The plug has an insulator (2) arranged in a body (1) that is made of base metallic materials, and an earth electrode (4) emanating from the body. A molded part (6) is welded to the earth electrode and is turned towards a central electrode (3), where the molded part is made from a set of noble metals. A spacer (9) is provided between the molded part and the earth electrode and is welded to the molded part and the earth electrode. The spacer is formed as a socket and has a thermal expansion co-efficient, which differs from the thermal expansion co-efficient of the earth electrode. An independent claim is also included for a method for reinforcing an earth electrode.