Spark Plug Gasket and Method of Attaching the Same

摘要

A spark plug and a method of manufacturing the same, where the spark plug has a metal shell, an insulator, a center electrode, a ground electrode, and a gasket located over a threaded portion of the shell and used to seal the spark plug against a cylinder head. Once the gasket is attached on the spark plug, it is shrunk to become a post-formed gasket with an inner diameter that prevents the post-formed gasket from slipping over a threaded portion of the metallic shell. This process may be carried out with a collet type machine that produces a post-formed gasket that is flat and has a substantially uniform thickness, which can improve the sealability of the gasket. This may be important when the spark plug is installed in a cylinder head made from a lost foam casting process or other process that creates a somewhat porous sealing surface.

主权项

1. A spark plug, comprising:
a metallic shell having an axial bore and a threaded portion; an insulator having an axial bore and being disposed at least partially within the axial bore of the metallic shell; a center electrode being disposed at least partially within the axial bore of the insulator; a ground electrode being attached to the metallic shell, and a post-formed gasket having a first gasket sealing surface, a second gasket sealing surface, and an inner diameter (DI) that prevents the post-formed gasket from slipping over the threaded portion of the metallic shell, wherein the post-formed gasket is flat and has a substantially uniform thickness (T).