Ignition plug for internal combustion engine

摘要

An ignition plug for an internal combustion engine is disclosed which comprises an elongate electrode means inserted at the center of a plug body, another cylindrical electrode means encircling the electrode means and an insulator means provided between the elongate and cylindrical electrode means and forming a small cavity which is in communication with a combustion chamber. A plasma gas is created in the cavity due to the generation of a spark between the elongate and cylindrical electrode means and is jetted into the combustion chamber to ignite the air-fuel mixture therein. A gap into which the burnt gas is introduced is formed between the insulator means and the cylindrical electrode means so as to warm the wall of the cavity and thereby avoid ignition misfiring.