Lean air-fuel mixture attraction method and attraction electrode plug in

Abstract

An improved apparatus for igniting a lien air-fuel mixture includes a spark plug having a straight longitudinally extending main electrode and a side electrode disposed adjacent to and electrically insulated from the main electrode. An attraction plug is mounted in the cylinder head at a location offset to one side of and adjacent to the spark plug. The attraction plug includes a straight longitudinally extending central electrode and an insulator which at least partially encases the central electrode for electrically insulating the central electrode and for isolating the portion of the central electrode disposed in the combustion chamber from the atmosphere in the combustion chamber. The central electrode has a longitudinal axis which extends transversely to the longitudinal axis of the main electrode of the spark plug. In addition, the central electrode has an end portion which is disposed adjacent to the main electrode of the spark plug. An electrical potential is applied to the central electrode of the attraction plug to establish an electrostatic field in the combustion chamber without establishing a corona discharge in the combustion chamber. In addition, an electrical potential is applied to the main electrode to establish a spark between the main and the side electrode to ignite fuel particles attracted to the vicinity of the spark plug by the electrostatic field from the attraction plug.