Corona suppression at the high voltage joint through introduction of a semi-conductive sleeve between the central electrode and the dissimilar insulating materials

Abstract

A corona ignition assembly comprising a plurality of different insulators disposed between an ignition coil assembly and firing end assembly is provided. A high voltage center electrode extends longitudinally between an igniter central electrode and the ignition coil assembly. A high voltage insulator formed of a fluoropolymer surrounds the high voltage center electrode, and a firing end insulator firing of alumina surrounds the igniter central electrode. A sleeve formed of a semi-conductive and complaint material, such as silicone rubber with conductive filler, is disposed radially between the electrodes and adjacent insulators. The sleeve fills air gaps and minimizes the peak electric field within the corona igniter assembly. The sleeve is able to prevent unwanted corona discharge, and thus extends the life of the materials and directs energy to the firing end.

Dependencies are inferred from the claim text.