Igniter assembly including arcing reduction features

摘要

A corona igniter (20) includes a metal shell (32) with a corona reducing lip (38) spaced from an insulator (26) and being free of sharp edges (40) to prevent arcing (42) in a rollover region and concentrate the electrical field at an electrode firing end (48). The corona reducing lip (38) includes lip outer surfaces (88) being round, convex, concave, or curving continuously with smooth transitions (90) therebetween. The corona reducing lip (38) includes lip outer surfaces (88) presenting spherical lip radii (r1) being at least 0.004 inches. The corona igniter (20) also includes shell inner surfaces (104) and insulator outer surfaces (75) facing one another being free of sharp edges (40).

主权项

1. A corona igniter for receiving a voltage from a power source and emitting an electrical field that forms a corona to ionize a mixture of fuel and air of an internal combustion engine comprising:
an electrode including an electrode body portion extending longitudinally from an electrode terminal end to an electrode firing end; an insulator disposed along said electrode body portion; a shell disposed along said insulator from an upper shell end to a lower shell end facing toward said electrode firing end; and said shell including a corona reducing lip at said upper shell end being free of sharp edges, and said corona reducing lip includes a lip outer surface presenting a plurality of spherical lip radii therealong and each of said spherical lip radii is at least 0.004 inches.