High voltage connection sealing method for corona ignition coil
View Patent ↗A corona igniter assembly 20 comprises an ignition coil assembly 22 , a firing end assembly 24 , and a metal tube 26 connecting the ignition coil assembly 22 to the firing end assembly 24 . A rubber boot 28 is disposed in the metal tube 26 and compressed symmetrically between a coil output member 30 of the ignition coil assembly 22 and an insulator 42 of the firing end assembly 24 . Thus, the rubber boot 28 fills any air gaps and provides a hermetic seal between the ignition coil assembly 22 and the firing end assembly 24 to prevent unwanted corona discharge from forming from those air gaps.
1. An ignitor assembly, comprising:
a tube including an interior space;
an ignition coil device coupled to one end of said tube;
an ignitor device coupled to an opposite end of said tube;
at least one opening extending through a wall of said metal tube in communication with said interior space;
an elastomeric plug disposed in said interior space sealing said at least one opening and providing a hermetic seal between said ignition coil device and said ignitor device; and
said ignitor device including an electrode and a firing tip crown disposed on a free end of said electrode, said firing tip crown including a plurality of branches extending radially outwardly relative to a center axis of said igniter device.
2. The assembly of claim 1 wherein said elastomeric plug includes a first cup-shaped recess at said one end surrounding a portion of said ignition coil device received therein.
3. The assembly of claim 2 wherein said elastomeric plug includes a second cup-shaped recess at said opposite end surrounding a portion of said ignitor device received therein.
4. The assembly of claim 3 wherein said elastomeric plug includes a channel connecting said first and second cup-shaped recesses.
5. The assembly of claim 4 including an electrical terminal disposed in said channel.
6. The assembly of claim 1 wherein said elastomeric plug includes a channel extending between said ignition coil device and said ignitor device and in which an electrical terminal is disposed.
7. The assembly of claim 3 wherein said ignitor device includes a ceramic insulator having said portion thereof received in said second cup-shaped recess.
8. The assembly of claim 7 wherein said ceramic insulator has a bore and said electrode is disposed in said bore.
9. The assembly of claim 8 wherein said firing tip crown is operative to produce a corona ignition when the ignitor assembly is fired.
10. The assembly of claim 9 wherein the firing tip crown projects beyond said opposite end of said tube and the ignitor assembly is devoid of a ground electrode and devoid of a spark gap.
11. The assembly of claim 1 wherein the elastomeric plug extends at least partially into said at least one opening.
12. The assembly of claim 1 wherein there is a plurality of said openings communicating with said interior space and all are sealed by said elastomeric plug.
13. The assembly of claim 1 wherein said ignitor device is a corona ignition device.
14. The assembly of claim 1 wherein said ignition coil device is spaced longitudinally from said ignitor device and electrically coupled by an electrode extending through a channel of said elastomeric plug.
15. The assembly of claim 1 , wherein said elastomeric plug includes a recess at said one end and a recess at said opposite end; said recesses being spaced longitudinally from one another by a central body portion of said elastomeric plug and interconnected by a central channel extending through said central body portion.
16. The assembly of claim 1 , wherein said tube is formed of metal.