Corona ignition device

Patent metadata

Field	Value
Publication number	US-9373941-B2
Application number	US-201414206695-A
Country	US
Kind code	B2
Filing date	Mar 12, 2014
Priority date	Mar 14, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

The invention relates to a corona ignition device for igniting fuel in a combustion chamber of an engine by means of a corona discharge, comprising a tubular housing, a coil arranged in the tubular housing, an insulator, which plugs into the tubular housing, and a center electrode, which is connected to the coil, plugs into the insulator and leads to at least one ignition tip. In order to increase the service life of the ignition tip, said ignition tip consists in part or completely of an iridium-based alloy containing 3 to 30% by weight of rhodium or is coated by a burn-up layer.

First claim

What is claimed is:

1. A corona ignition device for igniting fuel in a combustion chamber of an engine by means of a corona discharge, the corona ignition device comprising:
a tubular housing;
a coil arranged in the tubular housing;
an insulator plugged into the tubular housing;
a center electrode connected to the coil and plugged into the insulator, the center electrode leading to at least one ignition tip; and
a burn-up layer by which the ignition tip is ensheathed or is covered at least on two opposite sides;
wherein the ignition tip comprises an iridium-based alloy containing 3 to 30% by weight of rhodium.

2. The corona ignition device according to claim 1 , wherein the burn-up layer consists substantially of one or more transition metals.

3. The corona ignition device according to claim 1 , wherein the center electrode leads to an ignition head which is made of sheet metal and which has a plurality of ignition tips.

4. The corona ignition device according to claim 1 , wherein the ignition tip is made of wire.

5. The corona ignition device according to claim 1 , wherein the burn-up layer comprises a nickel-based alloy, chromium-based alloy or an iron-based alloy.

6. The corona ignition device according to claim 1 , wherein the ignition tip without the burn-up layer has a thickness of less than 0.3 mm.

7. The corona ignition device according to claim 1 , wherein the ignition tip is formed of a composite material that contains the iridium-based alloy and an alloy consisting substantially of one or more transition metals.

8. The corona ignition device according to claim 1 , wherein the iridium-based alloy contains 3 to 10% by weight of rhodium.

9. The corona ignition device according to claim 1 , wherein the iridium-based alloy contains at least 80% by weight iridium.

10. A corona ignition device for igniting fuel in a combustion chamber of an engine by means of a corona discharge, the corona ignition device comprising:
a tubular housing;
a coil arranged in the tubular housing;
an insulator plugged into the tubular housing; and
a center electrode connected to the coil and plugged into the insulator, the center electrode leading to at least one ignition tip comprising an alloy based on a metal from the platinum group; and
a metal burn-up layer by which the ignition tip is ensheathed or coated on opposing sides, the metal burn-up layer being less resistant to burn-up than the ignition tip.

11. The corona ignition device of claim 10 , wherein the ignition tip comprises an iridium-based alloy.

12. The corona ignition device of claim 11 , wherein the iridium-based alloy contains 3 to 30% by weight of rhodium.

13. The corona ignition device of claim 10 , wherein the ignition tip is made of wire.

14. The corona ignition device of claim 10 , wherein the burn-up layer comprises a nickel-based alloy, chromium-based alloy or an iron-based alloy.

15. An ignition tip for a corona ignition device, comprising:
an alloy based on a metal selected from the platinum group; and
a metal burn-up layer which ensheaths or coats the ignition tip on opposing sides, the metal burn-up layer being less resistant to burn up than the ignition tip.

Assignees

• Borgwarner Beru Systems Gmbh
• Borgwarner Ludwigsburg Gmbh

Inventors

• Achtstätter Tom
• Stifel Timo

Classifications

• H01T13/14

  Means for self-cleaning · CPC title

• H01T13/38

  Selection of materials for insulation · CPC title

• H01T19/00

  Devices providing for corona discharge (for charging electrographic elements G03G15/02) · CPC title

• H01T19/04

  having pointed electrodes · CPC title

• H01T13/50 Primary

  having means for ionisation of gap (H01T13/52 takes precedence) · CPC title