Method for igniting a fuel/air mixture, ignition system and glow plug

Patent metadata

Field	Value
Publication number	US-9534575-B2
Application number	US-201414338961-A
Country	US
Kind code	B2
Filing date	Jul 23, 2014
Priority date	Jul 31, 2013
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

What is described is a method for igniting a fuel/air mixture in a combustion chamber of an engine, wherein a pencil, which is electrically insulated with respect to walls of the combustion chamber and contains a heating resistor, is electrically heated to a temperature of at least 800° C. in the combustion chamber of the engine by applying a heating voltage, and a high voltage of at least 500 V, which is different from the heating voltage, is applied to the pencil and thereby ions are generated in the combustion chamber by field emission of electrons. The invention additionally relates to an ignition system and a glow plug.

First claim

What is claimed is:

1. A method for igniting a fuel/air mixture in a combustion chamber of an engine, comprising:
providing a pencil which is electrically insulated with respect to walls of the combustion chamber and contains a heating resistor;
applying a heating voltage to the heating resistor and thereby electrically heating the pencil to a temperature of at least 800° C. in the combustion chamber of the engine; and
applying a high voltage of at least 500 V, which is different from the heating voltage, to the heating resistor and thereby generating ions in the combustion chamber by field emission of electrons.

2. The method according to claim 1 wherein the pencil is a ceramic pencil.

3. The method according to claim 1 wherein the high voltage is a high-frequency AC voltage.

4. The method according to claim 3 wherein the high-frequency AC voltage has a frequency of at least 10 kHz.

5. The method according to claim 1 wherein the high voltage is at least one hundred times higher than the heating voltage.

6. The method according to claim 1 wherein the pencil is electrically heated by applying DC voltage pulses of less than 25 V.

7. The method according to claim 6 wherein the high voltage is applied between the DC voltage pulses.

8. The method according to claim 7 wherein the heating voltage has an effective value of less than 10 V.

Assignees

• Borgwarner Ludwigsburg Gmbh

Inventors

• Eberhardt Michael
• Allgaier Martin

Classifications

• F02P13/00

  Sparking plugs structurally combined with other parts of internal-combustion engines ({connection of ignition coil to spark plug connector F02P3/02;} with fuel injectors F02M57/06 {; spark plug connector per se H01T13/04 – H01T13/06; predominant aspects of sparking plug, see H01T13/40 – H01T13/44}) · CPC title

• F02P19/02 Primary

  electric, e.g. layout of circuits of apparatus having glowing plugs · CPC title

• F23Q2007/002

  with sensing means · CPC title

• F02M31/125

  Fuel · CPC title

• F23Q7/001

  Glowing plugs for internal-combustion engines · CPC title