Method and apparatus for controlling operation of an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9970407-B2
Application number	US-201514831912-A
Country	US
Kind code	B2
Filing date	Aug 21, 2015
Priority date	Sep 8, 2014
Publication date	May 15, 2018
Grant date	May 15, 2018

Abstract

An internal combustion engine includes a plasma ignition system having an in-cylinder dielectric barrier-discharge igniter, and a direct-injection fuel injector having an in-cylinder fuel nozzle. The fuel nozzle protrudes into the combustion chamber proximal to the igniter. A controller operatively connects to the internal combustion engine, the plasma ignition system and the fuel injection system. The controller controls the internal combustion engine at an air/fuel ratio that is lean of stoichiometry. The fuel injector injects a first fuel pulse prior to activation of the igniter, and then the igniter initiates a plasma energy pulse. The fuel injector is controlled to inject a second fuel pulse during the plasma energy pulse.

First claim

The invention claimed is:

1. An internal combustion engine system, comprising:
an internal combustion engine, including:
a plasma ignition system including a barrier-discharge igniter having a tip portion protruding into a combustion chamber of the internal combustion engine, wherein the tip portion of the igniter comprises an anode, an annular dielectric barrier formed around a periphery of the anode, and a discontinuous annular cathode, wherein an annular gap is formed between the dielectric barrier and the cathode, and
a fuel injection system including a direct-injection fuel injector including a fuel nozzle protruding into the combustion chamber proximal to the tip port of the igniter; and

a controller operatively connected to the internal combustion engine, the plasma ignition system and the fuel injection system, the controller including executable code operative to:
control the internal combustion engine to operate at an air/fuel ratio that is lean of stoichiometry,
control the internal combustion engine in a negative valve overlap mode,
control the fuel injector to inject a first fuel pulse prior to activation of the igniter during each engine cycle,
control the igniter to initiate a plasma energy pulse, and
control the fuel injector to inject a second fuel pulse during the plasma energy pulse.

2. The internal combustion engine of claim 1 , wherein the direct-injection fuel injector mounted on the cylinder head and protruding into the combustion chamber proximal to the igniter further comprises:
the fuel injector centrally located in the cylinder head, wherein the fuel injector has a first longitudinal axis; and
the igniter having a second longitudinal axis;
wherein the second longitudinal axis is located between 10° to 50° of rotation from the first longitudinal axis; and
wherein the tip portion of the igniter is located away from the fuel nozzle at a linear distance that is between 5 mm and 20 mm.

3. The internal combustion engine of claim 1 , wherein the fuel nozzle comprises a single hole device including a single opening into the combustion chamber; and wherein a fuel spray pattern from the fuel nozzle is a single plume having a conical shape, and wherein the single plume contacts the tip portion of the igniter during the plasma energy pulse.

4. The internal combustion engine of claim 1 , wherein the fuel nozzle comprises a multi-hole device including a plurality of openings into the combustion chamber; and wherein a fuel spray pattern from the fuel nozzle includes a plurality of radially projecting plumes, and wherein one of the plumes contacts the tip portion of the igniter during the plasma energy pulse.

5. The internal combustion engine of claim 1 , wherein the controller including executable code operative to control the internal combustion engine at an air/fuel ratio that is lean of stoichiometry further comprises the controller including executable code operative to control the internal combustion engine in a spark-assisted compression-ignition mode with the negative valve overlap.

6. The internal combustion engine of claim 1 , wherein the controller including executable code operative to control the internal combustion engine at an air/fuel ratio that is lean of stoichiometry further comprises the controller including executable code operative to control the internal combustion engine in a compression-ignition mode.

7. A plasma ignition system for an internal combustion engine, comprising:
a barrier-discharge igniter having a tip portion protruding into a combustion chamber of the internal combustion engine, wherein the tip portion is proximal to a fuel nozzle of a direct-injection fuel injector protruding into the combustion chamber, and wherein the tip portion of the igniter comprises an anode, an annular dielectric barrier formed around a periphery of the anode, and a discontinuous annular cathode, wherein an annular gap is formed between the dielectric barrier and the cathode; and
a controller operatively connected to the plasma ignition system, the controller including executable code operative to control the internal combustion engine to operate at an air/fuel ratio that is lean of stoichiometry, control the igniter to initiate a plasma energy pulse in the combustion chamber subsequent to an activation of the direct-injection fuel injector to inject a first fuel pulse into the combustion chamber during engine operation in a negative valve overlap mode;
wherein the direct-injection fuel injector is operable to inject a second fuel pulse into the combustion chamber during the plasma energy pulse.

8. The plasma ignition system of claim 7 , wherein the fuel injector has a first longitudinal axis and the igniter has a second longitudinal axis wherein the second longitudinal axis is located between 10° and 50° of rotation from the first longitudinal axis.

9. The plasma ignition system of claim 7 , wherein the tip portion of the igniter is located at a linear distance that is between 5 mm and 20 mm away from the fuel nozzle.

10. The plasma ignition system of claim 7 , wherein the tip portion of the igniter is contacted by a fuel plume of a fuel spray pattern from the direct-injection fuel injector.

11. A method for controlling an internal combustion engine including a plasma ignition system, including a barrier-discharge igniter having a tip portion protruding into a combustion chamber, wherein the tip portion of the igniter comprises an anode, an annular dielectric barrier formed around a periphery of the anode, and a discontinuous annular cathode, wherein an annular gap is formed between the dielectric barrier and the cathode, and a fuel injection system including a direct-injection fuel injector including a fuel nozzle protruding into the combustion chamber, wherein the fuel nozzle is proximal to the igniter, the method comprising:
controlling the internal combustion engine to operate at an air/fuel ratio that is lean of stoichiometry and in a negative valve overlap mode;
controlling the fuel injector to inject a first fuel pulse prior to activation of the igniter;
controlling the igniter to initiate a plasma energy pulse; and

controlling the fuel injector to inject a second fuel pulse during the plasma energy pulse.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Idicheria Cherian A
• Silvas Gerald A

Classifications

• H05H1/2406

  using dielectric barrier discharges, i.e. with a dielectric interposed between the electrodes · CPC title

• F02D37/02

  one of the functions being ignition · CPC title

• H01T19/02

  Corona rings · CPC title

• F02D2041/389

  for injecting directly into the cylinder · CPC title

• H01T13/50

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