Flame triggered and controlled volumetric ignition

Patent metadata

Field	Value
Publication number	US-11965455-B2
Application number	US-202217819830-A
Country	US
Kind code	B2
Filing date	Aug 15, 2022
Priority date	Sep 16, 2019
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

The subject matter of this specification can be embodied in, among other things, a method of igniting an air/fuel mixture in an internal combustion engine includes receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter, igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, directing the flame to eject the pre-combustion chamber through a collection of passages in a wall of the pre-combustion chamber, toward a peripheral wall of a main combustion chamber of the internal combustion engine, igniting, by the flame, air/fuel mixture in the main combustion chamber adjacent the peripheral wall, and then igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of the ignited air/fuel mixture or a portion of the directed flame adjacent the peripheral wall.

First claim

What is claimed is:

1. A method of igniting an air/fuel mixture in an internal combustion engine, the method comprising:
receiving an air/fuel mixture into a pre-combustion chamber, the pre-combustion chamber enclosing a portion of an igniter;
igniting the air/fuel mixture in in the pre-combustion chamber with the igniter to produce a flame, the pre-combustion chamber having a wall and a plurality of passages in the wall proximal a cylinder head;
moving a piston toward a top dead center position wherein at the top dead center position a portion of the wall extends into a bowl defined in a face of the piston of the internal combustion engine with the face and the bowl at a first end and the cylinder head at a second end opposite the first end, the bowl having a bowl wall defining a volume having a center;
directing, while the piston is moving to or at the top dead center position, the flame to eject the pre-combustion chamber through the plurality of passages in the wall of the pre-combustion chamber proximal to the cylinder head away from the center of the volume, wherein a first portion of the flame is ejected along a trajectory that is adjacent to and along a periphery of the cylinder head, to a peripheral sidewall of a main combustion chamber of the internal combustion engine through a gap defined between the cylinder head and the face of the piston, and a second portion of the flame is ejected to the portion of the bowl wall adjacent the face and is redirected by the bowl wall to along a periphery of the bowl wall; then
igniting, by the directed flame, air/fuel mixture in the main combustion chamber adjacent the periphery of the cylinder head, adjacent the bowl wall, and adjacent the peripheral sidewall; and then
igniting air/fuel mixture in the main combustion chamber in a central region of the main combustion chamber with a propagating flame front of ignited air/fuel mixture away from the periphery of the cylinder head, away from the bowl wall, and away from the peripheral sidewall.

2. The method of claim 1 , wherein the main combustion chamber comprises the bowl, an elongate cylindrical chamber having a cylindrical wall, and the cylinder head, and a portion of the bowl wall adjacent the directed flame has an orientation that is obtuse to a trajectory of the directed flame.

3. The method of claim 1 , wherein all air/fuel mixture received in the pre-combustion chamber is received from the main combustion chamber.

4. The method of claim 1 , wherein directing the flame to eject the pre-combustion chamber through the plurality of passages in the wall of the pre-combustion chamber proximal to the cylinder head, toward the gap and the portion of the bowl wall adjacent the face further comprises ejecting the flame orthogonal to a cylinder wall of the main combustion chamber more laterally than axially.

5. The method of claim 1 , further comprising:
receiving, from a pressure sensor in the pre-combustion chamber and configured to measure fluid pressure in the pre-combustion chamber and the main combustion chamber, a pressure signal; and
adjusting ignition timing of the internal combustion engine based on the pressure signal such that CA50 to CA90 is shorter than CA10 to CA50.

6. The method of claim 1 , further comprising:
compressing, by the propagating flame front propagating from the peripheral wall, the periphery of the cylinder head, and the peripheral sidewall toward the center of the defined volume, unburned air/fuel mixture in the center; and then
auto-igniting unburned air/fuel mixture in the center;
wherein later portions of mass fraction burned (MFB) rate are faster than initial MFB rates of the propagating flame front.

7. The method of claim 1 , further comprising:
receiving, from a pressure sensor in the pre-combustion chamber or a main combustion chamber of the internal combustion engine and configured to measure fluid pressure in the pre-combustion chamber and the main combustion chamber, a pressure signal; and
adjusting ignition timing of the internal combustion engine, in another combustion cycle after the pressure signal is received, based on the pressure signal such that about 85% of heat release (HR) occurs by a predetermined point about 20 degrees after top dead center.

8. A system for igniting a mixture in an internal combustion engine, the system comprising:
an igniter;
a main combustion chamber having a peripheral sidewall defining a center axis and comprising an elongate cylindrical chamber having a cylindrical wall, a piston of the internal combustion engine with a face at a first end, a cylinder head at a second end opposite the first end, a bowl defined in the face of the piston and having a bowl wall defining a volume having a center, and a gap defined between the cylinder head, the face of the piston, and the cylindrical wall;
a pre-combustion chamber centered on the center axis and enclosing a portion of the igniter, wherein a portion of a wall of the pre-combustion chamber extends into the bowl, and a portion of the bowl extends circumferentially around a portion of the wall of the pre-combustion chamber when the piston is configured at a top dead center position; and
a plurality of passages in a wall of the pre-combustion chamber, each passage fluidly connecting the pre-combustion chamber and the main combustion chamber and having a jet aperture proximal to the cylinder head away from the center of the defined volume and configured to direct a first portion of fluid flow from the passage along a periphery of the cylinder head through the gap to the peripheral sidewall more laterally than axially, and direct a second portion of fluid flow to a portion of the bowl wall adjacent the face and be redirected by the bowl wall along a periphery of the bowl wall.

9. The system of claim 8 , wherein the portion of the bowl wall adjacent the directed second portion of fluid flow has an orientation that is obtuse to a trajectory of the directed second portion of fluid flow.

10. The system of claim 8 , wherein the jet apertures of the plurality of passages are arranged radially.

11. The system of claim 8 , wherein the jet apertures of the plurality of passages are arranged to direct fluid flow, ejected from pre-combustion chamber through the plurality of passages, orthogonal to the cylindrical wall.

12. The system of claim 8 , further comprising a pressure sensor in the pre-combustion chamber or main combustion chamber configured to provide a pressure signal representative of a fluid pressure in the pre-combustion chamber and the main combustion chamber.

13. The system of claim 12 , further comprising a controller configured to adjust activation of the igniter based on the pressure signal such that CA50 to CA90 is shorter than CA10 to CA50.

14. The system of claim 12 , further comprising a controller configured to adjust activation of the igniter based on the pressure signal such that about 85% of heat release (HR) occurs by about 20 degrees after top dead center.

15. The system of claim 8 , wherein the jet aperture is configured to direct fluid flow from the passage along a periphery of the cylinder head and away from the center of the defined volume.

16. The system of claim 8 , wherein the jet aperture is configured to direct the fluid flow along a trajectory that is substantially orthogonal to a center axis of the pre-combustion chamber.

17. The system of claim 16 , wherein the trajectory is at an angle between +30 degrees and −30 degrees away from orthogonal to the center axis of the pre-combustion chamber.

18. An internal combu

Assignees

• Woodward Inc

Inventors

• Chiera Domenico
• Brennecke Charles
• Mccreery Samuel James
• Carlson Jeffrey
• Nair Suraj
• Hampson Gregory James

Classifications

• F02B19/12 Primary

  with positive ignition (engines with non-timed positive ignition, and with incandescent chambers F02B9/08) · CPC title

• F02B19/18

  Transfer passages between chamber and cylinder · CPC title

• F02F3/26

  having combustion chamber in piston head (the surface thereof being covered F02F3/14) · CPC title

• F02P5/103

  dependent on the combustion-air pressure in engine · CPC title

• F02B23/08

  with positive ignition · CPC title