PRE-CHAMBER FOR INTERNAL COMBUSTION ENGINE

• US 20140261298A1
• Filed: 03/15/2013
• Published: 09/18/2014
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Sasidharan, Premjee, LaPointe, Leon A.
• Granted Patent: US 9,797,296 B2
• Time in Patent Office: Days
• US Class Current: 123/275
• CPC Class Codes: F02B 1/04 with fuel-air mixture admission into cylinder
• CPC Class Codes: F02B 19/1014 design parameters, e.g. volume, torch passage cross sectional area, length, orientation, or the like
• CPC Class Codes: F02B 19/1019 with only one pre-combustion chamber F02B19/1004 take precedence
• CPC Class Codes: F02B 19/108 with fuel injection at least into pre-combustion chamber, i.e. injector mounted directly in the pre-combustion chamber
• CPC Class Codes: F02B 19/12 with positive ignition engines with non-timed positive ignition, and with incandescent chambers F02B9/08
• CPC Class Codes: F02B 19/14 with compression ignition
• CPC Class Codes: F02B 19/16 Chamber shapes or constructions not specific to sub-groups F02B19/02 - F02B19/10
• CPC Class Codes: F02B 19/18 Transfer passages between chamber and cylinder
• CPC Class Codes: F02B 21/00 Engines characterised by air-storage chambers
• CPC Class Codes: F02B 3/06 with compression ignition compression ignition engines using air or gas for blowing fuel into compressed air in cylinder F02B13/02
• CPC Class Codes: F02M 61/1833 Discharge orifices having changing cross sections, e.g. being divergent
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

Described herein is a combustion pre-chamber apparatus for a main combustion chamber of an internal combustion engine that includes a body that defines an internal combustion cavity. The apparatus also includes at least one orifice that extends through the body. The at least one orifice includes a first end open to the internal combustion cavity and a second end open to the main combustion chamber. The first end is bigger than the second end.

Claims

1. A combustion pre-chamber apparatus for a main combustion chamber of an internal combustion engine, comprising:

a body defining an internal combustion cavity; and

at least one orifice extending through the body, the at least one orifice comprising a first end open to the internal combustion cavity and a second end open to the main combustion chamber, wherein the first end is bigger than the second end.

2. The combustion pre-chamber apparatus of claim 1, wherein the orifice has a conical-frustum shape.

3. The combustion pre-chamber apparatus of claim 1, wherein the orifice converges from the first end to the second end.

4. The combustion pre-chamber apparatus of claim 1, wherein the at least one orifice has a substantially circular cross-sectional shape.

5. The combustion pre-chamber apparatus of claim 1, wherein the at least one orifice comprises a plurality of orifices.

6. The combustion pre-chamber apparatus of claim 1, further comprising a fillet at a transition between the second end of the at least one orifice and the body.

7. The combustion pre-chamber apparatus of claim 6, wherein the fillet has a radius, and wherein a ratio of the radius of the fillet and a diameter of the second end of the at least one orifice is between about 0.01 and about 0.2.

8. The combustion pre-chamber apparatus of claim 1, further comprising a first fillet at a transition between the first end of the at least one orifice and the body, and a second fillet at a transition between the second end of the at least one orifice and the body, wherein a ratio of a radius of the first fillet to a radius of the second fillet is between about 0.05 and 0.85.

9. The combustion pre-chamber apparatus of claim 1, wherein a transition between the second end of the at least one orifice and the body comprises an annular-shaped curved surface.

10. The combustion pre-chamber apparatus of claim 1, wherein a transition between the first end of the at least one orifice and the body comprises an annular-shaped curved surface.

11. The combustion pre-chamber apparatus of claim 1, wherein a transition between the first end of the at least one orifice and the body comprises a relatively sharp edge, and the transition between the second end of the at least one orifice and the body comprises a relatively smooth edge.

12. The combustion pre-chamber apparatus of claim 1, wherein a ratio of a cross-sectional area of the second end to a cross-sectional area of the first end is between about 0.5 and about 0.95.

13. The combustion pre-chamber apparatus of claim 1, wherein the first end has first discharge coefficient and the second end has a second discharge coefficient, the first discharge coefficient being different than the second discharge coefficient.

14. The combustion pre-chamber apparatus of claim 13, wherein the first discharge coefficient is smaller than the second discharge coefficient.

15. The combustion pre-chamber apparatus of claim 1, wherein a cross-sectional area of the at least one orifice decreases in a direction extending from the first end to the second end.

16. An internal combustion engine, comprising:

a block defining a main combustion cylinder;

a cylinder head coupled to the block above the main combustion cylinder, the cylinder head comprising a combustion pre-chamber, the cylinder head further comprising a plurality of orifices fluidly coupling the main combustion cylinder and the combustion pre-chamber, each of the plurality of orifices converging from the combustion pre-chamber to the main combustion cylinder; and

a spark plug at least partially positioned within the combustion pre-chamber.

17. The internal combustion engine of claim 16, wherein the cylinder head comprises at least one of a radiused fillet at an intersection between the orifice and the main combustion cylinder or a radiused fillet at an intersection between the orifice and the combustion pre-chamber.

18. The internal combustion engine of claim 16, further comprising a fuel and air mixture source in fluid communication with the main combustion cylinder, and a piston movable within the main combustion cylinder, wherein during a compression stroke of the piston a fuel and air mixture within the main combustion cylinder is driven into the combustion pre-chamber via the plurality of orifices.

19. The internal combustion engine of claim 16, further comprising a fuel injector in fuel injecting communication directly with the combustion pre-chamber.

20. An internal combustion engine, comprising:

a first combustion chamber;

a second combustion chamber; and

a plurality of converging orifices extending from the first combustion chamber to the second combustion chamber.