Internal combustion engine producing low emissions

• US 7,210,448 B2
• Filed: 09/16/2005
• Issued: 05/01/2007
• Est. Priority Date: 06/11/2002
• Status: Expired due to Term

• Current Assignee: Cummins Incorporated
• Original Assignee: Cummins Incorporated
• Inventors: Stanton, Donald W., Ntone, Francois, Zehr, Randall L., Eckerle, Wayne A.
• Primary Examiner(s): Argenbright; T. M.
• Application Number:
  US11/227,420
• Publication Number:
  US 20060070603A1
• Time in Patent Office: 592 Days
• Field of Search: 123/193.6, 123/276, 123/294, 123/298, 123/299, 123/301
• US Class Current: 123/298
• CPC Class Codes: F02B 23/0621 Squish flow
• CPC Class Codes: F02B 23/0651 the fuel spray impinging on reflecting surfaces or being specially guided throughout the combustion space
• CPC Class Codes: F02B 23/0669 having multiple fuel spray jets per injector nozzle
• CPC Class Codes: F02B 23/0672 Omega-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder center axis the surrounding wall being exactly vertical F02B23/0696
• CPC Class Codes: F02B 23/0696 W-piston bowl, i.e. the combustion space having a central projection pointing towards the cylinder head and the surrounding wall being inclined towards the cylinder wall
• CPC Class Codes: F02M 61/1846 Dimensional characteristics of discharge orifices
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An engine is provided which includes various precise configuration parameters, including dimensions, shape and/or relative positioning of the combustion chamber features, resulting in a combustion process minimizing NOx emissions and particulates. The combustion chamber includes one or more of the following: a spray angle relative to an inner bowl floor angle; a vertical distance from the tip of the piston bowl to the injection orifices; a number of injection orifices; a swirl ratio; a vertical distance from the injection orifices to an inner face of the cylinder head; a radius of curvature of an outer bowl section; chamfer with dimensional parameters; and a transition radius.

Claims

1. An internal combustion engine containing a combustion chamber, comprising;

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume;

wherein the intake air undergoes a swirling effect during operation to provide a swirl ratio in the range of 0.5–

2.5.

2. The engine of claim 1, wherein said plurality of orifices are no more than 8 orifices.

3. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume;

wherein a distance L₂ between said center of said outlet opening and said inner face of said cylinder head forming said combustion chamber is in the range of −

0.5 to 3 mm.

4. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume;

wherein said concave curvilinear shape of said outwardly flared outer bowl section has a radius of curvature R₁ in the range of 8 to 20 mm.

5. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead venter position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume;

wherein a distance BH between the top face of the piston crown and said center of said outlet opening is in the range of 0.5 to 8 mm.

6. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, a chamfer extending at an angle toward said top face, and a transition radius R₄ between end of said outer bowl section and said chamfer in the range of 1.5–

7 mm; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume.

7. The engine of claim 6, wherein said inner bowl floor section extends inwardly at an inner bowl floor angle α

from a plane perpendicular to an axis of reciprocation of the piston, and each of said plurality of orifices have a central axis oriented at a spray angle β

from a plane perpendicular to the axis of reciprocation of the piston, so that spray angle β

minus said inner bowl floor angle α

(β

−

α

) is in the range of −

7 to 19.

8. The engine of claim 6, wherein said chamfer extends toward said top face a vertical distance K in the range of 1 to 17 mm.

9. The engine of claim 6, wherein said piston bowl further includes, a transition radius R₄ between end of said outer bowl section and said chamfer in the range of 1.5 to 7 mm.

10. The engine of claim 6, wherein each of said plurality of orifices include an outlet opening having a center, said center being a distance L₁ in the range of 0.5 to 12 mm from said distal end of said projecting portion.

11. The engine of claim 6, wherein said plurality of orifices are no more than 8 orifices.

12. The engine of claim 6, wherein the intake air undergoes a swirling effect during operation to provide a swirl ratio in the range of 0.5–

2.5.

13. The engine of claim 6, wherein a distance L₂ between said center of said outlet opening and said inner face of said cylinder head forming said combustion chamber is in the range of −

0.5 to 3 mm.

14. The engine of claim 6, wherein said concave curvilinear shape of said outwardly flared outer bowl section has a radius of curvature R₁ in the range of 8 to 20 mm.

15. The engine of claim 6, wherein a distance BH between the top face of the piston crown and said center of said outlet opening is in the range of 0.5 to 8 mm.

16. The engine of claim 6, wherein said chamfer extends toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston.

17. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face a vertical distance K in the range of 1 to 17 mm; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume.

18. The engine of claim 17, wherein said inner bowl floor section extends inwardly at an inner bowl floor angle a from α

plane perpendicular to an axis of reciprocation of the piston, and each of said plurality of orifices have a central axis oriented at a spray angle β

from a plane perpendicular to the axis of reciprocation of the piston, so that spray angle β

minus said inner bowl floor angle a α

(β

−

α

) is in the range of −

7 to 19.

19. The engine of claim 17, wherein each of said plurality of orifices include an outlet opening having a center, said center being a distance L₁ in the range of 0.5 to 12 mm from said distal end of said projecting portion.

20. The engine of claim 17, wherein said plurality of orifices are no more than 8 orifices.

21. The engine of claim 17, wherein the intake air undergoes a swirling effect during operation to provide a swirl ratio in the range of 0.5–

2.5.

22. The engine of claim 17, wherein a distance L₂ between said center of said outlet opening and said inner face of said cylinder head forming said combustion chamber is in the range of −

0.5 to 3 mm.

23. The engine of claim 17, wherein said concave curvilinear shape of said outwardly flared outer bowl section has a radius of curvature R₁ in the range of 8 to 20 mm.

24. The engine of claim 17, wherein a distance BH between the top face of the piston crown and said center of said outlet opening is in the range of 0.5 to 8 mm.

25. The engine of claim 17, wherein said chamfer extends toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston.

26. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly at an inner bowl floor angle a from a plane perpendicular to an axis of reciprocation of the piston, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to form a spray plume, each of said plurality of orifices having a central axis oriented at a spray angle δ

from a plane perpendicular to the axis of reciprocation of the piston so that spray angle δ

minus inner bowl floor angle α

(β

−

α

) is in the range of −

7 to 19.

27. The engine of claim 26, wherein said chamfer extends at an angle δ

in the range of 30 to 75 degrees from the axis of reciprocation of the piston toward said top face.

28. The engine of claim 27, wherein said chamfer extends a vertical distance K in the range of 1 to 17 mm toward said top face.

29. The engine of claim 28, wherein said piston bowl further includes a transition radius R₄ between end of said outer bowl section and said chamfer in the range of 1.5 to 7 mm.

30. The engine of claim 26, wherein each of said plurality of orifices include an outlet opening having a center, said center being a distance L₁ in the range of 0.5 to 12 mm from said distal end of said projecting portion.

31. The engine of claim 26, wherein said plurality of orifices are no more than 8 orifices.

32. The engine of claim 26, wherein the intake air undergoes a swirling effect during operation to provide a swirl ratio in the range of 0.5–

2.5.

33. The engine of claim 26, wherein a distance L₂ between said center of said outlet opening and said inner face of said cylinder head forming said combustion chamber is in the range of −

0.5 to 3 mm.

34. The engine of claim 26, wherein said concave curvilinear shape of said outwardly flared outer bowl section has a radius of curvature R₁ in the range of 8 to. 20 mm.

35. The engine of claim 26, wherein a distance BH between the top face of the piston crown and said center of said outlet opening is in the range of 0.5 to 8 mm.

36. An internal combustion engine containing a combustion chamber, comprising:

an engine body including an engine cylinder, a cylinder head forming an inner face of the combustion chamber and at least one intake port formed in the cylinder head for directing intake air into the combustion chamber;

a piston positioned for reciprocal movement in said engine cylinder between a bottom dead center position and a top dead center position, said piston including a piston crown including a top face facing the combustion chamber, said piston crown containing a piston bowl formed by an outwardly opening cavity, said piston bowl including a projecting portion having a distal end, an inner bowl floor section extending inwardly, an outwardly flared outer bowl section having a concave curvilinear shape in cross section, and a chamfer extending toward said top face; and

an injector mounted on the engine body adjacent said projecting portion of said piston bowl to inject fuel into the combustion chamber, said injector including a plurality of orifices arranged to fonn a spray plume, each of said plurality of orifices having a central axis and including an outlet opening having a center, said center being a distance L₁ in the range of 0.5 to 12 mm from said distal end of said projecting portion.

37. The engine of claim 36, wherein said plurality of orifices are no more than 8 orifices.

38. The engine of claim 36, wherein the intake air undergoes a swirling effect during operation to provide a swirl ratio in the range of 0.5–

2.5.

39. The engine of claim 36, wherein a distance L₂ between said center of said outlet opening and said inner face of said cylinder head forming said combustion chamber is in the range of −

0.5 to 3 mm.

40. The engine of claim 36, wherein said concave curvilinear shape of said outwardly flared outer bowl section has a radius of curvature R₁ in the range of 8 to 20 mm.

41. The engine of claim 36, wherein a distance BH between the top face of the piston crown and said center of said outlet opening is in the range of 0.5 to 8 mm.

42. The engine of claim 36, wherein said chamfer extends toward said top face at an angle δ

in the range of 30 to 75 degrees from an axis of reciprocation of the piston.