Piston for internal combustion engine

Patent metadata

Field	Value
Publication number	US-RE46806-E
Application number	US-201615081441-A
Country	US
Kind code	E1
Filing date	Mar 25, 2016
Priority date	Mar 17, 2011
Publication date	Apr 24, 2018
Grant date	Apr 24, 2018

Abstract

A piston and an engine are provided that includes various precise configuration parameters, including dimensions, shape and/or relative positioning of combustion chamber features. More particularly, configuration parameters for a piston crown and a piston bowl located within the piston crown are provided. The piston bowl configuration results in a combustion process that yields decreased heat transfer to a cylinder head of the internal combustion engine as well as reduced NOx emissions.

First claim

We claim:

1. An internal combustion engine, comprising:
an engine body;
a cylinder head attached to the engine body;
a combustion chamber positioned between the cylinder head and the engine body; and
a piston, including a piston crown that forms a portion of the combustion chamber, located in the engine body, the piston crown including a central axis,
a plurality of valve pockets arranged about the periphery of the piston crown in a plane perpendicular to the central axis,
an uppermost surface portion, and
a piston bowl positioned radially inward from the valve pockets, the piston bowl including:
a compound radius including a radius R 1 , radius R 1 including a center of radius at a radial distance L 1 from the central axis, radius R 1 connected to and extending inwardly from the valve pockets to form a smooth transition between the valve pockets and the piston bowl;
a frustoconical outer floor portion connected to the compound radius, the frustoconical outer floor portion extending a distance L 4 from the compound radius at an angle of to a plane perpendicular to the central axis;
an annular outer bowl portion including a radius R 5 ; and
a spray-targeting feature positioned between the annular outer bowl portion and the frustoconical outer floor portion and including a radius R 3 with a center of radius located at an axial distance H 3 from the valve pockets,
wherein each of the valve pockets includes a rolled edge extending between the valve pocket and the uppermost surface portion, the rolled edge including a radius to form a smooth transition between the valve pocket and the uppermost surface portion;
wherein a ratio L4/R3 is in the range of 0.2 to 3.0.

2. The internal combustion engine of claim 1 , wherein a ratio L 4 /R 3 is in the range of 0.2 to 3.0.

3. The internal combustion engine of claim 2 1, wherein a ratio of H 3 /L 1 is in the range of 0.15 to 0.3.

4. The internal combustion engine of claim 3 , wherein α 1 is less than 60 degrees.

5. The internal combustion engine of claim 1 , wherein a ratio of H 3 /L 1 is in the range of 0.15 to 0.3.

6. The internal combustion engine of claim 5 , wherein α 1 is less than 60 degrees.

7. The internal combustion engine of claim 1 , wherein α 1 is less than 60 degrees.

8. The internal combustion engine of claim 1 , the piston bowl further including a ski jump feature located radially inward from the annular outer bowl portion, the ski jump feature tangentially connected to the annular outer bowl portion and including a radius R 4 .

9. The internal combustion engine of claim 8 , wherein a ratio R 5 /R 4 is in the range of 2.5 to 5.0.

10. The internal combustion engine of claim 9 , wherein a ratio L 4 /R 3 is in the range of 0.2 to 3.0.

11. The internal combustion engine of claim 10 , wherein a ratio of H 3 /L 1 is in the range of 0.15 to 0.3.

12. The internal combustion engine of claim 11 , wherein α 1 is less than 60 degrees.

13. The internal combustion engine of claim 9 , wherein a ratio of H 3 /L 1 is in the range of 0.15 to 0.3.

14. The internal combustion engine of claim 13 , wherein α 1 is less than 60 degrees.

15. The internal combustion engine of claim 9 , wherein α 1 is less than 60 degrees.

16. An internal combustion engine, comprising:
an engine body;
a cylinder head attached to the engine body;
a combustion chamber positioned between the cylinder head and the engine body; and
a piston, including a piston crown that forms a portion of the combustion chamber, located in the engine body, the piston crown including a central axis, an uppermost surface portion, a plurality of valve pockets arranged about the periphery of the piston crown in a plane perpendicular to the central axis, and a piston bowl positioned radially inward from the valve pockets, the piston bowl including: a compound radius including a radius R 1 , radius R 1 including a center of radius at a radial distance L 1 from the central axis, radius R 1 connected to and extending inwardly from the valve pockets to form a smooth transition between the valve pockets and the piston bowl; a frustoconical outer floor portion connected to the compound radius, the frustoconical outer floor portion extending a distance L 4 from the compound radius at an angle α 1 to a plane perpendicular to the central axis; an annular outer bowl portion; and a spray-targeting feature positioned between the annular outer bowl portion and the frustoconical outer floor portion and including a radius R 3 with a center of radius located at an axial distance H 3 from the end surface, each of the valve pockets including a rolled edge extending between the valve pocket and the uppermost surface portion, the rolled edge including a radius to form a smooth transition between the valve pocket and the uppermost surface portion;
wherein a ratio L 4 /R 3 is in the range of 0.2 to 3.0 and a ratio H 3 /L 1 is in the range of 0.15 to 0.3.

17. The internal combustion engine of claim 16 , wherein α 1 is less than 60 degrees.

18. An internal combustion engine, comprising:
an engine body;
a cylinder head attached to the engine body;
a combustion chamber positioned between the cylinder head and the engine body; and
a piston, including a piston crown that forms a portion of the combustion chamber, located in the engine body, the piston crown including a central axis, an uppermost surface portion, a plurality of valve pockets arranged about the periphery of the piston crown in a plane perpendicular to the central axis, and a piston bowl positioned radially inward from the valve pockets, the piston bowl including:
a compound radius connected to and extending inwardly from the valve pockets to form a smooth transition between the valve pockets and the piston bowl;
a frustoconical outer floor portion connected to the compound radius, the frustoconical outer floor portion extending from the compound radius at an angle α 1 to a plane perpendicular to the central axis;

an annular outer bowl portion including a radius R 5 ;
a spray-targeting feature positioned between the annular outer bowl portion and the frustoconical outer floor portion; and
a ski jump feature positioned between the annular outer bowl portion and the central axis and connected to the angular outer bowl portion, the ski jump feature including a radius R 4 ,

each of the valve pockets including a rolled edge extending between the valve pocket and the uppermost surface portion, the rolled edge including a radius to form a smooth transition between the valve pocket and the uppermost surface portion:
wherein a ratio R 5 /R 4 is in the range of 2.5 to 5.0.

19. The internal combustion engine of claim 18 , wherein angle α 1 is less than 60 degrees.

20. The internal combustion engine of claim 19 , wherein the frustoconical outer floor portion extends radially outward a distance L 4 at an angle α 1 and the spray-targeting feature has a radius R 3 and a ratio L 4 /R 3 is in the range of 0.2 to 3.0.

21. A piston, comprising:
a piston crown including a central axis, a plurality of valve pockets arranged about the periphery of the piston crown in a plane perpendicular to the central axis, an uppermost surface portion, and a piston bowl positioned radially inward from the valve pockets, the piston bowl including: a compound radius including a radius R1, radius R1 including a center of radius at a radial distance L1 from the central axis, radius R1 connected to and extending inwardly from the valve pock

Assignees

• Cummins Ip Inc

Inventors

• Venugopal Rishikesh
• Stanton Donald W
• Ranganath Bhargav
• Bodin Thomas

Classifications

• F02B23/0651 Primary

  the fuel spray impinging on reflecting surfaces or being specially guided throughout the combustion space · CPC title

• F02B23/0693

  the combustion space consisting of step-wise widened multiple zones of different depth · CPC title

• F02B2275/14

  Direct injection into combustion chamber · CPC title

• F02B23/0696

  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 title

• F02B23/0669 Primary

  having multiple fuel spray jets per injector nozzle · CPC title