Internal combustion engine

• US 8,511,271 B2
• Filed: 09/16/2005
• Issued: 08/20/2013
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: Daimler Truck AG (Daimler Truck Holding AG)
• Original Assignee: Daimler AG (Mercedes-Benz Group AG)
• Inventors: Hutmacher, Rolf
• Primary Examiner(s): McMahon, M.
• Application Number:
  US11/663,283
• Publication Number:
  US 20090007879A1
• Time in Patent Office: 2,895 Days
• Field of Search: 123/193.6, 123/294, 123/298, 123/262, 123/263
• US Class Current: 123/193.6
• CPC Class Codes: F02B 2275/14 Direct injection into combustion chamber
• CPC Class Codes: F02B 23/0669 having multiple fuel spray jets per injector nozzle
• 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: 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: Y02T 10/12 Improving ICE efficiencies

Abstract

In an internal combustion engine having at least one cylinder, in which a combustion chamber is delimited between a piston and a cylinder head, a fuel injector, is arranged in the cylinder head and has an injection nozzle with a plurality of injection bores. A piston depression is arranged in the piston, and a compression projection, with a projection cone angle, is positioned opposite the injection nozzle in the piston depression. The injection bores are formed such that, during a fuel injection in a range from 20° CA before top dead center to 35° CA after top dead center, the fuel jets emerging from the injection bores with a fuel cone angle impinge on the piston depression and are guided by a piston depression surface. The injection bores and the compression projection are formed such that a generated ratio of fuel cone angle to projection cone angle is in a range between 0.95 and 1.36, so that the injected fuel mass is distributed uniformly within the piston depressions, and a mixture of fuel with combustion air is intensified.

Claims

1. An internal combustion engine comprising:

at least one cylinder, in which a combustion chamber is delimited between a piston and a cylinder head,

a fuel injector arranged in the cylinder head and having an injection nozzle with a plurality of injection bores, and

a piston depression arranged in the piston and having a compression projection, with a projection cone angle, positioned in the piston depression opposite the injection nozzle,

wherein the injection bores are formed such that, during fuel injection which takes place in a range from 20°

CA before top dead center to 35°

after top dead center, fuel jets emerging from the injection bores with a fuel cone angle impinge on the piston depression,

wherein, to impede soot particle formation, the injection bores and the compression projection are formed such that a generated ratio β

/α

of fuel cone angle β

to projection cone angle α

is in a range of from 1.15 to 1.3,

wherein said piston depression has a piston depression contour with a depression base radius RK between a depression base and a depression edge,

wherein said depression base radius RK has a radius center disposed outside of the piston depression, and

wherein a ratio RK/DM of the depression base radius RK to a maximum depression diameter DM of said piston depression is in a range of from 0.1 to 0.35 so as to further impede soot particle formation, the piston depression having a rounded-off transition to a flat piston head surface in an edge region of the piston depression.

2. The internal combustion engine as claimed in claim 1, wherein the piston has a piston diameter DK, and wherein a ratio DK/DM of the piston diameter DK to the maximum depression diameter DM is in a range of from 1.05 to 1.4.

3. The internal combustion engine as claimed in claim 2, wherein the ratio DK/DM is in a range of from 1.1 to 1.2.

4. The internal combustion engine as claimed in claim 1, wherein the piston depression has a depression base with a maximum depression depth, and wherein a ratio Dmin/DK of a diameter Dmin at the maximum depression depth to a piston diameter DK is in a range of from 0.22 to 0.45.

5. The internal combustion engine as claimed in claim 4, wherein the ratio Dmin/DK is in a range of from 0.3 to 0.39.

6. The internal combustion engine as claimed in claim 1, wherein the ratio RK/DM is in a range of from 0.16 to 0.22.

7. The internal combustion engine as claimed in claim 1, wherein the piston depression contour has a projection radius RH between the compression projection and the depression base, and wherein a ratio RH/DM of the projection radius RH to the maximum depression diameter DM is in a range of from 0.45 to 1.1.

8. The internal combustion engine as claimed in claim 1, wherein the compression projection is formed such that a highest compression projection region is spaced apart from a piston head by a compression spacing H, and wherein a ratio H/TM of the compression spacing H to a maximum depression depth TM is in a range of from 0.1 to 0.45.

9. The internal combustion engine as claimed in claim 8, wherein the ratio H/TM is in a range of from 0.15 to 0.25.