Claims
- 1. An in-cylinder injection internal combustion engine having a cylinder with a central axis, a cylinder head, a piston positioned in the cylinder, and a combustion chamber formed by a cylinder head lower wall and a top wall of the piston, said engine comprising:at least one air inlet port for forming a swirl-type air flow in the combustion chamber; a spark plug positioned in the lower wall of the cylinder head; a fuel injector for directing injecting fuel into the combustion chamber; and a combustion bowl positioned in the top wall of the piston, said combustion bowl having an asymmetrical configuration with a first larger area downstream of the swirl airflow past the fuel injector and a second smaller harbor area upstream of the swirl airflow and adjacent the spark plug, said first larger area and said second smaller harbor area both being substantially circular in shape and intersecting at a substantially sharp corner.
- 2. The engine as claimed in claim 1 wherein the fuel injection is oriented in the range of 30-60° downstream from an imaginary plane from the fuel injector to the central axis of the cylinder.
- 3. The engine as claimed in claim 1 wherein the fuel injector is oriented in the range of 0-15 degrees from a plane transverse to the central axis of the cylinder.
- 4. The engine as claimed in claim 1 wherein the engine is a three-valve engine having two air inlet ports and one exhaust port in the lower wall of the cylinder head.
- 5. The engine as claimed in claim 1 wherein the engine is a four-valve engine having two air inlet ports and two exhaust ports in the lower wall of the cylinder head.
- 6. The engine as claimed in claim 1 wherein the combustion bowl in a vertical plane parallel to the cylinder axis has a flat bottom portion, curved side portions, and large radii curved portions without dead areas which might trap fuel.
- 7. The engine as claimed in claim 1 wherein the spark plug is positioned in line with the central axis of the cylinder.
- 8. The engine as claimed in claim 1 wherein the spark plug is positioned at a location spaced from the central axis of the cylinder, said location being in the range of 2-8 millimeters from the central axis.
- 9. The engine as claimed in claim 8 wherein the spark plug is positioned at a location in the harbor area at a distance further from the fuel injector than the central axis of the cylinder.
- 10. The in-cylinder injection internal combustion engine as set forth in claim 1 wherein a portion of said first wider area has a first radius R1 and a portion of said second harbor area has a second radius R2, and wherein R1 is greater than R2.
- 11. The in-cylinder injection internal combustion engine as set forth in claim 10 wherein said substantially sharp corner is positioned at the intersection of said portion of said first wider area and said portion of said second harbor area.
- 12. The in-cylinder injection internal combustion engine as set forth in claim 1 wherein neither said first larger area or said second smaller harbor area have a substantially linear portion.
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is related to U.S. Ser. No. 09/174,237, filed Oct. 16, 1998, and entitled “Cylinder Head Intake System”, and also related to U.S. Ser. No. 09/479,816, entitled “Three-Valve Cylinder Head System” and filed concurrently herewith, the disclosures of both of which are hereby incorporated by reference herein.
US Referenced Citations (11)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0 778 402 A1 |
Nov 1997 |
EP |