Direct injection engine

• US 6,928,997 B2
• Filed: 11/17/2004
• Issued: 08/16/2005
• Est. Priority Date: 12/30/2003
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Yu, Chul Ho
• Primary Examiner(s): MOHANTY, BIBHU R
• Application Number:
  US10/991,214
• Publication Number:
  US 20050139190A1
• Time in Patent Office: 272 Days
• Field of Search: 123/193.5, 123/301, 123/657, 123/659, 123/667, 123/671, 123/193.6
• US Class Current: 123/657
• CPC Class Codes: F02B 2023/106 Tumble flow, i.e. the axis of rotation of the main charge flow motion is horizontal
• CPC Class Codes: F02B 2075/125 Direct injection in the combustion chamber for spark ignition engines, i.e. not in pre-combustion chamber
• CPC Class Codes: F02B 2275/48 Tumble motion in gas movement in cylinder
• CPC Class Codes: F02B 23/104 the injector being placed on a side position of the cylinder
• CPC Class Codes: F02B 31/085 having two inlet valves
• CPC Class Codes: F02F 2001/241 specially adapted to pent roof shape of the combustion chamber
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies

Abstract

An exhaust-valve-side portion of a bottom surface of a bowl is connected to an upper surface of a piston by a smoothly curved surface. Therefore, a separation of a tumble flow can be minimized and air flow introduced into the bowl is more strongly tumbled. Fuel mixed with the air flow is also introduced into the bowl, so a generation of a carbon layer that is caused by contact of fuel and oil with the wall can be prevented. A width of the exhaust-valve-side portion of the bowl is greater than a width of the intake-valve-side portion of the bowl and the side walls of the bowl are formed as curved surfaces. The intake valve pocket is formed as a single groove, accumulation of carbon can be minimized, and propagation of a flame during the combustion occurs easily.

Claims

1. A direct injection engine comprising:

a combustion chamber formed between a lower surface of a cylinder head that is formed as a pent roof shape and an upper surface of a piston head with a pent-roof-shaped protrusion portion corresponding to a shape of the lower surface of the cylinder head;

an intake valve and an exhaust valve that are respectively disposed in an intake port and an exhaust port that are formed in the cylinder head;

a spark plug that is disposed in the cylinder head; and

a fuel injector for directly injecting fuel into the combustion chamber,

wherein the protrusion portion of the piston head is formed in a state of being biased toward an exhaust valve side from a cylinder center axis, a bowl is formed on the protrusion portion along a direction perpendicular to a direction of a crankshaft axis, an exhaust-valve-side portion of the bowl is opened, a width of the exhaust-valve-side portion of the bowl is wider than a width of an intake-valve-side portion thereof, side walls of the bowl are formed as curved surfaces that are indented toward the outside, a bottom surface of the bowl is slanted such that a depth of the bowl becomes deeper when approaching the intake-valve-side portion, and the intake port is formed such that intake air moves toward the exhaust-valve-side portion of the bowl.

2. The direct injection engine of claim 1, wherein the bowl is formed within the protrusion portion of the piston head.

3. The direct injection engine of claim 1, wherein side walls of the bowl are slanted toward the outside.

4. The direct injection engine of claim 1, wherein side walls of the bowl are formed as a whole as a curved line.

5. The direct injection engine of claim 1, wherein the exhaust-valve-side portion of the bowl is connected to a head surface of the piston through a curved surface having a predetermined curvature at a position advancing a predetermined distance toward the bowl from a starting position of an exhaust-valve-side upper slanted surface of the protrusion portion.

6. The direct injection engine of claim 1, wherein an intake-valve-side ramp portion of the bowl is slanted outside.

7. The direct injection engine of claim 1, wherein a summit portion of the protrusion portion of the piston head is formed as a curved surface.

8. The direct injection engine of claim 1, wherein an intake valve pocket is formed on an intake-valve-side upper slanted surface of the protrusion portion of the piston.

9. The direct injection engine of claim 8, wherein the intake valve pocket is formed as a single groove to receive all intake valves.

10. The direct injection engine of claim 1, wherein a split wall is disposed in the intake port such that the intake port is divided into an upper passageway and a lower passageway, the upper passageway acts as a tumble passage, and a valve is disposed at an entrance of the lower passageway to selectively open or close the lower passageway.

11. A direct injection engine, comprising:

a cylinder head defining;

an intake port and an exhaust port;

a lower surface of the cylinder head formed in a pent-roof shape, wherein the intake port penetrates a first side of the pent-roof shape lower surface and the exhaust port penetrates a second side of the pent-roof shape lower surface;

a cylinder block defining a cylinder, wherein the cylinder head couples with the cylinder block such that the pent-roof shape lower surface of the cylinder head is positioned with the cylinder; and

a piston configured to be slidable received within the cylinder, wherein the piston includes;

a head portion having a protrusion portion extending toward an exhaust valve side, wherein the protrusion portion defines a bowl formed along a direction perpendicular to a direction of a crankshaft axis, an exhaust-valve-side portion of the bowl is opened, a width of the exhaust-valve-side portion of the bowl is wider than a width of an intake-valve-side portion of the bowl, side walls of the bowl are formed as curved surfaces indented toward an outside circumference of the piston, a bottom surface of the bowl is slanted such that a depth of the bowl becomes deeper toward the intake-valve-side portion, and the intake port is formed such that intake air flows toward the exhaust-valve-side portion of the bowl.

12. The direct injection engine of claim 11, wherein side walls of the bowl are slanted toward the outside circumference of the piston.

13. The direct injection engine of claim 11, wherein the exhaust-valve-side portion of the bowl is connected to a head surface of the piston through a curved surface having a predetermined curvature at a position advancing a predetermined distance toward the bowl from a starting position of an exhaust-valve-side upper slanted surface of the protrusion portion.

14. The direct injection engine of claim 11, wherein an intake-valve-side ramp portion of the bowl is slanted outside.

15. The direct injection engine of claim 11, wherein a summit portion of the protrusion portion of the piston head is formed from a curved surface.

16. The direct injection engine of claim 11, wherein an intake valve pocket is formed on an intake-valve-side upper slanted surface of the protrusion portion of the piston.

17. The direct injection engine of claim 16, wherein the intake valve pocket is formed as a single groove to receive all intake valves.

18. The direct injection engine of claim 11, wherein a split wall is disposed in the intake port such that the intake port is divided into an upper passageway and a lower passageway.