Internal-combustion engine with direct fuel injection in the direction of the intake gas motion
The present invention relates to an internal-combustion engine comprising a combustion chamber provided with a single intake valve ( 2 ), a single exhaust valve ( 3 ), two plugs ( 4 a, 4 b ) and a fuel injector ( 5 ). Furthermore, the combustion chamber comprises means for forming an aerodynamic swirling motion structure of the intake gas in the combustion chamber. Besides, fuel injector ( 5 ) is oriented so as to inject the fuel into the central area of the combustion chamber in the direction of the aerodynamic swirling motion structure.
1. An internal-combustion engine comprising at least one cylinder in which a piston moves, the at least one cylinder being associated with a combustion chamber provided with a single intake valve, a single exhaust valve, a fuel injector and two plugs, wherein the combustion chamber comprises a structure for forming an aerodynamic motion structure of an intake gas with turbulences within the combustion chamber, the fuel injector is oriented so as to inject fuel into a central area of the combustion chamber between the two plugs, in a direction of the aerodynamic motion structure of the intake gas, the structure for forming an aerodynamic motion structure of the intake gas comprises a substantially elliptical shape of the combustion chamber, the intake and exhaust valves are arranged at the ends of a major axis of the substantially elliptical shape, the plugs are arranged close to a minor axis of the substantially elliptical shape, and the fuel injector is inclined with respect to a direction of an axis of the at least one cylinder at an angle ranging between 6° and 10°.
2. The internal-combustion engine as claimed in claim 1 , wherein the fuel injector is arranged between the intake valve and a plug of the two plugs.
3. The internal-combustion engine as claimed in claim 1 , wherein the fuel injector has a machined part of cylindrical shape.
4. The internal-combustion engine as claimed in claim 1 , wherein the fuel injector is arranged within the combustion chamber, close to a periphery of the combustion chamber.
5. The internal-combustion engine as claimed in claim 1 , wherein the plugs are positioned between the intake valve and the exhaust valve.
6. The internal-combustion engine as claimed in claim 1 , wherein the fuel injector is positioned at a distance ranging between 5 and 15 mm from the intake valve and at a distance ranging between 20 and 40 mm from the exhaust valve.
7. The internal-combustion engine as claimed in claim 1 , wherein the plugs are spaced apart by a distance ranging between 30% and 50% of a diameter of the at least one cylinder.
8. The internal-combustion engine as claimed in claim 1 , wherein the plugs and the intake and exhaust valves are positioned in such a way that the centers thereof form vertices of a square.
9. The internal-combustion engine as claimed in claim 8 , wherein the square has an edge of length ranging between 24 and 31 mm.
10. The internal-combustion engine as claimed in claim 1 , wherein a plug of the two plugs closest to the fuel injector is inclined with respect to the direction of an axis of the at least one cylinder at an angle ranging between 25° and 30°.
11. The internal-combustion engine as claimed in claim 1 , wherein a plug of the two plugs furthest from the fuel injector is inclined with respect to the direction of an axis of the at least one cylinder at an angle ranging between 25° and 35°.
12. The internal-combustion engine as claimed in claim 1 , wherein the structure for forming the aerodynamic motion structure of the intake gas further comprises a shape of the intake pipe.
13. A method of operating the internal-combustion engine as claimed in claim 1 , the method comprising operating the internal-combustion engine with a Miller cycle.
14. A method of operating the internal-combustion engine as claimed in claim 1 , the method comprising operating the internal-combustion engine in a Miller cycle in which the intake valve closes before bottom dead center of the piston.
15. The internal-combustion engine as claimed in claim 1 , wherein the fuel injector is inclined with respect to the direction of the axis of the at least one cylinder at an angle substantially equal to 8°.
16. The internal-combustion engine as claimed in claim 1 , wherein the plugs are spaced apart by a distance ranging between 35% and 45% of the diameter of the at least one cylinder.
17. The internal-combustion engine as claimed in claim 1 , wherein a plug of the two plugs closest to the fuel injector is inclined with respect to a direction of an axis of the at least one cylinder at an angle ranging between 28° and 29°.