A fuel injector, preferably a dual fuel injector, for an internal combustion engine is disclosed. The fuel injector comprises first and second valve needles (80, 100) arranged to control the injection of first and second fuels, first and second control chambers (88, 10) associated with the first and second valve needles (80, 100) respectively, a first control valve (26) comprising a first control valve member (48) and arranged to vary the pressure of a control fluid in the first control chamber (88) so as to cause opening and closing movement of the first valve needle (80), and a second control valve (28) comprising a second control valve member (60) and arranged to vary the control fluid 10 pressure in the second control chamber (110) so as to cause opening and closing movement of the second valve needle (100). The first and second control valve members (48, 60) are arranged for linear movement along a common control valve axis.

The present invention is a fuel injection method for a compression-ignition internal-combustion engine running in single-fuel or multi-fuel mode. The method, in a single-fuel mode, injects liquid fuel (Fuel1) into lower zone (Z1) and/or upper zone (Z2) of the combustion chamber and, in a multi-fuel mode, provides in the chamber mixing of an oxidizer with another fuel (Fuel2) and injection of liquid fuel (Fuel1) into lower zone (Z1) or both zones (Z1, Z2) of the combustion chamber.

The present invention relates to a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying fuel injection (14) projecting the fuel in at least two fuel jet sheets (36, 38) with different sheet angles (A1, A2), a piston (16) sliding in the cylinder, a combustion chamber (34) limited on one side by upper face (44) of the piston comprising a projection (48) extending in the direction of the cylinder head and arranged in the center of a concave bowl (46) with at least two mixing zones (Z1, Z2), and piston cooler (76) housed in the material of the piston. According to the invention, the piston cooler comprises at least one circumferential gallery (78, 82) concentric to piston bowl (46) and arranged opposite at least one mixing zone (Z1, Z2).

An improved fuel injection device for internal combustion engines comprising a slidable (pilot) valve instead of a needle valve principle. The valve does not comprise a seat, so, even in the case of a spring-loaded embodiment of the valve there is no risk of hammering of the valve on a seat with the pertaining generation of noise.

The improved fuel injector allows a larger nozzle diameter and, therefore, a larger number of nozzle holes, if required or deemed useful.

For rotating embodiments of the fuel injector, the valve or at least its spring, in the case of a spring-loaded embodiment of the valve, can be located in the static section of the rotating fuel injector, thus eliminating the balancing problem of prior art rotating fuel injectors which comprise a spring in the rotating section.

The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder, a cylinder head carrying fuel injection, a piston sliding in the cylinder, a combustion chamber limited on one side by upper face of the piston comprising a projection extending in the direction of the cylinder head and in the center of a concave bowl (46) with at least two mixing zones. The fuel injection projects fuel in at least two fuel jet sheets with different sheet angles, with a lower sheet having a jet axis C1 for one zone and an upper sheet having a jet axis for the other zone. The injection feeds fuel into the combustion chamber with a different flow rate for each sheet for dedicated targeting in the mixing zones of the combustion chamber.

A nozzle for a fuel injector the nozzle having a pivotably symmetrical nozzle member with a hollow space for introducing a nozzle needle, a nozzle tip at a longitudinal end of the nozzle member, at least one opening channel extending in a straight line for the discharge of fuel, and a nozzle needle arranged in the hollow space for selectively blocking an fuel inflow to the at least one opening channel. The nozzle is characterized in that the at least one opening channel has a center axis that is skewed with respect to the longitudinal axis of the nozzle member.

The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying fuel injection means (14), a piston (16) sliding in the cylinder, a combustion chamber (34) limited on one side by an upper face (44) of the piston comprising a projection (48) extending in the direction of the cylinder head and located in a center of a concave bowl (46). The engine comprises injection projecting fuel in at least two fuel jet sheets. One of the zones comprises a toroidal volume (64) having center B with a flat bottom (56) into which fuel jets (40) of the lower sheet are injected so that an axis C1 of the lower sheet jets is contained between center B and projection (48).

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

In an injection hole set, primary and secondary injection holes are formed to satisfy the following relationship: t1+t20.87P0.52, where (deg) is an injection-hole-to-injection-hole angle, which is an angle formed between a primary central axis of the primary injection hole and a secondary central axis of the secondary injection hole; t1 (deg) is a primary taper angle, which is an angle formed between outlines of a primary injection hole inner wall of the primary injection hole in a cross section of the primary injection hole inner wall; t2 (deg) is a secondary taper angle, which is an angle formed between outlines of a secondary injection hole inner wall of the secondary injection hole in a cross section of the secondary injection hole inner wall; and P (MPa) is an average pressure of the fuel in a fuel passage at a time of injecting the fuel from the injection holes.