A fuel and gas mixing structure for an engine is provided. This mixing structure includes a body configured to be positioned between a fuel injector and a cylinder of an engine. The body defines an interior volume that is configured to receive gas from outside the body and to receive one or more streams of fuel from the fuel injector in the interior volume. The body also defines one or more mixture conduits configured to conduct plumes of the fuel and gas, while mixing, from the interior volume to one or more exit ports and therethrough to the cylinder.

Operating an engine includes injecting a first charge of liquid fuel using a first set of nozzle outlets in a fuel injector, and injecting a second charge of liquid fuel using a second set of nozzle outlets in a fuel injector. The first charge is autoignited in a first engine cycle, and the second charge is autoignited in a second engine cycle, and may be used to pilot ignite a charge of gaseous fuel. Operating the engine further includes limiting errors in targeting of the second charge of liquid fuel caused by transitioning the engine from a first combination to a second combination of speed, load, and boost, by varying an injection pressure of the liquid fuel from the first engine cycle to the second engine cycle.

In the preferred embodiments an air flow diverting blade is integral to a base that doubles as a collar designed to co-axially attach to the nozzle tip end of a typical port fuel injector for internal combustion engines. Upon simple manual manipulation of the set rotational angle of the typically externally exposed portion of the port fuel injector along its longitudinal axis, as typical modern port injection systems allow after installation, the angle of the intra-port flow diverting blade can be selectively varied to either straighten existing swirl and increase top end flow, or, introduce lateral directional swirl to whatever angle and intensity in either direction is desired. The functional use of a typical port fuel injector is thereby elevated to a multifunction of tunable fuel and air flow control at the point of induction into a combustion chamber without any modification to existing engine designs or their engine management control systems employed therefore. The flow diverting blade can be configured to divert flow around the intake valve stem, guide and guide boss in such a manner to optimize the overall flow dimension of the induction system of a typical internal combustion engine. The flow diverting blade also provides an effective means by which the proximity and angle of fuel injection, relative to the combustion chamber, can be altered and improved as desired. The flow diverting blade also provides an effective means by which a modest increase in effective fuel injector nozzle pressure and fuel vaporization can be realized.

A fuel injector has an injector nozzle with nozzle body having internal room and nozzle wall hole connecting this room to exterior of the nozzle body. A valve needle is movable in a longitudinal direction and received in the internal room. The valve needle has an internal fuel channel with inlet located at a circumferential surface of a first portion. The nozzle wall hole has a circular cross-section with the same diameter as the first valve needle portion defined by walls extending in parallel with the longitudinal direction of the needle. The fuel inlet of the fuel channel is located on said walls of the nozzle wall hole in a second position to prevent fuel entering the fuel channel and located inside the internal room in a first position for receiving fuel from this internal room and injecting it into a combustion chamber of a cylinder of an engine.

A fuel delivery system and a direct injector for directly injecting fuel into a cylinder are provided. In one example, a direct fuel injector includes a nozzle in fluidic communication with a fuel source, the nozzle includes a first set of orifices, each of the orifices in the first set arranged at a first orifice angle on an intake side of the nozzle. The direct fuel injector further includes a second set of orifices, each of the orifices in the second set arranged at a second orifice angle greater than the first orifice angle on an exhaust side of the nozzle.

A fuel delivery system and a direct injector for directly injecting fuel into a cylinder are provided. In one example, a direct fuel injector includes a nozzle in fluidic communication with a fuel source, the nozzle includes at least one fuel flow path that divides into two exit flow paths within the nozzle defining a plurality of exit orifices stemming from a common inlet orifice thereby improving the atomization and mixing of the fuel as it enters the cylinder. A plurality of spaced-apart divided fuel flow paths may be positioned within the nozzle to further optimize mixing and reduce wall and piston wetting.

Among all combinations of two injection holes, in a combination in which when the injection holes are offset such that their central axes are coincident with each other in inlet openings, an inter-injection hole angle formed by the central axes is minimized, the inter-injection hole angle between the two injection holes is represented as yamin[deg], taper angles, which are formed by the respective contours of the injection hole inner walls in the cross sections along the virtual planes including the central axes of the two injection holes that allow the inter-injection hole angle to be minimized, are represented as a1 and a2[deg], and when fuel is injected from the injection holes, average pressure of the fuel in the fuel passage is represented as P[Mpa], and the injection holes are formed so as to satisfy a relationship: amina1+a2+0.5P.sup.0.6.

Provided is a structure capable of reducing dribbling of fuel generated when a valve body is closed. In order to achieve the above object, a fuel injection device includes: a valve body; and a seat member having a seat portion on which the valve body is seated and having a fuel injection hole formed on a downstream side of the seat portion. The seat member is formed such that a gap between the seat member and the opposing valve body in the whole region on the downstream side of the fuel injection hole is smaller than a diameter of the fuel injection hole.

An internal combustion engine includes a fuel injection nozzle provided with a nozzle hole for injecting fuel, the nozzle hole exposed from a cylinder head of the internal combustion engine to a combustion chamber, and a hollow duct, an inlet and an outlet of which are exposed to the combustion chamber. The duct is provided in a manner allowing fuel spray injected from the nozzle hole of the fuel injection nozzle to pass through from the inlet to the outlet. The fuel injection nozzle and the duct are configured such that a part of fuel spray that is injected in pilot injection that is performed before main injection directly adheres to an inner wall surface of the duct.

An internal combustion engine includes a fuel injection nozzle that is arranged at the center of an upper surface of a combustion chamber with an injection port thereof exposed in the combustion chamber, and a piston arranged in a cylinder. On a top surface of the piston, a flow guide passage is provided which extends from an inlet exposed on the side of a wall of a bore of the cylinder to an outlet exposed on the side of a center of the bore. The flow guide passage preferably includes a flow guide plate having a ring shape, and a strut that fixes the flow guide plate to the top surface of the piston in such a manner that a clearance extending from an outer edge to an inner edge of the flow guide plate is formed between the flow guide plate and the top surface of the piston.