Apparatuses and methods for fuel injection are disclosed. The apparatus includes an inner sac with one or more primary passages extending therefrom. The one or more primary passages inject fuel therethrough and comprising a first portion, a second portion, and a third portion, where the second portion is disposed between the first portion and the third portion and has a cross-sectional area smaller than that of both the first portion and the third portion. The apparatus also includes one or more secondary passages extending from an outer surface of the apparatus to fluidly couple with the second portion of the one or more primary passages. The one or more secondary passages inject air to form fuel-and-air mixture with the fuel injected from the one or more primary passages

A fuel injector includes an injector housing having a nozzle assembly with a nozzle piece, and a nested check assembly of an outer check and an inner check. Spray orifices are formed in the nozzle piece in a first orifice set equipped with a first spray duct set and a second orifice set equipped with a second spray duct set. The inner check can be opened to spray fuel from the first orifice set and the outer check can be opened to spray fuel from both the first orifice set and the second orifice set. The outer check is non-rotating while the inner check can be permitted to rotate during service. Spray ducts associated with the first orifice set may have a different duct length and duct inside diameter than spray ducts associated with the second orifice set. The first orifice set may include lower-flow spray orifices and the second orifice set may include higher-flow spray orifices. Related methodology is also disclosed.

An injection hole body has injection holes to inject fuel. A valve body forms a fuel passage with an inner surface of the injection hole body to communicate with inflow ports of the injection holes. The valve body opens and closes the fuel passage by being seated on and unseated from a seating surface of the injection hole body. An inflow port gap distance is a gap between the valve body and the inflow ports along a center axis of the valve body. An inter-injection hole distance is a distance between inflow ports, which are adjacent to each other, among the inflow ports placed around the center axis. The inter-injection hole distance is smaller than the inflow port gap distance in a state where the valve body is unseated from the seating surface and is at a farthest position in its movable range.

A nozzle body of a fuel injector includes a proximal end, a distal end spaced apart from the proximal end, and at least one spray hole positioned at the distal end. The at least one spray hole includes an inlet having a first cross-sectional shape and an outlet having a second cross-sectional shape different from the first cross-sectional shape. In other embodiments, the nozzle body has a first row of spray holes and a second row of spray holes, and a cross-sectional shape of spray holes in the first row is different from the cross-sectional shape of spray holes in the second row.

An injector for introducing a fluid. The injector has a valve seat in which a multiplicity of injection holes are formed, and a closing element that releases and closes a fluid path to the injection holes, a size of an inlet area of at least two injection holes being different, and a spacing of the injection holes in the circumferential direction to the adjacent injection hole in each case being selected as a function of the size of the inlet areas of the injection holes.

A throttle body fuel injection system including a throttle body with at least one air intake, a fuel injector coupled to the throttle body at a fuel port and an annular ring coupled to the cylindrical inner wall of the air intake. The annular ring includes a primary fuel discharge orifice adjacent to the fuel port and a plurality of secondary fuel discharge orifices arranged radially around the annular ring for spraying atomized fuel into the air intake.

In a fuel injection valve, a first injection hole and a second injection hole having reference inside diameters Dn1, Dn2 different from each other are formed as a plurality of injection holes. In such a configuration, an L/D value obtained by dividing the flow channel length Ln1 of the first injection hole by the reference inside diameter Dn1 of the first injection hole agrees to an L/D value obtained by dividing the flow channel length Ln2 of the second injection hole by the reference inside diameter Dn2 of the second injection hole.

A fuel injector for fuel injection systems of internal combustion engines has an excitable actuator for activating a valve closing element, which forms a sealing seat together with a valve face implemented on a valve seat element. Multiple spray-discharge openings are implemented in the valve seat element downstream from the valve face. The fuel injector is distinguished in that the spray-discharge openings include at least one upstream first spray-discharge opening section and one downstream second spray-discharge opening section having a different opening width and a wall area of the second spray-discharge opening section of all spray-discharge openings on a semi-circle runs either parallel or at a right angle to the longitudinal axis of the valve seat element having the spray-discharge openings. The valve seat element is manufactured using metal injection molding methods.

An apparatus and method for igniting a gaseous fuel directly introduced into a combustion chamber of an internal combustion engine comprises steps of heating a space near a fuel injector nozzle; introducing a pilot amount of the gaseous fuel in the combustion chamber during a first stage injection event; controlling residency of the pilot amount in the space such that a temperature of the pilot amount increases to an auto-ignition temperature of the gaseous fuel whereby ignition occurs; introducing a main amount of the gaseous fuel during a second stage injection event after the first stage injection event; and using heat from combustion of the pilot amount to ignite the main amount.

A compression ignition internal combustion engine includes: a cylinder block and a cylinder head; a piston including a cavity that defines a combustion chamber in cooperation with the cylinder block and the cylinder head; and a nozzle for injecting fuel into the combustion chamber.