A variable orifice fuel injector has an inward opening needle valve and an outward opening needle valve and has means to directly inject two types of fuels independently and collectively. Both needle valves are fully contained in a nozzle body, with a co-axial smaller needle valve at least partially being contained in a larger needle valve. The materials of the needle valves are individually chosen such that it provides good sealings for liquid and gas fuels.

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.

A control valve assembly of a fuel injector includes a first valve arrangement wherein a first valve spool is guided in a first hydraulic bore provided in a body of the assembly. The control assembly further includes a first tubular sleeve having a seating portion which end face defines the first seating face, the first sleeve being fixed in the first hydraulic bore and the first spool extending through the sleeve.

A fuel injector has means to directly inject one type of fuel or two types of fuels collectively with fuel ratios on demand. Once being used as a single fuel injector, the injector can enable injection rate shaping. Once being used as a dual fuel injector, the injector can tailor fuel properties on demand. The fuel injector has the capability to enable tailored chemical and thermal-physical fuel properties to enable high efficiency clean combustion for different engine loads and speeds.

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.

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.

This liquid injection nozzle atomizes and sprays liquid, while reducing loss of kinetic energy, thereby promoting mixing between the liquid and a gas and thus promoting the reaction between the liquid and the gas. In the liquid injection nozzle, a plurality of distal end tips each having an injection hole are provided on a distal end portion of a nozzle body. Each distal end tip has a conical swirling flow chamber. A communication thin hole is formed in the distal end portion. The communication thin hole extends from a hollow chamber to the conical swirling flow chamber of the distal end tip. When the valve needle is lifted, liquid flows through the communication thin hole into the swirling flow chamber in a tangential direction and generates a vortex flow, and the vortex flow is sprayed from the injection hole.

Methods and systems are provided for injecting fuel through three different rows of injector nozzles, where each row of the injector nozzle is arranged along a different vertical plane of the injector body. In one example, an injector needle housed movably inside the injector body may supply high-pressure fuel to each of the rows of injector nozzles sequentially to deliver up to five fuel injections in one actuation cycle of the fuel injector. In another example, a fuel injector may include three injector needles, where movement of each injector needle inside a respective chamber of the fuel injector body may supply high-pressure fuel to the chamber from where the fuel may be injected through the coupled fuel injector nozzles.

The invention relates to a nozzle needle (10) for a fuel injection device (100), in particular a fuel injector, comprising a nozzle needle tip (12) which is connected to a nozzle needle shaft (11). The nozzle needle tip (12) and the nozzle needle shaft (11) consist of different materials. According to the invention, the nozzle needle shaft (11) has a receiving area (20) formed by a blind bore (21) for the nozzle needle tip (12). The base (22) of the receiving area (20) forms an axial stop for the nozzle needle tip (12), and the nozzle needle tip (12) has an at least approximately constant diameter (d) within the receiving area (20), said diameter simultaneously forming the largest diameter of the nozzle needle tip (12).