The invention relates to a dual-fuel fuel injector that includes a plurality of stroke-controllable gas nozzle needles which are axially movably mounted on the dual fuel fuel-injector in a plurality of respective seats and which are distributed in a circumferential direction of the dual fuel fuel-injector, and a nozzle chamber provided for the plurality of stroke-controllable gas nozzle needles. The nozzle chamber includes a plurality of externally positioned bulges, wherein within each respective cross section of which an inlet cross section of a flow path is defined which can be blocked selectively via a respective stroke-controllable gas nozzle needle of the plurality of stroke-controllable gas nozzle needles to at least one nozzle opening.

A dual fuel injector may be used to inject both gas and liquid fuel into a cylinder of a compression ignition engine. An injector body defines a first set of nozzle outlets, a second set of nozzle outlets, a first fuel inlet and a second fuel inlet. A dual solenoid actuator includes a first armature, a first coil, a second armature and a second coil that share a common centerline. The dual solenoid actuator has a non-injection configuration at which the first armature is at an un-energized position and the second armature is at an un-energized position. The dual solenoid actuator has a first fuel injection configuration at which the first fuel inlet is fluidly connected to the first set of nozzle outlets, the first armature is at an energized position and the second armature is at the un-energized position.

A dual fuel injection valve includes a primary fuel treatment space and a secondary fuel treatment space formed extending the fuel valve block and the hybrid nozzle block in the longitudinal direction and side by side with each other. The primary fuel treatment space includes a primary cylinder passage, a primary fuel passage and a primary nozzle hole. The secondary fuel treatment space includes a secondary cylinder passage formed separately form the primary cylinder passage, a secondary fuel passage formed separately form the primary fuel passage hole, a secondary nozzle hole. The dual fuel injection valve further includes a first chamber formed in a lower portion of the secondary cylinder passage, a second chamber disposed between the first chamber and the secondary nozzle hole and formed to surround the secondary cylinder passage, and a primary fuel movement hole connecting the primary cylinder passage and the second chamber.

A fuel injector includes a nozzle having a combined-fuel outlet passage fluidly connected to a first fuel passage and a second fuel passage and extending to a plurality of nozzle outlets. A nozzle check movable in the nozzle includes a plurality of transfer holes fluidly connecting the first fuel passage through the nozzle check to the combined-fuel outlet passage. The plurality of transfer holes are orientated to limit mixing between two liquid fuels in a combined fuel charge in the combined-fuel outlet passage. The combined fuel charge may be formed of a leading compression-ignition liquid fuel such as diesel and a trailing liquid fuel such as methanol. Related apparatus and methodology is also disclosed.

Fuel injector for supplying fuel to a combustion chamber of a cylinder, having a first nozzle needle guided in a first nozzle guide, which interacts with first fuel injection orifices such that the first nozzle needle either opens or blocks a fuel flow of a first fuel through the first fuel injection orifices, a second nozzle needle guided in a second needle guide, which interacts with second fuel injection orifices such that the second nozzle needle, either opens or blocks a fuel flow of a second fuel through the second fuel injection orifices, a first fuel storage space for the first fuel, and a second fuel storage space for the second fuel me. The first and second fuel storage spaces are arranged next to one another in the transverse or radial direction of the fuel injector and overlap in the longitudinal or axial direction of the fuel injector.