A fuel injector for an internal combustion engine is disclosed. The fuel injector is particularly suitable for use as a dual fuel injector, and comprises a generally tubular outer valve needle, an inner valve needle slidably received in the outer valve needle, and a nozzle body assembly comprising a tip part and a needle guide part. The tip part defines a seating region for the outer valve needle, and the needle guide part comprises a guide bore for slidably receiving the outer valve needle. In one embodiment, a lower bore region of the needle guide part defines a cavity around the outer valve needle which houses a biasing spring for the outer valve needle and a fuel. A collar for seating the biasing spring can be dimensioned to allow free flow of the fuel from the cavity into an annular accumulator volume defined between the outer valve needle and the bore of the tip part.

A fluid injector includes a fluid inlet; a valve seat located downstream of the fluid inlet and having a valve seat aperture extending therethrough; a valve member moveable between a closed position and an open position to control flow through the valve seat aperture; and director plate including a first aperture and a second aperture extending therethrough. A fluid flow channel is formed between the valve seat and the director plate and extends from an inlet end to an outlet end. The first aperture and the second aperture extend through the director plate from the fluid flow channel. The first aperture is located between the inlet end and the second aperture. The fluid flow channel decreases in cross-sectional area from the inlet end toward the first aperture and the fluid flow channel increases in cross-sectional area from the first aperture toward the second aperture.

A fluid injector includes a fluid inlet; a valve seat located downstream of the fluid inlet and having a valve seat aperture extending therethrough; a valve member moveable between a closed position and an open position to control flow through the valve seat aperture; and director plate including a first aperture and a second aperture extending therethrough. A fluid flow channel is formed between the valve seat and the director plate and extends from an inlet end to an outlet end. The first aperture and the second aperture extend through the director plate from the fluid flow channel. The first aperture is located between the inlet end and the second aperture. The fluid flow channel decreases in cross-sectional area from the inlet end toward the first aperture and the fluid flow channel increases in cross-sectional area from the first aperture toward the second aperture.

A valve assembly for an injection valve includes a valve body that includes a cavity with a fluid inlet portion and a fluid outlet portion. The cavity includes a first portion extending from the fluid inlet portion to a bottom surface and a second portion extending from a central opening in the bottom surface down towards the fluid outlet portion. The valve assembly includes a valve needle axially movable in the cavity. The valve needle includes a shaft and a ball; the ball cooperating with a valve seat to prevent a fluid flow through the fluid outlet portion in a closing position and to release the fluid flow through the fluid outlet portion in further positions. The valve assembly includes a seat body forming the valve seat and a ball guide. The valve assembly includes where a lower particle filter is entirely arranged in the second portion of the cavity.

A fuel injection valve includes a valve body, a fixed core, a movable core, a spring, a cup, and a guide. The cup contacts the spring and the valve body to transmit a valve closing elastic force to the valve body, and includes a cylindrical portion having a cylindrical shape. The guide has a sliding surface on which an outer peripheral surface of the cylindrical portion slides so as to guide the movement of the cylindrical portion in an axial direction while restricting the movement of the cylindrical portion in a radial direction. The guide has a recessed surface connected to the sliding surface and recessed to increase a gap between the recessed surface and the cup in the radial direction.

A nozzle assembly of a fuel injector includes a nozzle body in which a needle member is adapted to translate. The nozzle assembly is further provided with an electrical circuit so that an electrical signal enabling contact detection is measurable between the needle member and the nozzle body. The nozzle assembly also includes a piezoresistive device which continuously varies the electrical signal during the final closing displacements, or the initial opening displacements, of the needle, the variations of the signal being a function of a differential pressure.

A nozzle assembly of a fuel injector includes a nozzle body in which a needle member is adapted to translate. The nozzle assembly is further provided with an electrical circuit so that an electrical signal enabling contact detection is measurable between the needle member and the nozzle body. The nozzle assembly also includes a piezoresistive device which continuously varies the electrical signal during the final closing displacements, or the initial opening displacements, of the needle, the variations of the signal being a function of a differential pressure.

A valve assembly for an injection valve includes a valve body having a central longitudinal axis and a cavity with a fluid inlet portion and a fluid outlet portion, a valve needle axially movable in the cavity to prevent a fluid flow through the fluid outlet portion in a closing position and to allow fluid flow through the fluid outlet portion in further positions, and a guiding device arranged in the cavity and configured to guide the valve needle relative to the valve body. The guiding device has a first guide element fixedly coupled to the valve body and a second guide element fixedly coupled to the valve needle. The first guide element includes a magnetic material with a first magnetic field and the second guide element includes a magnetic material with a second magnetic field, the first and second magnetic fields being orientated in opposite directions.

A valve assembly for an injection valve includes a valve body having a central longitudinal axis and a cavity with a fluid inlet portion and a fluid outlet portion, a valve needle axially movable in the cavity to prevent a fluid flow through the fluid outlet portion in a closing position and to allow fluid flow through the fluid outlet portion in further positions, and a guiding device arranged in the cavity and configured to guide the valve needle relative to the valve body. The guiding device has a first guide element fixedly coupled to the valve body and a second guide element fixedly coupled to the valve needle. The first guide element includes a magnetic material with a first magnetic field and the second guide element includes a magnetic material with a second magnetic field, the first and second magnetic fields being orientated in opposite directions.

A spray disc arrangement for a fluid injector includes a first disc having a dimple with an orifice defined through the dimple. A second disc includes a dimple and a plurality of orifices defined through the dimple. The first disc dimple is received in the second disc dimple. The second disc includes a plurality of channels defined along a concave surface of the dimple, with the plurality of orifices located in the channels. The first disc and the second disc are coupled together such that a convex surface of the dimple of the first disc contacts a concave surface of the dimple of the second disc. The first disc is disposed along a downstream side of a valve seat of the fluid injector.