A fuel injector includes a needle valve including a spring-retaining section and a guide section that is adjacent to the spring-retaining section. The spring-retaining section includes an elongated portion and a flange that are together configured to support a spring assembly. The guide section includes a plurality of constricted portions alternatingly arranged with a plurality of expanded portions to define an undulating shape of the guide section. Each of the plurality of expanded portions includes a plurality of indentations to permit fuel to travel therealong to exit an outlet of the fuel injector. The guide section has a length that is substantially equal to a length of the spring-retaining section.

A fuel injector includes a collar, which may be formed of a porous, sintered material, the collar being located around the needle and allowing a restricted fluid pathway, such as orifices through the collar, between first and second volumes of fuel, the collar being located in a section of the nozzle body which has a greater cross-sectional area than the rest of the bore.

The housing (18) of the fuel injection valve (10) of the device for intermittently injecting fuel into the combustion chamber of an internal combustion engine comprises a high-pressure inlet (34) with a conical sealing face (44). The high-pressure chamber (36) is disposed in the housing (18) from the high-pressure inlet (34). A cartridge-like, independent component (56) is inserted into the high-pressure chamber (36). Said component comprises the valve carrier (46), the non-return valve (48), the holding element (50), and preferably the filter body (52′). The valve carrier (46) is provided with a conical outer sealing face (69), by which the valve carrier rests against the conical sealing face (44). A fixing element (74) presses the supply line (16) against the valve carrier (46).

A high-pressure fuel supply pump includes a plunger, a valve member, a valve seat, a pressurizing chamber, and a fuel passage. The fuel passage includes a gap passage portion formed in a gap between the valve seat and the valve member. The fuel passage also includes a bent passage portion extending in a bent direction with respect to the gap passage portion, on the downstream side of the gap passage portion. The inner surface of the valve member, on a side thereof that faces the valve seat, has a convex shape in an area of the valve member that is between the bent passage portion and the gap passage portion.

A fuel valve includes a housing, a nozzle with nozzle holes opening to a volume inside the nozzle at the front end of the housing, a gaseous fuel inlet port in the housing connected to high pressure gaseous fuel, an axially displaceable valve needle received in a longitudinal bore in the housing, and rests on a valve seat in a closed position and has lift from the valve seat in an open position, the valve seat placed between a fuel chamber and an outlet port, the fuel chamber connected to the fuel inlet port, the outlet port connected to the volume in the nozzle, an actuator system for moving the needle between the closed and open positions, an ignition liquid inlet port connected to high pressure ignition liquid, and conduit connecting the ignition liquid inlet port to the fuel chamber, the conduit including a fixed flow restriction.

A quantity control valve comprises a valve needle configured to move in an axial direction, a damping chamber having a wall, and a valve element delimiting the damping chamber. The valve needle is configured to move the valve element in an opening direction. A gap is defined between the wall of the damping chamber and the valve element. The gap has at least one recess and connects the damping chamber to a flow duct.

An injector has an injector body including an injector cavity defining an inner wall and a longitudinal axis, an injector orifice and a plunger slidably disposed within the injector cavity. The plunger has an outer portion and an inner portion at different locations longitudinally along the plunger. The inner portion has a plurality of surface portions including a guiding portion configured to substantially mate with the inner wall of the injector cavity, guide the plunger to slidably move in a direction along the longitudinal axis and substantially prevent the plunger from laterally translating within the injector cavity. The plurality of surface portions also includes a restriction portion configured to form a restrictive cavity between an exterior surface of the inner portion and the inner wall of the injector cavity axially along a length of the inner portion.

A fuel injection system of an internal combustion engine includes: an injector having a hydraulic control chamber controlling the delivery of fuel through the injector, an actively controlled first valve system controlling the pressure relief from the control chamber, movable between: a first position in which the first valve system closes the injector by deterring the pressure from being relieved from the control chamber through the first relief circuit, and a second position in which the first valve system opens the injector by allowing the pressure to be relieved from the control chamber through the first relief circuit. A second relief circuit allows the pressure to be relieved from the control chamber through the second relief circuit. The second relief circuit includes a second valve system passively controlled by the fuel pressure and movable between two positions deterring or allowing the pressure to be relieved from the control chamber through the second relief circuit.

A throttle device for controlling a fuel quantity to be supplied to a fuel injection nozzle includes a control chamber and a supply device for supplying fuel to the control chamber. The supply device includes an inlet throttle having a length selected such that a fuel flowing through the inlet throttle, when in operation, flows through the inlet throttle in a turbulent flow. An injection device including the throttle device is also provided.

A combined assembly for filtering and calibrating a fuel injector arranged in an internal combustion engine, the combined filtration and calibration assembly extending along a longitudinal axis and comprising a calibration sleeve provided with a longitudinal bore and defining a multitude of filtration holes. The combined filtration and calibration assembly has a calibrated opening in the bore.