The invention relates to an injection nozzle (1) for fuels, comprising a nozzle body (2), in which a pressure chamber (4) that can be filled with fuel under high pressure is formed, in which pressure chamber a piston-shaped nozzle needle (3) is arranged in such a way that the nozzle needle can be moved longitudinally. A sealing surface (6) is formed at one end of the nozzle needle (3) and an end face (9) is formed at the opposite end, wherein the sealing surface (6) interacts with a nozzle seat (5) in order to open and close at least one injection opening (8). A control chamber (10) that can be filled with fuel under changing pressure is bounded by the end face (9) of the nozzle needle (3) such that a force can be applied to the end face (9) in the direction of the nozzle seat (5) by means of the hydraulic pressure. The nozzle needle (3) has an elastic longitudinal segment (25), which has a longitudinal stiffness of less than 40,000 N/mm.

The invention relates to an injection nozzle (1) for fuels, comprising a nozzle body (2), in which a pressure chamber (4) that can be filled with fuel under high pressure is formed, in which pressure chamber a piston-shaped nozzle needle (3) is arranged in such a way that the nozzle needle can be moved longitudinally. A sealing surface (6) is formed at one end of the nozzle needle (3) and an end face (9) is formed at the opposite end, wherein the sealing surface (6) interacts with a nozzle seat (5) in order to open and close at least one injection opening (8). A control chamber (10) that can be filled with fuel under changing pressure is bounded by the end face (9) of the nozzle needle (3) such that a force can be applied to the end face (9) in the direction of the nozzle seat (5) by means of the hydraulic pressure. The nozzle needle (3) has an elastic longitudinal segment (25), which has a longitudinal stiffness of less than 40,000 N/mm.

An injector has an injector needle (2) by means of which an outlet opening (4) of an injector housing (1) can be closed. The injector needle (2) can be adjusted in pressure-controlled fashion from a closed position into an open position. The injector needle (2) is axially fixedly connected to a piston (26) which is under closing pressure in one direction so that the injector needle (2) closes the outlet opening (4). In the other direction, the piston (26) and thus the injector needle (2) can be displaced by a valve-controlled control pressure, whereby the injector needle (2) passes into its open position and releases the outlet opening (4).

An injector has an injector needle (2) by means of which an outlet opening (4) of an injector housing (1) can be closed. The injector needle (2) can be adjusted in pressure-controlled fashion from a closed position into an open position. The injector needle (2) is axially fixedly connected to a piston (26) which is under closing pressure in one direction so that the injector needle (2) closes the outlet opening (4). In the other direction, the piston (26) and thus the injector needle (2) can be displaced by a valve-controlled control pressure, whereby the injector needle (2) passes into its open position and releases the outlet opening (4).

In general, the subject matter described in this disclosure can be embodied in a fuel injector that includes an upper housing portion that defines an inlet passage adapted to receive fuel, and a lower housing portion that is attached to the upper housing portion and that defines an injector outlet adapted to dispense fuel. The fuel injector includes an electromagnetic coil assembly that is user removable while the upper housing portion remains attached to the lower housing portion. The fuel injector includes a movable pintle that is biased to a closed position that is adapted to prevent fuel from flowing through the injector outlet, and movable, responsive to magnetic force produced by energizing the electromagnetic coil assembly, to an open position that is adapted to permit fuel to flow through the injector outlet.

Gas admission valve assembly includes a housing, an elongated valve guide disposed within a central bore of the housing, a valve including a valve stem slidably disposed within the valve guide and a valve head selectively engagable with a valve seat of the housing to control flow between gas entry and exit openings into a housing entry chamber. First and second stem seals are disposed at opposite ends of the valve guide in sealing engagement with the valve stem between the valve stem and the central bore of the housing distally and the valve guide proximally.

A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux () is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i.sub.1) and an eddy current (i.sub.2). The magnetic flux () is obtained based at least partially on a third model matrix (C.sub.0), the coil current (i.sub.1) and the eddy current (i.sub.2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (). In one example, the solenoid actuator is an injector.

A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux () is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i.sub.1) and an eddy current (i.sub.2). The magnetic flux () is obtained based at least partially on a third model matrix (C.sub.0), the coil current (i.sub.1) and the eddy current (i.sub.2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (). In one example, the solenoid actuator is an injector.

A fuel injector includes a valve stack forming a seal cavity, and an outlet check extending through the seal cavity. A check seal is positioned within the seal cavity and seals about the outlet check. The valve stack also includes a back-up plate trapping the check seal within the seal cavity, such that a crevice is formed within the seal cavity between the check seal and the back-up plate. The back-up plate has a vent formed therein that fluidly connects the crevice to a drain.

A valve for metering a fluid is described, which is used, in particular, as a fuel injector for internal combustion engines, including an electromagnetic actuator and a valve needle actuatable by the actuator, an armature of the actuator being guided on valve needle, a stop element which limits a movement of the armature relative to the valve needle being situated on the valve needle, and the armature including a spring receptacle which is open toward the stop element and in which a spring supported on the stop element is inserted. The valve needle is guided via the armature and/or the stop element along a longitudinal axis of a housing. Furthermore, as viewed along the longitudinal axis, a length of the spring receptacle is smaller than a spring length of the spring in the non-actuated initial state.