A fuel injector includes a noise sensor fixed to the body fixed on the injector body to record knocks relevant to the end travel of a control valve and of a needle.

Various embodiments may include a method for operating a diesel-common-rail piezo-operated servo injector comprising: partially charging the piezo-actuator from a non-charged state at 0 V (method a); partially discharging the piezo-actuator from an already charged state to a remaining limited charge (method b); measuring the piezo-voltage with both methods and comparing the results; when the comparison demonstrates correspondence within a predefined threshold, using method b in ranges in which method a cannot be carried out; and when the comparison does not demonstrate correspondence within the predefined threshold, using method a without using method b.

A fuel injection control device includes a reference interval calculation section that calculates a reference interval between an end time of a decrease interval where the pressure decreases as a fuel injection rate increases and a start time of an increase interval where the pressure increases as the fuel injection rate decreases on a pressure waveform detected by the pressure sensor, an integration interval setting section that sets, in the reference interval, an integration interval where an influence of a disturbance on the fuel pressure decrease due to a target injection is suppressible, and a decrease amount calculation section that calculates a corresponding pressure decrease amount, which is a fuel pressure decrease amount corresponding to a maximum injection rate of fuel of the target injection, based on an integral value obtained by integrating the fuel pressure decrease amount due to the target injection in the integration interval.

A fuel injector system includes an injector body having a proximal end and a distal end, the injector body defining a nozzle having an outlet. The injector system includes a spill valve fluidly connected to the outlet and having a spill valve member movable between an open position and a closed position. The injector system includes a control valve including a control valve member movable between an open position and a closed position. The injector system includes a check valve fluidly connected to the outlet, the control valve including a check valve needle movable between an open position and a closed position. The injector system also includes an electrical monitoring circuit configured to output a signal indicative of at least one of the open position or the closed position of the spill valve member.

A method for operating a fuel injection system for a vehicle is provided. In particular, the fuel injection system includes an injection nozzle having a nozzle body, a nozzle orifice and a nozzle needle movable in the nozzle body. The method including: measuring an actual injection timing of the injection nozzle during injection based on an electrical signal generated by the nozzle needle through an electric contact with the nozzle body so that the electrical signal identifies an open state and a closed state of the injection nozzle; calculating a deviation of the actual injection timing from a scheduled injection timing of the fuel injection system; and controlling the injection nozzle by adjusting injection parameters of the injection nozzle based on the evaluated deviation.

A method for operating an electromagnetic actuator includes an actuation event utilizing a current waveform for the actuator characterized by an initial peak pull-in current in a first direction of current flow when the actuator is commanded to an actuated position; and a reversed peak current in a second opposite direction of current flow applied after the actuator is commanded to a rest position. The reversed peak current has a magnitude that is greater than the magnitude of the initial peak pull-in current.

An electrical connector includes two lateral mounting bush. A knock sensor which delivers data representative of the operation of a fuel injector is integrally overmoulded in one of the mounting bush. The knock sensor includes a piezoelectric member arranged between a base member and a seismic member.

Various embodiments may include a method for operating a piezo-actuator in a piezo-operated injector for a fuel injection system comprising: producing a measuring pulse at a position at which the usable signal which is to be measured is expected; then producing a reference pulse which corresponds to the measuring pulse, in the same cycle; subtracting a first actuator voltage measured during the reference pulse from a second actuator voltage measured during the measuring pulse; using a resulting voltage signal difference to calculate a force sensed by the piezo-actuator; and using the force sensed to correct an injection amount for the injector.

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 filter assembly for a fuel injector is provided. The filter assembly includes a first ring. The first ring includes a plurality of first apertures provided along a circumference thereof. The filter assembly also includes a second ring disposed concentrically with respect to the first ring. The second ring includes a plurality of second apertures provided along a circumference thereof. Each of the plurality of second apertures is disposed misaligned with respect to each of the plurality of first apertures respectively. The filter assembly further includes an actuation mechanism operably coupled to the second ring. The actuation mechanism is adapted to selectively rotate the second ring about an axis with respect to the first ring to, at least partially, align each of the plurality of first apertures with respect to each of the plurality of second apertures respectively to provide an unfiltered flow of a fluid through the filter assembly.