The present invention relates to an injector for injecting fuel, comprising an injector housing, a movable nozzle needle which is arranged in the injector housing and has a nozzle needle tip, a nozzle needle seat for receiving the nozzle needle tip, and a mechanical switch which upon contact of the nozzle needle tip with the nozzle needle seat assumes a closed state and upon interruption of the contact assumes an open state, wherein the injector is provided with an input line and an output line for actuating a movement of the nozzle needle, and the switch includes a first terminal and a second terminal. The injector is characterized in that the first terminal of the switch is connected to the input line and the second terminal of the switch is connected to the injector housing.

A metering valve comprising a solenoid having: a coil mounted on a core; and an armature moveable axially with respect to the core and against a return bias in response to a current in the coil; a variable capacitor having a first plate mounted for movement with the armature and a second plate fixed with respect to the core. The metering valve comprises an electronic feedback loop which is used to adjust the current in the coil based on a feedback signal derived from of the capacitance of the variable capacitor. A reference capacitor may be provided having opposing third and fourth plates at a set separation. A valve body may house the solenoid, the variable capacitor and the reference capacitor.

A method for operating a combustion engine performing an injection quantity correction is described. A total injection quantity per pulse of an injector is divided into a plurality of smaller equal quantity pulses. The smaller quantity pulses are implemented in ballistic injector mode. On the basis of this step, a corresponding offset correction is carried out. After the offset correction has been applied, a further correction is carried out in linear injector mode. An additional alternative for performing an injection quantity correction without additional sensor hardware is thereby provided.

A fuel injection control device is applied to an internal combustion engine including a fuel injection valve and causes a valve body to be in a valve open state accompanying an energization of the fuel injection valve to inject fuel. The fuel injection control device acquires a dynamic parameter. The fuel injection control device acquires an injection amount parameter. The fuel injection control device calculates, based on the dynamic parameter, a dynamic correction value. The fuel injection control device calculates, based on the injection amount parameter, an injection amount correction value. The fuel injection control device corrects a fuel injection using the dynamic correction value and the injection amount correction value.

A method for adapting the injection characteristic of a fuel injection valve of an internal combustion engine to production-related tolerances is described. In the method, an injection quantity correction value is determined from the deviation of the idle travel and the deviation of the injection quantity of the injection valve before the operating phase of the injector. This injection quantity correction value is used to determine the injection-specific deviation of the injection quantity during the operating phase at the start of the operating phase of the injector in conjunction with the current deviation of the idle travel which is determined in the system. The injector-specific deviation of the injection quantity which is determined is used to correct the injection characteristic. As a result, changes in the injection quantity of an injector can be detected and corrected particularly precisely on the basis of production tolerances.

A control device for an engine includes an ECU. The ECU is configured to: control an actual fuel pressure supplied to a fuel injector to a target fuel pressure; calculate a required energization time required for fuel injection equivalent in amount to a required injection quantity; set a energization time for each injection based on the required energization time; execute a switching processing for switching a manner in which the energization time is set when the required energization time is shorter than a predetermined time; set the required energization time as a set value of the energization time through the switching processing when a deviation between the actual fuel pressure and the target fuel pressure is equal to or larger than a predetermined value; and set the predetermined time as the set value of the energization time when the deviation is less than the predetermined value.

A method for operating a fuel injector having at least one injection orifice that is controlled by an injector needle, in which pressure variations during the opening and/or closing of the injector needle are ascertained with the aid of a sensor. In order to determine the opening/closing instant of the injector needle, a variable that characterizes the velocity of sound of a pressure wave by the opening and/or closing is measured, and the wave propagation time, by which the needle or valve opening/closing instant is corrected, is inferred therefrom.

A fuel injection system for an engine, the fuel injection system includes injectors and an electronic control unit. The injectors include needle valves; and the ECU is configured to: (i) execute partial lift injection and full lift injection with the injectors, the partial lift injection being injection during which the needle valve does not reach a fully-open state and the full lift injection being injection during which the needle valve reaches the fully-open state; (ii) operate the engine in a partial lift injection region where the injection of a required injection amount of a fuel is shared by the partial lift injection and the full lift injection; and (iii) perform the amount of correction of the required injection amount with respect to the injection amount shared by the full lift injection when the required injection amount is corrected while the engine is operated in the partial lift injection region.

A method for operating an internal combustion engine having at least one fuel injector that is activated for opening and closing via a solenoid valve of a respective fuel injector. Commencing with the activation of the fuel injector for opening, structure-borne sound waves emitted by the fuel injector over the time are detected by measurement. A structure-borne sound wave signal detected by measurement over the time is evaluated such that dependent on the amount of at least one maximum of the structure-borne sound wave signal and/or dependent on the number of the maximums of the structure-borne sound wave signal and/or in the presence of multiple maximums dependent on the time sequence and/or on the amount of the maximums, an operating state of the respective fuel injector is deduced.

In some embodiments, a method includes: setting an actuation time based on a predefined injection quantity; detecting a duration of a resulting closing process; calculating an injection quantity based on the time and the duration; determining the difference of the injection quantity and the predefined quantity; and determining a corrected value of the actuation time based on the difference; and using the corrected value to control further actuation of the fuel injector. The injection quantities and the actuation time are on a characteristic diagram of the relationship between the actuation time, the duration of the closing process, and the injection quantity.