A method for controlling a piezoelectric actuator of a fuel injector of an internal combustion engine of a vehicle, the actuator acting on valve elements to open or close the injector, respectively enabling or stopping the injection of fuel into a combustion chamber of the engine, includes the steps of: applying to the actuator a first nominal electric charge required to open the injector in accordance with the torque requested and the engine speed, to open the valve elements for fuel injection, instructing the closure of the injector to stop the fuel injection, by applying an electric discharge to the actuator to close the valve elements, the method applied from an on-board engine control unit during operation, and including applying to the actuator between these 2 steps at least one second electric charge to polarize the actuator during an opening phase of the injector and during fuel injection.

A method is described to control an actuation profile of an electromechanical linear actuator device of an internal combustion engine designed to control the movement of a component; the internal combustion engine comprises a sensor, which faces the actuator device and is designed to detect the noise generated by the movement of the component; the method comprises the steps of acquiring, by means of the sensor, the intensity of a signal generated by the impact of the component against a limit stop; identifying a first listening window of the signal associated with said impact; calculating a noise index inside the listening window; comparing the noise index with a reference value; and controlling the actuation profile of the actuator device based on this comparison.

A control unit (2) for a fuel injector (3) comprising a solenoid actuator (31) having an armature (33), the control unit configured to drive a current through an electromagnet coil (34) of the solenoid actuator in a voltage mode during at least a portion of an injection cycle.

The subject matter of this specification can be embodied in, among other things, a method for characterizing a fluid injector that includes receiving a collection of waveform data, identifying a pull locus, determining a detection threshold level value, identifying a first subset of the collection of data representative of a selected first electrical waveform of the collection of electrical waveforms, identifying an opening value, identifying a representative closing value, identifying an anchor value, identifying a second subset of the collection of data based on the collection of data, the pull locus, the first subset, and the opening value, identifying a maximum electrical value, identifying an opening locus based the collection of data, the anchor value, and the maximum electrical value, identifying a hold value, and providing characteristics associated with the fluid injector comprising the pull locus, the opening locus, the hold value, the anchor value, and the representative closing value.

Provided is a high-pressure fuel pump in which responsiveness of closing a suction valve can be maintained even when the high-pressure fuel pump is increased in pressure or capacity of the high-pressure fuel pump is increased, thereby ensuring discharge efficiency. Therefore, the high-pressure fuel pump includes the rod that urges the suction valve in the valve opening direction, the mover that drives the rod in the valve closing direction, and the solenoid that generates a magnetic attraction force for moving the mover in the valve closing direction. After the suction valve starts moving from the suction valve closing position in the valve opening direction, the rod reaches the suction valve closing position and further moves in the valve opening direction.

A drive device capable of detecting individual variations of an injection quantity of a fuel injection device of each cylinder and adjusting a current waveform provided to an injection pulse width and a solenoid such that the individual variations of the fuel injection devices are reduced. The fuel injection device in the present invention includes a valve body that close a fuel passage by coming into contact with a valve seat and opens the fuel passage by separating from the valve seat and a magnetic circuit constructed of a solenoid, a fixed core, a nozzle holder a housing and a needle and when a current is supplied to the solenoid a magnetic suction force acts on the needle and the needle has a function to open the valve body by colliding against the valve body after performing a free running operation and changes of acceleration of the needle due to collision of the needle against the valve body are detected by a current flowing through the solenoid.

The present disclosure teaches a method for operating an injector with piezoelectric direct drive of an injection system of an internal combustion engine. The method may comprise providing a current to the piezoelectric actuator at a first level, then quickly reducing the current for charging the piezoelectric actuator before or after the opening of the nozzle needle and before the mechanical impacting of the needle or the hydraulic equilibrium point of the needle, the current reduced to such an extent that the sum of the forces acting on the nozzle needle become approximately zero in the case of a small needle lift (part lift), and after reducing the current, supplying a low current in a constant or ramp-shaped fashion until a predetermined setpoint energy is reached.

An electromagnetic actuation system includes an electrical coil, a magnetic core, an armature, a controllable bi-directional drive circuit for selectively driving current through the coil in either of two directions, and a control module providing an actuator command to the drive circuit. Current is driven though the electrical coil in a first direction when an actuation is desired. When the actuation is not desired current is driven through the electrical coil including in a second direction sufficient to reduce residual flux within the actuator below a level passively attained within the actuator at zero coil current.

A drive device capable of detecting individual variations of an injection quantity of a fuel injection device of each cylinder and adjusting a current waveform provided to an injection pulse width and a solenoid such that the individual variations of the fuel injection devices are reduced. The fuel injection device in the present invention includes a valve body that closes a fuel passage by coming into contact with a valve seat and opens the fuel passage by separating from the valve seat and a magnetic circuit constructed of a solenoid, a fixed core, a nozzle holder, a housing, and a needle and when a current is supplied to the solenoid, a magnetic suction force acts on the needle and the needle has a function to open the valve body by colliding against the valve body after performing a free running operation and changes of acceleration of the needle due to collision of the needle against the valve body are detected by a current flowing through the solenoid.

When a plunger of a high pressure pump is rising, a high pressure pump controller closes a regulator valve by energizing a solenoid of an electromagnetic actuator of the high pressure pump to discharge fuel into a delivery pipe. Further, this fuel discharge energization is stopped before the plunger reaches top dead center at a pump TDC timing. Further, a fuel pressure of the delivery pipe is detected at the pump TDC timing, and based on that detected value, a time Td from the pump TDC timing until a valve opening timing of the regulator valve is estimated. Once the estimated time Td elapses from the pump TDC timing, the solenoid is reenergized to removed a movement speed of a movable portion in a direction that pushes the regulator valve in an opening direction.