Low noise control of a high-pressure fuel pump is performed by reducing noise generated by an anchor colliding with a fixing core. A control device 800 for a high-pressure fuel pump controls a suction valve that opens and closes an inflow port through which fuel flows to a pressurizing chamber by performing energization to a solenoid 205 in synchronization with a reciprocating motion of a plunger. A current energized to the solenoid 205 includes a peak current for giving a force to start closing a valve to the suction valve in a stationary state and a holding current for performing switching in a range smaller a maximum value of the peak current in order to hold the suction valve in a valve closing state. When the control device 800 reduces a peak current application amount of the peak current from a value sufficient to close the high-pressure fuel pump, a valve closing speed of the suction valve becomes small up to a certain application amount, and when the peak current application amount becomes smaller than the application amount, there is a saturation range of a current application amount of the peak current in which the valve closing speed of the suction valve is saturated. The control device 800 controls the current application amount of the peak current to fall in the saturation range.

A fuel injection valve control device controlling a fuel injection valve that injects a fuel into a combustion chamber includes an operation-condition calculation portion that calculates a fuel injection condition of the fuel injection valve based on a crank angle detected by a crank angle sensor that detects the crank angle of an engine, a current-waveform setting portion that sets a current waveform of a current supplied to the fuel injection valve on the basis of the fuel injection condition calculated by the operation-condition calculation portion, and so on. The current-waveform setting portion sets the current waveform so as to set a temporal change of a pickup current of a needle provided in the fuel injection valve to be equal to or less than a predetermined reference value when a fuel injection start timing is equal to or more than 180 degrees BTDC. The current-waveform setting portion sets the current waveform so as to set a temporal change of the pickup current of the needle to be more than the predetermined reference value when the fuel injection start timing is smaller than 180 degrees BTDC.

Operating an engine system and fuel system includes energizing a solenoid actuator for a spill valve in a fuel injector in a first engine cycle via a standard waveform to inject a shot of fuel. Operating an engine system and fuel system further includes determining suitability for reduced energy operating of the fuel system, and energizing the solenoid actuator via a reduced energy waveform based on the determining suitability so as to inject one or more shots of fuel in a second engine cycle. The operating methodology and control logic can extend an engine speed range for multi-shot fuel injection in an engine.

Methods and systems are provided for detection of a closing time for a solenoid valve. In one example, a method may include monitoring a current of the solenoid valve, filtering the current, and determining the closing time of the solenoid valve based on each of the current and the filtered current. In some examples, the solenoid valve may be an electrically-actuated fuel injection valve. In some examples, determining the closing time may include using the filtered current to determine an inflection point of the current.

An injection control device for a fuel injection valve includes: a current detection unit, a current area correction control unit, a storage unit, and a reference current value correction unit. The current area correction control unit corrects, based on an energization current profile, an area correction amount of an energization time to equalize the integrated current value of the energization current profile and an integrated current value of the detected current, and obtains the integrated current value of the current based on an attainment time from a start of energization of the fuel injection valve to an attainment of each of plural reference current values. The storage unit stores a reference attainment time. The reference current value correction unit corrects each reference current value based on a difference between the reference attainment time and a detected attainment time at a time of actual drive.

An electromagnetically-activated actuator includes an electrical coil, an armature moveable between rest and actuated positions, and a bi-directional driver. A method for controlling an actuator event includes applying a supply voltage at a first polarity across the coil for a first duration to drive a forward current through the coil effective to move the armature away from the rest position. The forward current has a forward current peak at the end of the first duration. After the first duration, the supply voltage is applied at a second polarity across the coil for a second duration to drive a reverse current through the coil. The second duration terminates when the reverse current attains a predetermined reverse current peak, wherein the predetermined reverse current peak is coincident with the armature returning to the rest position.

An engine includes a fuel injector. The fuel injector includes a valve body and an electromagnetic part that moves by energizing the valve body from a valve-closed position to a valve-open position. The fuel injector injects fuel when the valve body is moved to the valve-open position. In fuel injection, an ECU feeds a pre-charge current smaller than a current for operating the valve body, to the electromagnetic part in a pre-charge period at the beginning of a start of energization, and subsequently feeds a drive current for operating the valve body, to the electromagnetic part. Further, the ECU acquires a current change parameter as a parameter correlated with a speed of a rising change in drive current, and controls the feed of the pre-charge current to the electromagnetic part of the fuel injector, based on the acquired current change parameter.

A method for detecting variations between the quantities of fuel injected into cylinders by fuel injection devices and correcting the fuel injection quantity variation while minimizing the computational load on a drive device and the level of performance required of a pressure sensor includes a drive device for fuel injection control, wherein movable valves are driven so that predetermined quantities of fuel are injected by applying, for the duration of a set energization time, a current that will reach an energization current to solenoids of a plurality of fuel injection devices which open/close fuel flow paths. The drive device is characterized in that the set energization time or energization current is corrected on the basis of a pressure detection value from a pressure sensor that is attached to a fuel supply pipe disposed upstream of the plurality of fuel injection devices.

A fluid injector comprising a coil arranged to drive a pump from a first state to a second state when energized, so as to pump a dosing fluid; a PN junction electrically arranged across the coil to discharge energy stored in the coil when the voltage across the coil is above a threshold. In one particular embodiment, the fluid injector is a selective catalytic reduction dosing fluid injector.

Methods and systems are provided for detection of a closing time for a solenoid valve. In one example, a method may include monitoring a current of the solenoid valve, filtering the current, and determining the closing time of the solenoid valve based on each of the current and the filtered current. In some examples, the solenoid valve may be an electrically-actuated fuel injection valve. In some examples, determining the closing time may include using the filtered current to determine an inflection point of the current.