A fuel system includes a fuel injector, and a fueling control unit electrically connected to a solenoid actuator in the fuel injector. The fueling control unit is structured to energize and deenergize the solenoid actuator to lift and return an armature coupled with an injection control valve. The fueling control unit also reenergizes the solenoid actuator with an armature retarding current while the armature is in flight to stabilize closing of the injection control valve. The armature retarding current can be used to electronically trim the fuel injector to limit an error in a quantity of injected fuel.

A method for injecting a predetermined total fuel quantity via multiple injections using a fuel injector having a solenoid drive for an internal combustion engine of a motor vehicle is disclosed. The method includes determining a first target injection quantity to be injected per injection to inject the total fuel quantity throughout a series of consecutive injections; and performing a first subseries of consecutive injections, where the fuel injector is actuated according to the first target injection quantity. The method also includes determining a first fuel quantity injected during the first subseries of injections; determining a second target injection quantity to be injected per injection in a second subseries of consecutive injections, to inject the total fuel quantity throughout the first subseries and the second subseries of consecutive injections; and performing the second subseries of injections. The fuel injector is actuated according to the second target injection quantity.

An injector for injecting fuel including an injector housing, a movable nozzle needle with a nozzle needle tip arranged in the injector housing, and a nozzle needle seat for receiving the nozzle needle tip. A contact pairing of the nozzle needle and the nozzle needle seat here represents a mechanical switch that adopts a closed state upon contact of the nozzle needle tip with the nozzle needle seat and an open state upon interruption of the contact. Provision is additionally made that the injector has an input line and an output line for controlling movement of the nozzle needle, the switch has a first connector connected to the input line and a second connector connected to the injector housing, and a resistor connected between the first connector of the switch and the input line.

Appropriate detection of an abnormality of voltage information, which is a basis for correcting a fuel injection amount, becomes possible. For this reason, a fuel injection control device 127, which has a drive IC 208 controlling a fuel injection drive unit 207a to supply a high voltage to a solenoid 405 so as to open a fuel injection valve 105 and controlling the fuel injection drive unit 207a to supply a low voltage to the solenoid 405 so as to hold a valve-open state of the fuel injection valve 105, includes: a drive voltage input unit 211 that measures and outputs voltage information based on an upstream voltage of the solenoid 405 of the fuel injection valve 105 and a downstream voltage of the solenoid 405; a fuel injection amount correction unit 213 that corrects a fuel injection amount of the fuel injection valve 105 based on the voltage information output from the drive voltage input unit 211; and a voltage input function abnormality detection unit 212 that detects whether an output of the drive voltage input unit 211 is abnormal based on the voltage information output from the drive voltage input unit 211.

Provided is a fuel injection control device capable of reducing variations in injection amounts of a plurality of fuel injection valves. Thus, the fuel injection control device of the present invention includes a control unit that controls voltages applied to coils of a plurality of fuel injection valves, the coils being adapted for energization. The control unit performs control such that the voltage being applied to the coil is cut off. The control unit changes a timing at which the cutoff of the voltage to the coil of at least one fuel injection valve is started or a timing at which the cutoff of the voltage to the coil of at least one fuel injection valve is ended, based on a valve closing time until closing of the fuel injection valve is completed or a valve opening time until opening of the fuel injection valve is completed.

An injection control device includes: an area correction unit that calculates an energization time correction amount when executing a current drive of the fuel injection valve to inject a fuel from the fuel injection valve; an estimation unit that independently calculates an estimated energization time correction amount; a comparison unit that compares the energization time correction amount c with the estimated energization time correction amount; and a first abnormality determination unit that determines that the energization time correction amount is abnormal.

Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, a maximum fuel injector holding current value is adjusted from a higher value to a lower value within a predetermined amount of time of an end of fuel injection. By adjusting the maximum fuel injector holding current value, it may be possible to reduce variation in an amount of fuel that is injected via the fuel injector.

An energization control unit is configured to perform a constant current control by repeatedly switching between an on-state and an off-state of at least one upstream switch provided in an energization path of a coil of a fuel injection valve to control opening of the fuel injection valve in a drive period in which the coil is energized to drive the fuel injection valve. A current detection unit is configured to detect a coil current flowing through the coil. A valve-opening detection unit is configured to detect valve-opening timing of the fuel injection valve based on a change in at least one frequency spectrum of the coil current in a constant current control period in which the constant current control is performed. A valve-opening correction unit is configured to correct valve opening of the fuel injection valve based on a detection result of the valve-opening detection unit.

Systems and methods for improving accuracy of an amount of fuel injected to an engine are disclosed. In one example, a maximum fuel injector holding current value is adjusted from a higher value to a lower value within a predetermined amount of time of an end of fuel injection. By adjusting the maximum fuel injector holding current value, it may be possible to reduce variation in an amount of fuel that is injected via the fuel injector.

A fuel injector is provided. The fuel injector includes a sleeve having a first end proximate an outlet; a piston slidingly received in the sleeve, the piston having a first end proximate the outlet; a pumping chamber at least partially defined by the sleeve between the first end of the piston and the outlet; and a normally-open inlet valve through which fuel passes to enter the pumping chamber.