A device and a method are provided for determining a stroke of an armature of a magnetic valve which has a coil and the armature is displaceable by magnetic force, including: providing at least one reference data set which includes a magnitude of a current through the coil and a magnitude of the magnetic flux in the case of a known magnitude of the stroke; generating a current flow through the coil of the magnetic valve in order to generate a magnetic field for generating a magnetic force on the armature, which magnetic force displaces the armature in the direction for the opening of a closure element coupled to the armature; determining a magnitude of the magnetic flux when the armature abuts against a driver of the closure element; and determining the magnitude of the stroke based upon the determined magnitude of the magnetic flux and the reference data set.

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 fuel injection control device divides an amount of fuel corresponding to an injection amount required for a single combustion into portions corresponding to multiple fuel injections, causes the direct injector to inject the fuel in the multiple times, and causes the direct injector to execute a partial-lift injection as a final fuel injection. The device includes a total injection amount calculation section, an individual injection amount calculation section, and an injection amount changing section. The injection amount changing section executes, as a first changing process, a process for increasing the injection amount at the final fuel injection to a value between a partial-lift injection lower limit value and a partial-lift injection upper limit value and reducing the injection amount at a fuel injection other than the final fuel injection by the increased amount of the injection amount at the final fuel injection.

Disclosed is a control device of an engine 1 including an injector. The injector has a needle which is displaced between a close position where no fuel is allowed to flow into a sac portion and an open position where the fuel is allowed to flow into the sac portion. The control device has a fuel injection controller controlling a fuel injection period and an injector controller controlling a motion of the needle. The injector controller executes control to reduce a moving speed of the needle before the needle reaches the closed position when the injection period ends.

A fuel injection system for fuel metering may include an injection nozzle, which includes a nozzle body, a nozzle needle, and a nozzle orifice, wherein nozzle needle is disposed in the nozzle body; a control piston configured to mechanically and electrically contact the nozzle needle in an axial direction opposite to the nozzle orifice; a transmitter configured to communicate with a controller and electrically contact the nozzle needle via the control piston; wherein the controller is configured to determine an open state and a closed state between the nozzle needle and the nozzle body via an electrical signal detected by the transmitter; and wherein the controller is configured to adjust the open state and the closed state in correlation with a fuel injection quantity.

An engine controller according to one aspect of the invention is applied to a cylinder injection engine including a fuel injection valve that directly injects fuel into a cylinder. The engine controller determines whether knocking is occurring based on a signal from a knocking sensor. When the knocking is occurring, the engine controller performs partial lift fuel injection at a predetermined timing close to an ignition timing. The partial lift fuel injection is performed with a lift amount of a valve body of the fuel injection valve limited within a range between a minimum lift amount (0) and a partial lift amount, which is smaller than a maximum lift amount.

A fuel system for an internal combustion engine includes a fuel control system having a fueling control unit structured to determine a test point on a tip wear-sensitive region of a fuel injector delivery curve, and store measurements of pressure drops in a pressurized fuel reservoir caused by injections of fuel at the test point. The fueling control unit is further structured to produce an injector health signal based on the stored measurements of pressure drop. Related methodology and control logic for calculation of wear parameters for injection signal duration electronic trimming and prognostic health determinations are also disclosed.

A fuel injection control device includes: an energization control unit that controls a fuel injection valve; an inter-terminal voltage acquiring unit that acquires an inter-terminal voltage of the fuel injection valve at a predetermined time interval; and a state determining unit that determines an open-close operation state of the fuel injection valve based on the acquired inter-terminal voltage, wherein the state determining unit sets, for each of the plurality of fuel injections in the fuel injection period, a valve closing determination period after the electricity to the fuel injection valve is turned off, the period having a time length determined according to a number of injection stages of the multi-stage injection, and determines that the fuel injection valve is in a fully closed state when the voltage change due to a valve body movement of the fuel injection valve appears in the inter-terminal voltage acquired in the valve closing determination period.

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.

During rapid warm-up operation, a CPU executes full lift injection processing, in which a nozzle needle reaches a maximum lift amount, in an intake stroke of each cylinder of a four-cylinder internal combustion engine, and then executes partial lift injection processing, in which the nozzle needle does not reach the maximum lift amount, in a compression stroke. On the other hand, during learning of injection characteristics of partial lift injection processing, the CPU executes full lift injection processing after executing partial lift injection processing, both of which are executed within a predetermined period in an intake stroke. The CPU learns the injection characteristics based on an inflection point in the temporal change of the induced electromotive force in a coil following the end of the partial lift injection processing.