A fuel system for an internal combustion engine includes a fuel injector, and a fueling control unit electrically connected to a solenoid in the fuel injector. The fueling control unit energizes the solenoid with a lift current pulse to lift an armature, then energizes the solenoid with a separate capture current pulse to capture the armature at a lifted position. The solenoid is deenergized a dwell time while the armature is in flight toward the lifted position. Armature lifting speed is retarded based on the deenergizing of the solenoid so as to limit bouncing of a valve pin in the fuel injector against a stop. The techniques assist in linearizing a fuel delivery curve.

A fuel injection control device includes an additional energization unit. Concerning an undershoot state caused by a first energization for fuel injection, a return period is an estimated period required for a movable core to return to an initial position from a first energization. An injection interval ranges from the first energization to a second energization that is for a next fuel injection. An allowable period is obtained by subtracting a rise period estimated for the second energization from the return period. The additional energization unit adds an additional energization between the first energization and the second energization when the injection interval is longer than or equal to the allowable period and is shorter than or equal to the return period.

There is provided a method of energising a solenoid of a valve assembly, comprising the steps of applying a positive over boost voltage to the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, and then applying a negative braking voltage to brake the movement of the plunger during movement of the moveable plunger. There is also provided a method of energising a solenoid of a valve assembly, the method comprising the steps of receiving a demand signal to actuate the valve, applying a wait time after receipt of the demand signal, applying a positive over boost voltage across the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, monitoring the solenoid closure time, and adjusting one or more input variables in order to control the solenoid closure time. There is also provided a method of monitoring the solenoid closure time over a plurality of different energising and de-energising cycles of the solenoid and generating an output to indicate a need for valve maintenance. Finally, there is provided a controller and a valve assembly configured to perform these methods.

An example embodiment relates to a method for switching a current in an electromagnet of a switchable solenoid valve, wherein, in successive switching cycles, the current is in each case switched on in order to close the valve against a force of a spring, and thereby the current is generated by electrical connection of the electromagnet to a voltage source. The example embodiment makes provision for the current in the electromagnet to be generated with a current direction opposite to the respective previous switching cycle in at least two successive switching cycles in a switched operation of the valve.

A method is provided for controlling a solenoid actuated fuel injector having a solenoid actuator which moves a pintle and needle arrangement such that the needle moves away from a valve seat to an open position and also includes circuitry which applies chopped hysteresis control subsequent to an energisation phase. The method includes a) obtaining a signal of the current or voltage across the solenoid; b) analyzing the voltage or current to detect a chopped hysteresis pulse; c) determining the time point of the end of said chopped hysteresis pulse; and d) applying a braking pulse to the solenoid, the timing of which is dependent on the results of step c).

The invention relates to a method for operating a piston pump (10) which is driven by means of a coil (1) of an electromagnet. A piston (2) of the piston pump (10) can be moved in a cylinder (3) for pumping purposes by means of the electromagnet. A voltage (U) is applied to the coil (1) during a switch-on period such that a current flows through the coil (1) and the piston (2) is accelerated, said voltage being applied by means of an actuation device (11). A time curve of an electric state variable (I, U) of the coil (1) is qualitatively detected, and the curve or a curve derived therefrom is analyzed in order to detect an impact of the piston (2) against a stop. The invention further relates to an actuation device and a piston pump.

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.

A control method of a fuel supply pump includes moving an anchor in the closing valve direction by passing a maximum drive current through the solenoid, and thereafter holding the anchor at a closing valve position by passing a holding current for keeping a closing valve state through the solenoid. The holding current is smaller than the maximum drive current. A current value of a first drive current is smaller than a current value of the holding current. A current value of a second drive current overlaps a range of the current value of the holding current. A current value of a third driving current is equal to or more than the current value of the holding current.

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.

Various embodiments include a method for controlling a pressure dissipation valve comprising a closure element, a spring applying a spring force urging the closure element toward the closed position, and an electromagnetic actuator responding to an applied voltage to urge the closure element to an open position. The method may include: applying a constant voltage until the closure element begins motion counter to the spring force; immediately ending the voltage upon the beginning of motion; thereafter, applying a pulsed voltage to the actuator to induce a substantially constant holding-open current intensity; maintaining the pulsed voltage for a predetermined duration to hold the closure element open; and interrupting the application of voltage after the predetermined duration, wherein the closure element moves into the closed position as a result of the spring force.