A method for switching over a solenoid valve having a movable valve body between a first position and a second position, wherein the method comprises at least the following method steps: a) adjusting a switching current to a pre-energization current intensity, in which the valve body remains in the present position, for a first time interval, and b) adjusting the switching current to a first switchover current intensity, which introduces a switchover movement of the valve body, for a second time interval.

In view of the foregoing issues, an object of the present invention is to provide a vehicle control device that reduces the constraints of heat generation and charging time of a booster circuit, and decreases favorably the fuel consumption and exhaust emission of an engine. A vehicle control device installed in a vehicle, the device includes: a battery; a high-voltage battery that has a voltage higher than a voltage of the battery; and a fuel injection device that injects fuel into an internal combustion engine, wherein the vehicle control device includes a control unit that determines whether to supply a drive current to the fuel injection device by the battery or supply a drive current to the fuel injection device by the high-voltage battery, and controls the fuel injection device.

An increase control unit causes to apply a first voltage to a coil of a fuel injection valve to increase a driving current of the coil to a peak value. A holding control unit stops application of the first voltage, when the driving current increases to the peak value, and subsequently switches between a first holding control and a second holding control. The first holding control is to apply a second voltage lower than the first voltage to the coil based on at least one of the peak value, the second voltage, and a fuel pressure, to hold the driving current at a target current. The second holding control is to apply the first voltage to the coil to hold the driving current at the target current. The holding control unit performs one of the first holding control and the second holding control which is switched.

A method of controlling the operation of a solenoid activated fuel injector, actuator being operated by applying a activation pulse profile to the solenoid. The method includes measuring the voltage across, or current through, the solenoid during a time period of the valve closing phase, subsequent to a valve opening phase. The method also includes determining at least one parameter from the measuring step. The method also includes controlling and varying the activation pulse profile during a subsequent activation/fueling cycle of the fuel injector based on the parameter.

Various embodiments include a method for operating a fuel injector with a solenoid drive having a hydraulic stop at a predetermined fuel pressure comprising: applying a first current profile to the solenoid including a first holding current value prespecifying the current flowing during a holding phase; determining a resulting first flux; determining a first force based on the first flux corresponding to a hydraulic force exerted on the armature by fuel; determining a deviation between the first force and an optimal force corresponding to the predetermined fuel pressure; determining a second holding current based on the first holding current and the determined deviation; and applying a second current profile to carry out a second injection process using the second holding current value to apply a hydraulic force on the armature by the fuel adapted to the optimal force value.

The objective of the present invention is to correct deviation in the injection amount and changes in the injection timing when the voltage of a high-voltage source for a drive device decreases. This drive device for a fuel injection device is equipped with a function whereby, when the pulse width of the injection pulse is set to an energization time 815 that closes a valve after a drive current has been switched to a maintenance current, the injection pulse width when the voltage of a high-voltage source has decreased is corrected so as to be longer than the injection pulse width when the voltage of the high-voltage source has not decreased, and, when the pulse width of the injection pulse is set to an energization time 804 that closes the valve before the drive current has been switched to the maintenance current, the absolute value of the amount of correction of the injection pulse width is made smaller than when the injection pulse width is set to the energization time 815 that closes the valve after the drive current has been switched to the maintenance current.

A valve device for liquids, especially for liquid plastic constituents of single- or multiple-constituent plastic mixtures, includes a valve housing with a liquid inlet and a metering valve, which has a discharge opening that can be closed by a closure element, a pressure control device acting on the liquid in the liquid inlet and comprising a control membrane which acts on the closure element. A shut-off diaphragm separates the pressure control device from the liquid inlet, and the pressure control device comprises a fluid-tight control chamber which is at least partially arranged in the valve housing, for storing a substantially incompressible fluid. A pressure generating device allows the control membrane to be subjected to pressure by the incompressible fluid arranged in the control chamber.

An injection control unit includes a constant-current control unit executing a constant current control to control a current of a coil to be in a predetermined current range lower than a peak current by allowing or interrupting a first voltage applied to the coil after the peak current starting to open an injector is applied to the coil driving the injector, and a high-voltage applying control unit applying a second voltage higher than the first voltage to the coil in a case where a condition that the current of the coil becomes lower than the predetermined current range is met when the constant-current control unit executes the constant current control.

Various embodiments include a method for operating a fuel injector with a solenoid drive having a hydraulic stop at a predetermined fuel pressure comprising: applying a first current profile to the solenoid including a first holding current value prespecifying the current flowing during a holding phase; determining a resulting first flux; determining a first force based on the first flux corresponding to a hydraulic force exerted on the armature by fuel; determining a deviation between the first force and an optimal force corresponding to the predetermined fuel pressure; determining a second holding current based on the first holding current and the determined deviation; and applying a second current profile to carry out a second injection process using the second holding current value to apply a hydraulic force on the armature by the fuel adapted to the optimal force value.

A method for simulating malfunctioning solenoid valves is disclosed. A current flows through a solenoid valve in order to achieve opening and closing. The closing is forced after the current supplied to the solenoid valve is activated at an activation time, and the opening is forced after the current is deactivated. The current is applied with a charging current strength before activation for a charging phase, and after activation, the current is increased to peak current strength and subsequently reduced to a holding current strength. The current strength is reduced to a deactivation current strength, after which the current strength increases again. A variation of the value or duration of the current strength or an application of an additional magnetic force is used to simulate a premature activation, a delayed activation, a premature deactivation, or a delayed deactivation.