An engine fuel control system includes a fuel metering valve operable to control the flow of fuel between a supply line and a delivery line. The delivery line is configured to receive fuel from one or more fuel pumps. The engine fuel control system further includes a pressure raising arrangement which receives the fuel flow from the delivery line and raises the fuel pressure therein. The engine fuel control system further includes a pressure sensor arranged to sense the pressure of the fuel in the supply line between the one or more fuel pumps and the fuel metering valve, or to sense the pressure of the fuel in the delivery line between the fuel metering valve and the pressure raising arrangement.

An engine fuel control system includes a fuel metering valve operable to control the flow of fuel between a supply line and a delivery line. The delivery line is configured to receive fuel from one or more fuel pumps. The engine fuel control system further includes a pressure raising arrangement which receives the fuel flow from the delivery line and raises the fuel pressure therein. The engine fuel control system further includes a pressure sensor arranged to sense the pressure of the fuel in the supply line between the one or more fuel pumps and the fuel metering valve, or to sense the pressure of the fuel in the delivery line between the fuel metering valve and the pressure raising arrangement.

A gas injector for the direct injection of gaseous fuel into a combustion chamber of an internal combustion engine, including a valve seat, a valve needle, which in response to a lift releases a first cross-sectional area at the valve seat, and a gas control region, which is situated at the valve needle and defines a second cross-sectional area together with a component surrounding the valve needle, and in response to a lift, a change in the first cross-sectional area at the valve seat differs from a change in the second cross-sectional area at the gas control region.

A gas injector for the direct injection of gaseous fuel into a combustion chamber of an internal combustion engine, including a valve seat, a valve needle, which in response to a lift releases a first cross-sectional area at the valve seat, and a gas control region, which is situated at the valve needle and defines a second cross-sectional area together with a component surrounding the valve needle, and in response to a lift, a change in the first cross-sectional area at the valve seat differs from a change in the second cross-sectional area at the gas control region.

Various embodiments include a method for operating a fuel injector comprising: applying a first current to a solenoid to perform a first injection process and inject a predefined injection quantity; determining a value of a system parameter indicating the relationship between the actual fuel quantity and the predefined quantity; determining, on the basis of the value of the system parameter, whether the actually injected fuel quantity is smaller than the predefined fuel quantity by a predefined amount corresponding to a disparity between a magnetic force exerted on the armature in the direction of the pole piece and an opposite hydraulic force exerted on the armature by fuel; and if it was determined that the quantities differ by enough, applying a second current to the solenoid to perform a second injection; wherein the second current exerts a lower magnetic force on the armature in the direction of the pole piece.

Various embodiments include a method for operating a fuel injector comprising: applying a first current to a solenoid to perform a first injection process and inject a predefined injection quantity; determining a value of a system parameter indicating the relationship between the actual fuel quantity and the predefined quantity; determining, on the basis of the value of the system parameter, whether the actually injected fuel quantity is smaller than the predefined fuel quantity by a predefined amount corresponding to a disparity between a magnetic force exerted on the armature in the direction of the pole piece and an opposite hydraulic force exerted on the armature by fuel; and if it was determined that the quantities differ by enough, applying a second current to the solenoid to perform a second injection; wherein the second current exerts a lower magnetic force on the armature in the direction of the pole piece.

A drive unit of a fuel injection device includes a driver circuit. The driver circuit opens and closes a valve element of the fuel injection device by supplying a drive current to the fuel injection device. The driver circuit supplies the drive current to open the valve element and sets the drive current to zero in an intermediate lift area. The intermediate lift area is an area is which a lift amount of the valve element is smaller than a maximum target lift amount.

A drive unit of a fuel injection device includes a driver circuit. The driver circuit opens and closes a valve element of the fuel injection device by supplying a drive current to the fuel injection device. The driver circuit supplies the drive current to open the valve element and sets the drive current to zero in an intermediate lift area. The intermediate lift area is an area is which a lift amount of the valve element is smaller than a maximum target lift amount.

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 invention relates to a method and a device for actuating an injection valve, which has a piezo actuator and a nozzle needle, of a fuel injection system of an internal combustion engine, in which method a control unit, in a manner dependent on a setpoint stroke height of the piezo actuator in successive injection cycles, outputs a control signal for changing the actual stroke height of the piezo actuator, characterized in that the control unit changes the setpoint stroke height of the piezo actuator, for compensation of the temperature dependency of the capacitance of the piezo actuator, in a manner dependent on the temperature of said piezo actuator.