A method for determining a reference current curve for a fuel injector having a magnetic coil drive in an internal combustion engine of a motor vehicle includes: (a) applying a first voltage pulse to the magnetic coil drive to open the fuel injector, (b) applying a holding voltage to the magnetic coil drive to hold the fuel injector open, (c) switching off the holding voltage, (d) waiting for substantially no current to flow through the magnetic coil drive for a predetermined time period that is sufficiently short that the fuel injector remains open, (e) applying a second voltage pulse to the magnetic coil drive, and (f) recording a time-based curve of the current that flows through the magnetic coil drive during the second voltage pulse, which forms the reference current curve. This reference current curve is used for determining a time of a predetermined opening state of the fuel injector.

In voltage boosting circuit for performing rapid power supply to a plurality of electromagnetic coils that drive fuel-injection electromagnetic valves, an overcurrent from vehicle battery is suppressed, and continuous noise is prevented from being produced. Each of rapid-power-supply voltage boosting capacitors that are connected in parallel with each other is charged from corresponding one of a pair of induction devices, which are asynchronously on/off-magnetized by first and second voltage boosting control circuits, by way of corresponding one of charging diodes in a pair; when addition value of exciting currents for induction devices in a pair continuously exceeds predetermined value, driving modes of one of and the other one of voltage boosting control circuits are set to large-current low-frequency mode and to small-current high-frequency mode, respectively, so that on/off timing of exciting current becomes irregular even when respective inductances values of induction devices in a pair are close to each other.

A method for determining the point in time of a predetermined open state of a fuel injector having a solenoid drive for a combustion engine of a motor vehicle. The method includes detection of a time profile of the current level of a current flowing through the solenoid drive during a boost phase, where the solenoid drive is subjected to a first voltage during a first part of the boost phase and a second voltage during a second part of the boost phase. The second voltage is selected so that the current level of the current flowing through the solenoid drive during the second part of the boost phase essentially remains unchanged, and determination of a point in time at which the detected time profile of the current level has an extreme value, where the determined point in time is the point in time of the predetermined open state.

A system and method are described for providing hydrogen gas to an internal combustion engine based, in part, on selected data retrieved from a vehicle interface to reduce particulate and harmful matter from emissions and improve efficiency.

In a drive unit of a fuel injection device, an electric current is supplied to the fuel injection device by applying a high voltage to the fuel injection device from a high voltage source whose voltage is boosted to a voltage higher than a battery voltage at the time of opening a valve of the fuel injection device. Thereafter, the electric current supplied to the fuel injection device is lowered to a current value at which a valve element cannot be held in a valve open state by stopping the applying of the high voltage from the high voltage source. Thereafter, in a stage where a supply current is switched to a hold current, another high voltage is applied to the fuel injection device from the high voltage source.

The present disclosure relates to injection valves. The teachings thereof may be embodied in various valves, fuel injectors, and methods for controlling valves. An example method for setting operational parameters of a fuel injector may include: determining a measurement-specific maximum current value; applying a voltage pulse to the coil drive of the fuel injector; detecting a time curve of the current intensity of a current flowing through the coil drive; ending the voltage pulse when the detected current intensity reaches the maximum current value; and storing the time curve of the detected current intensity. The method may include generating a plurality of differential curves each based on two stored time curves of the detected current intensity for successive measurements; determining a peak current for driving the actuator of the fuel injector based at least in part on the plurality of differential curves; and operating the coil at the determined peak current.

A booster circuit installed in a fuel injection device of an internal combustion engine, wherein malfunctions and characteristic changes of the booster circuit are detected, among which the detection distinguishes between decreases in capacity caused by deterioration or broken wires in a booster capacitor, and failures of a current monitor circuit, coil, externally connected fuel injection valve, and other components. The range of decrease in boost voltage when the fuel injection valve is opened is monitored, as is the range of increase per switch performed in order to restore the boost voltage. This makes it possible to detect malfunctions and characteristic changes of the booster circuit.

In a drive unit of a fuel injection device, an electric current is supplied to the fuel injection device by applying a high voltage to the fuel injection device from a high voltage source whose voltage is boosted to a voltage higher than a battery voltage at the time of opening a valve of the fuel injection device. Thereafter, the electric current supplied to the fuel injection device is lowered to a current value at which a valve element cannot be held in a valve open state by stopping the applying of the high voltage from the high voltage source. Thereafter, in a stage where a supply current is switched to a hold current, another high voltage is applied to the fuel injection device from the high voltage source.

A fuel injection controller includes an increase control portion applying the boost voltage to the coil to increase a coil current to a first target value, and a constant current control portion applying a voltage to the coil to hold the coil current to a second target value. A threshold is an energization time period that is necessary to reach a boundary point between a seat throttle area of a property line and an injection-port throttle area of the property line from an energization start time point. An initial-current applied time period is from the energization start time point that the boost voltage starts to be applied to the coil to a time point that the coil current is decreased to the second target value. The increase control portion controls the coil current such that the initial-current applied time period is less than the threshold.