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.

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.

Temperature measuring device for measuring the temperature of a member, the member including a component controlled by a control signal, active at most during at least one limited activity interval, and transmitted to the component via two wires, a temperature probe connected to the two wires, in parallel with the component, and a diode, connected between a terminal of the component and a terminal of the probe connected to the same wire, in order to allow the passage of a current in the component only in a first direction, the temperature measurement being performed by a current flowing in a second direction, opposite to the first direction, outside of the activity interval.

The invention relates to a method for determining an electrical resistance value for a fuel injector having a solenoid drive. The method comprises the following: (a) applying a voltage pulse to the solenoid drive of the fuel injector, (b) sensing a temporal progression of the current intensity of a current (I) flowing through the solenoid drive, (c) calculating a series of linked fluxes () as a function of current intensity (I), wherein each linked flux () is calculated on the basis of the temporal progression of voltage and current intensity (I) and on the basis of a hypothetical resistance value from a series of hypothetical resistance values, and (d) selecting one of the hypothetical resistance values as a determined resistance value on the basis of an analysis of the calculated series of linked fluxes (). The invention further relates to a method for determining a temperature of a coil of a fuel injector having a solenoid drive, to a motor controller, and to a computer program.

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.

A fuel injection controller includes an energization time period calculation portion adapted to calculate an energization time period of a coil responsive to a target injection amount; and a rise control portion adapted to apply a boosted voltage to the coil, along with start of the energization time period, and to raise an current flowing through the coil to a predetermined threshold value. When a range where timing of the current raised to have a peak value at the threshold value appears in accordance with a range of an operating temperature of the coil is defined as a peak appearance range W1, the target injection amount is set such that timing of completion of the energization time period Ti is timing deviated from the peak appearance range W1.

A boost switching device (115) for generating a boosted high voltage (Vh) includes a slew rate selection circuit (115s), decreases a selection value (k) to suppress noises when the temperature of the boost switching device (115) is low, and increases the selection value (k) to suppress a temperature increase when the temperature thereof is high. An internal average temperature of an in-vehicle engine control apparatus (100) is detected by an environmental temperature detection device (139), reference data (400) provided in a calculation control circuit unit (130) is used to calculate a relationship between a permissible engine rotational speed (Nk) at which the split injection can be continued at a current measured environmental temperature (Tx) and the selection value (k), and an appropriate selection value (k) corresponding to a current engine rotational speed (Ne) is determined.

An in-vehicle engine control apparatus allowing split injection frequency or split injection of fuel while preventing a driving switch element for fuel injecting electromagnetic coils and a boosting switch element for generating a boosted high voltage from being overheated. An operation control circuit portion has reference data of measured environmental temperature vs allowable engine rotational speed with a selected value of the split injection frequency being a parameter, and determines the selected value having, as an upper limit, a split injection frequency which makes the internal temperature of the boosting switch element or a rapidly exciting switch element a predetermined allowable limit value in association with the present environmental temperature detected by an average environmental temperature detection element in a case and the present engine rotational speed detected by an engine rotation sensor.

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.

The present disclosure is a method of controlling an operation of a swirl control valve for a diesel engine, which predicts an internal temperature of a swirl control valve for a diesel engine, and limit a motor duty ratio of the swirl control valve based on the predicted temperature. In particular, the method predicts an internal temperature (a temperature of a motor coil) of a swirl control valve in real time through modelling, and controls a motor duty ratio of the swirl control valve, so that the internal temperature does not reach a maximum coil temperature, at which the swirl control valve is damaged and/or is irresistible, based on the predicted temperature.