A metering valve supplies fuel to and block fuel from a pressurizing chamber by moving a valve body by switching between energization and de-energization of an electromagnetic unit. An energization control unit performs a valve closing control and a valve opening control to reduce operating sound in one opening and closing period in which the valve body opens and closes. A time control unit controls, on determination that the energizing period of the electromagnetic unit exceeds the upper limit value, a moving speed of the valve body when the valve body moves to a valve closing side, such that the energization period of the electromagnetic unit in the one opening and closing period does not exceed the upper limit value, thereby to cause the energization control unit to perform both the valve closing control and the valve opening control in the one opening and closing period.

A metering valve supplies fuel to and block fuel from a pressurizing chamber by moving a valve body by switching between energization and de-energization of an electromagnetic unit. An energization control unit performs a valve closing control and a valve opening control to reduce operating sound in one opening and closing period in which the valve body opens and closes. A time control unit controls, on determination that the energizing period of the electromagnetic unit exceeds the upper limit value, a moving speed of the valve body when the valve body moves to a valve closing side, such that the energization period of the electromagnetic unit in the one opening and closing period does not exceed the upper limit value, thereby to cause the energization control unit to perform both the valve closing control and the valve opening control in the one opening and closing period.

A system, method and circuit restricts the amount of a first fuel being provided to a duel-fuel engine, for example a diesel—natural gas engine; wherein a secondary circuit is provided, in parallel, to the circuit formed between the engine control unit, first fuel injector, and ground comprising a dummy load, and a normally closed switch inserted in the first fuel injection circuit; such that when the normally open switch is in a closed state the dummy load provides a resistance to the second sub-circuit, such that a total resistance in the second sub-circuit is equal to a total resistance in the first sub-circuit when the normally closed switch is in a closed state.

A system, method and circuit restricts the amount of a first fuel being provided to a duel-fuel engine, for example a diesel—natural gas engine; wherein a secondary circuit is provided, in parallel, to the circuit formed between the engine control unit, first fuel injector, and ground comprising a dummy load, and a normally closed switch inserted in the first fuel injection circuit; such that when the normally open switch is in a closed state the dummy load provides a resistance to the second sub-circuit, such that a total resistance in the second sub-circuit is equal to a total resistance in the first sub-circuit when the normally closed switch is in a closed state.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

A method to estimate the temperature of an electromagnetic actuator, which entails a preliminary step in which to define a first threshold value for the current or for the voltage; and define a characteristic curve of the actuator family in the plane temperature/time needed to reach the threshold value; a step in which to carry out a reference measurement, in which, using the characteristic curve, a reference time needed by the electromagnetic actuator to reach the first threshold value is associated with a known reference temperature; and a step in which to carry out a series of measurements in which to determine the time needed by the electromagnetic actuator to reach the first threshold value, calculate the deviation between the time needed by the electromagnetic actuator to reach the first threshold value and the reference time; and determine the temperature of the electromagnetic actuator, using the characteristic curve, by associating the temperature of the electromagnetic actuator with the sum of the deviation and of the reference time.

Disclosed is a method for discharging the pressure in a fuel supply rail of an injection system of an engine, the fuel injection rail connected to a fuel tank by piezo-electric injectors, each including a needle and a piezo-electric actuator pressing on a servo valve of the injector. The injection system includes a fuel pressure sensor and an electrical generator transmitting electric current pulses to each actuator. When the accelerator is released, a first electrical command allows determination of a moment of opening of the respective servo valve without triggering an injection. A second electrical command triggers a discharge of fuel from the fuel supply rail to the tank and therefore to discharge the pressure of the supply rail without triggering an injection. The second electrical command charges the piezo-electric actuator between a first voltage level that opens the servo valve, and a second voltage level triggering an injection.

A method for determining a characteristic variable for opening and/or closing a flow-through opening of a solenoid valve, in which solenoid valve a solenoid coil is energized to raise an armature to open the flow-through opening for a fluid. During operation of the solenoid valve, a profile of a current in the solenoid coil being determined, and using a pattern recognition method based on artificial intelligence, the characteristic variable(s) is/are determined based on at least one section of the profile or a profile derived therefrom using a neural network. A method for applying and for training a pattern recognition method based on artificial intelligence are also described.

A method for determining a characteristic variable for opening and/or closing a flow-through opening of a solenoid valve, in which solenoid valve a solenoid coil is energized to raise an armature to open the flow-through opening for a fluid. During operation of the solenoid valve, a profile of a current in the solenoid coil being determined, and using a pattern recognition method based on artificial intelligence, the characteristic variable(s) is/are determined based on at least one section of the profile or a profile derived therefrom using a neural network. A method for applying and for training a pattern recognition method based on artificial intelligence are also described.

An injection control device includes: an instruction output unit outputting an instruction energization time that is an instruction value of an energization time of a fuel injection valve corresponding to a target injection amount; an energization controller controlling energization of the fuel injection valve based on the instruction energization time; an area corrector correcting an area of an electric current flowing through the fuel injection valve when the fuel injection valve is driven by the electric current, calculating a correction time of the energization time, and correcting the instruction energization time; an abnormality determiner determining that an abnormality related to the area correction has occurred when the correction time reaches a predetermined upper limit value; and a normal-return determiner executing, after the abnormality determiner determines that the abnormality related to the area correction has occurred, a normal-return determination at an execution timing of when a degree of influence of the abnormality on an emission becomes equal to or less than a predetermined value, for determining whether or not an abnormal state in which the abnormality related to the area correction has been caused has returned to a normal state.