A fuel injection control apparatus including a microprocessor. The microprocessor is configured to perform calculating a target injection time, determining a first crank angle defining a start of fuel injection and a second crank angle defining an end of fuel injection, controlling a fuel injector in a first injection mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or a second injection mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, and the controlling including controlling the fuel injector so as to inject the fuel in the first injection mode first and in the second injection mode last when the fuel is injected multiple times between an intake stroke and a compression stroke.

An object of the present invention is to provide a control device of an injector capable of suppressing the influence of pressure reduction boiling even if pressure in a combustion chamber is low. In a case where the temperature of fuel injected from a fuel injection valve is within a set high temperature region and the pressure of the combustion chamber is within a set low pressure region, the control device of an in-cylinder direct injection-type injector according to the present invention controls to increase a lift amount of the injector as compared to the case of a low temperature region or a high pressure region.

Various embodiments include a method for operating a fuel injector having a hydraulic stop comprising: applying a first current profile to a solenoid drive to inject a predetermined injection quantity; ascertaining a first value of a parameter correlating to a velocity of the armature when reaching the hydraulic stop; determining whether the first value of the parameter is greater than a first threshold value; and if the first value of the parameter is greater than the first threshold value, applying a second current profile to the solenoid drive to carry out a second injection procedure. The second current profile in comparison with the first current profile exerts a lower magnetic force in the direction of the pole piece on the armature.

A fuel injection control apparatus including a microprocessor. The microprocessor is configured to perform calculating a target injection time, determining a first crank angle defining a start of fuel injection and a second crank angle defining an end of fuel injection, controlling a fuel injector in a first injection mode in which the fuel is injected for the first target injection time from a first time point corresponding to the first crank angle or a second injection mode in which the fuel is injected for the second target injection time from a second time point corresponding to a target crank angle, and the controlling including controlling the fuel injector so as to inject the fuel in the first injection mode first and in the second injection mode last when the fuel is injected multiple times between an intake stroke and a compression stroke.

Disclosed is a method for regulating the duty cycle of a controlled current signal of a conversion module of a voltage converter including a step of measuring, by the microcontroller, the duty cycle of the envelope of the controlled current signal, and when the value of the duty cycle is below a predetermined threshold, a step of controlling, by the microcontroller, the current control module to decrease the amplitude of the control signal and that the duty cycle of the envelope of the controlled current signal thus tends toward a predetermined threshold, or when the value of the duty cycle is higher than the predetermined threshold, a step of controlling, by the microcontroller, the current control module so the current control module increases the amplitude of the controlled current signal and that the duty cycle of the envelope of the controlled current signal thus tends toward the predetermined threshold.

An object of the present invention is to provide a control device of an injector capable of suppressing the influence of pressure reduction boiling even if pressure in a combustion chamber is low. In a case where the temperature of fuel injected from a fuel injection valve is within a set high temperature region and the pressure of the combustion chamber is within a set low pressure region, the control device of an in-cylinder direct injection-type injector according to the present invention controls to increase a lift amount of the injector as compared to the case of a low temperature region or a high pressure region.

A control device controls a drive current that flows through a drive coil of a fuel injection valve that is electromagnetically driven. A control device includes a determination unit configured to determine whether a supply fuel pressure, which is a pressure of fuel supplied to the fuel injection valve, is higher than a determination pressure at which the fuel pressure is determined abnormally high; a first control unit configured to control the drive current in a first mode when the determination unit determines that the supply fuel pressure is not higher than the determination pressure; and a second control unit configured to control the drive current in a second mode that facilitates maintaining of the fuel injection valve in an open state more than in the first mode when the determination unit determines that the supply fuel pressure is higher than the determination pressure.

A method of injecting fuel with a fuel injector includes applying a spill valve current to close a spill valve and applying a control valve current to move a control valve to an injection position. The method also includes discontinuing the application of the spill valve current to open the spill valve and preventing a return of the control valve to a non-injection position while detecting a timing when the spill valve opens.

A fuel injection control method of injecting fuel to a combustion chamber of an engine through an injector, the method may include pre-energizing to drive the injector during a predetermined pre-energizing time; and performing, by the controller, a main injection in which the injector is controlled by the controller to inject the fuel into the combustion chamber by a target injection amount, after the pre-energizing of the injector, wherein the pre-energizing magnetizes an injector coil of the injector in advance by applying the amount of current preventing the flow rate of the fuel from being generated by the pre-energizing, to the injector during the pre-energizing time.

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.