An injection control device controls the opening and closing of a fuel injection valve by performing peak current drive and constant current drive with respect to the fuel injection valve and controls injection of fuel from the fuel injection valve to an internal combustion engine. The injection control device includes an energization control unit that performs constant current switching control of an energization current to the fuel injection valve. The energization control unit is configured to, when the energization current to the fuel injection valve is to be stopped, controls an energization stop timing of the energization current such that a flyback period is equal to a first predetermined time period.

An injection control device of capable of correcting an energization time even in an S/N non-guaranteeable situation includes: an energization controller calculating an energization time correction amount based on an area correction performed by an energization time correction amount calculator regarding electric current flowing in a fuel injection valve when the fuel injection valve is electrically driven for injecting fuel; and an energization instruction time calculator correcting an energization instruction time for fuel injection in a next cycle and thereafter by using the energization instruction time correction amounts in or before a current cycle.

Appropriate detection of an abnormality of voltage information, which is a basis for correcting a fuel injection amount, becomes possible. For this reason, a fuel injection control device 127, which has a drive IC 208 controlling a fuel injection drive unit 207a to supply a high voltage to a solenoid 405 so as to open a fuel injection valve 105 and controlling the fuel injection drive unit 207a to supply a low voltage to the solenoid 405 so as to hold a valve-open state of the fuel injection valve 105, includes: a drive voltage input unit 211 that measures and outputs voltage information based on an upstream voltage of the solenoid 405 of the fuel injection valve 105 and a downstream voltage of the solenoid 405; a fuel injection amount correction unit 213 that corrects a fuel injection amount of the fuel injection valve 105 based on the voltage information output from the drive voltage input unit 211; and a voltage input function abnormality detection unit 212 that detects whether an output of the drive voltage input unit 211 is abnormal based on the voltage information output from the drive voltage input unit 211.

An injection control device includes: a conversion coefficient setter setting a conversion coefficient for each injection when a fuel injection valve is driven by an electric current to inject fuel from the fuel injection valve; and an area correction unit calculating an energization time correction amount by performing area correction using the conversion coefficient for each injection regardless of whether a drive current of the fuel injection valve has reached a target peak current or not.

An electromagnetic valve driving device which drives a fuel injection valve having a solenoid coil, includes: a regenerative switching element disposed between a first end portion of the solenoid coil and the ground; and a control unit configured to control the regenerative switching element to be in an ON state or an OFF state, wherein the control unit includes: a voltage detection unit configured to detect a voltage of the first end portion of the solenoid coil; and an abnormality detection unit configured to detect an abnormality of the regenerative switching element on the basis of the voltage detected by the voltage detection unit.

This detector includes: a filtering unit performing a first filtering process of performing a filtering process on a first waveform or a second filtering process of performing a filtering process on a second waveform; a detection unit detecting a timing of a first peak value corresponding to a predetermined peak value of a third waveform; a correction unit which corrects a deviation of a detection value corresponding to a timing detected by the detection unit with respect to a timing when the fuel injection valve is actually opened or closed based on a difference between the first peak value of the third waveform and a second peak value of the third waveform appearing after the first peak value; and a detecting unit which detects one or both of the opening and closing of the fuel injection valve based on the detection value corrected by the correction unit.

An electromagnetic valve driving device which drives a fuel injection valve having a solenoid coil, includes: a regenerative switching element disposed between a first end portion of the solenoid coil and the ground; and a control unit configured to control the regenerative switching element to be in an ON state or an OFF state, wherein the control unit includes: a voltage detection unit configured to detect a voltage of the first end portion of the solenoid coil; and an abnormality detection unit configured to detect an abnormality of the regenerative switching element on the basis of the voltage detected by the voltage detection unit.

Provided is an injector control unit capable of preventing unintended fuel injection other than an engine drive period. The injector control unit includes a cutoff mechanism for cutting off current supply to the injector from at least the ignition OFF to the next ignition ON.

There is provided a method of energising a solenoid of a valve assembly, comprising the steps of applying a positive over boost voltage to the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, and then applying a negative braking voltage to brake the movement of the plunger during movement of the moveable plunger. There is also provided a method of energising a solenoid of a valve assembly, the method comprising the steps of receiving a demand signal to actuate the valve, applying a wait time after receipt of the demand signal, applying a positive over boost voltage across the solenoid to actuate a moveable plunger to open or close a flow path through the valve assembly, monitoring the solenoid closure time, and adjusting one or more input variables in order to control the solenoid closure time. There is also provided a method of monitoring the solenoid closure time over a plurality of different energising and de-energising cycles of the solenoid and generating an output to indicate a need for valve maintenance. Finally, there is provided a controller and a valve assembly configured to perform these methods.

This detector includes: a filtering unit performing a first filtering process of performing a filtering process on a first waveform or a second filtering process of performing a filtering process on a second waveform; a detection unit detecting a timing of a first peak value corresponding to a predetermined peak value of a third waveform; a correction unit which corrects a deviation of a detection value corresponding to a timing detected by the detection unit with respect to a timing when the fuel injection valve is actually opened or closed based on a difference between the first peak value of the third waveform and a second peak value of the third waveform appearing after the first peak value; and a detecting unit which detects one or both of the opening and closing of the fuel injection valve based on the detection value corrected by the correction unit.