Ignitability of a fuel by a spark plug is improved while an increase in the number of ignition coils is suppressed. A control device for an internal combustion engine includes an ignition control unit 83 which controls energization of an ignition coil 300a and an ignition coil 300b which each provide electric energy to a spark plug which discharges in a cylinder of an internal combustion engine to ignite a fuel, and a discharge amount detection unit which detects an inter-electrode voltage of the spark plug. After the ignition control unit 83 discharges the spark plug using the electric energy of the ignition coil 300a, the ignition control unit estimates a voltage which is supply-able from the ignition coil 300a to the spark plug, and controls energization of the ignition coil so as to supply the electric energy of the second ignition coil 300b to the spark plug when a difference d between the estimated supply-able voltage and a required voltage based on the voltage detected by the discharge amount detection unit is equal to or less than a predetermined threshold value.

Ignitability of a fuel by a spark plug is improved while an increase in the number of ignition coils is suppressed. A control device for an internal combustion engine includes an ignition control unit 83 which controls energization of an ignition coil 300a and an ignition coil 300b which each provide electric energy to a spark plug which discharges in a cylinder of an internal combustion engine to ignite a fuel, and a discharge amount detection unit which detects an inter-electrode voltage of the spark plug. After the ignition control unit 83 discharges the spark plug using the electric energy of the ignition coil 300a, the ignition control unit estimates a voltage which is supply-able from the ignition coil 300a to the spark plug, and controls energization of the ignition coil so as to supply the electric energy of the second ignition coil 300b to the spark plug when a difference d between the estimated supply-able voltage and a required voltage based on the voltage detected by the discharge amount detection unit is equal to or less than a predetermined threshold value.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

A method of controlling an ignitor for a spark-ignition engine includes receiving, by a controller, at least one of fuel quality data regarding a fuel for the spark-ignition engine or a characteristic regarding the ignitor for the spark-ignition engine. The method additionally includes controlling, by the controller, an ignition energy characteristic of the ignitor in response to the at least one of the fuel quality data regarding the fuel or the characteristic regarding the ignitor for the spark-ignition engine.

A barrier-discharge-type ignition apparatus that can accurately determine the application voltage, of a barrier ignition plug, that causes a non-ignition discharge to occur. In the barrier-discharge-type ignition apparatus, in a combustion assist control, the voltage difference between the one-period-prior application voltage and the present-period application voltage in the AC period is calculated based on an application voltage detected by a voltage detection circuit; then, it is determined whether or not a discharge exists in the barrier ignition plug, based on the comparison between the voltage difference and a preliminarily set discharge determination threshold value.

Ignitability of a fuel by a spark plug is improved while an increase in the number of ignition coils is suppressed. A control device for an internal combustion engine includes an ignition control unit 83 which controls energization of an ignition coil 300a and an ignition coil 300b which each provide electric energy to a spark plug which discharges in a cylinder of an internal combustion engine to ignite a fuel, and a discharge amount detection unit which detects an inter-electrode voltage of the spark plug. After the ignition control unit 83 discharges the spark plug using the electric energy of the ignition coil 300a, the ignition control unit estimates a voltage which is supply-able from the ignition coil 300a to the spark plug, and controls energization of the ignition coil so as to supply the electric energy of the second ignition coil 300b to the spark plug when a difference d between the estimated supply-able voltage and a required voltage based on the voltage detected by the discharge amount detection unit is equal to or less than a predetermined threshold value.

Ignitability of a fuel by a spark plug is improved while an increase in the number of ignition coils is suppressed. A control device for an internal combustion engine includes an ignition control unit 83 which controls energization of an ignition coil 300a and an ignition coil 300b which each provide electric energy to a spark plug which discharges in a cylinder of an internal combustion engine to ignite a fuel, and a discharge amount detection unit which detects an inter-electrode voltage of the spark plug. After the ignition control unit 83 discharges the spark plug using the electric energy of the ignition coil 300a, the ignition control unit estimates a voltage which is supply-able from the ignition coil 300a to the spark plug, and controls energization of the ignition coil so as to supply the electric energy of the second ignition coil 300b to the spark plug when a difference d between the estimated supply-able voltage and a required voltage based on the voltage detected by the discharge amount detection unit is equal to or less than a predetermined threshold value.

An ignition control device is provided with an ignition coil including a primary coil and a secondary coil, a main ignition circuit performing a main ignition operation, an energy input circuit that performs an energy input operation for superposing a current having the same polarity to a secondary current, in which a signal generation circuit is provided to generate, based on a main ignition signal that controls the main ignition operation, at least one of an energy input signal controlling the energy input operation and a target secondary current command signal commanding a target secondary current value.

An ignition control device is provided with an ignition coil including a primary coil and a secondary coil, a main ignition circuit performing a main ignition operation, an energy input circuit that performs an energy input operation for superposing a current having the same polarity to a secondary current, in which a signal generation circuit is provided to generate, based on a main ignition signal that controls the main ignition operation, at least one of an energy input signal controlling the energy input operation and a target secondary current command signal commanding a target secondary current value.

An ignition device for an internal combustion engine includes an ignition coil, a first switch, a secondary current adjuster, and controller. The ignition coil includes a primary coil, a core, and a secondary coil. The first switch switches an energized state of the primary coil between an ON state and an OFF state. The secondary current adjuster adjusts a current value of a secondary current flowing through the secondary coil. The controller controls the secondary current adjuster so that a current value of the secondary current in at least a part of a charging period of the ignition plug, which is a period from when the energized state of the primary coil is switched from the ON state to the OFF state by the first switch to when dielectric breakdown occurs in the ignition plug, becomes smaller than a peak value of the secondary current after the dielectric breakdown occurs.