Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

An internal combustion engine control device includes an ignition control unit which executes an ignition control for controlling an ignition plug which discharges electricity in a cylinder of an internal combustion engine to ignite fuel. The ignition control unit executes the ignition control such that a predetermined ignition electric energy is supplied to the ignition plug when the ignition plug performs ignition, and a predetermined pre-heating electric energy smaller than the ignition electric energy is supplied to the ignition plug before the ignition plug performs ignition.

An internal combustion engine control device includes an ignition control unit which executes an ignition control for controlling an ignition plug which discharges electricity in a cylinder of an internal combustion engine to ignite fuel. The ignition control unit executes the ignition control such that a predetermined ignition electric energy is supplied to the ignition plug when the ignition plug performs ignition, and a predetermined pre-heating electric energy smaller than the ignition electric energy is supplied to the ignition plug before the ignition plug performs ignition.

An ignition device for an internal combustion engine includes a switching circuit and a control circuit. The control circuit monitors a voltage level inputted to a switching device which is installed in the switching circuit and connected to a primary winding of an ignition coil. The control circuit includes an overvoltage protection circuit which outputs an energization inhibit signal to inhibit energization of the switching device when the monitored voltage level is higher than an overvoltage threshold level. When the monitored voltage level exceeds the overvoltage threshold level in an output duration in which the energization control signal is outputted, the overvoltage protection circuit stops output of the energization inhibit signal until the output duration expires. This enables the switching device to be protected from damage and an ignition operation to be executed at a correct timing to eliminate a risk of damage to the internal combustion engine.

An ignition control device includes an ignition coil, a main ignition circuit unit for performing a main ignition operation, and an energy input circuit unit for performing an energy input operation. A main ignition signal generation circuit generates a main ignition signal such that a point in time when a waiting time has passed from a detection start time of a first signal of an ignition control signal at which a signal level of the ignition control signal changed from a first level to a second level for the first time, and the signal level of the ignition control signal is the second level, is a start of the main ignition signal, and a detection end time of a second signal of the ignition control signal at which the signal level of the ignition control signal shifts to the first level thereafter is an end of the main ignition signal.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

Due to changes in a flow of an air-fuel mixture in a cylinder, reliable ignition due to spark discharge may not be possible. Therefore, an ignition control unit 24 includes a secondary voltage calculation unit 31 that calculates an average value of a secondary voltage generated on a secondary side of an ignition coil, an irregular flow ratio calculation unit 32 that calculates a ratio of cycles in which the average value of the secondary voltage is equal to or less than a set average value with respect to a cycle of the internal combustion engine in a predetermined period as an irregular flow ratio indicating that the flow of the air-fuel mixture in the cylinder is irregular, and an ignition operation amount correction unit 37 that corrects an ignition operation amount so that the irregular flow ratio is equal to or less than the set ratio value that is the target to be reached of the irregular flow ratio.

In an ignition control device for an internal-combustion engine, signal separation circuitry receives and separates an ignition control signal that is an integrated signal of a main ignition signal for controlling the main ignition operation, an energy input signal for controlling the energy input operation, and a target secondary current command signal. The ignition control signal is formed of a first signal and a second signal that are pulsed signals. The signal separation circuitry is configured to generate, from the ignition control signal, the main ignition signal based on rising edges of the first signal and the second signal as pulse-waveform information of the first signal and the second signal, generate the energy input signal based on a pulse width of the second signal as pulse-waveform information of the second signal, and generate the target secondary current command signal based on pulse-waveform information of the first signal.

In an ignition control device for an internal-combustion engine, signal separation circuitry receives and separates an ignition control signal that is an integrated signal of a main ignition signal for controlling the main ignition operation, an energy input signal for controlling the energy input operation, and a target secondary current command signal. The ignition control signal is formed of a first signal and a second signal that are pulsed signals. The signal separation circuitry is configured to generate, from the ignition control signal, the main ignition signal based on rising edges of the first signal and the second signal as pulse-waveform information of the first signal and the second signal, generate the energy input signal based on a pulse width of the second signal as pulse-waveform information of the second signal, and generate the target secondary current command signal based on pulse-waveform information of the first signal.