An ignition apparatus inputs energy during a predetermined energy input period after the interruption of a primary electric current by an ignition switch and a discharge of an ignition plug caused by a secondary electric current. Moreover, the ignition apparatus includes a blow-off detection unit that detects, during the energy input period IGW after the start of the discharge by the ignition plug, occurrence of blow-off of the discharge. When the secondary electric current I2 drops below a blow-off detection electric current threshold value Ibo at a time instant tbo in a second region where it is impossible to perform a re-discharge after blow-off, the blow-off detection unit determines that blow-off has occurred and the ignition apparatus stops the energy input from an energy input unit to an ignition coil. By preventing unnecessary energy input, it is possible to suppress unnecessary electric power consumption and wear of electrodes of the ignition plug.

An ECU outputs an ignition signal and a discharge waveform control signal. An ignition device closes an ignition switching element in a period during which the ignition signal is input. After a stop of the input of the ignition signal and in a period of input of the discharge waveform control signal, the ignition device controls current flowing through a primary coil to a discharge current command value that is determined by the discharge waveform control signal by opening or closing a control switching element. A discharge control unit determines whether there is an abnormality. When it is determined that there is an abnormality, the ECU avoids control executed by the discharge control unit, and causes the discharge control unit to execute control during times of low-rotation and low-load operation of an internal combustion engine in order to determine whether the discharge control unit has returned to a normal state.

An ECU outputs an ignition signal and a discharge waveform control signal. An ignition device performs a closing operation of an ignition switching device while the ignition signal is input into the ignition device. The ignition device adjusts a current flowing through a primary coil to a discharge current command value determined based on the discharge waveform control signal, by performing an opening-closing operation of a control switching device in a period in which the discharge waveform control signal is input into the ignition device after an input of the ignition signal into the ignition device is stopped. The ECU sets the discharge current command value that is a command value for a discharge current of a spark plug to a higher value as a rotation speed is higher, and prolongs a duration, in which discharge controller controls the discharge current, as the rotation speed is lower.

An ECU outputs an ignition signal and a discharge waveform control signal. An ignition device performs a closing operation of an ignition switching device while the ignition signal is input into the ignition device. The ignition device adjusts a current flowing through a primary coil to a discharge current command value determined based on the discharge waveform control signal, by performing an opening-closing operation of a control switching device in a period in which the discharge waveform control signal is input into the ignition device after an input of the ignition signal into the ignition device is stopped. The ECU sets the discharge current command value that is a command value for a discharge current of a spark plug to a higher value as a rotation speed is higher, and prolongs a duration, in which discharge controller controls the discharge current, as the rotation speed is lower.

An ignition apparatus inputs energy during a predetermined energy input period after the interruption of a primary electric current by an ignition switch and a discharge of an ignition plug caused by a secondary electric current. Moreover, the ignition apparatus includes a blow-off detection unit that detects, during the energy input period IGW after the start of the discharge by the ignition plug, occurrence of blow-off of the discharge. When the secondary electric current I2 drops below a blow-off detection electric current threshold value Ibo at a time instant tbo in a second region where it is impossible to perform a re-discharge after blow-off, the blow-off detection unit determines that blow-off has occurred and the ignition apparatus stops the energy input from an energy input unit to an ignition coil. By preventing unnecessary energy input, it is possible to suppress unnecessary electric power consumption and wear of electrodes of the ignition plug.

In an ignition device of a spark-ignition internal combustion engine that performs ignition with high energy efficiency while reducing power to be input to a spark plug, after a DC-voltage-pulse generation circuit that generates a DC voltage pulse between electrodes of a spark plug is operated by a control circuit, an AC-pulse generation circuit that generates an AC pulse between the electrodes of the spark plug is operated. Furthermore, the control circuit controls the AC-pulse generation circuit with a plurality of group pulses and quiescent periods between the group pulses are provided.

An ignition apparatus includes a blow-off determining unit. The blow-off determining unit determines, when a secondary electric current drops below a predetermined threshold value Ia during a determination period, that blow-off has occurred; the determination period is a predetermined time period T from the start of a spark discharge by a main ignition circuit. Further, when it is determined that blow-off has occurred during a main ignition (full-transistor ignition), it is controlled to perform a continuing spark discharge after the main ignition in a next cycle. Moreover, a secondary electric current command value I2a in performing the continuing spark discharge is set to an electric current value that is obtained by adding a predetermined electric current value to the predetermined threshold value Ia used in the blow-off determination. Consequently, in the next cycle, it is possible to reliably prevent blow-off, thereby reliably preventing a misfire.

A maximum value of a discharge current from a capacitor 13, detected by a primary-side current detection means 24 disposed at a grounded end of the capacitor 13, is controlled such as not to exceed a predetermined first control value Y1. The first control value Y1 is derived based on magnetic saturation of a primary winding 3, with the control being performed by controlling the on-off state of an energy injection switching means 20. As a result, magnetic saturation of the primary winding 3 can be prevented, and the reliability of an ignition apparatus which incorporates an energy injection circuit 6 can be increased.

A method for controlling the operation of an ignition exciter with a rechargeable energy source supplying electricity to a solid-state switch is disclosed. The method includes charging the energy source at a first rate when the voltage of the energy source is less than a first voltage reference value.

A control apparatus for an internal combustion engine includes an ignition device and an electronic control unit. The ignition device includes an ignition plug that is provided in a combustion chamber of the internal combustion engine, and an ignition coil that is connected to the ignition plug. The electronic control unit is configured to: (i) acquire a temperature of the ignition device, and ii) make a discharge time of the ignition plug longer when the acquired temperature is low than when the acquired temperature is high.