An ignition control device includes a main ignition circuit to generate a spark discharge to a spark plug by controlling energization of a primary coil of an ignition coil for an internal combustion engine, an energy supply circuit that supplies energy based on a discharge continuation signal by controlling the energization of the primary coil during the spark discharge started by the operation of the main ignition circuit to supply a secondary current in the same direction as a main ignition continuously in a secondary coil of the ignition coil, a secondary current command circuit for outputting a command value of the secondary current based on the secondary current command signal, and an ignition control unit for setting signal values of the secondary current command signal and the discharge continuation signal.

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.

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 ignition device for an internal combustion engine with a charging coil, in particular disposed on a yoke core, with a starter wheel to induce a charging voltage in the charging coil by its rotation, with a first energy store which is connected to the charging coil via a rectifier, as well as with an electrical load which for its power supply, in particular during the starting process of the internal combustion engine is connected to a second energy store, wherein the second energy store is connected to the first energy store via a voltage converter. Furthermore, the invention relates to an internal combustion engine with such an ignition device and a method for its operation.

The subject matter of this specification can be embodied in, among other things, a method that includes receiving a collection of measurements of electric current amplitude in a primary winding of an engine ignition system having the primary winding and a spark plug, identifying an ignition start time, identifying an inflection point based on the plurality of measurements, determining an inflection point time representative of a time at which the identified inflection point occurred, determining a spark start time based on an amount of time between the ignition start time and the inflection point time, and providing a signal indicative of the spark start time.

An ignition control device includes a main ignition circuit to generate a spark discharge to a spark plug by controlling energization of a primary coil of an ignition coil for an internal combustion engine, an energy supply circuit that supplies energy based on a discharge continuation signal by controlling the energization of the primary coil during the spark discharge started by the operation of the main ignition circuit to supply a secondary current in the same direction as a main ignition continuously in a secondary coil of the ignition coil, a secondary current command circuit for outputting a command value of the secondary current based on the secondary current command signal, and an ignition control unit for setting signal values of the secondary current command signal and the discharge continuation signal.

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 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.

An ignition device includes a secondary current control circuit that receives a secondary current control signal IGa from an ECU, and a feedback circuit outputs a control signal for controlling energization of an primary coil to an energy supply circuit according to a result of comparison of a control value of the secondary current outputted from the secondary current control circuit and a detected value of the secondary current. Further, the ECU outputs a secondary current control signal IGa in accordance with engine parameters. Thereby, the secondary current substantially indicating the amount of energy that is supplied into the ignition coil from the energy supply circuit can be controlled in accordance with the operating condition of the engine. Therefore, it is possible to suppress excess or shortage of energy supplied from the energy supply circuit to an ignition coil from occurring.

An ignition apparatus for an internal combustion engine is provided. The ignition apparatus includes an ECU. The ECU calculates a target value E* of an energy input amount of energy inputted into a spark plug based on an in-cylinder flow velocity v, a cylinder pressure P, and an air-fuel ratio AFR. The ECU also calculates a command value I* of a secondary current based on the in-cylinder flow velocity and control an operation of a second circuit according to the target value E* and the command value I*. The calculation of the target value E* using the in-cylinder flow velocity v, the cylinder pressure P, and the air fuel ratio AFR enables the energy input amount to be controlled according to the operating state of the internal combustion engine. The calculation of the command value I* based on the in-cylinder flow velocity v enables the secondary current to be controlled so as to eliminate a risk of the blowout of sparks. The ignition apparatus is, thus, capable of variably changing the amount of energy inputted to the spark plug to improve the fuel consumption.