An ignition apparatus includes a spark plug having a high voltage electrode and an external electrode facing each other across a gap and being configured to generate a spark discharge in the gap to ignite a combustible fuel mixture in a combustion chamber of an internal combustion engine, an ignition coil device configured to generate a predetermined high voltage and supply the high voltage to the high voltage electrode to form a path for the spark discharge in the gap, a high frequency power supply having a band-pass filter and being configured to supply an alternating current to the spark discharge path, and a control device configured to control operation timing of the high frequency power supply. The band-pass filter passes a frequency of from 1 MHz to 4 MHz.

An ignition apparatus includes a spark plug having a high voltage electrode and an external electrode facing each other across a gap and being configured to generate a spark discharge in the gap to ignite a combustible fuel mixture in a combustion chamber of an internal combustion engine, an ignition coil device configured to generate a predetermined high voltage and supply the high voltage to the high voltage electrode to form a path for the spark discharge in the gap, a high frequency power supply having a band-pass filter and being configured to supply an alternating current to the spark discharge path, and a control device configured to control operation timing of the high frequency power supply. The band-pass filter passes a frequency of from 1 MHz to 4 MHz.

Air/fuel mixture is received from a combustion chamber of the internal combustion engine into an enclosure about a flame kernel initiation gap between a first ignition body and a second ignition body. Air/fuel mixture received into the enclosure is directed into a flame kernel initiation gap. The mixture is then ignited in the flame kernel initiation gap.

In a method for creating a spark across a spark gap, in particular for igniting a flammable liquid to measure its flash point, by means of a spark generator which comprises an ignition transformer, wherein the spark generator, on the primary side of the ignition transformer, comprises at least one DC voltage source and, on the secondary side of the ignition transformer, comprises two electrodes delimiting the spark gap to be formed, wherein voltage pulses from the DC voltage source are applied to the ignition transformer on the primary side thereof, which voltage pulses generate ignition voltage pulses on the secondary side, the ignition transformer is operated in a first phase according to the flyback converter principle and in a subsequent, second phase according to the forward converter principle.

To suppress a failure of ignition of a fuel caused by a spark plug while suppressing wear of an electrode of the spark plug in an internal combustion engine. A control device 1 for an internal combustion engine includes an ignition control unit that controls energization of an ignition coil 300 that applies electric energy to a spark plug 200 that discharges in a cylinder 150 of an internal combustion engine 100 to ignite a fuel. The ignition control unit continuously transmits a first pulse signal (pulse signal for corona discharge) to an igniter connected to the ignition coil 300 before dielectric breakdown between electrodes of the spark plug 200, and continuously transmits a second pulse signal (pulse signal for arc discharge) to the igniter after the dielectric breakdown between the electrodes of the spark plug 200 to control the energization of the ignition coil 300. At this time, a period of the pulse signal for corona discharge is shorter than a period of the pulse signal for arc discharge.

There is provided an ignition apparatus that performs optimum energy control by suppressing a secondary current at a time when the ignition plug is consumed, while maintaining the simplicity, the small size, and the low cost and while securing the flammability. The ignition apparatus is provided with a first switching circuit that turns on or off energization from a power source to a primary coil, a secondary coil that is magnetically coupled with the primary coil and supplies a secondary current to an ignition plug, and a controller that decreases the secondary current for a spark discharge by use of an energy-changeable circuit, when determining that the ignition plug has been consumed, based on an output of a plug-consumption detection circuit.

An ignition device for an internal combustion engine includes: an ignition plug; a primary coil; a secondary coil magnetically linked to the primary coil and connected to the ignition plug; a main ignition circuit causing a spark discharge to occur in the ignition plug; an energy supply circuit that supplies and stops electrical energy to the predetermined winding of the primary coil to accordingly cause the spark discharge to continue; a recirculation circuit that permits and prohibits current recirculation through a recirculation path including the predetermined winding; and a controller configured to: control the main ignition circuit, and determine a start time of a permission of the current recirculation by the recirculation circuit using, as a trigger, the interruption signal which causes the main ignition circuit to interrupt the current through the primary coil, and end the permission after a predetermined time period has elapsed since the start time.

In an ignition control device for controlling operation of an ignition apparatus, an ignition section has first and second electrodes disposed in a combustion chamber of an internal combustion engine. A voltage application between the first and second electrodes enables a discharge to be generated between the first and second electrodes for igniting a gas mixture in the combustion chamber. A voltage application section performs at least one application of a determination voltage between the first and second electrodes. An occurrence ratio acquisition section acquires a discharge occurrence ratio at the ignition section for the at least one application of the determination voltage. A comparison section compares the discharge occurrence ratio acquired by the occurrence ratio acquisition section with a predetermined determination threshold to thereby determine a degree of wear of at least one of the first and second electrodes.

The present invention relates to an ignition coil for generating a high-voltage pulse with a superimposed high-frequency voltage. The ignition coil comprises a first coil arranged on the primary side, a second coil arranged on the secondary side, a magnetic core and a third coil. The windings of the first coil and of the second coil are wound around the magnetic core. The second coil and the third coil are electrically connected to one another. A high-frequency terminal, which receives the high-frequency voltage, is electrically connected to the second coil and to the third coil.

An igniter having at least two electrodes spaced from each other by an insulating member having a substantially continuous surface along a path between the electrodes. The electrodes extend substantially parallel to each other for a distance both above and below said surface. The insulating member has a channel (recess) for receiving at least a portion of a length of at least one of said electrodes below and to said surface of the insulating member. The surface of the insulating member may preferably be augmented with a conductivity enhancing agent. The insulating member and electrodes are configured so that an electric field between the electrodes at said surface does not have abrupt field intensity changes, whereby when a potential is applied to the electrodes sufficient to cause breakdown to occur between the electrodes, discharge occurs at said surface of the insulating member to define a plasma initiation region.