A method for controlling a corona ignition system in which a corona discharge is produced at an ignition electrode by exciting a resonating circuit with an AC voltage produced by a high-frequency generator. The AC voltage is adjusted to a target value depending on an operating state of the engine. Combustion onset is determined by evaluating an electrical variable of the resonating circuit and the target value of the AC voltage is reduced by a predefined value following a predefined number of engine cycles or a predefined operating period. The determined combustion onset is evaluated in one or more engine cycles. The target value for the momentary engine operating state is then increased if, by evaluation of the combustion onset, it is found that a predefined requirement is no longer met. Otherwise, the reduced target value is stored as a new target value for the momentary engine operating state.

An internal combustion engine is described and includes a combustion chamber formed by cooperation of a cylinder bore formed in a cylinder block, a cylinder head and a piston. A plasma ignition controller is electrically connected to a groundless barrier discharge plasma igniter that includes a tip portion disposed to protrude into the combustion chamber. A current sensor is disposed to monitor secondary current flow between the plasma ignition controller and the groundless barrier discharge plasma igniter. The plasma ignition controller is disposed to execute a plasma discharge event. A controller is disposed to monitor a magnitude of the secondary current flow via the current sensor during the plasma discharge event. The controller includes an instruction set executable to evaluate integrity of the groundless barrier discharge plasma igniter based upon the magnitude of the secondary current flow during the plasma discharge event.

An internal combustion engine is described and includes a combustion chamber formed by cooperation of a cylinder bore formed in a cylinder block, a cylinder head and a piston. A plasma ignition controller is electrically connected to a groundless barrier discharge plasma igniter that includes a tip portion disposed to protrude into the combustion chamber. A current sensor is disposed to monitor secondary current flow between the plasma ignition controller and the groundless barrier discharge plasma igniter. The plasma ignition controller is disposed to execute a plasma discharge event. A controller is disposed to monitor a magnitude of the secondary current flow via the current sensor during the plasma discharge event. The controller includes an instruction set executable to evaluate integrity of the groundless barrier discharge plasma igniter based upon the magnitude of the secondary current flow during the plasma discharge event.

A laser ignition device for an internal combustion engine, in which the laser ignition device has at least one laser spark plug and a cooling device for temperature control, in particular cooling, of the laser spark plug. The cooling device has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, a volume of the coolant contained in the cooling circuit being less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine, which may be less than or equal to approximately 10% of a compression volume of the cylinder of the internal combustion engine.

A laser ignition device for an internal combustion engine, in which the laser ignition device has at least one laser spark plug and a cooling device for temperature control, in particular cooling, of the laser spark plug. The cooling device has a cooling circuit, containing a coolant, which is thermally connectable to at least one component of the laser spark plug, a volume of the coolant contained in the cooling circuit being less than or equal to approximately 50% of a compression volume of a cylinder of the internal combustion engine, which may be less than or equal to approximately 10% of a compression volume of the cylinder of the internal combustion engine.

Described is a method for controlling an internal combustion engine, wherein an ignition control device is prompted by control signals of an engine control device to activate an ignition device by means of which an ignition of a fuel-air mixture in a cylinder of the internal combustion engine is affected. It is provided according to this disclosure, that the engine control device communicates a target ignition angle or information about an operating condition of the internal combustion engine to the ignition control device, and the ignition control device sets an operating parameter of the ignition device in dependence on the target ignition angle or the information about the operating condition of the internal combustion engine.

A high-frequency discharge ignition device includes a current supply device which supplies an AC current to a spark discharge path formed in a gap of an ignition plug, a control device which controls the operation of the current supply device, and a voltage detection device which outputs a signal of a section where a magnetic induction voltage of a primary coil generated after a switch element of an ignition coil device is placed in a shutoff state exceeds a predetermined voltage, and the control device determines the timing when the spark discharge path has been formed in the gap of the ignition plug according to an output signal of the voltage detection device and operates the current supply device based on the timing when the spark discharge path has been formed in the gap of the ignition plug to supply the AC current to the spark discharge path.

A high-frequency discharge ignition device includes a current supply device which supplies an AC current to a spark discharge path formed in a gap of an ignition plug, a control device which controls the operation of the current supply device, and a voltage detection device which outputs a signal of a section where a magnetic induction voltage of a primary coil generated after a switch element of an ignition coil device is placed in a shutoff state exceeds a predetermined voltage, and the control device determines the timing when the spark discharge path has been formed in the gap of the ignition plug according to an output signal of the voltage detection device and operates the current supply device based on the timing when the spark discharge path has been formed in the gap of the ignition plug to supply the AC current to the spark discharge path.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 having a fuel injecting port 20 that injects the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The motion device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.

A small-size injector having a built-in ignition device which can surely inject fuel and ignite the fuel with low electric power by the ignition device with a simple configuration is provided. The injector comprises a fuel injecting device 2 having a fuel injecting port 20 that injects the fuel, an ignition device 3 configured to ignite the injected fuel, and a casing 10 inside housing therein the fuel injecting device 2 and the ignition device 3 together. The motion device 3 is constituted of a plasma generator 3 which integrally comprises a booster 5 having a resonation structure capacity-coupled with an electromagnetic wave oscillator MW configured to oscillate an electromagnetic wave, and a discharger 6 configured to cause a discharge of a high voltage generated by the booster 5.