A vehicle that can cool an ignition coil is provided. The vehicle has an engine having a cylinder head and an ignition coil with a first end exposed from the cylinder head, a CVT that varies and outputs rotary power from the engine, and an exhaust duct having a first exhaust port for exhausting a gas within a CVT case to outside of the CVT case, and a second exhaust port for exhausting a part of the gas flowing to the first exhaust port to outside of the CVT case, wherein the second exhaust port is provided for exhausting the gas within the CVT case to at least a part of the first end of the ignition coil.

A vehicle that can cool an ignition coil is provided. The vehicle has an engine having a cylinder head and an ignition coil with a first end exposed from the cylinder head, a CVT that varies and outputs rotary power from the engine, and an exhaust duct having a first exhaust port for exhausting a gas within a CVT case to outside of the CVT case, and a second exhaust port for exhausting a part of the gas flowing to the first exhaust port to outside of the CVT case, wherein the second exhaust port is provided for exhausting the gas within the CVT case to at least a part of the first end of the ignition coil.

There is provided an ignition apparatus that makes it possible that after a spark discharge starts, a secondary current is reduced so that a plug is suppressed from being consumed. The ignition apparatus is provided with an ignition coil including a primary coil, a secondary coil, and a tertiary coil, a first switching circuit for performing on/off-switching of energization of the primary coil from a power source, a second switching circuit for performing on/off-switching of energization of the tertiary coil, and a controller that performs on/off-control of the first switching circuit so as to generate a secondary current in the secondary coil, thereby causing a spark discharge in an ignition plug, and then turns on the second switching circuit so as to reduce the secondary current through a change in flux in the tertiary coil.

A booster circuit for use with an ignition system for an internal combustion engine is provided. The booster circuit includes a relay control circuitry disposed in parallel between the voltage source and the one or more ignition coils for igniting fuel in the engine in synchronism with engine operation; a controllable switching element for selectively completing a booster circuit for connecting the relay control circuitry in series with the voltage source and the one or more ignition coils; and the booster circuit having electronic circuitry including at least one output for providing booster energy at the at least one output, when the booster circuit is completed by the controllable switching element to assure producing of a suitable voltage applied to the one or more ignition coils.

An ignition apparatus for an internal combustion engine includes at least one pre-chamber and at least one ignition source. The pre-chamber is coupled to the ignition source in the longitudinal extension direction of the ignition apparatus such that it can rotate about a center axis of the ignition apparatus without offset between at least two rotation direction positions of the pre-chamber relative to the ignition source. In at least one decoupling rotation direction position, the pre-chamber is reversibly detachable from the ignition source and can be spaced from the ignition source in the longitudinal extension direction.

An ignition apparatus for an internal combustion engine includes at least one pre-chamber and at least one ignition source. The pre-chamber is coupled to the ignition source in the longitudinal extension direction of the ignition apparatus such that it can rotate about a center axis of the ignition apparatus without offset between at least two rotation direction positions of the pre-chamber relative to the ignition source. In at least one decoupling rotation direction position, the pre-chamber is reversibly detachable from the ignition source and can be spaced from the ignition source in the longitudinal extension direction.

An ignition device according to the present invention includes: an ignition plug, which includes a first electrode, a second electrode, and a dielectric body arranged between the electrodes; an AC power supply configured to generate an AC voltage to be applied between the electrodes; a thermal plasma detection portion configured to output a thermal plasma occurrence signal when thermal plasma has occurred between the electrodes; and an application time period determination portion configured to determine an application time period for the AC voltage during one cycle of the internal combustion engine in advance before the application, and when the thermal plasma occurrence signal is received while the AC voltage is being applied based on the application time period, change the application time period so as to shorten the application time period.

A quarter wave coaxial cavity resonator for producing corona discharge plasma from is presented. The quarter wave coaxial cavity resonator has a folded cavity made of opposing concentric cavity members that are nested together to form a continuous cavity ending in a aperture. A center conductor with a tip is positioned in the cavity. The folded cavity advantageously permits the coaxial cavity resonator to resonate at a lower operating frequency than an unfolded quarter wave coaxial cavity resonator of the same length. Embodiments of the quarter wave coaxial cavity resonator use narrower apertures to reduce radiative losses, and include center conductors that are reactive load elements, such as helical coils. When a radio frequency (RF) oscillation is produced in the quarter wave coaxial cavity resonator, corona discharge plasma is formed at the tip of the center conductor. The corona discharge plasma can be used to ignite combustible materials in combustion chambers of combustion engines.

A quarter wave coaxial cavity resonator for producing corona discharge plasma from is presented. The quarter wave coaxial cavity resonator has a folded cavity made of opposing concentric cavity members that are nested together to form a continuous cavity ending in a aperture. A center conductor with a tip is positioned in the cavity. The folded cavity advantageously permits the coaxial cavity resonator to resonate at a lower operating frequency than an unfolded quarter wave coaxial cavity resonator of the same length. Embodiments of the quarter wave coaxial cavity resonator use narrower apertures to reduce radiative losses, and include center conductors that are reactive load elements, such as helical coils. When a radio frequency (RF) oscillation is produced in the quarter wave coaxial cavity resonator, corona discharge plasma is formed at the tip of the center conductor. The corona discharge plasma can be used to ignite combustible materials in combustion chambers of combustion engines.

An ignition device for an internal combustion engine is provided which includes a spark plug and a controller. The spark plug has a housing with a head protruding into a combustion chamber of the engine. The head has at least a portion located downstream of a spark gap of the spark plug in an air-fuel mixture flow within the combustion chamber. The controller works to perform a plurality of discharge events in the spark plug in each cycle of an operation of the engine. This improves the ability of the spark plug to ignite the mixture without need to increase an ignition energy.