An internal combustion engine with a piston having a piston head with a resonance cavity opening onto the head, and where a fuel nozzle located in a cylinder head is positioned to inject a fuel such as natural gas into the combustion chamber where resonance formed within the resonance cavity will ignite the fuel without the need of a spark plug. Inlet and exhaust ports in the cylinder head allow for air and combustion gas enter or leave the combustion chamber.

An ignition unit improves an air-fuel-ratio, i.e., good mileage and lean burn without changing a gasoline engine structure significantly. The ignition unit comprises a discharge device including a booster and a discharger provided at an output side of the booster, the booster having a resonance structure configured to boost the electromagnetic wave inputted from the electromagnetic wave oscillator so as to cause a discharge from the discharger, and an electromagnetic wave emitter electrically connected to the electromagnetic wave oscillator and configured to emit the electromagnetic wave inputted from the electromagnetic wave oscillator. Moreover, the ignition unit further includes a housing part including a first hole into which the discharge device is inserted and a second hole into which the electromagnetic wave emitter is inserted such that the housing part houses therein both the discharge device and the electromagnetic wave emitter, and the housing part can be inserted into a single hole of a cylinder head of an internal combustion engine.

A piston discharge structure for a plasma cloud excitation engine is provided. The piston discharge structure includes a movement electrode, a distributed multi-cavity combustion chamber, a fixed electrode, and a variable interval discharge region. The movement electrode is provided at a top portion of a piston and includes a first combination shape and a first movement electrode structure, the distributed multi-cavity combustion chamber is provided at the top portion of the piston, the fixed electrode is provided at a top portion of a cylinder block or a bottom portion of a cylinder head and including a second combination shape and a second structure, and the variable interval discharge region is defined by the movement electrode and the fixed electrode.

A piston discharge structure for a plasma cloud excitation engine is provided. The piston discharge structure includes a movement electrode, a distributed multi-cavity combustion chamber, a fixed electrode, and a variable interval discharge region. The movement electrode is provided at a top portion of a piston and includes a first combination shape and a first movement electrode structure, the distributed multi-cavity combustion chamber is provided at the top portion of the piston, the fixed electrode is provided at a top portion of a cylinder block or a bottom portion of a cylinder head and including a second combination shape and a second structure, and the variable interval discharge region is defined by the movement electrode and the fixed electrode.

A piston discharge structure for a plasma cloud excitation engine is provided. The piston discharge structure includes a movement electrode, a distributed multi-cavity combustion chamber, a fixed electrode, and a variable interval discharge region. The movement electrode is provided at a top portion of a piston and includes a first combination shape and a first movement electrode structure, the distributed multi-cavity combustion chamber is provided at the top portion of the piston, the fixed electrode is provided at a top portion of a cylinder block or a bottom portion of a cylinder head and including a second combination shape and a second structure, and the variable interval discharge region is defined by the movement electrode and the fixed electrode.

A piston discharge structure for a plasma cloud excitation engine is provided. The piston discharge structure includes a movement electrode, a distributed multi-cavity combustion chamber, a fixed electrode, and a variable interval discharge region. The movement electrode is provided at a top portion of a piston and includes a first combination shape and a first movement electrode structure, the distributed multi-cavity combustion chamber is provided at the top portion of the piston, the fixed electrode is provided at a top portion of a cylinder block or a bottom portion of a cylinder head and including a second combination shape and a second structure, and the variable interval discharge region is defined by the movement electrode and the fixed electrode.

Provided is an in-combustion chamber flow control device used in an engine having an intake passage connected to an intake opening formed in a ceiling surface of a combustion chamber, at an angle inclined with respect to a direction of an axis of a cylinder. This in-combustion chamber flow control device comprises a plasma actuator (28) disposed inside the combustion chamber (16). The plasma actuator comprises: a dielectric body (38) disposed along the ceiling surface (16a) of the combustion chamber, at a position closer to a center of the ceiling surface than the intake opening (18a); an exposed electrode (40) disposed on one side of the dielectric body facing the combustion chamber; and an embedded electrode (42) disposed on a side opposite to the exposed electrode across the dielectric body. The embedded electrode is disposed at a position closer to the intake opening than the exposed electrode.

An ignition device for an extraneously igniting combustion piston engine with an ignition chamber located between a cylinder head and a piston, wherein the cylinder head has an end surface which defines the ignition chamber and which is at least partially formed as a cylinder head electrode, and wherein an ignition chamber electrode is disposed within the ignition chamber and forms an ignition gap with the cylinder head electrode.

An internal combustion engine comprising at least one cylinder and a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween. The engine has at least one combustion igniter associated with the cylinder, a portion of the combustion igniter being exposed within the combustion chamber formed between the opposed pistons.

An internal combustion engine comprising at least one cylinder and a pair of opposed, reciprocating pistons within the cylinder forming a combustion chamber therebetween. The engine has at least one combustion igniter associated with the cylinder, a portion of the combustion igniter being exposed within the combustion chamber formed between the opposed pistons.