A torch igniter and a method of igniting a torch flame. An example embodiment includes a body including an oxidizer inlet configured to facilitate oxidizer flow through the body toward an output end of the body. The body includes a group of fuel inlet passages configured to distribute fuel in a direction tangential to the oxidizer flow through the body to create a swirling fuel-oxidizer mixture. A sparking element can be mounted on the body to produce a spark in the path of the swirling fuel-oxidizer mixture to ignite the mixture. The output end of the body is configured to emit a torch flame when the fuel-oxidizer mixture is ignited. Thus, a swirl torch igniter is configured for oxidizer and fuel flow through the igniter body to create an internal swirling fuel-oxidizer mixture to be ignited by a sparking element.

An ignition control apparatus applied to an internal combustion engine including a spark plug includes an in-cylinder pressure acquisition section, a frequency signal transmitting section which transmits a frequency signal having a predetermined frequency to a switching element, and a weak discharge generating section which causes the frequency signal to be transmitted during an intake stroke and controls the frequency signal such that a weak discharge is generated at the spark plug a plurality of times. The weak discharge generating section controls the frequency signal so as to cause a duty ratio of the switching element to be changed in accordance with the in-cylinder pressure, such that the frequency of generating weak discharges during a time period in which the frequency signal is transmitted becomes higher than a predetermined frequency.

An opposed-piston engine contains opposed pistons wherein each piston has a piston face containing a recess. The recesses formed in the piston faces define a combustion chamber when contained within a cylinder. An ignition system is at least partially contained within the combustion chamber to enhance the combustion efficiency of a fuel-air mixture within the combustion system.

An opposed-piston engine optionally contains an ignition system that is at least partially contained within the combustion chamber to enhance the combustion efficiency of a fuel-air mixture within the combustion system. More specifically, the ignition system contains at least one spark plug having an elongated center electrical delivery electrode, and, an elongated ground electrode. Accordingly, the elongated electrodes extend from an area adjacent to the inner periphery of the cylinder to a radially central area within the combustion chamber. Yet further, a cooling jacket is incorporated to provide cooling of the spark plug.

By grounding a metal first housing, radiation noise generated from the coupling circuit is shielded. Further, by enclosing the first housing in a metal second housing in a manner such that the first housing and the second housing do not come into contact with each other, and grounding the second housing by connecting the second housing to an engine block, radiation noise generated by the capacitive component between the coupling circuit and the first housing is shielded by the second housing. As a result, the influence of this noise on peripheral devices of the high frequency discharge ignition device can be suppressed.

An ignition control apparatus applied to an internal combustion engine including a spark plug includes an in-cylinder pressure acquisition section, a frequency signal transmitting section which transmits a frequency signal having a predetermined frequency to a switching element, and a weak discharge generating section which causes the frequency signal to be transmitted during an intake stroke and controls the frequency signal such that a weak discharge is generated at the spark plug a plurality of times. The weak discharge generating section controls the frequency signal so as to cause a duty ratio of the switching element to be changed in accordance with the in-cylinder pressure, such that the frequency of generating weak discharges during a time period in which the frequency signal is transmitted becomes higher than a predetermined frequency.

A spark plug with shuttle electrode is provided for an internal combustion engine which includes a combustion chamber in which a main charge diluted with a neutral gas is ignited, the spark plug housing a lamination cavity in which a central electrode opens and in which a lamination injector is able to inject under pressure a pilot charge consisting of an easily flammable combustive-AF fuel mixture, the cavity being connected to the combustion chamber by a lamination duct, while a shuttle electrode is interposed between the central electrode and a ground electrode and can translate in the lamination duct.

By grounding a metal first housing, radiation noise generated from the coupling circuit is shielded. Further, by enclosing the first housing in a metal second housing in a manner such that the first housing and the second housing do not come into contact with each other, and grounding the second housing by connecting the second housing to an engine block, radiation noise generated by the capacitive component between the coupling circuit and the first housing is shielded by the second housing. As a result, the influence of this noise on peripheral devices of the high frequency discharge ignition device can be suppressed.

A piston for a premixed spark-ignited or premixed dual fuel internal combustion engine is disclosed. The piston may be configured to reciprocate along a longitudinal axis of a combustion chamber defined by a cylinder of the engine. The piston may comprise a piston head, a top annular groove configured to receive a top annular ring, and a skirt having a pin bore extending along a pin bore axis that is configured to receive a wrist pin for connecting the piston to a connecting rod. The piston may further comprise a top land formed in the piston head that is chamfered in a direction perpendicular to the pin bore axis such that the top land does not contact an inner wall of the cylinder when the piston rocks about the pin bore axis. The top land may be non-chamfered in a direction parallel to the pin bore axis.

A spark plug with shuttle electrode is provided for an internal combustion engine which includes a combustion chamber in which a main charge diluted with a neutral gas is ignited, the spark plug housing a lamination cavity in which a central electrode opens and in which a lamination injector is able to inject under pressure a pilot charge consisting of an easily flammable combustive-AF fuel mixture, the cavity being connected to the combustion chamber by a lamination duct, while a shuttle electrode is interposed between the central electrode and a ground electrode and can translate in the lamination duct.