An ignition coil for an internal combustion engine includes a primary bobbin including a winding cylinder part and a connection part between the winding cylinder part and a connector part, a primary coil including a primary main coil and a primary sub coil, and a secondary coil. When one of the primary main coil and the primary sub coil that includes an innermost coil part around the winding cylinder part is defined as a firstly-wound coil and the other is defined as a secondly-wound coil, firstly-wound ends, which are ends of the firstly-wound coil, and secondly-wound ends, which are ends of the secondly-wound coil, are attached to the connection part, and a shortest distance from a central axis of the winding cylinder part to each of the firstly-wound ends is smaller than a shortest distance from the central axis of the winding cylinder part to each of the secondly-wound ends.

An ignition coil for an internal combustion engine includes a primary bobbin including a winding cylinder part and a connection part between the winding cylinder part and a connector part, a primary coil including a primary main coil and a primary sub coil, and a secondary coil. When one of the primary main coil and the primary sub coil that includes an innermost coil part around the winding cylinder part is defined as a firstly-wound coil and the other is defined as a secondly-wound coil, firstly-wound ends, which are ends of the firstly-wound coil, and secondly-wound ends, which are ends of the secondly-wound coil, are attached to the connection part, and a shortest distance from a central axis of the winding cylinder part to each of the firstly-wound ends is smaller than a shortest distance from the central axis of the winding cylinder part to each of the secondly-wound ends.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air spark gap is formed between the earth electrode and the electrically conductive element or the slot.

A passive prechamber spark plug for use in a combustion chamber of a vehicle engine includes an upper prechamber having an upper opening where the upper prechamber is connectable to the combustion chamber via the upper opening. An air ignition spark is formable via an upper air spark gap. A central electrode is disposed in an upper region of the upper prechamber where a base of the upper prechamber opposite the upper region is an insulator. An electrically conductive element or a slot is guided by the insulator continuously from the upper prechamber into a lower region under the base and the lower region is either a lower prechamber or is arrangeable directly in the combustion chamber. An earth electrode is disposed in the lower region such that a lower air spark gap is formed between the earth electrode and the electrically conductive element or the slot.

An ignition coil is described for an internal combustion engine, with a housing, a transformer, which is arranged in an interior space of the housing, and potting compound, with which the interior space of the housing is cast. In accordance with this disclosure provision is made for the transformer to be covered by a mat, which is embedded in the potting compound.

An ignition coil is described for an internal combustion engine, with a housing, a transformer, which is arranged in an interior space of the housing, and potting compound, with which the interior space of the housing is cast. In accordance with this disclosure provision is made for the transformer to be covered by a mat, which is embedded in the potting compound.

An ignition coil includes a primary coil and a secondary coil magnetically coupled from each other; a core cover disposed around the primary coil and the secondary coil; and an outer peripheral core supported by the core cover. The core cover includes a pair of support portions that support the outer peripheral core; and at least one of the pair of support portions includes a flexible portion that elastically presses the outer peripheral core, the flexible portion having flexibility in an arrangement direction separating the pair of support portions.

A spark ignited engine is disclosed. The spark ignited engine includes a main combustion chamber and a cylinder head at least partially surrounding the main combustion chamber. A spark plug having a central axis is arranged in the cylinder head and an ignition end of the spark plug faces the main combustion engine. A pre-chamber with at least two nozzles is arranged in the main combustion chamber and connects the ignition end and the main combustion chamber via the at least two nozzles. A pre-chamber volume ratio corresponds to a ratio of a volume of the pre-chamber to a volume of the main combustion chamber at a top-dead-center and is between 1.9% and 3.1%. A nozzle factor corresponds to a ratio of a summed flowed-through area of the at least two nozzles to the volume of the pre-chamber and is between 0.085 l/cm and 1.15 l/cm.

A spark ignited engine is disclosed. The spark ignited engine includes a main combustion chamber and a cylinder head at least partially surrounding the main combustion chamber. A spark plug having a central axis is arranged in the cylinder head and an ignition end of the spark plug faces the main combustion engine. A pre-chamber with at least two nozzles is arranged in the main combustion chamber and connects the ignition end and the main combustion chamber via the at least two nozzles. A pre-chamber volume ratio corresponds to a ratio of a volume of the pre-chamber to a volume of the main combustion chamber at a top-dead-center and is between 1.9% and 3.1%. A nozzle factor corresponds to a ratio of a summed flowed-through area of the at least two nozzles to the volume of the pre-chamber and is between 0.085 l/cm and 1.15 l/cm.

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.