A pre-chamber spark plug has a pre-chamber which has openings, where, with respect to a first plane running in the longitudinal direction of the pre-chamber and dividing the pre-chamber into two halves of equal size, first openings are disposed in a first of the halves and second openings are disposed in a second of the halves. The first openings are spaced apart from a second plane running in the longitudinal direction of the pre-chamber and extending perpendicular to the first plane by a first angle in the circumferential direction of the pre-chamber. The second openings are spaced apart from the second plane by a second angle in the circumferential direction of the pre-chamber. The mean value of the first angles is smaller than the mean value of the second angles.

A pre-chamber spark plug has a pre-chamber which has openings, where, with respect to a first plane running in the longitudinal direction of the pre-chamber and dividing the pre-chamber into two halves of equal size, first openings are disposed in a first of the halves and second openings are disposed in a second of the halves. The first openings are spaced apart from a second plane running in the longitudinal direction of the pre-chamber and extending perpendicular to the first plane by a first angle in the circumferential direction of the pre-chamber. The second openings are spaced apart from the second plane by a second angle in the circumferential direction of the pre-chamber. The mean value of the first angles is smaller than the mean value of the second angles.

In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

In certain embodiments with large size prechambers and/or with prechambers that have large spark-gap electrode assemblies, a poor scavenge of the crevice volume may cause deterioration of the preignition margin, which then may limit the power rating of the engine, may cause the flow velocity field of the fuel-air mixture to be excessively uneven and may result in the deterioration of the misfire limit. One or more auxiliary scavenging ports may allow admission of fuel rich mixture to the crevice volume, thereby cooling the residual gases and preventing occurrence of preignition. More organized and powerful flow velocity fields may be obtained in the spark-gap electrode assembly region. This condition may result in a significant extension of the flammability limit and may significantly improve the combustion efficiency of the prechamber. Passive prechambers using the active scavenge concept may increase the engine power output and reduce the emission of pollutants from engine combustion.

An internal combustion engine including a pre-chamber connected to a pre-chamber feed conduit for supplying the pre-chamber with a fuel (F), and a main combustion chamber. Fuel (F) in the main combustion chamber can be ignited by an ignition flare which passes from the at least one pre-chamber into the at least one main combustion chamber and which is produced by ignition of fuel (F) in the pre-chamber. At least one valve can be open-loop or closed-loop controlled by an open-loop or closed-loop control device depending on a parameter characteristic of a change in a power produced by the internal combustion engine, and/or by which a pre-chamber fuel flow directed through the pre-chamber feed conduit to the at least one pre-chamber can be at least partially diverted into a volume separate from the at least one pre-chamber.

An internal combustion engine including a pre-chamber connected to a pre-chamber feed conduit for supplying the pre-chamber with a fuel (F), and a main combustion chamber. Fuel (F) in the main combustion chamber can be ignited by an ignition flare which passes from the at least one pre-chamber into the at least one main combustion chamber and which is produced by ignition of fuel (F) in the pre-chamber. At least one valve can be open-loop or closed-loop controlled by an open-loop or closed-loop control device depending on a parameter characteristic of a change in a power produced by the internal combustion engine, and/or by which a pre-chamber fuel flow directed through the pre-chamber feed conduit to the at least one pre-chamber can be at least partially diverted into a volume separate from the at least one pre-chamber.

Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

Generally, embodiments of a pre-chamber unit having a pre-combustion chamber including one or more induction ports in a configuration which achieves flow fields and flow field forces inside the pre-combustion chamber which act to direct flame growth away quenching surface of the pre-combustion chamber.

A cylinder head for an internal combustion engine comprising a prechamber (3), wherein a prechamber gas valve (5) is fitted into a cavity in the cylinder head (2) and the prechamber gas valve (5) is connected to the prechamber (3) by way of a flow transfer passage (10), wherein the flow transfer passage (10) has a first portion (8) adjoining the prechamber gas valve (5) and a second portion (1) into which the first portion (8) opens, wherein the second portion (1) extends at least around a part of a periphery of the prechamber (3), wherein the second portion (1) has an uninterrupted peripheral surface apart from that opening (7) with which it passes into the prechamber (3).

A cylinder head for an internal combustion engine comprising a prechamber (3), wherein a prechamber gas valve (5) is fitted into a cavity in the cylinder head (2) and the prechamber gas valve (5) is connected to the prechamber (3) by way of a flow transfer passage (10), wherein the flow transfer passage (10) has a first portion (8) adjoining the prechamber gas valve (5) and a second portion (1) into which the first portion (8) opens, wherein the second portion (1) extends at least around a part of a periphery of the prechamber (3), wherein the second portion (1) has an uninterrupted peripheral surface apart from that opening (7) with which it passes into the prechamber (3).