A prechamber spark plug. The spark plug includes a housing, a cap, which defines a prechamber at least partially, and which includes a plurality of through holes that are configured to produce a connection between the prechamber and a combustion chamber of an internal combustion engine; the through holes each having a hole center line; the cap including a recess at a region pointed towards the housing, the recess abutting the housing at a combustion-chamber-side end of the housing; a distance from an exit point of a through hole lying on the hole center line, to a recess, being in a range of 2 mm to 7 mm; and a first angle between a center axis of the prechamber spark plug and the hole center line being in a range of 30° to 70°. An internal combustion engine including such a prechamber spark plug is also described.

A precombustion chamber gas engine includes a main-chamber forming portion forming a main combustion chamber, a precombustion-chamber forming portion forming a precombustion chamber communicating with the main combustion chamber via a plurality of nozzle holes, and an ignition device disposed in the precombustion chamber and having an ignition portion spaced from a main chamber central axis of the main combustion chamber at a predetermined distance. In a plan view, the precombustion chamber has a near-ignition region including the ignition portion and a far-ignition region opposite to the near-ignition region separated by a borderline passing through a precombustion chamber central axis of the precombustion chamber and perpendicular to a straight line passing through the precombustion chamber central axis and the ignition portion. The distance between the precombustion chamber central axis and a precombustion-chamber-side opening end, connected to the precombustion chamber, of a specific far nozzle hole which is at least one nozzle hole in the far-ignition region is shorter or longer than the distance between the precombustion chamber central axis and a precombustion-chamber-side opening end of a specific near nozzle hole which is at least one nozzle hole in the near-ignition region.

The invention relates to an engine having prechamber ignition, in particular a gas engine, that comprises a main combustion space in a cylinder of the engine for combusting an air-fuel mixture and a prechamber having an ignition device arranged therein and a fuel injector arranged therein, wherein the prechamber has at least one transfer port that fluidically connects the prechamber to the main combustion space. The engine is characterized in that the fuel injector arranged in the prechamber is the only fuel injector via which fuel can be introduced into the associated main combustion space.

Systems, devices, and methods described herein provide one or more radical chemicals generators (RCGs) and/or mini-chambers (M-Cs) that can be used to provide enhanced radical ignition (ERI) in an internal combustion engine. RCGs as described herein can include quenching systems (QSs) that can be configured to quench a flame of combustion products to produce a jet of partial combustion products containing radical species (RS). The jet of partial combustion products can be injected to a main combustion chamber (MCC) of an engine to induce ERI. ERI can proceed under leaner fuel conditions and lower temperatures compared to those needed for conventional thermally induced, fuel oxidation chain initiation reaction processes.

The invention relates to a cylinder head (1) with at least one recess (23) for arranging at least one gas valve (20) and at least one spark plug (15). The spark plug (15) reaches into a pre-chamber (17) and is arranged along a spark plug rotational axis (16), and the gas valve (20) is arranged along a gas valve rotational axis (19), wherein the gas valve rotational axis (19) is inclined relative to the spark plug rotational axis (16). and the distance (A) between the gas valve rotational axis (19) and the spark plug rotational axis (16) decreases as the distance to the pre-chamber (17) increases in a direction facing away from the combustion chamber (2). The aim of the invention is to provide an improved cylinder head (1) which allows an improved assembly and requires less installation space. According to the invention, this is achieved by the aforementioned cylinder head (1) in that the recess (23) for the spark plug (15) and the gas valve (20) has a surface (0) which is formed by a primary molding process, preferably a casting process, and is post-processed particularly preferably without machining.

A precombustion chamber engine comprises: a cylinder head defining a main combustion chamber together with a cylinder liner and a piston top surface; a precombustion chamber cap mounted on the cylinder head by inserting a distal end portion of the precombustion chamber cap into an insertion hole formed in the cylinder head; a precombustion chamber holder disposed inside the cylinder head; and a precombustion chamber cap holding member fixed to the precombustion chamber holder and configured to suspend and support the precombustion chamber cap. The precombustion chamber cap includes a reduced diameter portion with a diameter decreasing from a proximal end portion of the precombustion chamber cap to an intermediate portion that has a smaller diameter than the proximal end portion. The precombustion chamber cap holding member is configured to lock the reduced diameter portion and to have a gap between the precombustion chamber cap holding member and the proximal end portion when the precombustion chamber cap holding member suspends and supports the precombustion chamber cap.

A prechamber assembly includes a cylinder head including a coolant cavity, a prechamber body located within the cylinder head, the prechamber body including a nozzle, and an annular sleeve radially surrounding a portion of the prechamber body. The sleeve includes a plurality of coolant inlet holes. A portion of the prechamber body is radially spaced from the sleeve to form a coolant sleeve annulus extending along a length of the prechamber body above the coolant inlet holes. The coolant cavity and the coolant sleeve annulus are in fluid communication through the plurality of coolant inlet holes.

An igniter system for a reciprocating piston internal combustion engine having one or more cylinders including at least one igniter per cylinder is disclosed. The igniter system can comprise: a combustion chamber connected to a main cylinder of the engine by a restricted diameter bore, wherein a lean burn fuel mixture is introduced into the combustion chamber by the normal compression stroke of the engine; a hydrogen valve that injects a hydrogen rich gas into the combustion chamber forming a mixture of hydrogen and air having a hydrogen concentration above the stoichiometric ratio for hydrogen and air in the combustion chamber; and a spark ignition source that injects hot unburned hydrogen into the main cylinder, thereby initiating ignition.

An ignition device with a pre-combustion chamber for an internal combustion engine is disclosed. The internal combustion engine may have a plurality of cylinders. Each cylinder may define a main combustion chamber. The ignition device may have a first pre-combustion chamber part configured to at least partially accommodate a spark plug. The ignition device may also have a second pre-combustion chamber part defining at least a portion of the pre-combustion chamber. The second pre-combustion chamber part may include at least one orifice configured to be fluidly connected to the main combustion chamber. The second pre-combustion chamber part may be detachably mountable to the first pre-combustion chamber part, such that the first and second pre-combustion chamber parts are axially secured to one another and rotatable with respect to one another.

In certain embodiments, a unique method and pre-combustion chamber (PCC) structure may ensure very efficient flame propagation of lean fuel-air mixture in natural gas engines by reducing the amount of fuel admitted to the PCC. A PCC may include an enclosed volume of 1-3% of the main combustion chamber volume, with a spark plug and a fuel passage located opposite one or more PCC discharge nozzles to create a relatively richer fuel-air mixture with relatively lower turbulence in the spark plug region and a relatively leaner fuel-air mixture with relatively high turbulence in the nozzle region, which can be reliably and efficiently ignited, resulting in a high velocity flame jet/torch emerging from the prechamber into the main chamber. The PCC may be threaded with a 22 mm×1.5 or ⅞″-18 thread size, to allow the PCC to be screwed into a cylinder head in place of a spark plug.