A pre-chamber arrangement (100) for a gas engine (1), including a pre-chamber body (20) accommodating a volume (30); and a supply device (50) for supplying a gaseous medium (52) into the pre-chamber volume (30); wherein the pre-chamber body (20) has a bottom portion (22) with channels (40) for allowing gas to flow between the pre-chamber volume (30) and a main combustion chamber (10) of the gas engine (1). Each channel (40) extends along a channel axis (C) from an inner opening (42) facing the pre-chamber volume (30) to an outer opening (44) configured to face the main combustion chamber (10). The bottom portion (22) has a curved outer surface (24). The channels (40) are obliquely arranged in relation to a radius (r) of the bottom portion (22). The bottom portion has flat surfaces (46) surrounding the outer openings of the channels.

An air-assisted jet flame ignition device includes a housing, a fuel-air premixing unit, and a prechamber. The fuel-air premixing unit includes a fuel injector, an air injection valve, a premixing sleeve, a premixing sleeve inner core placed in the premixing sleeve, and a fuel injector fastening bolt. An inner wall surface of the premixing sleeve and an outer wall surface of the premixing sleeve inner core form a premixing sleeve inner cavity. An inner wall surface of the premixing sleeve inner core, a lower end surface of a nozzle of the fuel injector, and an upper end surface of an air inlet of the air injection valve form a premixing cavity. The premixing cavity coupled to the premixing sleeve inner cavity via a through hole on the sidewall of the premixing sleeve inner core. A prechamber nozzle is fixedly coupled to the lower part of the housing.

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.

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.

A pre-combustion chamber system is presented. The pre-combustion chamber system includes a pre-combustion chamber housing defining a pre-combustion chamber, a cooling chamber housing surrounding the pre-combustion chamber housing, a cooling chamber defined between the pre-combustion chamber housing and the cooling chamber housing. The pre-combustion chamber system includes a flow agitator arranged in the pre-combustion chamber housing protruding into the pre-combustion chamber. The flow agitator increases flow disturbance in the pre-combustion chamber for improving mixture of fuel and air. Cooling of the pre-combustion chamber system is improved by dividing the cooling chamber into a cooling inner chamber and a cooling outlet chamber or by arranging cooling fins in the pre-combustion chamber housing extending into the cooling 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).

Systems are provided for cooling combustion chamber gasses and increasing an amount of air entrained in an injected fuel spray. In one example, a cooling passage may be included in an internal combustion engine, the cooling passage positioned exterior to a cylinder bore of the engine and coupled to the cylinder bore at a first opening and a second opening. The cooling passage may receive gasses from the cylinder bore via the first opening, and may cool the gasses as they travel through the cooling passage before returning the gasses to the cylinder bore via the second opening.

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.

To meet both a request to improve the thermal efficiency in medium load operation of an engine and a request to suppress knocking in high load operation of the engine, the engine includes a main combustion chamber including a cylinder block, a cylinder head, and a piston; a pre-chamber having a plurality of injection holes that open into the main combustion chamber; and a spark plug that ignites an air-fuel mixture in the pre-chamber. A compression ratio of the main combustion chamber is not less than 14 and not more than 24, an aperture ratio, which is the ratio of a total cross-sectional area of the plurality of injection holes to a volume of the pre-chamber, is not less than 0.0078 mm.sup.-1 and not more than 0.0145 mm.sup.-1, and the volume of the pre-chamber 15 is not less than 0.0430 cm.sup.3 and not more than 0.5631 cm.sup.3.

Methods and systems are provided for injecting gaseous fuel during an engine start. In one example, a method comprises generating gaseous fuel via a fuel gasification device and injecting the gaseous fuel via a fuel injector. The fuel injector is configured to inject adjacent to an ignition device.