A pre-chamber component for an internal combustion engine includes a chamber for accommodating an air-fuel-mixture to be ignited, wherein the pre-chamber component includes a first opening into the chamber for arranging an ignition device, in particular a spark plug, and a second opening for introducing the air-fuel-mixture in the form of a mixture flow into the chamber. The pre-chamber component includes a mixture flow guiding device, which is shaped such that the mixture flow of the air-fuel-mixture in the chamber is oriented substantially transversely with respect to a longitudinal axis from the second opening of the chamber to at least a part of the chamber adjacent to the first opening and/or in the form of a turbulent flow.

An engine has, for each cylinder, a combustion chamber and a combustion pre-chamber communicating with the combustion chamber. First and second spark plugs are associated with the pre-chamber and combustion chamber, respectively. Gasoline is injected by an injector device directly into the combustion chamber and/or by an injector device into a cylinder intake duct. There is no device for injecting gasoline, air or an air/gasoline mixture directly into the pre-chamber. The engine operates with an air/gasoline mixture substantially corresponding to stoichiometric for compatibility with an exhaust system having a trivalent catalyst. The pre-chamber is, not used for engine operation with poor dosing, but to increase resistance to engine detonation. The engine can thus be configured with a high compression ratio, with a significant reduction in fuel consumption at the same power level. The second spark plug is only activated at low and medium engine loads to stabilize combustion.

An internal combustion engine 10 comprises a spark plug 70 which has a spark generation part 71, and a partition wall part 80. The partition wall part 80 partitions a combustion chamber CC into a main combustion chamber CM and an ignition chamber CI. The combustion chamber is defined by a cylinder bore wall 21, a piston crown surface part 31 and a cylinder head wall 41. The cylinder bore wall and the piston crown surface part are exposed to the main combustion chamber, and the spark generation part is exposed to the ignition chamber. A through hole 81 and a through hole 82 are formed in the partition wall part such that the main combustion chamber and the ignition chamber are in communication with each other. Flame is generated in the ignition chamber when combustion of fuel-air mixture is started by a spark generated from the spark generation part in the ignition chamber. The flame is ejected from the ignition chamber into the main combustion chamber through the first and second through holes. Distance between the first through hole and the cylinder bore wall is longer than distance between the second through hole and the cylinder bore wall. The first and second through holes are formed such that penetration of the flame ejected from the first through hole is larger than penetration of the flame ejected from the second through hole.

An internal combustion engine includes a pre-chamber. In another aspect, pressure within a pre-chamber is equal to or greater than pressure within a main combustion chamber at least prior to ignition in the main combustion chamber. In yet another aspect, internal combustion engine control software automatically controls pressure within a turbulent jet ignition pre-chamber, controls a valve-actuator to admit a fuel-air charge into the pre-chamber, and causes an igniter to initiate combustion in the pressurized pre-chamber. This also permits the rate of combustion to be controlled in the primary chamber regardless of the air-fuel ratio or the diluent fraction in the main chamber. Another aspect employs a pre-chamber purge pump with separate air and fuel injection.

A method of combusting fuel, e.g. heavy fuel, in a rotary engine, including injecting a main quantity of fuel directly into a combustion chamber to form a first fuel-air mixture having a first air-fuel equivalence ratio higher than 1, injecting a pilot quantity of fuel into a pilot subchamber to form a second fuel-air mixture having a second air-fuel equivalence ratio smaller than the first air-fuel equivalence ratio, igniting the second fuel-air mixture within the pilot subchamber, using the ignited second fuel-air mixture from the pilot subchamber to ignite the first fuel-air mixture, and injecting a supplemental quantity of fuel directly into the combustion chamber after igniting the first fuel-air mixture, upstream of an exhaust port of the rotary engine with respect to a direction of rotation of the rotor. A rotary engine with interburner fuel injector is also discussed.

A two-stroke engine according to the present invention includes: a separating wall which confines a tip end portion of an ignition device; an ignition promoting chamber which is formed by means of the separating wall, is independent of a combustion chamber, and encloses the tip end portion of the ignition device; and a plurality of communicating holes which are provided in the separating wall, each of which is provided with a first opening that opens in the combustion chamber and a second opening that opens in the ignition promoting chamber, and which provide communication between the combustion chamber and the ignition promoting chamber.

A combustion driven fastener hand tool is disclosed having a fuel system subassembly including a fuel nozzle and a metering valve, disposed in a common bore of the combustion driven fastener apparatus. The metering valve comprises a hollow cylindrical housing having a cap at each end and a central dual valve stem therebetween. Movement of the dual central valve stem closes an inlet valve at one end and opens an outlet valve at an opposite end in a coordinated manner to release a metered amount of fuel through the outlet valve while preventing additional fuel through the inlet valve. The combustion driven fastener hand tool includes numerous other features affording improvements over the prior art.

An engine controller, for an internal combustion engine, is configured to: control at least one actuator to provide an air-fuel mixture with a lambda value higher than 3 to a main combustion chamber via at least one intake valve, wherein the at least one actuator is arranged upstream of at least one intake port or which is arranged in the intake port; control at least one fuel supply system to provide fuel directly to the main combustion chamber and/or a pre-combustion chamber of a piston-cylinder unit such that at the time of ignition of the air-fuel mixture the lambda value of that air-fuel mixture in the main combustion chamber is lower than the lambda value of the air-fuel mixture provided to the main combustion chamber via the at least one intake valve.

Particular embodiments may provide a piston for a prechamber-type gas engine and a prechamber-type gas engine taking into consideration the shape of the piston top surface portion so that the region where flame propagation due to torch jet is delayed, a piston for a prechamber-type gas engine where torch jet formed by combustion a prechamber fuel in a precombustion chamber is injected to a main combustion chamber through a plurality of injection holes, may include a piston top surface portion comprising a land portion formed in a first region extending between axis line directions of adjacent injection holes, and the first region is positioned at a higher position than a second region extending across the axis line direction. The land portion may be formed on a cavity formed in the piston top surface portion. A plurality of land portions are provided corresponding to the plurality of injection holes, and the plurality of land portions are provided so as to be offset toward a same direction from a middle position between axis line directions of adjacent injection holes.

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.