An efficient engine combustion system with multiple combustion modes, includes a valve actuating mechanism, a pre-combustion chamber (30), and a main combustion chamber. The valve actuating mechanism is a fully variable valve mechanism; an intake valve (2) and an exhaust valve (26) are driven by high-pressure oil; ignition is implemented by means of an ignition apparatus of the pre-combustion chamber (30); and a spark plug (24) and a single-hole fuel injector (25) are mounted in the pre-combustion chamber (30), a bottom end of which is provided with a flame jet hole. The air inlet valve (2) and the exhaust valve (26) are respectively mounted thereon with an air inlet valve spring (4) and an exhaust valve spring (22); and the air inlet valve spring (4) and the exhaust valve spring (22) are separately connected to a hydraulic piston (21) that has an ejector rod; and the opening and closing of the air inlet valve (2) and the exhaust valve (26) are performed by the hydraulic piston (21). The efficient engine combustion system with multiple combustion modes may achieve smooth transition between different combustion modes, thus ensuring that the engine has optimal thermal efficiency under different operating condition regions.

An inlet manifold includes a main inlet oriented along a first direction and a pilot inlet oriented along a second direction perpendicular to the first direction. A wye passage includes an inlet branch in fluid communication with the main inlet. The inlet manifold also includes a first main passage in fluid communication with a first outlet branch of the wye passage and a second main passage in fluid communication with a second outlet branch of the wye passage. The first main passage extends generally along the first direction between the wye passage and a first main outlet. The second main passage extends generally along the first direction between the wye passage and a second main outlet. The inlet manifold also includes a pilot passage in fluid communication with the pilot inlet. The pilot passage extends generally along the first direction between the pilot inlet and a pilot outlet.

An auxiliary chamber (51) having a spark plug (54) and an auxiliary fuel injector is formed at the central part of the top surface of the main combustion chamber (2). When making an air-fuel mixture in the auxiliary chamber (51) burn by the spark plug (54), an air-fuel mixture in the main combustion chamber (2) is made to burn by jet flames ejected from the communicating holes (52). The injection ports of the auxiliary fuel injector (53) are oriented toward a tumble flow inflow peripheral region (R) which is located on the peripheral part of the end portion of the auxiliary chamber (51) at a place located on a side where the tumble flow W flows in from the communicating holes (52). When the tumble flow (W) is made to be generated in the main combustion chamber (2) by the tumble flow control valve (48), auxiliary fuel (QF) is injected from the auxiliary fuel injector (53) toward the tumble flow inflow peripheral region (R) of the auxiliary chamber (51).

A pre-chamber is formed between the front end of a spark plug attached to the cylinder head and a thin pre-chamber wall sticking out from the inside wall surface of the cylinder head to the inside of a main combustion chamber. The communication holes communicating the inside of the pre-chamber and the inside of the main combustion chamber are formed inside the thin pre-chamber wall. The thin pre-chamber wall is formed into a shape with a cross-sectional area gradually decreasing from the inside wall surface of the cylinder head toward the inside of the main combustion chamber such as a conical shape, frustoconical shape, polygonal conical shape, or polygonal frustoconical shape. A ground side electrode portion of the spark plug is positioned inside the gas pocket, and a discharge is caused between the center electrode sticking out from the front end of the center electrode insulator and the ground side electrode portion at the time of ignition.

Methods and systems are provided for increasing an amount of oxygen in a pre-chamber of a cylinder prior to combustion. In one example, a method may include purging residual gases from a pre-chamber to a cylinder via a pre-chamber air injection, and reducing a flow of the oxygen from the pre-chamber to the cylinder via a cylinder fuel injection directed toward an orifice fluidically connecting the pre-chamber with the cylinder. In this way, a composition of pre-chamber gases may be adjusted during a combustion cycle of a cylinder.

Methods and systems are provided for operating a cylinder of an engine including a pre-chamber ignition system. In one example, a method may include determining amounts of pre-chamber gases in the cylinder prior to combustion, and adjusting an amount of fuel injected into the cylinder based on the amounts of pre-chamber gases in the cylinder. In this way, cylinder fueling may be compensated for additional air and/or fuel from the pre-chamber gases, which may increase an accuracy of the cylinder fueling and increase cylinder efficiency.

A pre-chamber assembly of an internal combustion engine comprises a pre-chamber housing and a plurality of nozzles extending through a portion of the pre-chamber housing. The plurality of nozzles are directed to one location.

The ignition insert with an active pre-chamber (1) comprises an insert well (72) arranged in a cylinder head (3) of an internal combustion engine (2), said well (72) accommodating a cylindrical insert body (70) which is indexed in rotation and in which are arranged an ignition pre-chamber (71), an insert spark plug well (83) receiving a spark plug (12), and a injector radial orifice (88) which is aligned with a injector lateral well (73) arranged in the cylinder head (3) so as to receive an injector nose (16), said body (70) being terminated by a pre-chamber nose (75) opening into a combustion chamber (5), and being held in the insert well (72) by fixing means (82) cooperating with clamping means (74).

An engine system comprising an internal combustion engine and a turbocharger, where a diameter of the at least one intake valve is greater than a diameter of the at least one exhaust valve, the salient angle of the piston bowl is at least 10 degrees, the ratio between the piston bowl opening diameter and the piston bowl depth is approximately 0.5 to 2.0, the intake valve opens before top dead center on an exhaust stroke of the internal combustion engine and closes before bottom dead center of an intake stroke of the internal combustion engine, and the turbocharger has a combined efficiency of more than 50%.

A gas engine system controller: calculates a delay calculation value of a knocking occurrence ratio; determines a primary target ignition timing; sets the primary target ignition timing as a current ignition timing if the occurrence ratio difference is positive and an ignition timing does not exceed a converted value of a first advance rate; determines whether a rapid advance condition is satisfied if the occurrence ratio difference is positive and the ignition timing difference exceeds the converted value of the first advance rate; sets a secondary target ignition timing as the current ignition timing if the rapid advance condition is not satisfied, the secondary target ignition timing obtained by adding the converted value of the first advance rate to the previous ignition timing; and determines the current ignition timing so as to achieve a second advance rate greater than the first advance rate if the rapid advance condition is satisfied.