A combustion control device for a compression autoignition engine includes an engine, a state quantity setting device, a spark plug, a controller, and a sensor. The spark plug receives a control signal from the controller and ignites air-fuel mixture at predetermined ignition timing such that the ignited air-fuel mixture is combusted by flame propagation and then unburned air-fuel mixture in a combustion chamber is combusted by autoignition. The controller outputs a control signal to an injector such that, in a compression stroke, fuel is injected at specific timing at which a line obtained by extending an axis of each hole of the injector overlaps with a specific portion including an opening edge of a cavity in an upper surface of a piston.

The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder, a cylinder head carrying fuel injection, a piston sliding in the cylinder, a combustion chamber limited on one side by upper face of the piston comprising a projection extending in the direction of the cylinder head and in the center of a concave bowl (46) with at least two mixing zones. The fuel injection projects fuel in at least two fuel jet sheets with different sheet angles, with a lower sheet having a jet axis C1 for one zone and an upper sheet having a jet axis for the other zone. The injection feeds fuel into the combustion chamber with a different flow rate for each sheet for dedicated targeting in the mixing zones of the combustion chamber.

A control device for an engine is provided, which includes a fuel injector attached to the engine, a spark plug disposed to be oriented into a combustion chamber, a swirl control valve provided in an intake passage, and a controller connected to the fuel injector, the spark plug, and the swirl control valve and configured to control the fuel injector, the spark plug, and the swirl control valve. The swirl control valve closes in a given operating state of the engine. The fuel injector injects fuel after the swirl control valve is closed, between intake stroke and an intermediate stage of compression stroke. The fuel injector injects the fuel after the first fuel injection. The spark plug performs the ignition after the second fuel injection so that the mixture gas starts combustion by flame propagation and then unburned mixture gas self-ignites.

A fuel injector assembly for an engine. The engine includes a cylinder head defining a through-hole. The fuel injector assembly includes an insert, having a first end and a second end, configured to be received within the through-hole and coupled to the cylinder head. The insert defines a bore extending from the first end to the second end. The fuel injector assembly further includes a fuel injector including a plurality of orifices, received within the bore of the insert; and a duct structure including a plurality of ducts, coupled to the insert such that the plurality of ducts align with the plurality of orifices to at least partially receive one or more fuel jets from the plurality of orifices of the fuel injector.

The present invention is a compression-ignition direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying fuel injection means (14), a piston (16) sliding in the cylinder, a combustion chamber (34) limited on one side by an upper face (44) of the piston comprising a projection (48) extending in the direction of the cylinder head and located in a center of a concave bowl (46). The engine comprises injection projecting fuel in at least two fuel jet sheets. One of the zones comprises a toroidal volume (64) having center B with a flat bottom (56) into which fuel jets (40) of the lower sheet are injected so that an axis C1 of the lower sheet jets is contained between center B and projection (48).

An internal combustion engine includes a piston and a fuel injection valve. The fuel injection valve includes a first injection hole, a second injection hole, a first needle configured to open and close the first injection hole, and a second needle configured to open and close the second injection hole. The first injection hole and the second injection hole are configured such that a portion of a fuel spray injected from the first injection hole and a portion of a fuel spray injected from the second injection hole overlap each other at a position apart at a predetermined distance from a side wall of a cavity of the piston. The second needle is configured to start operation in order to open the second injection hole after a predetermined time has elapsed from a point of time when the first needle starts operation in order to open the first injection hole.

A fuel injection valve has first injection holes, second injection holes, a first needle that opens and closes the first injection holes, and a second needle. The fuel injection valve is arranged such that a part of fuel injected from the first injection hole and a part of fuel injected from the second injection hole are gathered together at a position spaced from the side wall of the cavity by a predetermined distance. The second needle starts operating to open the second injection holes, after a predetermined time elapses from a point in time at which the first needle starts operating to open the first injection holes.

A variable-compression ratio direct-injection internal-combustion engine comprising at least a cylinder (10), a cylinder head (12) carrying a fuel injection means (14) spraying fuel in a single sheet (34) of fuel jets (36), a piston (16) sliding in this cylinder, and a combustion chamber (32) delimited on one side by upper face (42) of the piston comprising a projection (46) rising up towards the cylinder head and arranged in the cent of a concave bowl (44). According to the invention, the combustion chamber comprises at least two mixing zones (Z1, Z2) into which fuel jets (36) are injected, one (Z1) of the zones being used for a maximum compression ratio (Tmax) and the other (Z2) zone being used for a minimum compression ratio (Tmini).

This invention discloses a combustion method, which is for an internal combustion engine, which utilizes variable spray patterns matched with a combustion chamber composing of multiple connected spaces based on injection timings and engine loads. This invention provides means to control propagation paths of combustion reaction radicals and control pressure rise rate, and also provides means to promote stratification of premixed charges. An internal combustion engine utilizing the disclosed combustion methods is also disclosed.

A piston crown is provided for a piston in an internal combustion engine arrangement that includes a cylinder, the piston crown having a piston bowl surface adapted for facing a combustion chamber in the cylinder, wherein the piston bowl surface including a circumferential rim portion, a floor portion connected to and surrounded by the circumferential rim portion, a plurality of circumferentially spaced protrusions in the circumferential rim portion, at least one spray impingement portion, located between two adjacent protrusions. The spray impingement portion includes a reflection surface, being defined by that each possible normal to the reflection surface is directed towards a central axis of the piston, and forming an angle being within a range of a constant angle 10 with the central axis, wherein the constant angle is at least 50.