Methods and systems are provided for a pre-chamber. In one example, a pre-chamber comprises a plurality of slots fluidly coupling it to a primary combustion chamber. The plurality of slots comprising a plurality of corresponding flaps configured to direct gases through the plurality of slots.

An internal combustion engine for a motor vehicle includes a combustion chamber in which a first tumble-shaped current of a fuel-air mixture is settable. A pre-chamber spark plug is allocated to the combustion chamber which has a pre-chamber which is fluidically connected to the combustion chamber via a plurality of openings where via the plurality of openings a part of the fuel-air mixture flows out of the combustion chamber and into the pre-chamber. The plurality of openings are formed such that the part of the fuel-air mixture that flows into the pre-chamber via the plurality of openings has a second tumble-shaped current where the second tumble-shaped current is opposite to the first tumble-shaped current.

A structure of a combustion chamber for an engine includes: a crown surface of a piston; a combustion chamber ceiling surface formed on a cylinder head; and an ignition plug mounted on the combustion chamber ceiling surface, and including an ignition portion disposed in such a way as to face the combustion chamber. The crown surface of the piston includes a cavity which is recessed in a cylinder axis direction in a region including a position below the ignition portion of the ignition plug in a plan view from the cylinder axis direction. A rim portion of the cavity includes a guide portion, raised in the cylinder axis direction with respect to an inner region of the rim portion, interposing the ignition portion when the piston is at a compression top dead center, and configured to guide an air-fuel mixture within the combustion chamber to the ignition portion.

A fuel injection control device for an engine is provided. A fuel injector with multiple nozzle holes forms a lean mixture gas inside a combustion chamber, a spark plug ignites to cause the mixture gas to start combustion accompanied by flame propagation, then combust by self-ignition. A first atomized fuel spray injected from a first nozzle hole and a second atomized fuel spray injected from a second nozzle hole separate from each other by a swirl flow, and a third atomized fuel spray injected from a third nozzle hole and a fourth atomized fuel spray from a fourth nozzle hole approach each other by the swirl flow so that a first area and a second area where mixture gas is richer are formed inside the combustion chamber. The fuel injector sequentially performs first, second, and third injections with an injection interval therebetween in an intake stroke.

Methods and systems are provided for a pre-chamber. In one example, a pre-chamber comprises a plurality of slots fluidly coupling it to a primary combustion chamber. The plurality of slots comprising a plurality of corresponding flaps configured to direct gases through the plurality of slots.

In an internal combustion engine provided with an electro-hydraulic system for variable actuation of the intake valves of the engine, each cylinder has two intake valves, which are associated with two intake conduits and are controlled by a single cam of a camshaft through a single hydraulic circuit. The communication of the hydraulic actuators of the two intake valves with a discharge channel is controlled by two electrically-actuated control valves, both of an on/off two-position type, arranged in series with each other along a hydraulic line for communication between the a pressure volume and the discharge channel.

An internal combustion engine includes: a piston guided by a cylinder to reciprocate along a cylinder axis and forming a combustion chamber with a crown surface facing a cylinder head; and a fuel injection valve having an injection port facing the combustion chamber and injecting fuel to a forward tumble flow in the combustion chamber. A ridge formed on the crown surface rises toward a ceiling surface side relative to a reference plane, orthogonal to the cylinder axis and including an outer peripheral edge of the crown surface, and has a ridge line formed by a curved surface to surround a recessed part. The recessed part is recessed toward a center of the crown surface in a direction orthogonal to a virtual plane including the cylinder axis and parallel to a rotation axis of a crankshaft, and is recessed toward the center in an axial direction of the crankshaft.

The center injection engine is an engine equipped with the direct injector and an ignition apparatus at center of a ceiling part of the combustion chamber. The positive tumble flow flows from the intake port side to the exhaust port side on the ceiling part side of the combustion chamber, and also flows from the exhaust port side to the intake port side on the piston top part side. The ECU calculates the injection timing of the direct injector based on the engine load. In the first injection control, the higher the engine load becomes, the more the end crank angle is retarded.

A combustion chamber structure for an engine includes a combustion chamber where SI combustion by spark ignition and CI combustion by self-ignition are conducted. A crown surface includes a cavity recessed to have a bowl-shape; a pair of first raised portions having a mound-shape along a pent roof shape; and a second raised portion provided to protrude at a position orthogonal to a ridge extending direction of the pair of first raised portions. With a height of the first raised portion relative to a height position of a deepest portion of the cavity being represented as H1 and a height of the second raised portion being represented as H2, H1/H2 as a ratio of the height H1 of the first raised portion to the height H2 of the second raised portion is set to be in a range of 1.92 or more and 2.75 or less.

A fuel injection device is provided with reduced adherence of fuel spray with respect to an intake valve, a wall surface in an engine cylinder, or a piston. The fuel injection device includes a valve body and a seat surface to perform sealing of fuel cooperatively and injection holes. Inlet opening surfaces are formed on the seat surface. A first injection hole and a second injection hole arranged closest to the first injection hole. The first injection hole is larger than the second injection hole in an injection hole angle to be an angle formed by a normal direction of the seat surface and a center axis of the injection hole. The second injection hole is larger than the first injection hole in an area of a cross-section perpendicular to the center axis of the injection hole.