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, an injector and an ignition plug provided on the combustion chamber ceiling surface, and an intake opening and an exhaust opening opened in the combustion chamber ceiling surface. A side where the intake opening is opened is defined as an intake port side, and a side where the exhaust opening is opened is defined as an exhaust port side, with respect to a position, as a reference, where an ignition portion of the ignition plug is disposed in a plan view from one side in a cylinder axis direction, the injector is configured to inject fuel toward the exhaust port side, and a reverse squish flow generation portion, which draws an air-fuel mixture toward the intake port side, is provided in the combustion chamber.

A structure of a combustion chamber for an engine includes a crown surface of a piston, a cylinder wall surface, a combustion chamber ceiling surface, and an ignition plug which includes an ignition portion. The crown surface of the piston includes: a cavity recessed in the cylinder axis direction; a parallel surface portion which is in parallel to a corresponding region on the combustion chamber ceiling surface at a position above the cylinder axis direction with a gap, when the piston is at a compression top dead center; and an inclined surface portion formed to continue to the parallel surface portion in such a way as to be directed to the ignition plug, when the piston is at a compression top dead center. The parallel surface portion and the corresponding region, in combination, constitute a squish flow generation portion generating a squish flow when the piston is lifted.

An engine apparatus includes an ignition control section and an injection control section. When the partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate the SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes the injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Energy of the preceding ignition is set to be lower when a swirl flow is gentle than when the swirl flow is intense.

A control apparatus for a compression-ignition type engine is applied to an engine capable of carrying out partial compression ignition combustion. When the partial compression ignition combustion is carried out, an ignition control section of the control apparatus causes an ignition plug to carry out: main ignition in which a spark is generated to initiate the SI combustion; and preceding ignition in which the spark is generated at an earlier time point than the main ignition. An injection control section causes the ignition plug to inject fuel in an intake stroke. The ignition control section sets energy of the preceding ignition to be lower than energy of the main ignition and causes the ignition plug to carry out the preceding ignition after the fuel injection in the intake stroke or an early period or a middle period of a compression stroke.

The invention is provided with an ignition control section and an injection control section. When partial compression ignition combustion is carried out, the ignition control section causes an ignition plug to carry out: main ignition in which a spark is generated in a late period of a compression stroke or an initial period of an expansion stroke to initiate SI combustion; and preceding ignition in which the spark is generated at earlier timing than the main ignition. Also, when the partial compression ignition combustion is carried out, the injection control section causes an injector to inject fuel at such timing that the fuel exists in a cylinder at an earlier time point than the preceding ignition. Timing of the preceding ignition is set to be more retarded when an engine speed is high than when the engine speed is low.

The proposed solution relates to a combustion chamber assembly of an engine (T), in which an overrun of a spark plug is defined with a specific outer cone and a specific inner cone, and mixing air holes of a first arrangement and of at least one second arrangement that lie at least partially in a partial region of the overrun of the spark plug, said overrun being defined by the outer cone and the inner cone and extending downstream of the spark plug as far as an inner apex point (Si) of the inner cone, are formed with a flow cross section which is different from a flow cross section which the mixing air holes adjoining in the circumferential direction (U) of the respective arrangement have.

A fuel delivery system and a direct injector for directly injecting fuel into a cylinder are provided. In one example, a direct fuel injector includes a nozzle in fluidic communication with a fuel source, the nozzle includes at least one fuel flow path that divides into two exit flow paths within the nozzle defining a plurality of exit orifices stemming from a common inlet orifice thereby improving the atomization and mixing of the fuel as it enters the cylinder. A plurality of spaced-apart divided fuel flow paths may be positioned within the nozzle to further optimize mixing and reduce wall and piston wetting.

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.

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.