A method for operating an internal combustion engine having at least two cylinders and having a single injector for central point injection of fuel into an air intake connected to the cylinders, wherein for each of the cylinders an injection quantity of the fuel and a starting time of the injection are specified and set as a function of the present engine load and the present engine speed. The invention further relates to such an internal combustion engine.

An internal combustion engine for a motor vehicle has at least one cylinder for accommodating a piston and at least one pre-chamber spark plug allocated to the combustion chamber of the cylinder. The engine also has a pre-chamber, fluidically connected with the combustion chamber via several openings, in which at least one ignition spark is generable by the pre-chamber spark plug. At the induction stroke of the internal combustion engine, a rinsing of the pre-chamber with inlet gas including at least fuel and air occurs, so that, at the ignition point, an ignitable mixture of fuel and air is accommodated in the pre-chamber.

In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the engine includes a lower cavity, an upper cavity, and a lip portion therebetween. A controller causes a main injection and at least one pilot injection to be executed when the engine operates in a first state and a second state in which the load is lower than the load in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller sets the timing of the pilot injection(s) so that the distribution ratio of the fuel spray of the pilot injection(s) for the lower cavity is higher when the engine operates in the first state than when in the second state.

In a compression-ignition engine having a two-stage cavity, the distribution ratio between fuel for an upper cavity and fuel for a lower cavity is maintained even when the operational state of the engine changes. A piston of the engine includes a lower cavity, an upper cavity, and a lip portion between the lower cavity and the upper cavity. A controller causes a main injection and at least one pilot injection to be executed when the engine operates in a first state and a second state in which the load is lower than the load in the first state. The fuel spray is distributed to the lower cavity and the upper cavity. The controller outputs a control signal to a fuel injection valve so that a distribution ratio for the upper cavity is higher when the engine operates in the second state than when in the first state.

A spark ignition internal combustion engine includes: intake and exhaust valves disposed at a ceiling part of a combustion chamber; and a fuel injection valve including a tip end portion including injection holes, and being structured to inject fuel through the injection holes toward a crown of a piston, wherein the tip end portion of the fuel injection valve is arranged in a region of the ceiling part surrounded by the intake and exhaust valves. A fuel injection control includes: determining a tip end portion fuel temperature directly or indirectly, which is a temperature of fuel at the tip end portion of the fuel injection valve; and setting a fuel injection timing advanced, in response to a condition that the tip end portion fuel temperature is higher than a temperature threshold value, wherein the temperature threshold value relates to flash boiling of fuel at the injection holes.

A direct-injection stratified charge internal combustion engine includes a combustion cylinder to receive an air-fuel mixture, and an air intake port to inlet air into the combustion cylinder. The direct-injection engine also includes a fuel injector configured to deliver fuel within the cylinder in a spray pattern substantially aligned to a cylinder central axis to create the air-fuel mixture. A spark igniter is located within a path of the spray pattern to ignite combustion of the air-fuel mixture. The direct-injection engine further includes a movable piston defining a lower boundary of the combustion cylinder to contain the combustion of the air-fuel mixture. The piston is configured to include a bowl portion having local geometric features located on an intake port side of the combustion cylinder to redirect fluid flow towards a vortex in fluid communication with a combustion location near the cylinder central axis.

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 control system of a compression-ignition engine includes an intake variable mechanism and a controller. In a second operating range, the controller controls the intake variable mechanism so that, while partial compression-ignition combustion is performed under an air-fuel ratio (A/F) lean environment, an intake valve open timing takes timing at an advanced side of an exhaust TDC. In a first operating range on a lower load side, the controller controls the intake variable mechanism so that, while the partial compression-ignition combustion is performed under the A/F lean environment, under the same engine speed condition, the intake valve close timing is more retarded within a range on a retarded side of an intake BDC as the engine load decreases, and an absolute value of a change rate of the intake valve close timing to the engine load becomes larger than in the second range.

Provided is a hybrid vehicle that includes a power train including an internal combustion engine equipped with a plurality of cylinders and a drive motor unit. The drive motor unit includes an electric motor coupled to the internal combustion engine without a clutch. The internal combustion engine includes one or more decompression devices that are each installed for a subset of one or more cylinders and that operate to release compression pressure in the subset of one or more cylinders in at least one of the course of an engine stop and course of an engine start-up in which combustion is not performed. The subset of one or more cylinders are selected such that, when the one or more decompression devices are operating, compression is not produced sequentially in cylinders that are adjacent to each other in terms of the firing order.

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.