Abstract: A method for operating an internal combustion engine of a motor vehicle involves directly injecting fuel into a combustion chamber using an injection device, and a mixture of the fuel and air is ignited in the combustion chamber by an ignition device. The internal combustion engine is operated selectively in at least one first operating mode with at least one first valve lift of at least one gas exchange valve of the internal combustion engine, associated with the combustion chamber, or in at least one second operating mode with at least one second valve lift of the gas exchange valve, which is smaller than the first valve lift. For assisting a charge movement of the mixture in the second operating mode, at least one further injection of fuel directly into the combustion chamber is carried out prior to the ignition.

Abstract: A method for operating an internal combustion engine of a motor vehicle involves directly injecting fuel into a combustion chamber using an injection device, and a mixture of the fuel and air is ignited in the combustion chamber by an ignition device. The internal combustion engine is operated selectively in at least one first operating mode with at least one first valve lift of at least one gas exchange valve of the internal combustion engine, associated with the combustion chamber, or in at least one second operating mode with at least one second valve lift of the gas exchange valve, which is smaller than the first valve lift. For assisting a charge movement of the mixture in the second operating mode, at least one further injection of fuel directly into the combustion chamber is carried out prior to the ignition.

Abstract: In an arrangement and method for operating an internal combustion engine with at least two intake pipe tracts connected each to one group of cylinders, with each of the intake pipe tracts including at least one independently adjustable throttle element for controlling the intake air pressures in the respective intake pipe tract, at least one pressure equalizing means is provided for equalizing the intake pipe pressures in at least one operating mode under the control of a control unit which actuates the throttle element and the pressure equalizing means depending on the engine operating state.

Abstract: In a fuel supply arrangement for supplying fuel from a fuel tank to the fuel injectors of an internal combustion engine by an electrically operated fuel pump, a first fuel pressure level adequate for normal engine operation is provided by the fuel pump and means are provided for increasing the fuel injection pressure provided by the pump for supplying fuel at a higher pressure level to the fuel injectors during an engine start-up or warm-up phase.

Abstract: In a direct-injection spark-ignition internal combustion engine having one injector per cylinder for injecting fuel into a combustion chamber, wherein the injector has an injection nozzle with a plurality of injection holes which are distributed over its circumference, so that the jets of fuel from the injection holes form during an injection process a conical cloud of fuel, the piston opposite the injection nozzle includes a piston recess provided with a plurality of radial cavities extending from the recess radially into the piston head for receiving fuel injected into the combustion chamber.

Abstract: In a fuel injector for a direct-injection internal combustion engine comprising an injection nozzle, on the circumference of which a plurality of injection orifices are arranged so as to line up with one another, to form an orifice arrangement for the formation of an essentially conical fuel cloud from the individual fuel jets of the respective injection orifices the nozzle orifice locations are displaced so as to form a recess in the jet envelope in an area where a spark plug is located into which the spark plug extends so as to safely ignite the fuel cloud without getting wetted by the fuel.

Abstract: In a fuel supply arrangement for supplying fuel from a fuel tank to the fuel injectors of an internal combustion engine by an electrically operated fuel pump, a first fuel pressure level adequate for normal engine operation is provided by the fuel pump and means are provided for increasing the fuel injection pressure provided by the pump for supplying fuel at a higher pressure level to the fuel injectors during an engine start-up or warm-up phase.

Abstract: In a fuel injector for a direct-injection internal combustion engine comprising an injection nozzle, on the circumference of which a plurality of injection orifices are arranged so as to line up with one another, to form an orifice arrangement for the formation of an essentially conical fuel cloud from the individual fuel jets of the respective injection orifices the nozzle orifice locations are displaced so as to form a recess in the jet envelope in an area where a spark plug is located into which the spark plug extends so as to safely ignite the fuel cloud without getting wetted by the fuel.

Abstract: In a direct injection internal combustion engine with a combustion chamber which is delimited in each cylinder by a longitudinally movable piston and by the inner wall of a cylinder head, an injector injects fuel into the combustion chamber in order to form an ignitable fuel/air mixture with combustion air that is supplied separately, the mixture being ignited by a spark plug. The fuel is injected in a conical shape and the electrodes are protected from being wetted by fuel and from coking if they are located outside the lateral surface of the cone of fuel produced by the injection nozzle.

Abstract: In internal combustion engines with direct fuel injection an injector injects fuel into the combustion chamber to form an ignitable fuel/air mixture with separately supplied combustion air, with the mixture to be ignited by a spark plug. The fuel is injected in a cone shape and the electrodes are protected from being wetted with fuel and coking if they are disposed outside the lateral surface of the conical fuel jet generated by the injection nozzle. In order to bring ignitable mixture between the electrodes and to ensure optimal operating behavior of the internal combustion engine by improving the combustion sequence, a combustion chamber configuration is provided such that the conical fuel jet is injected in a free jet which is substantially uninfluenced by the combustion chamber perimeter, and the electrodes of the spark plug project into a fuel vortex extending from the lateral surface during injection.

Abstract: In a device for controlling an injection valve which can be operated by a piezo-actuator and which comprises a charging and discharging circuit for the controlled charging of the piezo-actuator to a certain piezo-voltage, the charging and discharging circuit includes a power supply with a multitude of voltage levels which correspond to various valve opening positions and a switching device for the controlled switch-over between the plurality of voltage levels.

Abstract: In a device for controlling an injection valve which can be operated by a piezo-actuator and which comprises a charging and discharging circuit for the controlled charging of the piezo-actuator to a certain piezo-voltage, the charging and discharging circuit includes a power supply with a multitude of voltage levels which correspond to various valve opening positions and a switching device for the controlled switch-over between the plurality of voltage levels.

Abstract: Direct-injected, four-cycle internal combustion engines can be operated advantageously with charge stratification, with the fuel being injected into the combustion chamber during the compression stroke of the piston in the cylinder as a conical fuel stream. To ignite the stratified mixture cloud, an igniting spark jumps between the electrodes of a spark plug and thus contacts an ignitable mixture. In order to guarantee sufficient preparation and stable ignition and combustion of the fuel/air mixture in the long term, it is proposed that the electrodes be located outside a conical jacket of the fuel stream and that the combustion chamber roof be so designed that the conical jacket is formed during injection between the injector and the spark plug close to the wall of the combustion chamber roof. The mixture guided in the conical jacket is deflected outward in the direction of the electrodes as a result.