Daimler Chrysler Ag

Daimler Ag

Diamler Chrysler Ag

Götz Brachert

Matthias Pfau

Rüdiger Herweg

Kai Kanning

Jochen Schäflein

Hans-Jürgen Weimann

Hans-Jürgen Weiman

In a method of operating a 4-stroke internal combustion engine selectively in a compression ignition operation, in which an outlet valve of the internal combustion engine is closed at a comparatively early closing time point with respect to a crank angle (&#x3b1;) and in spark ignition operation, in which the outlet valve is closed at a comparatively late closing time point with respect to the crank angle (&#x3b1;), during the changeover from the spark ignition mode of operation to the compression ignition mode of operation, the closing time point of the outlet valve is transferred from the late closing time point to the early closing time point in steps distributed over multiple 4-stroke cycles.

Method for the operation of an internal combustion engine

In a method for operating an internal combustion engine in which the angular locations where the fuel/air mix combustions takes place can be controlled by an adjustment of the inlet and outlet valve timing, the timing of at least one of the intake and exhaust valve opening phases is shifted depending on the engine speed so as to reduce engine emissions.

Method for operating an internal combustion engine

In a method of operating a reciprocating-piston internal combustion engine with a combustion chamber in which a fuel mix with fresh gas is provided via intake ports and combustion exhaust gases are discharged through exhaust ports which can be opened by intake valves and, respectively, exhaust valves which are actuated by a valve operating mechanism, wherein an operating mode with external ignition, in which the fuel mix is ignited by a spark plug, is provided in part of the load range of the internal combustion engine, and an operating mode with compression ignition, in which the control of the gas exchange valves is altered so as to retain combustion exhaust gases in the combustion chamber for participation in the formation of the fresh mix is provided in another load range of the internal combustion engine, during a change in the operating mode the valve lift of at least one of the gas exchange valves is altered.

In a method for operating an internal combustion engine in which the fuel is injected into a combustion chamber of a pre-injection and a main injection quantity, the quantity of fuel for the pre-injection, which is selected depending on the combustion location, is injected before the top dead center of the gas exchange, and the fuel for the main injection is injected synchronously with the induction of the air. The method is used in connection with internal combustion engines, in particular for passenger and commercial motor vehicles.

In a method of operating a supercharged internal combustion engine in which exhaust gas is retained in the combustion chamber during a charge change, wherein the engine is operated with compression ignition or with spark ignition depending on the operating point and in which a charge pressure can be established for the fresh air supplied to the combustion chamber, and the exhaust gas is compressed during the charge change, and a first fuel quantity is optionally injected into the retained exhaust gas and a second fuel quantity is subsequently supplied to the combustion chamber, such that a homogeneous fuel/air mixture is formed in the combustion chamber, the retained exhaust gas quantity in the combustion chamber is corrected in such a way that the center of the combustion is displaced in the direction toward a set point value when the center of the combustion deviates from the set point value because of a change in the charge pressure of the fresh air or because of a change in the temperature of the fresh air.

Method for operating and internal combustion engine

In a method of operating an internal combustion engine in which exhaust gas is retained in the combustion chamber of the internal combustion engine and compressed during a charge change together with fresh combustion air, a first fuel quantity is injected into the retained exhaust gas by means of direct fuel injection, a second fuel quantity is subsequently supplied to the combustion chamber together with the fresh combustion air so that a homogeneous fuel/gas/air mixture is formed in the combustion chamber, and an auto-ignition time of the fuel/gas/air mixture is established as a function of a quantity ratio of the first fuel quantity and the second fuel quantity.

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Stuttgart, Germany

Götz Brachert