Abstract: 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.

Abstract: In a method for controlling a reciprocating piston internal combustion engine having a plurality of cylinders in a compression ignition operating mode in which a lean fuel/air mixture is burnt, wherein an actual value of at least one characteristic variable which is influenced by the fuel burning process is compared with a pre-definable set point value in order to form a control value, with which the setting of an operating parameter affecting the mixture formation is adjusted in order to approximate the actual value of the characteristic variable, in a first control circuit, a mean value of the characteristic variable is determined and adjusted to an overall set point value using the control value, which is supplied to all the cylinders, and, in a second control circuit, characteristic variables which are measured at each cylinder are matched by means of individually determined control values in order to ensure a stable combustion in the compression operating mode.

Abstract: In a method of operating an internal combustion engine with a switch-over capability between a compression ignition mode of operation and a spark ignition mode of operation in higher load ranges which includes a cam-operated valve drive with a valve control providing, in the compression ignition mode of operation, for an increased valve overlap of the valve opening times, smooth engine operation and optimal exhaust gas emissions are obtained also during rapid load changes upon changing the engine operating mode as the change-over is accompanied by changes of the injection parameters, the throttling parameter and the valve control, which are coordinated with respect to one another as the valve control is switched over by changing the amplitude and phase position of the valve stroke of at least one of the inlet and outlet valves.

Abstract: 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 (?) 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 (?), 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.

Abstract: 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 ai

Abstract: In a method for operating an internal combustion engine having a variable compression ratio either in a compression ignition or in a spark ignition operating mode depending on the engine operating point, a higher compression ratio is provided in the compression ignition mode than in the spark ignition mode so as to optimize the operation of the internal combustion engine at low and medium engine loads, and to reduce engine emissions.

Abstract: In an internal combustion engine, wherein a combustible fuel mix is formed in a combustion chamber of the engine by fuel and by fresh gas supplied through intake ports and combustion gases discharged through exhaust ports including intake and exhaust valves, respectively, which valves are actuated by a valve operating mechanism and a spark ignition operating mode is provided in part of the load range and an operating mode with compression ignition is provided in another part of the load range and, in the event of a change in the operating mode, the opening duration of the gas exchange valves is altered while the opening times of the exhaust valves are maintained.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: In a method for operating an internal combustion engine with direct fuel injection, in which air and a first fuel quantity are fed to a combustion chamber, in such a manner that a homogenous lean base mixture is formed in the combustion chamber, and a second fuel quantity is introduced into the combustion chamber in the region of a top dead center position of the piston, in such a manner that an ignitable mixture cloud is formed within the homogenous lean base mixture in the region of an ignition source, and the mixture cloud formed by the second fuel quantity is ignited by means of the ignition source, so that the lean homogenous base mixture which is present in the combustion chamber is compressed by the combustion of the mixture cloud formed by the second fuel quantity and ignited thereby.