Patent ID: 7263982
Filing Date: 2007-09-04
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A method of operating a supercharged internal combustion engine having a cylinder, a cylinder head including inlet and outlet valves, a piston movably disposed in the cylinder and defining a combustion chamber between the cylinder head and the piston, to which fresh air is supplied by an air supply device whose air charge pressure can be controlled for supplying fresh air to the combustion chamber of the engine under a controllable pressure, said method comprising the steps of: operating the internal combustion engine selectively in a compression ignition or in a spark ignition mode of engine operation depending on the engine operating point, and, in the compression ignition mode, retaining exhaust gas in the combustion chamber which is compressed during a charge change, optionally injecting a first fuel quantity into the retained exhaust gas, subsequently supplying a second fuel quantity to the combustion chamber together with fresh air so that a homogeneous fuel/air mixture is formed in the combustion chamber, combusting the fuel/air mixture over a period having a center of combustion, and correcting the amount of the exhaust gas quantity retained in the combustion chamber when the center of combustion deviates from a 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 in such a way that the center of the combustion is displaced toward the set point value.