Patent ID: 8096279
Filing Date: 2012-01-17
Classification: F02D,Y02T

Abstract:
1. A method of controlling a premixed compression ignition type engine having at least one cylinder, a combustion chamber, an intake valve, an exhaust valve, an intake valve cam for spark ignition combustion, an intake valve cam for compression ignition combustion, an exhaust valve cam for spark ignition combustion, and an exhaust valve cam for compression ignition combustion, and that is operated while changing over between spark ignition combustion and compression ignition combustion by changing over between said cams for spark ignition combustion and said cams for compression ignition combustion, the method comprising: performing control to retard valve-opening timing of the intake valve and to advance valve-closing timing of the exhaust valve to set a negative overlap period in which the exhaust valve is closed earlier and the intake valve is opened later with respect to exhaust top dead center during steady operation under the compression ignition combustion; performing control to advance valve-closing timing of the exhaust valve after change over from the spark ignition combustion to the compression ignition combustion with respect to the valve-closing timing of the exhaust valve before the change over in the same cylinder; and performing control to advance valve-opening timing of the intake valve with respect to the valve-opening timing thereof during steady operation under the compression ignition combustion in the cylinder in which the intake valve is opened by the intake valve cam for compression ignition combustion before the exhaust valve is closed by the exhaust valve cam for compression ignition combustion after start of the change over from the spark ignition combustion to the compression ignition combustion.