Control device for compression ignition type internal combustion engine and method for determining smoke generation state in compression ignition type internal combustion engine

摘要

The engine system 1 has an engine ECU 10 including: an equivalent ratio calculation means that calculates an average value of equivalent ratio for one cycle in a combustion chamber of the engine 100, a maximum combustion temperature calculation means that calculates a maximum value of combustion temperature in the combustion chamber for the same cycle as for calculation of the average value of equivalent ratio by the equivalent ratio calculation means; and a determination means that determines a smoke-generating state of the engine 100 based on a calculation result by the equivalent ratio calculation means and a calculation result by the maximum combustion temperature calculation means. The engine ECU 10 determines that the smoke-generating state is in a first region when the average value of equivalent ratio is less than a given first threshold value and the maximum value of combustion temperature in the combustion chamber is less than a given second threshold value, and commands an electric VVT mechanism 26 to retard a closing timing of an intake valve 22. When the smoke-generating state is determined to be in a region other than the first region, the electric VVT mechanism 26 is commanded to advance the closing timing of the intake valve 22.