Internal combustion engine system

摘要

An internal combustion engine system is capable of reducing soot and NOx simultaneously, and prevents the occurrence of an undesirable situation where a generation amount of soot is increased in accordance with frequent transitions between a first combustion mode and a second combustion mode. In the system, the first combustion mode in which an amount of inert gas supplied to the combustion chamber is larger than an amount of the inert gas that causes the generation amount of soot to become a peak, such that soot is hardly generated, and a second combustion mode in which an amount of the inert gas supplied to the combustion chamber is smaller than the amount of the inert gas that causes the generation amount of soot to become a peak, are selectively performed. When conditions are such that switching between the first combustion mode and the second combustion mode has or may occur frequently, the execution of the first combustion mode is controlled. The frequency of switching can be determined, for example, based on a frequency of change of the engine load, an operational state of the engine, or road information. <IMAGE>