Combustion chamber of a compression-ignition type internal combustion engine

A compression-ignition type internal combustion engine comprising a combustion chamber and an accumulation chamber which are interconnected to each other via an accumulation valve. The opening operation of the accumulation valve is controlled so that the accumulation valve remains opened during the compression stroke. In the first half of the compression stroke, a jet of air is spouted into the combustion chamber from the accumulation chamber to create a strong swirl motion in the combustion chamber. In the latter half of the compression stroke, the air in the combustion chamber flows into the accumulation chamber where the air is accumulated under high pressure, which air is then spouted from the accumulation chamber into the combustion chamber at the next cycle.