To appropriately maintain the concentration and quantity of air-fuel mixture in a combustion chamber by forming a communicating passage between a combustion chamber and a chamber continued to fuel injection devices out of a first communicating passage in which compressed air flows, and a second communicating passage in which air-fuel mixture or compressed air flows, and opening or closing the respective communicating passaged by means of individual control valves.
A control valve (rotary valve) 32 is arranged on a communicating passage between the combustion chamber on the top part of a piston and a chamber 20 provided on the side in parallel and continued to fuel injection devices 26. The communicating passage is formed out of a first communicating passage 28 in which compressed air flows from the combustion chamber to the chamber 20, and a second communicating passage 21 in which air-fuel mixture or compressed air flows from the chamber to the combustion chamber. The control valve 32 is constituted of first and second control valves provided on the respective communicating passages 28, 21. The first control valve is controlled so as to open nearby closing of an exhaust opening and close on the way of compression stroke, and the second control valve is controlled so as to open nearby closing of a scavenging opening and close before closing the first communicating passage 28 on the way of compression stroke.
ASAI MASAHIRO
ISOMURA SHINICHI
