Two-cycle internal combustion engine

摘要

A two-cycle internal combustion engine having three, or a multiple of three, cylinders comprises a cylinder head having an intake port and exhaust port opened to a combustion chamber, to which fresh air compressed by a supercharger is introduced via an intake valve. The intake and exhaust valves are operated in response to a crank angle. A one-way valve is provided in the intake port so as to prevent air or gas from flowing back toward the supercharger. The exhaust valve is opened earlier than the intake valve when the speed of the downward movement of the piston is relatively high, so that a part of exhaust gas in the exhaust port flows back to the combustion chamber in the condition. In a heavy load condtion, cross scavenging and air charging effects due to exhaust pulsation can be achieved.