| 摘要 |
PURPOSE:To prevent blow-through of new intaken gas by opening an opening/ closing valve, which operates in linkage with revolutions of the crank shaft, in such a timing as after the piston having opened the scavenging port, and thereby retarding the commencement timing of the scavenging stroke without requiring shift of the open position for scavenging or exhaust port from the arrangement according to conventional method. CONSTITUTION:When a piston 4 passes the upper dead point into the downward stroke and has reached a point 90 deg. after the upper dead point, the exhaust port 6 opens and exhaustion of the gas commences. Then a main 7 and an aux. 8 scavenging port open, when no scavenging stroke will begin because an opening/ closing valve 18 is closed. When the piston 4 reaches a point 140 deg. after the upper dead point, this opening/closing valve 18 opens, and the mixture gas compressed in the crank chamber 11 passages through a scavenging gas passage 14 and flows into the combustion chamber 5 from the main 7 and aux. 8 scavenging ports, to cause pressing-out of the combusted gas having filled the inside from the exhaust port 6. |
