Internal combustion engine having scavenging control valve

摘要

The invention aims to provide an internal combustion engine equipped with a scavenging control valve, in which blow-by of combustion gas from the upper annular space above the top piston ring to the scavenging ports is prevented by which reduction in engine performance due to deposition of combustion gas residuum to the scavenge openings and occurrence of piston ring sticking due to deposition of combustion gas residuum to the piston rings can be prevented, and further the amount of working oil to drive the scavenging control valve can be reduced resulting in decreased energy loss for pressurizing the working oil. An annular-shaped scavenging control valve is fitted-in to a fitting face formed on the inner side of the cylinder liner movably in circumferential direction of the cylinder liner for opening and closing said scavenging ports in order to allow scavenge air to be supplied into the cylinder or interrupted, said scavenging control valve has a plurality of scavenge openings arranged along circumferential direction and in a plurality of stages in axial direction thereof so that the scavenge openings are brought into communication or discommunication with the scavenging ports of the cylinder liner by moving the scavenging control valve in circumferential direction thereof, and the scavenge openings of each stage has a height L1 which is smaller than a inside distance L2 between a top piston ring and a bottom piston ring equipped to a piston of the engine as shown in FIG.3.