| 摘要 |
PURPOSE:To set a scavenging port area at discretion according to a crank angle as well as to prevent the occurrence of prefiring and improve the extent of engine output, by installing a rocking plate in an upper part of a scavenging port, while driving a rod rocking this plate with a cam rotating the circumference of a cylinder. CONSTITUTION:A scavenging control plate 3 to be rocked with a fulcrum 4 as the center is installed in a scavenging port of a two-cycle engine, and a tip end of the scavenging control plate 3 is opened up to an upper edge of the scavenging port 10 by means of projection of a rod 6. A cam plate 8 to be turned round by a gear 6 rotating synchronously with engine rotation is installed in the circumference of a cylinder 1, and when an inner surface projection of the cam plate 8 pushes the rod 6, the scavenging control plate 3 is opened. At a period of time ranging from exhaust, when a piston 2 goes down, to scavenging, blow-by of the exhaust to the scavenging port 10 is liable to occur, so that the tip end of the scavenging control plate 3 is lowered down, thus the blow-by is prevented from occurring. When the piston 2 goes up, the tip end is also lowered down whereby sufficient scavenging air is secured. |
