| 摘要 |
¢Problems to be Solved! To provide a compact two-cylinder engine in which cylinders are juxtaposed closely, exhaust control valves have a simple shape, a mechanism for activating the exhaust control valves are simplified in order to facilitate assembling and main tenance of components, and improve exhaust gas purification. ¢Means to Solve the Problems! In the two-cycle engine 9, the scavenging passages 54(f) of the scavenging ports 53 adjacent to the exhaust ports 39 are flat in their cross section and extend t o the sides of the exhaust ports 39. This structure can maintain the predetermined cross sectio nal area of the scavenging passages but reduce a width of the cylinder section. Further, in the two-cycle engine having a plurality of juxtaposed cylinders, the exhaust passage s 58 of the cylinders are arranged in the direction substantially orthogonal with the ju xtaposed direction of the cylinders, and the exhaust control valves 40 are positioned nea r the exhaust ports in order to control an opening amount of the exhaust ports. The ex haust control valves 40 are rotatably supported by the pivot 48 extending substantiall y in parallel with the juxtaposed direction of the cylinders, and are turned in the p lane which is parallel with the opening direction of the exhaust ports 39.
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