| 摘要 |
.vertline.Problems to be Solved.vertline. To provide a compact two-cylinder engine in which cylinders are juxtapos ed closely, exhaust control valves have a simple shape, a mechanism for activating the exhaust control valves are simplified in order to facilitate assembling and maintenance of components, and improve exhaust gas purification. .vertline.Means to Solve the Problems.vertline. 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 exte nd to the sides of the exhaust ports 39. This structure can maintain the predetermined cross sectional 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 passages 58 of the cylinders are arranged in the direction substantially orthogonal with th e juxtaposed direction of the cylinders, and the exhaust control valves 40 are positioned near the exhaust ports in order to control an opening amount of the exhaust ports. Th e exhaust control valves 40 are rotatably supported by the pivot 48 extending substantially in parallel with the juxtaposed direction of the cylinders, and are turned in t he plane which is parallel with the opening direction of the exhaust ports 39.
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