SCAVENGING PORT AND SCAVENGING PASSAGE OF TWO-CYCLE ENGINE

摘要

PURPOSE:To reduce blow-off in a Schnurle scavenging type two-cycle engine, by forming a passage of a scavenging port in such a shape that each wall of the passage on an exhaust port side and on the opposite side of the exhaust port is directed opposite to the exhaust port toward the outlet of the scavenging port. CONSTITUTION:Each of three scavenging ports is symmetrically arranged with respect to an exhaust port 20, and walls 18 and 19 on the exhaust port 20 side and walls 16 and 17 on the opposite side as forming a scavenging passage of each scavenging port are formed by plural walls or curved surfaces in such a manner that the scavenging passage is directed opposite to the exhaust port 20 toward the outlet of the scavenging port. With this arrangement, fuel mixture in each of the scavenging ports 13-15 is collected on the opposite side of the exhaust port 20 upon entering a cylinder 12, and accordingly blow-off of scavenging air into the exhaust port 20 may be reduced.