| 摘要 |
PURPOSE:To prevent a fresh mixture from blowing through a two-cycle engine, by introducing air into the scavenging passage to inject the air into the cylinder ahead of the mixture in the scavenging process. CONSTITUTION:An air intake pipe 10 is provided near a scavenging port 2 and connected to a scavenging passage 4 through a one-way valve 11. An air control valve 12 is installed in the air intake pipe 10 and interlocked with a throttle valve 7. When the pressure of a crankcase 5 has become negative due to the ascent of a piston 6, a reed valve 8 and the one-way valve 11 are opened so that a mixture is filled in the crankcase 5 and air is filled in the scavenging chamber 4. After that, explosive combustion is caused to move the piston 6 down to open the scavenging port 2 and subsequently open the scavenging port 2 so that the air in the scavenging passage 4 flows into the cylinder 1 to scavenge the combustion gas. According to this constitution, the fresh mixture is prevented from blowing through the cylinder 1, to lower the hydroarbon content of the exhaust gas to improve the fuel efficiency. |
