| 摘要 |
PURPOSE:To reduce the mixing of exhaust to fresh air and increase scavenge efficiency, in a uniflow unsymmetrical scavenging 2-cycle engine of overhead intake-scavenge valve type, by causing a positive swirl flow of the fresh air and performing scavenging action at replacement of scavenged air with the fresh air. CONSTITUTION:A combustion and swirl forming chamber 7 is provided in a cylinder head part to cause a positive swirl flow of fresh air and perform scavenging action at replacement of scavenged air with the fresh air. A piston 2 is lowered, if exhaust ports 12 in the lower wall of a cylinder 1 are opened, exhaust is discharged to the outside of the cylinder rapidly at a time. Thereafter, overhead intake and scavenge valves 4 are opened to a position about half the chamber 7, and replacement of scavenged air with fresh air, provided with a swirl, can be performed in the chamber 7 till the exhaust ports 12 are closed, after closing of the exhaust ports 12, the intake and scavenge valves 4 are closed to transfer the piston to a compression stroke. |
