| 摘要 |
PURPOSE:To make it possible to keep a high scavenging pressure at the time of low and medium speed operations of the engine by a method wherein a check valve corresponding to a throttle valve is provided in a scavenging passage close to the opening in the cylinder. CONSTITUTION:A fresh gas sucked into a crank chamber 9 is pressurized within the crank chamer 9 because the check valve 2 for controlling the flow rate of a scavenged fresh gas is provided near the outlet of a scavenging port 1. When the engine is operating at the low and medium speeds with the opening degree of the check valve 2 kept small, the pressurized fresh gas becomes a high speed and high pressure scavenging stream 8 and is fed into the upper part of the cylinder 5. On the other hand, when the engine is rotated at hgih speed and with full load, the opening degree of the check valve 2 becomes large so that the engine maintains the same performance as the conventional engine. |
