| 摘要 |
PURPOSE:To form a strong turbulence in a cyinder for improving combustion and fuel consumption of an engine by providing a controlling valve in a predetermined position ranging from a crank chamber through a throttle section to the middle portion of an auxiliary chamber to reduce sufficiently or completely shut off freah air amount flowing from the crank chamber into the auxiliary chamber only in a certain partial load region of the engine. CONSTITUTION:An auxiliary chamber 9 is provided which communicates through a controlling valve 7 to a crank chamber 3. The controlling valve 7 is mechanically interocked with a throttle valve 5, the effective section of the controlling valve 7 being fully opened or approximately fully closed only in a certain partial region such as low load region of an engine to bring to a nill or sufficiently reduce a fresh air amount flowing from the crank chamber 3 into the auxiliary chamber 9. Thus, pressure P in the crank chamber 3 at the beginning of scavenging is raised by one corresponding to the volume of the auxiliary chamber 9 so that the injection speed of fresh air injected from a scavenging path 4 becomes high to provide a strong turbulence formed in a cylinder 2 for improving combustion and the fuel consumption of the engine. |
