| 摘要 |
PURPOSE:To improve combustion to reduce deposit of carbon near a throttle valve by providing an auxiliary intake path directed to the interior of a combustion chamber and opened to wall surface near an intake valve and opening a fuel nozzle for low speed to said path. CONSTITUTION:The downstream end of an auxiliary intake path 21 formed in a cylinder head 16 is opened to the wall surface of an intake path 3 near an intake valve 18 and directed to the interior of a combustion chamber 2 directly from a gap provided by the opened intake valve 18. The upstream side of the auxiliary intake path 21 communicates to a start path 23 in a carbureter 4 through a communication path 22. In starting, rich mixture produced in a starting valve 24 provides high speed gas flow flowing through a path 23 having a small sectional area and the auxiliary intake path 21 into the combustion chamber 2 to provide a good starting property. When an engine is sufficiently warmed up, the starting valve 24 is closed. Only mixture for low speed flows through the auxiliary intake path 21 and mixtures in the othr cylinders under nonintake stroke are introduced to provide an auxiliary intake flow for higher speed. |
