| 摘要 |
PURPOSE:To improve the cooling efficiency of a piston with stabilizing combustion by controlling an auxiliary fuel injection device so that fuel is supplied to a passage leading to an intake passage only in the region where opening degree of a throttle valve is more than a certain value. CONSTITUTION:A main fuel injection device 31 for supplying fuel in all the driving regions is provided at a cylinder head 4 so that it faces a combustion chamber 28, and an auxiliary fuel injection device 61 is provided at a passage leading to an intake passage 19 having a throttle valve 21 from a scavenging port 23a which is opened and closed by a piston 6 through a lead valve 22. And when the throttle valve 21 is opened more than a certain opening degree, fuel is supplied to the intake passage 19 from the auxiliary fuel injection device 61, and mixture is flown into a cylinder 5 from the scavenging port 23a and carbureted by contact with the piston 6. In this way, cooling effect of the piston is improved with stabilizing combustion, and durability can be improved. |
