| 摘要 |
PURPOSE:To improve fuel consumption and starting performance by obtaining appropriate air-fuel mixture always, by a method wherein fuel is measured by varying an effective area of a fuel jet through action of a suction air flow detector and negative pressure acting upon a fuel spouting part is controlled at a fixed state. CONSTITUTION:Fuel from a fuel supply device 8 having a float 8' led to a fuel jet 7 through a fuel supply duct 9 is spouted out from a fuel spouting part 14 by a carburetor through a connecting duct 12 and a fuel duct 13 after it has been mixed up with suction air flowing in a fuel spouting duct 10 at the confluence 11. In this case, atomization of the fuel from a spouting part 14 is contrived by spouting air to be fed by pressure from a pump 17 after pressure of the air is controlled at a fixed level by a constant-pressure valve device 18 by providing an injection nozzle 21 upstream of the spanting part 14. Fuel quantity is controlled appropriately by a method wherein a diaphragm device 16 detecting negative pressure downstream of a plate valve 4 is provided, an opening of the plate valve 4 is adjusted through a lever 15 by an output of the device 16 and a metering needle 6 is displaced. |
