| 摘要 |
PURPOSE:To simplify the mechanism of a low-speed system by providing a mixture passage equipped with a low-speed air bleed jet and a sub fuel passage to pass only fuel in parallel for changing openings of control valves provided in these passages in accordance with the driving condition of an engine. CONSTITUTION:A low-speed system 6 connecting between a constant oil-surface chamber 5 and a port 4 opend on the downstream side of a throttle valve 2 in a downward suction passage 3 provided with a Venturi tube 1 and a throttle valve 2, is divided into two passages in parallel. The one is formed into an air- fuel mixture passage 12 provided with a low-speed jet 7, the first bleed jet 8, an economizer 9, the second bleed jet 10, and a control valve 11, while the other is shaped into a sub fuel passage 14 provided with a control valve 13. Thereby, control valves 11 and 13 are controlled by the drive current of a control circuit 23 into which the signal of engine temperature is inputted. This construction permits to disuse a former choke device and obtain a small-sized carburetter as a whole. |
