| 摘要 |
PURPOSE:To lower the specific fuel consumption of an engine, by extending the fuel decreasing range of a variable venturi carburetor downward at the time of declerating a vehicle. CONSTITUTION:An air-bleed branch passage 32 is branched from an air-bleed passage 30 and it is communicated with an intake passage 2 at the portion thereof located on th upstream side of a suction piston 3. A shut-off valve 33 and an air-bleed jet 34 are inserted into the air-bleed brach passage 32. On the other hand, another air-bleed passage 35 is opened in a fuel passage 20 at the portion thereof located on the opposite side of a metering jet 21 with respect to the fuel inlet port of a by-pass passage 28. The air-bleed passge 35 is communicated with the intake passage 2 at the portion thereof located on the upstream side of the suction piston 3, and a shut-off valve 36 and an air-bleed jet 37 are inserted into the air-bleed passage 35. The above two shut-off valves 33, 36 are opened when the vehicle is decelerated and the engine speed is higher than about 2,100rpm, so that the specific fuel consumption of an engine can be reduced considerably. |
