| 摘要 |
PURPOSE:To prevent occurrence of shocks at the time of deceleration, by preventing back-bleeding at the time of high-load operation of an engine. CONSTITUTION:The upper end portion of a main fuel passage 8 is connected to a main nozzle 5, and a slow-speed fuel passage 11 is branched from the lower end portion of the main fuel passage 8. The right-side end of a horizontal portion 11c of the slow-speed fuel passage 11 is communicated with a vacuum port 15 opened in a large venturi 3 via an air bleed jet 16 and an air bleed passage 17. At the time of high-load operation of an engine, the negative pressure P2 at the portion of the slow-speed fuel passage 11 located on the downstream side of a slow jet 14 becomes higher than that P1 at the portion of the fuel passage 11 located on the upstream side of the slow jet 14 by the function of the air bleed passage 17. Therefore, fuel is passed normally from the upstream side to the downstream side of the slow jet 14, so that it is enabled to prevent occurrence of back-bleeding. |
