| 摘要 |
PURPOSE:To improve the air-fuel ratio when a throttle valve is fully opened by providing the opening of an enrichment nozzle on the downstream side of another throttle valve equipped between the throttle valve and a main system fuel injection part and opening the latter throttle valve by a cam and negative pressure. CONSTITUTION:The opening of an enrichment nozzle 15 is provided on the downstream of a throttle valve 12 equipped in a mixing chamber 13 between a main nozzle 14 and another throttle valve 5, while the throttle valve 12 is characterized to be forcedly opened by a cam 17 until the opening degree of a medium speed area and then by a actuator 18 reacting to the resultant negative pressure of a negative pressure in a Venturi tube part 3 and that in the downstream of the throttle valve 12 until a high speed area. When the throttle valve 5 is fully opened at a low speed, according as the negative pressure in the Venturi tube is reduced, the throttle valve 12 is inclined to be closed. The negative pressure between both throttle valves 5 and 12 in the chamber 13 is increased to operate the enrichment system, and fuel is injected from the nozzle 15 to prevent the delay of the main system fuel. |
