| 摘要 |
PURPOSE:To obtain flatness of a transient characteristic of air fuel ratio, by constituting a carburetor such that at least two accelerating nozzles with different height of their openings to the bottom part of subwells are provided to a main well communicated to a float chamber and the delivery can be controlled in plural stages. CONSTITUTION:If a throttle valve 7 in a secondary side is fully opened by accelerating operation, intake negative pressure reaches to the inside of a bore 6 and air horn 5, and the negative pressure is applied to jets 17, 18 of accelerating nozzles 19, 20 in accordance with opening of an air valve 4. In this way, fuel 23 in a main well 9 is sucked from subwells 15, 16 and delivered from each jet 17, 18. Here at the beginning of acceleration, a large amount of fuel is delivered mostly from the jet 18, when a level of oil lowers to reach the bottom part of an opening part 22 in the subwell 16, the delivery of fuel from the nozzle 20 is stopped. And then if the level of oil is lowered below an opening part 21 of the subwell 15, fuel is balanced with a supply quantity of a jet 10 and delivered in a steady state from the acceleration nozzle 19. |
