| 摘要 |
PURPOSE:To improve emission, operability and fuel economy, by a method wherein a required quantity of a fuel is fed out toward an acceleration nozzle of a carburetor at the time of acceleration, and the fuel supplied to the nozzle is cut off or reduced in quantity at the time of slow acceleration. CONSTITUTION:When the change rate of the negative pressure in an intake pipe is, for example, not lower than +100mm.Hg/sec and the negative pressure becomes nearer to the atmospheric pressure than -200mm.Hg, the condition is discriminated as a rapid acceleration, and a rapid acceleration signal A is outputted from an AND gate 22 to close a solenoid ON-OFF valve 23 in a return passage 15. Then, a piston 8 in an accelerating pump 4 is lowered in response to a throttle valve 2, and the fuel is discharged from a pump chamber 6. The fuel is led to the acceleration nozzle 5 through an outlet passage 14, and is supplied into an intake line 27. On the other hand, when the condition is discriminated as a slow acceleration or when the change rate is lower than +100mm.Hg/sec, the ON-OFF valve 23 is maintained in an opened condition. Accordingly, the fuel is returned into a float chamber 3 through a leak passage 15. |
