| 摘要 |
PURPOSE:To widen the range of operation wherein purging is effected and to reduce the amount of fuel vapor that will dissipate into the atmosphere, by adding a passage through which, even when the suction pressure becomes positive, the fuel in a canister is forced into a suction system using the positive pressure. CONSTITUTION:While during supercharging the pressure downstream of a suction throttle valve 6 becomes positive to close a purge control valve 15, the air of a compressor downstream suction passage 5 whose pressure becomes positive as in the case of idling flows via the canister 14 due to the difference of its pressure with that of a compressor upstream suction passage 3, so that purge is effected. By setting the diameter of an orifice 22 suitably, as the degree of the rise in the internal pressure of the canister 14 can be limited, the vapor of the fuel in a fuel tank 19 can be suitably metered and introduced into the canister 14. |
