| 摘要 |
PURPOSE:To obtain a stable air fuel ratio by interposing a temp. sensing valve in a sensing line from a carburetor side which is connected to the operating side of a control valve, making a negative pressure leak at the time of high temp. operation, and making a Venturi negative pressure act on with another line. CONSTITUTION:A canister 6 is connected to a fuel tank via a line 9 to receive evaporated fuel in the tank, and also connected to a carburetor via a line 10 to receive evaporated fuel in a float chamber. When an engine is operated at a high temp. and with low load, a temp. sensing valve 11 is opened and a negative pressure applied to a sensing line 12 acts on a negative pressure chamber 21 of a control valve 8. And, the negative pressure is allowed to leak to a bypass 18, restraining the operation of the valve 8 in the opening direction, without enabling a valve 23 so far as to open a throttle part 19, without purging evaporated fuel from the canister 6, and without greatly varying air fuel ratio. When the engine is operated at a high speed and with high load, the negative pressure acts on a negative pressure chamber 22, purging evaporated fuel from the canister 6 into an intake pipe 5. |
