| 摘要 |
PROBLEM TO BE SOLVED: To prevent fuel vapor emission during fueling to a fuel tank. SOLUTION: An electromagnetic type bent valve 131 is arranged in a breather pipe 13 connecting a space above an oil level in a sealed fuel tank 11, with a canister 10. A connecting portion between the breather pipe and the vent valve is provided with an exhaust chamber having a passage cross-section area larger than that of the breather pipe. When fuel vapor in a tank is discharged to the canister 10 by opening and closing the vent valve during fueling, an opening valve time in vent valve opening and closing operation is controlled so that the fuel vapor is expanded by an exhaust chamber pressure, thereby maintaining a low pressure sufficient to liquefy the vapor. The fuel vapor in the tank is discharged to the canister before fueling to reduce a pressure in the tank, so that the fuel vapor in the fuel tank is prevented from emitting to the atmosphere when opening a fuel port 114, one portion of the fuel vapor is liquefied, and is recovered into the fuel tank, thereby allowing to reduce an adsorbent amount in the canister.
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