| 摘要 |
PURPOSE:To improve safety by providing a selective transmission film for suppressing transmission of nitrogen between a pair of openings of canisters to be coupled respectively to the fuel tank and engine intake side thereby opening the space between the fuel tank and fuel catching layer to the atmosphere. CONSTITUTION:Upon pressure rise of gas in fuel tank 1, a check valve 6 will open while check valve 17 will close to leak gas in tank 1 through fuel catching layer 7, selective transmission film 8 and check valve 6 to engine intake system thus to absorb fuel components to adsorbent 9. The transmission film 8 will pass oxygen easily but will not pas nitrogen easily thereby the pressure in tank 1 is balanced with the atmospheric pressure to produce gas rich of notrogen. Upon operation of engine to produce intake negative pressure, the check valve 6 will open to flow outer air through three-way changeover valve 16, fuel catching layer 7 and transmission film 8 to the intake system. Consequently, fuel components adsorbed to adsorbent 9 are mixed with air to cencentrate nitrogen through transmission film 8 in the intermediate chamber 14 while to inactivate the interior of tank 1. |
