| 摘要 |
An evaporative emission canister, for use with the fuel system for an internal combustion engine, includes a canister housing defined by a cylindrical outer wall, a closed lower end wall, an upper end wall and a cylindrical inner wall depending from the upper end wall. An air-vapor permeable support means is positioned within the housing above the lower end wall in abutment against the lower free end of the inner wall to define with the lower end wall an air chamber in flow communication with the atmosphere and to define with the outer wall and the inner wall, an outer canister chamber and an inner canister chamber, respectively, that contain fuel vapor adsorbing material. The inner canister chamber is connected by a fuel bowl vent valve so as to receive vapors emitted from the float bowl of the carburetor of the engine when the engine is not in operation and the outer canister chamber is connected to receive vapors emitted from the fuel in the fuel tank for the engine. First and second orifice passages from the inner and outer canister chambers, respectively, are connected to the vapor purge chamber of a vapor purge control valve whereby fuel vapors can be purged from the canister assembly to the engine during engine operation. In the preferred embodiment, the above-described valves are incorporated into the upper end wall of the canister.
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