| 摘要 |
<p>An apparatus is provided for controlling discharge of fuel vapors from a vehicle fuel tank having a filler neck. The apparatus comprises a housing defining an interior region, the housing being formed to include first and second inlet ports, a signal port, and an outlet port. The apparatus further comprises a first valve assembly movable between a blocking position preventing fuel vapor received from the first inlet port from flowing through the interior region during vehicle refueling and a venting position allowing fuel vapor received from the first inlet port to flow through the interior region to the outlet port during vehicle operation. A signal passageway extends between the filler neck and the signal port to expose the first valve assembly to fuel vapor pressure from the filler neck to move the first valve assembly toward its venting position during vehicle operation. The apparatus further comprises second valve assembly movable between a blocking position preventing fuel vapor received from the second inlet port from flowing through the interior region when the first valve assembly is positioned in its venting position during vehicle operation and a venting position allowing fuel vapor received from the second inlet port to flow through the interior region to the outlet port when the first valve assembly is positioned in its blocking position during the vehicle refueling.</p> |
