Refueling vapor recovery system

摘要

A fuel vapor recovery system (12) of a vehicle has a fill pipe (24) inlet assembly (46) located at a distal end of a fuel tank fill pipe (24). The inlet assembly has a cylindrical wall (28) defining an elongated cavity (50) divided axially into upstream and downstream regions (54,52) by a restrictor plate (48) which carries a hole (60) for close receipt of a fuel supply nozzle (32) of a remote fuel pump. During refueling of the tank (20), fuel vapor flows from the tank (20) via a recirculation tube (84) and into the inlet cavity (50) of the fill pipe (24) to become entrained into the flowing liquid fuel as oppose to being released to atmosphere. The fuel vapor enters the upstream region (54) at an aperture (90) carried by the wall disposed immediately upstream from the restrictor plate (48) and downstream from a hood (92). The hood (92) limits vapor release to atmosphere and draws the vapor downstream through a port (62) carried by the restrictor plate (48) for entrainment of vapor into the liquid fuel in the downstream region. Toward the end of the refueling process, any fuel welling or backing up within the fill pipe (24) is generally limited to the downstream region (52) of the cavity (50) via the restrictor plate (48) and an automatic shutoff feature of the remote fuel pump. Liquid fuel is thus less likely to enter the recirculation tube (84) in the upstream region (54) even if the automatic shut-off feature of the remote refuel pump should fail. Consequently, it is less likely that liquid fuel will flow into the canister (72) of the vapor recovery system (12) even when the automatic shut-off feature of the remote refuel pump has failed.