Refueling shut-off system with fill-limit vent valve
First Claim
1. A refueling shut-off system for use with a fuel vapor recovery canister and a fuel tank formed to include an interior region for containing fuel vapor and liquid fuel, the system comprisinga filler neck adapted to be coupled to fuel tank at a first end, the filler neck being formed to include an open mouth at an opposite second end and a fuel-conducting passageway extending between the first and second ends and communicating with an interior region of the fuel tank,a fuel vapor discharge conduit formed to include an outlet end adapted to mate with the fuel vapor recovery canister to discharge fuel vapor flowing in the fuel vapor discharge conduit into the fuel vapor recovery canister,a vent unit adapted to be coupled to the fuel tank and configured to receive and regulate flow of fuel vapor discharged from the interior region of the fuel tank to the fuel vapor discharge conduit for delivery to the fuel vapor recovery canister, the vent unit including a vent line formed to include an inlet and an outlet, a vent channel formed to include an outlet coupled to the fuel vapor discharge conduit to discharge any fuel vapor flowing in the vent channel into the fuel vapor discharge conduit, a normally closed flow-control valve formed to include an inlet port coupled to the outlet of the vent line and an outlet port coupled to an inlet end of the fuel vapor discharge conduit to allow fuel vapor discharged from the normally closed flow-control valve to flow into the fuel vapor discharge conduit and toward a fuel vapor recovery canister coupled to the outlet end of the fuel vapor discharge conduit, a normally opened fill-limit vent valve formed to include an inlet port adapted to be exposed to fuel vapor extant in the interior region of the fuel tank and an outlet port coupled to the inlet of the vent line to allow fuel vapor discharged from the normally opened fill-limit vent valve to reach the normally closed flow-control valve, and a normally opened first rollover valve formed to include an inlet port adapted to be exposed to fuel vapor extant in the interior region of the fuel tank and an outlet port coupled to an inlet formed in the vent channel to allow fuel vapor discharged from the normally opened first rollover valve to flow into the fuel vapor discharge conduit and toward a fuel vapor recovery canister coupled to the outlet end of the fuel vapor discharge outlet, anda fuel vapor recirculation conduit configured to interconnect the vent line and the fuel-conducting passageway formed in the filler neck in fluid communication, the fuel vapor recirculation conduit including a one-way liquid-fuel check valve configured to allow flow of fuel vapor discharged from the vent line through the fuel vapor recirculation conduit into the fuel-conducting passageway formed in the filler neck and to block flow of liquid fuel passing from the fuel-conducting passageway into the fuel vapor recirculation conduit into the vent line.
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0 Petitions
Accused Products
Abstract
A refueling shut-off system is provided for use with a vehicle fuel system including a fuel tank, a fuel tank filler neck, and a fuel vapor recovery canister. The system includes a fill-limit vent valve and a flow-control valve.
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Citations
15 Claims
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1. A refueling shut-off system for use with a fuel vapor recovery canister and a fuel tank formed to include an interior region for containing fuel vapor and liquid fuel, the system comprising
a filler neck adapted to be coupled to fuel tank at a first end, the filler neck being formed to include an open mouth at an opposite second end and a fuel-conducting passageway extending between the first and second ends and communicating with an interior region of the fuel tank, a fuel vapor discharge conduit formed to include an outlet end adapted to mate with the fuel vapor recovery canister to discharge fuel vapor flowing in the fuel vapor discharge conduit into the fuel vapor recovery canister, a vent unit adapted to be coupled to the fuel tank and configured to receive and regulate flow of fuel vapor discharged from the interior region of the fuel tank to the fuel vapor discharge conduit for delivery to the fuel vapor recovery canister, the vent unit including a vent line formed to include an inlet and an outlet, a vent channel formed to include an outlet coupled to the fuel vapor discharge conduit to discharge any fuel vapor flowing in the vent channel into the fuel vapor discharge conduit, a normally closed flow-control valve formed to include an inlet port coupled to the outlet of the vent line and an outlet port coupled to an inlet end of the fuel vapor discharge conduit to allow fuel vapor discharged from the normally closed flow-control valve to flow into the fuel vapor discharge conduit and toward a fuel vapor recovery canister coupled to the outlet end of the fuel vapor discharge conduit, a normally opened fill-limit vent valve formed to include an inlet port adapted to be exposed to fuel vapor extant in the interior region of the fuel tank and an outlet port coupled to the inlet of the vent line to allow fuel vapor discharged from the normally opened fill-limit vent valve to reach the normally closed flow-control valve, and a normally opened first rollover valve formed to include an inlet port adapted to be exposed to fuel vapor extant in the interior region of the fuel tank and an outlet port coupled to an inlet formed in the vent channel to allow fuel vapor discharged from the normally opened first rollover valve to flow into the fuel vapor discharge conduit and toward a fuel vapor recovery canister coupled to the outlet end of the fuel vapor discharge outlet, and a fuel vapor recirculation conduit configured to interconnect the vent line and the fuel-conducting passageway formed in the filler neck in fluid communication, the fuel vapor recirculation conduit including a one-way liquid-fuel check valve configured to allow flow of fuel vapor discharged from the vent line through the fuel vapor recirculation conduit into the fuel-conducting passageway formed in the filler neck and to block flow of liquid fuel passing from the fuel-conducting passageway into the fuel vapor recirculation conduit into the vent line.
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10. A refueling shut-off system for use with a fuel vapor recovery canister and a fuel tank formed to include an interior region for containing fuel vapor and liquid fuel, the system comprising
a filler neck adapted to be coupled to fuel tank at a first end, the filler neck being formed to include an open mouth at an opposite second end and a fuel-conducting passageway extending between the first and second ends and communicating with an interior region of the fuel tank, a fuel vapor discharge conduit formed to include an outlet end adapted to mate with the fuel vapor recovery canister to discharge fuel vapor flowing in the fuel vapor discharge conduit into the fuel vapor recovery canister, a vent unit adapted to be coupled to the fuel tank and configured to receive and regulate flow of fuel vapor discharged from the interior region of the fuel tank to the fuel vapor discharge conduit for delivery to the fuel vapor recovery canister, the vent unit including a vent line formed to include an inlet and an outlet, a normally closed flow-control valve formed to include an inlet port coupled to the outlet of the vent line and an outlet port coupled to an inlet end of the fuel vapor discharge conduit to allow fuel vapor discharged from the normally closed flow-control valve to flow into the fuel vapor discharge conduit and toward a fuel vapor recovery canister coupled to the outlet end of the fuel vapor discharge conduit, and a normally opened fill-limit vent valve formed to include an inlet port adapted to be exposed to fuel vapor extant in the interior region of the fuel tank and an outlet port coupled to the inlet of the vent line to allow fuel vapor discharged from the normally opened fill-limit vent valve to reach the normally closed flow-control valve, and a fuel vapor recirculation conduit configured to interconnect the vent line and the fuel-conducting passageway formed in the filler neck in fluid communication to communicate an aspiration-induced vacuum generated in the fuel-conducting passageway during fuel tank refueling to the normally closed flow-control valve.
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15. A process for operating a vehicle fuel system including a fuel tank, a filler neck coupled to the tank, a fuel vapor recovery canister, and a fuel vapor conductor communicating fuel vapor from the fuel tank to the fuel vapor recovery canister, in series, first through a normally opened fill-limit vent valve and second through, when opened, a normally closed flow-control valve, the process comprising the steps of
opening the normally closed flow-control valve to allow pressurized fuel vapor to flow from the fuel tank through the fill-limit vent valve, the flow-control valve, and the fuel vapor conductor to the fuel vapor recovery canister during discharge of liquid fuel from a fuel-dispensing pump nozzle into the fuel tank through the filler neck as long as liquid fuel extant in the fuel tank remains below a fill-limit vent valve closure level in the fuel tank associated with a first volume of liquid fuel in the fuel tank, closing the normally opened fill-limit vent valve in response to accumulation of liquid fuel in the fuel tank to an amount equal to the first volume of liquid fuel once liquid fuel rises to the fill-limit vent valve closure level, and using a vacuum of a first magnitude generated in the filler neck to close the normally closed flow-control valve that had been opened during the opening step to allow the vacuum generated in the filler neck to rise to a higher second magnitude sufficient to activate a vacuum-sensitive nozzle shut-off mechanism associated with the fuel-dispensing pump nozzle to halt further discharge of liquid fuel into the fuel tank through the filler neck.
Specification