초록 ▼

An onboard vapor recovery system for a vehicle fuel system having a fuel tank, a filler neck dynamically sealed by high pressure fuel flow from a filler nozzle, and a vapor recovery apparatus such as a carbon canister. The system includes a liquid level operated control valve which shuts off refueli

An onboard vapor recovery system for a vehicle fuel system having a fuel tank, a filler neck dynamically sealed by high pressure fuel flow from a filler nozzle, and a vapor recovery apparatus such as a carbon canister. The system includes a liquid level operated control valve which shuts off refueling with a two-stage closing operation providing an initial soft shutoff and a final shutoff. The system also preferably includes a valve in the fuel tank to maintain a predetermined pressure head sufficient to hold the system closed against further refueling at least temporarily, and a positive action, one-way check valve in the lower end of the filler pipe to prevent spitback of fuel from the pressurized tank once refueling has ceased.

대표청구항 ▼

[ The invention claimed is:] [1.] In a vehicle fuel system having a fuel tank, a filler pipe, and onboard vapor recovery apparatus such as a vapor canister, a fuel vapor venting control system comprising:control valve in the fuel tank adapted to vent fuel vapor from the tank to the canister at a fir

[ The invention claimed is:] [1.] In a vehicle fuel system having a fuel tank, a filler pipe, and onboard vapor recovery apparatus such as a vapor canister, a fuel vapor venting control system comprising:control valve in the fuel tank adapted to vent fuel vapor from the tank to the canister at a first higher rate when the fuel level is below a near-full refueling level, at a second lower rate when the fuel level reaches the near-full refueling level, and for closing when a higher maximum refueling fuel level is reached;a head valve in the fuel tank adapted to selectively vent fuel vapor to the canister at a predetermined pressure head independently of the control valve;a check valve in a lower end of the filler pipe adapted to close the filler pipe with respect to the fuel tank between refueling activity.