Fuel tank pressure control system
AssigneeFord Global Technologies, LLC
InventorsPatrick Joseph Curran, Douglas Joseph Mancini, David Chester Waskiewicz, Jae Doo Chung
Life of this patent
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Abstract
A method is presented for controlling fuel tank pressure in an internal combustion engine. The engine, the fuel tank and the carbon canister are connected in a three-way connection. The engine can be selectively isolated by a purge control valve, and the fuel tank can be selectively isolated by a fuel tank control valve. The operation of both valves is coordinated by an electronic engine controller. By isolating the fuel tank during the carbon canister purge, vapor spikes into the engine are eliminated, thus preventing engine stalls. Also, canister durability is improved by continuously storing and purging vapors in opposite directions.
Claims45
A system for controlling fuel vapor purging in a vehicle, comprising:
- an internal combustion engine;
- a fuel tank;
- a fuel vapor storage device;
- and
- a valve assembly routing fuel vapors in a first direction only from said fuel tank to said fuel vapor storage device and for routing fuel vapors in a second direction opposite said first direction into said engine only from said fuel vapor storage device.
A method for controlling fuel vapor purging in a vehicle having an internal combustion engine coupled to a fuel tank, a fuel vapor storage device, and a valve assembly, the method comprising:
- providing a first mode of operation wherein fuel vapors are routed from the fuel tank to the fuel vapor storage device only in a first direction;
- and
- providing a second mode of operation wherein fuel vapors are routed from the fuel vapor storage device only to the internal combustion engine in a second direction opposite said first direction.
A system for controlling fuel vapor purging from a fuel tank and a fuel vapor storage device into an internal combustion engine, the system comprising:
- a purge control valve coupled between the fuel vapor storage device and the engine;
- a fuel tank control valve coupled between the fuel tank and the engine;
- and
- a controller for closing said purge control valve and opening said fuel tank control valve to route a fuel vapor from the fuel tank to a fuel vapor storage device only and for closing said fuel tank valve and opening said purge control valve to route said fuel vapor from said fuel vapor storage device to the engine only.
A system for controlling fuel vapor purging comprising:
- an internal combustion engine;
- a fuel tank;
- a fuel vapor storage device;
- a passageway connecting said engine, fuel tank, and fuel vapor storage device in a three-way connection;
- a purge control valve coupled between said connection and said engine via said passageway;
- a fuel tank control valve coupled between said connection and said fuel tank via said passageway;
- and
- a controller for selectively opening and closing said fuel tank control valve and said purge control valve.
A method for controlling fuel vapor purge in a vehicle having an internal combustion engine coupled to a fuel tank, a fuel vapor storage device, a fuel tank control valve and a purge control valve, comprising the steps of:
- providing a first indication when an internal pressure of the fuel tank is greater than a predetermined value;
- in response to said first indication, opening the fuel tank control valve and closing the purge control valve to allow fuel vapor flow from the fuel tank into the fuel vapor storage device in a first direction;
- providing a second indication when the fuel vapor storage device is ready to be purged based on an operating condition;
- and
- in response to said second indication, closing the fuel tank control valve and opening the purge control valve to allow fuel vapor flow from the fuel vapor storage device only into the internal combustion engine in a second direction opposite said first direction.
Dependencies are inferred from the claim text.