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US 9,650,974 B2Granted
System and methods for purging residual exhaust and uncombusted fuel to a fuel vapor canister
AssigneeFord Global Technologies, LLC
InventorAed M. Dudar
Life of this patent
Estimating the term…
Abstract
A method for an engine is presented, comprising, following an engine-off event, positioning a first engine cylinder with an intake valve open, opening a canister purge valve; and purging contents of the first engine cylinder to a fuel vapor canister. In this way, uncombusted fuel that may otherwise be emitted from the engine during a prolonged diurnal soak may be stored within the fuel vapor canister, thus decreasing overall vehicle emissions.
Claims20
A method for an engine, comprising:
- with a controller,
- following an engine-off event, sending a signal to open an intake valve of a first engine cylinder;
- sending a signal to open a canister purge valve;
- and
- purging contents of the first engine cylinder to a fuel vapor canister.
2 more elements
A system for a vehicle, comprising:
- an engine comprising one or more cylinders, each cylinder comprising an intake valve and an exhaust valve;
- a fuel vapor canister coupled to an engine intake via a canister purge valve;
- a throttle coupled between the engine intake and atmosphere;
- a vacuum pump coupled between the fuel vapor canister and atmosphere;
- and
- a controller configured with instructions stored in non-transitory memory, that when executed cause the controller to:
- following an engine-off event, position a first engine cylinder with an intake valve open;
- close the throttle;
- open the canister purge valve;
- turn the vacuum pump on;
- and
- purge contents of the first engine cylinder to the fuel vapor canister.
9 more elements
A method for a hybrid-electric vehicle, comprising:
- with a controller,
- following an engine-off condition, and responsive to a canister load being less than a threshold, sending a signal to spin an engine unfueled for a duration;
- sending a signal to stop the engine spinning and sending a signal to open an intake valve of a first engine cylinder;
- sending a signal to couple the first engine cylinder to a fuel vapor canister;
- sending a signal to apply a vacuum to the fuel vapor canister;
- purging contents of the first engine cylinder to the fuel vapor canister;
- sending a signal to open an intake valve of a second engine cylinder;
- sending a signal to couple the second engine cylinder to the fuel vapor canister;
- sending a signal to apply a vacuum to the fuel vapor canister;
- purging contents of the second engine cylinder to the fuel vapor canister;
- sending a signal to sequentially open an intake valve of each remaining unpurged engine cylinder;
- sending a signal to sequentially couple each unpurged engine cylinder to the fuel vapor canister;
- sending a signal to apply a vacuum to the fuel vapor canister;
- sending a signal to sequentially purge contents of each unpurged engine cylinder to the fuel vapor canister;
- and
- following purging contents of each engine cylinder to the fuel vapor canister, sending a signal to restore the engine to a default engine-off position.
13 more elements
Dependencies are inferred from the claim text.