Method and system of controlling oxygen purge of three-way catalyst
AssigneesHyundai Motor Company, Kia Motors Corporation
InventorJin Woo CHOUNG
Life of this patent
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Abstract
A method of controlling an oxygen purge of a three-way catalyst (TWC) may include: rapidly adjusting, by a controller, an air-fuel ratio (AFR) at an upstream of the TWC to a target AFR when the oxygen purge of the TWC after a fuel cut-off is performed; and maintaining the target AFR until an oxygen purge finish time has passed. According to the method, concentration of NOx slipped from the TWC after the oxygen purge may be reduced.
Claims19
A method of controlling an oxygen purge of a three-way catalyst (TWC), the method comprising:
- adjusting, by a controller, an air-fuel ratio (AFR) at an upstream of the TWC to a target AFR when the oxygen purge of the TWC after a fuel cut-off is performed;
- and
- maintaining, by the controller, the target AFR until the oxygen purge is finished.
A method of controlling an oxygen purge of a three-way catalyst (TWC), the method comprising:
- adjusting, by a controller, an air-fuel ratio (AFR) at an upstream of the TWC to a target AFR when the oxygen purge of the TWC after a fuel cut-off is performed;
- maintaining, by the controller, the target AFR until the oxygen purge is finished;
- determining, by the controller, when a vehicle accelerates;
- and
- adjusting, by the controller, upon determining that the vehicle accelerates, the AFR at the upstream of the TWC to a stoichiometric AFR after the target AFR is maintained for a predetermined delay time.
A system of controlling an oxygen purge of a three-way catalyst (TWC), the system comprising:
- an engine configured of generating power by burning a mixture of an air and a fuel and exhausting an exhaust gas through an exhaust pipe;
- an injector configured of supplying the fuel into the engine;
- a controller connected to the injector and configured to adjust an air-fuel ratio (AFR) at an upstream of the TWC,
- wherein the TWC is mounted on the exhaust pipe at a downstream of the engine and is configured to purify emission contained in the exhaust gas,
- wherein the controller is configured to adjust the AFR at the upstream of the TWC by determining a fuel amount which is to be supplied to the engine based on a current intake amount and controlling the injector to inject the determined fuel amount, and
- wherein the controller is configured to adjust the AFR at the upstream of the TWC to a target AFR and to maintain the target AFR until the oxygen purge is finished, when the oxygen purge during which oxygen in the TWC is purged after a fuel cut-off during which fuel injection is stopped, is performed.
Dependencies are inferred from the claim text.