US Patent No. 9,394,844

FUEL CONTROL FOR SPARK IGNITED ENGINE HAVING A PARTICULATE FILTER SYSTEM


Patent No. 9,394,844
Issue Date July 19, 2016
Title Fuel Control For Spark Ignited Engine Having A Particulate Filter System
Inventorship Carolyn Parks Hubbard, Canton, MI (US)
Robert Walter McCabe, Novi, MI (US)
Eva Thanasiu, Trenton, MI (US)
Jeffrey Scott Hepburn, Birmingham, MI (US)
Helmut Hans Ruhland, Eschweiler (DE)
Moritz Klaus Springer, Hagen (DE)
Thomas Lorenz, Koeln (DE)
Georg Louven, Neuwied (DE)
David Karl Bidner, Livonia, MI (US)
Assignee Ford Global Technologies, LLC, Dearborn, MI (US)

Claim of US Patent No. 9,394,844

8. A method for processing particulate matter, comprising:
directing exhaust gases from a spark-ignited gasoline engine to an exhaust system, said exhaust system an upstream three-way
catalyst followed by a particulate filter, followed by a downstream three-way catalyst;

during particulate filter regeneration, adjusting a gasoline engine air-fuel mixture, including oscillating the air-fuel mixture
between a lean air-fuel mixture and a rich air-fuel mixture while shifting an entire oscillating air-fuel ratio lean entering
the particulate filter; and

during non-particulate filter regeneration, adjusting the gasoline engine air-fuel mixture, including oscillating the air-fuel
mixture between a lean air-fuel mixture and a rich air-fuel mixture while maintaining an overall stoichiometric air-fuel entering
the particulate filter, a period of oscillation during the regeneration based on an amount of soot trapped in the particulate
filter.