The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 28, 2013
Filed:
Dec. 09, 2008
Paul M. Najt, Bloomfield Hills, MI (US);
Kushal Narayanaswamy, Sterling Heights, MI (US);
Kevin L. Perry, Fraser, MI (US);
Wei LI, Troy, MI (US);
David J. Cleary, Shanghai, CN;
James Donald Smith, Ann Arbor, MI (US);
Paul M. Najt, Bloomfield Hills, MI (US);
Kushal Narayanaswamy, Sterling Heights, MI (US);
Kevin L. Perry, Fraser, MI (US);
Wei Li, Troy, MI (US);
David J. Cleary, Shanghai, CN;
James Donald Smith, Ann Arbor, MI (US);
GM Global Technology Operations LLC, Detroit, MI (US);
Abstract
Operation of a spark ignition, direct injection engine having an aftertreatment system including an oxidation catalyst and a selective catalyst reduction device is described. The method includes controlling to a stoichiometric air/fuel ratio and retarding spark ignition timing. Engine fueling is then controlled to a lean air/fuel ratio and spark is retarded. The engine is then operated to generate ammonia reductant. Engine operation then comprises operating at a preferred air/fuel ratio and controlling spark ignition timing to a preferred timing.