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:
Aug. 05, 2003
Filed:
May. 16, 2001
Lothar Mussmann, Offenbach, DE;
Dieter Lindner, Hanau, DE;
Martin Votsmeier, Bruchköbel, DE;
Joerg Michael Richter, Frankfurt am Main, DE;
Egbert Lox, Hanau, DE;
dmc2 Degussa Metal Catalysts Cerdec AG, Hanau-Wolfgang, DE;
Abstract
A process for operating an exhaust gas treatment device in a gasoline engine which is operated mainly with a stoichiometric air/fuel ratio and is operated with a rich-mix air/fuel ratio when accelerating or under full load. The exhaust gas treatment device contains a three-way converter catalyst and a first lambda probe upstream of the catalyst and a second lambda probe downstream of the catalyst. The air/fuel ratio is controlled by using the signal from the first lambda probe, whereas the signal from the second lambda probe is used to check the first lambda probe (trim control) and to diagnose the function of the catalyst. Trim control with the second lambda probe is enabled only when, in the event of rich exhaust gas, the voltage difference between the probe voltage for the second lambda probe and a set point voltage is not larger than a predetermined value.