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. 13, 1996
Filed:
Mar. 31, 1995
Christopher K Davey, Farmington Hills, MI (US);
Donald F Dickison, Sterling Heights, MI (US);
Robert J Jerger, Livonia, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
An air/fuel control system (10) and method for an engine (28) coupled to a catalytic converter (50) includes monitoring of the converter (50). Engine air/fuel ratio is controlled (104-178) in response to a pair of two-state signals generated by comparing the outputs of respective upstream (44, 55) and downstream (52) exhaust gas oxygen sensors to a reference voltage. The transitions in the downstream sensor are indicated when a difference in its output amplitude changes signs and a difference between stored peak values occurring during two successive changes in the sign exceeds a predetermined value (200-350). Converter efficiency is indicated from a ratio of transitions in the downstream sensor transitions to transitions in the upstream sensor output which are generated in a similar manner (690-770).