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:
Jul. 06, 1982
Filed:
Jun. 20, 1980
Kenji Masaki, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A system for feedback control of air/fuel ratio in an internal combustion engine operated with a nonstoichiometric air-fuel mixture. The control system includes two oxygen-sensitive air/fuel ratio sensors which are of the concentration cell type having a solid electrolyte layer provided with two electrode layers and both disposed in an exhaust passage substantially at the same section. The first sensor is supplied with a constant DC current to cause migration of oxygen ions through the solid electrolyte layer and exhibits a slope output characteristic when a lean mixture or a rich mixture is supplied to the engine, depending on the direction of flow of the current. The second sensor exhibits on-off type output characteristic and can discriminate between a lean mixture and a rich mixture. A control circuit to produce a fuel feed rate control signal based on the output of the first sensor includes a discriminating means for ascertaining whether the output of the first sensor is truly attributed to the slope output characteristic with reference to the output of the second sensor.