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:
Apr. 29, 1997
Filed:
Feb. 18, 1994
Fumio Yukawa, Kanagawa, JP;
Tsutomu Kikuchi, Kanagawa, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
An air-fuel ratio control system for an automotive internal combustion engine provided with a three-way catalytic converter disposed in an exhaust gas passageway of the engine. The air-fuel ratio control system is comprised of an oxygen sensor disposed in the exhaust gas passageway downstream of the catalytic converter. The air-fuel ratio of air-fuel mixture to be supplied to the engine is controlled toward a stoichiometric value to cause the three-way catalytic converter to efficiently work under the action of a control unit including a microcomputer. In the control unit, a control constant is set in accordance with the output voltage of the oxygen sensor, and a cycle signal (pulse signal) is cyclically generated. The control constant is compulsorily minutely vibrated under the action of the cycle signal, thereby obtaining an air-fuel ratio correction coefficient. The amount of fuel to be supplied to the engine is calculated in accordance with the air-fuel ratio correction coefficient and injected from a fuel injector valve.