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. 23, 1995
Filed:
Dec. 20, 1993
Kazumi Ishida, Nishikasugai, JP;
Hiroshi Haraguchi, Kariya, JP;
Masakazu Hishinuma, Yokohama, JP;
Akio Fujiwara, Yokohama, JP;
Nippondenso Co., Ltd., Tokyo, JP;
Tokyo Gas Co., Ltd., Kariya, JP;
Abstract
An air fuel ratio controlling apparatus for an internal combustion engine, comprises: a catalytic converter, provided in an exhaust system for purifying an exhaust gas of the engine; a first oxygen density sensor, provided upstream from the catalytic converter in the exhaust system, responsive to a first oxygen density of a first exhaust gas of the engine for detecting whether an air fuel ratio of the engine is in a rich condition or a lean condition with respect to a theoretical air fuel ratio of the engine; a second oxygen density sensor, provided downstream from the catalytic converter in the exhaust system, responsive to a second oxygen density of a second exhaust gas passed through the catalytic converter for detecting whether the air fuel ratio of the engine is in a rich or a lean condition with respect to a theoretical air fuel ratio of the engine; and an air fuel ratio control portion for controlling the air fuel ratio in accordance with the detection results of the first and second oxygen sensors, wherein; the first oxygen sensor has a function for oxidizing and reducing a specific component more powerful than that of the second oxygen density sensor.