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. 07, 1992
Filed:
Nov. 05, 1990
Applicant:
Inventors:
Assignee:
Nippondenso Co., Ltd., Kariya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01N / ;
U.S. Cl.
CPC ...
60276 ;
Abstract
In an apparatus for controlling an air-fuel ratio in an internal combustion engine, a main air-fuel ratio sensor having an element temperature strongly affected by the temperature thereof, a sub air-fuel ration sensor having an element temperature weakly affected by the temperature thereof, and a heater associated with the main air-fuel ratio sensor are provided. The resistance value or electric power of the heater is controlled in accordance with the output of the sub air-fuel ratio sensor.