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:
Dec. 04, 1984
Filed:
Jul. 15, 1983
Applicant:
Inventor:
Yuichi Kashimura, Katsuta, JP;
Assignee:
Hitachi, Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02D / ;
U.S. Cl.
CPC ...
123440 ; 123489 ; 123589 ;
Abstract
In an air-fuel ratio control apparatus for controlling the air-fuel ratio of an engine in accordance with the output of an O.sub.2 sensor, in response to the starting of the engine the output voltage of the O.sub.2 sensor is sampled at intervals of a unit time. The slope of the output voltage waveform of the O.sub.2 sensor is computed from the successively sampled values. The computed value is compared with a predetermined value indicative of a slope value attained when the O.sub.2 sensor is activated and thus it is considered that the O.sub.2 sensor is activiated when the computed value is greater than the predetermined value.