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:
Jan. 31, 1989
Filed:
Jan. 20, 1988
Naoki Tomisawa, Isesaki, JP;
Nippon Denshi Kiki Co., Ltd., Isesaki, JP;
Abstract
An apparatus for learn-controlling the air-fuel ratio for an internal combustion engine is disclosed. Every time area-wise learning correction coefficients for a predetermined number of different engine running condition areas are corrected, it is judged whether or not the deviations of the present area-wise learning correction coefficients for said areas from a reference value have the same direction. If all the deviations have the same direction, a mean value of said deviations or a minimum value among the deviations in terms of the absolute value is calculated. The calculated mean or minimum value is added to a global learning correction coefficient stored in global learning correction coefficient storing means to thereby rewrite the stored data. The mean or minimum value is regarded as a deviation component due to a change in the air density which may uniformly be employed for all the areas and is substituted for the global learning correction coefficient. Thus, it is possible to promptly learn a deviation component due to a change in the air density, and it is therefore possible to effect excellent learning control of the air-fuel ratio even when the vehicle abruptly goes up or down a slope.