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.

Date of Patent:
Mar. 27, 1990

Filed:

Mar. 10, 1989
Applicant:
Inventors:

Toshihisa Takahashi, Himeji, JP;

Masanobu Uchinami, Himeji, JP;

Ryoji Nishiyama, Amagasaki, JP;

Seiya Kominami, Himeji, JP;

Shinichi Nishida, Himeji, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F02D / ; G01N / ;
U.S. Cl.
CPC ...
123489 ; 204425 ;
Abstract

An air-fuel (A/F) controller of an internal combustion engine, which computes an average value of a plurality of duty ratios of the voltage supplied to the heater according to the engine speed and the engine load periodically detected during a period from a predetermined moment up to the present, and fixes said average value as the present duty ratio of the voltage to be supplied to the heater, since the A/F ratio sensor is heated not only by the heater but also by exhaust gas. The A/F ratio controller smoothes the variation of voltage to be supplied to the heater by applying the computed average value as the present duty ratio of the supply voltage which is to be supplied to the heater. Accordingly, even when the driving condition is in high-speed, variation of the temperature borne by the heater is mild and smooth, and thus, the temperature of the oxygen-concentration detecting element does not rise suddenly. Furthermore, the A/F ratio controller corrects the above-mentioned present duty ratio of the voltage to be supplied to the heater according to the supply voltage to be supplied to the heater.


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