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:
Jul. 31, 1990
Filed:
Oct. 04, 1989
Hitachi, Ltd, Tokyo, JP;
Hitachi Automotive Engineering Co., Ibaraki, JP;
Abstract
An air-fuel ratio control apparatus for an internal combustion engine includes a solid electrolyte having a first electrode disposed on one surface thereof to contact with the atmosphere and a second electrode disposed on the other surface thereof to contact with the exhaust gas from the engine through a diffusing resistor, and means for applying a voltage across the first and second electrodes to detect an oxygen pump current flowing in the solid electrolyte whereby a correction factor relating to a change in the diffusion coefficient of the diffusing resistor is computed so that the oxygen pump current detected by the detecting means is corrected in accordance with the correction factor and the air-fuel ratio of the exhaust gas is determined in accordance with the corrected oxygen pump current, thereby controlling the quantity of fuel supplied to the engine in accordance with the determined air-fuel ratio.