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:
May. 18, 2010
Filed:
Oct. 04, 2006
Seiji Asano, Hitachinaka, JP;
Seiji Asano, Hitachinaka, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An apparatus for controlling air-fuel ratio of an internal combustion engine having: a three-way catalytic converter; an oxygen sensor, which is installed at the upstream side of said catalytic converter in respect to exhaust gas flow direction, for generating a switching signal showing rich/lean relative to a certain air-fuel ratio; and an air-fuel ratio sensor, which is installed at the downstream side of said catalytic converter, for generating a linear output signal corresponding to the air-fuel ratio, wherein the apparatus includes a deviation calculation unit for calculating deviation between air-fuel ratio measured by the air-fuel ratio sensor, and target air-fuel ratio; and a feedback control unit of the air-fuel ratio for carrying out feedback control of air-fuel ratio based on the deviation calculated by a deviation calculation unit, and the output signal of the oxygen sensor.