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:
Nov. 24, 2015
Filed:
Nov. 26, 2009
Yasushi Iwazaki, Ebina, JP;
Hiroshi Miyamoto, Susono, JP;
Hiroshi Sawada, Gotemba, JP;
Keiichiro Aoki, Sunto-gun, JP;
Yasushi Iwazaki, Ebina, JP;
Hiroshi Miyamoto, Susono, JP;
Hiroshi Sawada, Gotemba, JP;
Keiichiro Aoki, Sunto-gun, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
An air-fuel ratio imbalance among cylinders determining apparatus (a determining apparatus) according to an aspect of the present invention, obtains a parameter X for imbalance determination which becomes larger as a variation of an air-fuel ratio of an exhaust gas passing through a position at which the air-fuel ratio sensor is disposed becomes larger, based on an output value Vabyfs of an air-fuel ratio sensor. At the same time, the determining apparatus changes a target air-fuel ratio which is a target value of an air-fuel ratio of a mixture supplied to an engine to 'an air-fuel ratio (a target rich air-fuel ratio AFrich or a target lean air-fuel ratio AFlean) other than a stoichiometric air-fuel ratio' from the stoichiometric air-fuel ratio. Accordingly, the determining apparatus can obtain the parameter X for imbalance determination in a state in which a responsivity of the air-fuel ratio sensoris not low. As a result, it can make a determination on the air-fuel ratio imbalance among cylinders with high accuracy.