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. 19, 2013
Filed:
Jul. 30, 2011
Masashi Hakariya, Nagoya, JP;
Masahide Okada, Kariya, JP;
Masashi Hakariya, Nagoya, JP;
Masahide Okada, Kariya, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, JP;
Abstract
The invention provides an inter-cylinder air/fuel ratio imbalance determination apparatus and method. The determination apparatus includes a 'limiting current type air/fuel ratio sensor', and acquires a pre-correction index quantity that is greater the greater the degree of non-uniformity of the cylinder-by-cylinder air/fuel ratios, on the basis of a time differential value of the output value of the air/fuel ratio sensor. The determination apparatus obtains as the correction-purpose output value an average value of the output value obtained during a fuel-cut operation. The correction-purpose output value is greater the higher the responsiveness of the air/fuel ratio sensor. The determination apparatus acquires an air/fuel ratio imbalance index value by correcting the pre-correction index quantity so that the pre-correction index quantity is smaller the greater the correction-purpose output value. It is determined that an inter-cylinder air/fuel ratio imbalance state has occurred, when the air/fuel ratio imbalance index value is greater than or equal to an imbalance determination threshold value.