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:
Feb. 27, 2018
Filed:
Dec. 09, 2014
Toyota Jidosha Kabushiki Kaisha, Toyota-shi, Aichi-ken, JP;
Yukihiro Nakasaka, Shizuoka-ken, JP;
TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota-shi, Aichi-ken, JP;
Abstract
A diagnostic system for an internal combustion engine includes an in-cylinder pressure sensor and an ECU. The ECU is configured to: (a) determine whether each cylinder of the evaluation target cylinder group is a lean cylinder; (b) estimate a degree of leanness of the air-fuel ratio of the present lean cylinders when the lean cylinders are present in the evaluation target cylinder group; (c) calculate a polytropic index in an expansion stroke for each cylinder; (d) correlate relationship information for defining a relationship between the polytropic index in the expansion stroke and an air-fuel ratio index value with the polytropic index in the expansion stroke of a reference lean cylinder; and (e) calculate the difference in air-fuel ratio between cylinders on the basis of the polytropic index of the reference lean cylinder, the relationship information correlated with the polytropic index of the reference lean cylinder.