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:
Apr. 04, 2006
Filed:
Dec. 31, 2001
Takashi Mukaihara, Katsuta, JP;
Toshio Ishii, Mito, JP;
Kiyoshi Miura, Ibaraki-ken, JP;
Kazuya Kawano, Katsuta, JP;
Takashi Mukaihara, Katsuta, JP;
Toshio Ishii, Mito, JP;
Kiyoshi Miura, Ibaraki-ken, JP;
Kazuya Kawano, Katsuta, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A diagnostic system in which the accuracy of the diagnosis of the deterioration state of a catalyst in a catalytic converter for cleaning the exhaust gas of an internal combustion engine is enhanced without incurring a rise in cost. The temperature of the catalyst is estimated using the operating-state signal (for example, the flow rate of intake air or the width of a fuel injection pulse) of the engine by a diagnostic device. The conversion efficiency of the catalyst calculated from the outputs of oxygen sensors is corrected using the estimated temperature by the diagnostic device. The deterioration state of the catalyst is diagnosed on the basis of the corrected temperature by the diagnostic device.