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:
Jun. 02, 1998
Filed:
May. 22, 1996
Rogelio B Agustin, Farmington Hills, MI (US);
Akihito Numata, Ibaraki-ken, JP;
Kazuya Kawano, Hitachinaka, JP;
Yutaka Takaku, Mito, JP;
Toshio Ishii, Mito, JP;
Hitachi, Ltd., , JP;
Abstract
A diagnosing system of a catalytic converter in an internal combustion engine has a detecting unit to detect an operating state of the engine and an air/fuel ratio control unit to adjust a fuel injection amount so as to keep an air/fuel ratio of a mixture that is inhaled into the engine to a target value. The operating state of the engine is detected, whereby it is confirmed that the engine lies in a predetermined operating region to execute a catalyst diagnosis on the basis of the detected operating state. In each of a plurality of different catalyst diagnosis regions, the performance of the catalytic converter or the performance of the catalytic converter array is diagnosed on the basis of the output signal of the first exhaust gas component sensor arranged on the upstream side of the catalytic converter array and the output signal of the second exhaust gas component sensor arranged on the downstream side.