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:
Oct. 29, 1991
Filed:
Jul. 26, 1990
Takashi Aramaki, Kanagawa, JP;
Nissan Motor Company, Limited, Yokohama, JP;
Abstract
In an exhaust emission control system for an internal combustion engine, a secondary air is selectively introduced into an exhaust passage at a first position upstream of a catalytic converter. A failure detection system utilizes a plurality of temperatures of an exhaust gas for detecting a failure of the exhaust emission control system. A first temperature is derived at a second position between the first position and the catalytic converter when the secondary air is introduced into the exhaust passage at the first position. A second temperature is derived at the second position when no secondary air is introduced into the exhaust passage at the first position. By comparing the first and second temperature, it is detected whether the exhaust emission control system includes a failure. Third and fourth temperatures may also be derived at a third position located inside or downstream of the catalytic converter, which respectively correspond to the first and second temperatures. By comparing a difference between the first and third temperatures and a difference between the second and fourth temperatures, it is detected whether the exhaust emission control system includes a failure.