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:
Dec. 01, 1998
Filed:
Jul. 31, 1997
Kazuya Kibe, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Aichi, JP;
Denso Corporation, Aichi-Pref., JP;
Abstract
An exhaust emission gas purification apparatus for an internal combustion engine is disclosed, in which a proper purification rate can be maintained even at a transient time by suppressing an excessive temperature increase of a lean NO.sub.x catalyst. In order to improve the purification efficiency of a lean NO.sub.x catalyst 307, diesel fuel constituting a hydrocarbon material capable of reducing the NO.sub.x is supplied by way of a diesel fuel injection hole 311. A basic amount of diesel fuel to be supplied is determined on the basis of a space velocity SV providing a quantity of state representing the operating conditions of the catalyst calculated from the intake air amount detected by an air flowmeter 302 and the catalyst temperature detected by an outlet exhaust gas temperature sensor 322. The basis amount of diesel fuel to be supplied is corrected based on the difference between the catalyst temperature and the inlet exhaust gas temperature detected by the inlet exhaust gas temperature sensor 321. The purification rate of the catalyst can thus be prevented from being deteriorated at a transient time.