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. 18, 1995
Filed:
Dec. 02, 1993
Shinya Hirota, Susono, JP;
Yasushi Araki, Susono, JP;
Kiyoshi Kobashi, Mishima, JP;
Tomohiro Oda, Aichi, JP;
Fumitada Murakami, Susono, JP;
Toyota Jidosha Kabushiki Kaisha, Toyota, JP;
Abstract
A NO.sub.x absorbent which absorbs NO.sub.x in exhaust gas when the air-fuel ratio of the exhaust gas is lean and releases absorbed NO.sub.x when the oxygen concentration of the exhaust gas is lowered, is disposed in an exhaust passage of an engine. When the amount of the NO.sub.x absorbed by the NO.sub.x absorbent is increased, the regenerating process of the NO.sub.x absorbent is performed by supplying a reducing agent to the NO.sub.x absorbent so that the NO.sub.x absorbed by the NO.sub.x absorbent is released and reduced by the reducing agent. Usually, to reduce the amount of the reducing agent required for the regenerating process, the inflowing exhaust gas into the NO.sub.x absorbent is shut off. In the present invention, even in the regenerating process of NO.sub.x absorbent, a small amount of the exhaust gas (carrier gas) is introduced to the NO.sub.x absorbent to carry the supplied reducing agent through the NO.sub.x absorbent to thereby reduce the amount of the reducing agent required for the regenerating process and to shorten the time required to complete the regenerating process.