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. 15, 2019
Filed:
Jul. 03, 2017
Mazda Motor Corporation, Aki-gun, Hiroshima, JP;
Takayuki Yamaguchi, Hatsukaichi, JP;
Masanobu Kanno, Hiroshima, JP;
Masayuki Tetsuno, Hiroshima, JP;
Mazda Motor Corporation, Aki-gun, Hiroshima, JP;
Abstract
An exhaust emission control system of an engine including a NOcatalyst disposed in an exhaust passage and for storing NOwithin exhaust gas when an air-fuel ratio of the exhaust gas is lean, and reducing the stored NOwhen the air-fuel ratio is approximately stoichiometric or rich, is provided. The system includes a SCR catalyst disposed downstream of the NOcatalyst and for purifying NOby causing a reaction with ammonia, and a processor configured to execute a NOreduction controlling module for controlling the air-fuel ratio to a target ratio so that the stored NOis reduced. The controlling module limits the performance of the NOreduction control when a temperature of the SCR catalyst is above a given temperature and loosens the limitation in a given engine operating state in which an exhaust gas flow rate is above a given rate despite the SCR catalyst temperature.