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:
Nov. 15, 2016
Filed:
Feb. 20, 2013
Kenji Sakurai, Gotenba, JP;
Kohei Yoshida, Gotenba, JP;
Yuki Bisaiji, Susono, JP;
Shigeki Nakayama, Gotenba, JP;
Kenji Sakurai, Gotenba, JP;
Kohei Yoshida, Gotenba, JP;
Yuki Bisaiji, Susono, JP;
Shigeki Nakayama, Gotenba, JP;
TOYOTA JIDOSHA KABUSHIKI KAISHA, Toyota, JP;
Abstract
A three way catalyst and an NOstorage catalyst are arranged in an engine exhaust passage. In an engine low load operating region, a combustion is performed under a lean air-fuel ratio, and when NOshould be released from the NOstorage catalyst, the air-fuel ratio in a combustion chamber is made rich. In an engine medium load operating region, the base air-fuel ratio is made lower as compared with the engine low load operating region, and the air-fuel ratio in the combustion chamber is made rich at a shorter period as compared with the engine low load operating region. When the operating state of the engine is switched from the engine low load operating region to the engine medium load operating region, the air-fuel ratio in the combustion chamber is temporarily made rich, and the degree of richness of the air-fuel ratio at this time is stepwise lowered.