Title:
触媒劣化診断システムおよび触媒劣化診断方法
Document Type and Number:
Japanese Patent JP7169826
Kind Code:
B2
Abstract:
A catalyst deterioration diagnosis system includes an air-fuel ratio detection element and a NOx detection element on a downstream side with respect to a catalyst, and a control element. The control element causes an engine to perform diagnosis operation performed with an exhaust gas temperature being kept at 600° C. or higher, such that at a timing when a downstream air-fuel ratio in a lean operation state reaches a threshold value, the engine is transitioned to a rich operation state, and at a timing that is a predetermined period after a downstream air-fuel ratio in a rich operation state reaches a threshold value, the engine is transitioned to a lean operation state. The diagnosis element compares NOx concentration during the rich operation state to a diagnosis threshold value, thereby to diagnose a degree of deterioration of NOx reduction capability of the catalyst.
Inventors:
Taku Okamoto
Osamu Nakasone
Osamu Nakasone
Application Number:
JP2018177125A
Publication Date:
November 11, 2022
Filing Date:
September 21, 2018
Export Citation:
Assignee:
Nippon Insulator Co., Ltd.
International Classes:
F01N3/20; F01N3/24; F01N11/00; F02D41/04; F02D45/00
Domestic Patent References:
| JP9125937A | ||||
| JP2010168923A | ||||
| JP2012241652A | ||||
| JP2004124870A | ||||
| JP2010163885A | ||||
| JP201623617A |
Attorney, Agent or Firm:
Hidetoshi Yoshitake
Takahiro Arita
Takahiro Arita
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