Catalyst degradation detection apparatus

Patent metadata

Field	Value
Publication number	US-8938947-B2
Application number	US-201113583139-A
Country	US
Kind code	B2
Filing date	Feb 24, 2011
Priority date	Mar 9, 2010
Publication date	Jan 27, 2015
Grant date	Jan 27, 2015

Abstract

A catalyst degradation detection apparatus includes: calculation means for calculating, as an oxygen storage amount of a catalyst, an amount of oxygen stored into or desorbed from the catalyst during a period from when a change that corresponds to a change in an air/fuel ratio occurs in the signal of a pre-catalyst sensor to when the signal of a post-catalyst sensor reaches a criterion value regarding the change in the air/fuel ratio; catalyst degradation determination means for determining of degradation of the catalyst on the basis of the oxygen storage amount; and correction means for correcting the oxygen storage amount calculated for use for determining of degradation of the catalyst more to a decrease side as a measured responsiveness of the post-catalyst sensor becomes more deteriorated relative to a reference value.

First claim

What is claimed is:

1. A catalyst degradation detection apparatus comprising:
a pre-catalyst sensor that is provided in an exhaust passageway of an internal combustion engine upstream of a catalyst and that outputs a signal based on an oxygen concentration in exhaust gas;
a post-catalyst sensor that is provided in the exhaust passageway downstream of the catalyst and that outputs a signal based on the oxygen concentration in the exhaust gas; and
an electronic control unit havi…

Assignees

• Nakamura Takashi
• Toyota Motor Co Ltd

Inventors

• Nakamura Takashi

Classifications

• Y02T10/47

  Cross-Sectional Technologies · mapped topic

• F02D41/0295

  Mechanical Engineering · mapped topic

• F02D41/2454

  Mechanical Engineering · mapped topic

• F01N2550/02

  Mechanical Engineering · mapped topic

• F02D2200/0808

  Mechanical Engineering · mapped topic