Title:
EXHAUST EMISSION CONTROL DEVICE FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JP2003049681
Kind Code:
A
Abstract:
To improve purifying capacity of a front-end catalyst without degrading purifying capacity of an NOx catalyst, in an exhaust emission control device for an internal combustion engine where the front-end catalyst having oxygen storing capacity is disposed upstream of the NOx catalyst.
The exhaust emission control device for an internal combustion engine disposes the front-end catalyst 46 having oxygen storing capacity upstream of the NOx catalyst 48, and executes air-fuel ratio reduction control to consume stored oxygen in the front-end catalyst 46 just before execution of rich spike control. During the execution of rich spike control, lean spike control for increasing an exhaust air-fuel ratio temporarily is executed.
Inventors:
MIYASHITA SHIGEKI
Application Number:
JP2001239617A
Publication Date:
February 21, 2003
Filing Date:
August 07, 2001
Export Citation:
Assignee:
TOYOTA MOTOR CORP
International Classes:
F02D43/00; B01D53/94; F01N3/08; F01N3/20; F01N3/28; F02D41/04; F02D45/00; (IPC1-7): F02D41/04; B01D53/94; F01N3/08; F01N3/20; F01N3/28; F02D43/00; F02D45/00
Attorney, Agent or Firm:
Tsutomu Toyama (3 others)