Title:
DEVICE FOR PREVENTING DETERIORATION OF CATALYST
Document Type and Number:
Japanese Patent JP3804732
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To prevent the deterioration of a selective-reduction catalyst capable of purifying NOx in an oxygen-excess atmosphere and admixed with a specified catalytic species such as iridium to increase the purification capacity.
SOLUTION: When a catalyst temp. Tc reaches a specified catalyst temp. Tc1 lower than an allowable catalyst temp. Tc2 relating to lean operation while an engine is operated in a lean region, a rich spike air-fuel mixture is supplied to the engine under the control of the electronic control unit of a catalyst deterioration preventing device. Consequently, an air-fuel ratio of an exhaust is transiently made rich a reducing atmosphere is formed around the catalyst, and the liberation of a specified catalytic species as the oxide is prevented.
Inventors:
Takashi Dogahara
Hiromitsu Ando
Kojiro Okada
Katsunori Kaneko
Hiromitsu Ando
Kojiro Okada
Katsunori Kaneko
Application Number:
JP28092298A
Publication Date:
August 02, 2006
Filing Date:
October 02, 1998
Export Citation:
Assignee:
MITSUBISHI JIDOSHA KOGYO KABUSHIKI KAISHA
International Classes:
B01D53/94; B01J33/00; B01J23/46; (IPC1-7): B01J33/00; B01D53/94; B01J23/46
Domestic Patent References:
| JP62223427A | ||||
| JP11093729A |
Attorney, Agent or Firm:
Koji Nagato