Catalyst deterioration diagnosis system for internal combustion

Details Catalyst deterioration diagnosis system for internal combustion Catalyst deterioration diagnosis system for internal combustion

1995-10-18

1997-06-24

Kwon, John T.

Power plants

Internal combustion engine with treatment or handling of...

Having means analyzing composition of exhaust gas

60277, F01N 300

Patent

active

056408471

ABSTRACT:
A catalyst deterioration diagnosis system for an internal combustion engine having an exhaust gas passageway in which a catalytic converter having a catalyst is disposed. The diagnosis system comprises a first air-fuel ratio sensor disposed in the exhaust gas passageway upstream of the catalytic converter, and a second air-fuel ratio sensor disposed in the exhaust gas passageway downstream of the catalytic converter. The diagnosis system further comprises a control unit connected to the air-fuel ratio sensors and arranged to make an air-fuel ratio feedback control mainly in response to an output signal of the first air-fuel ratio sensor. The control unit includes means for calculating an inversion ratio value relating to an inversion ratio of output signals from the first and second air-fuel ratio sensors when the engine operating condition is within a diagnosis region requiring a diagnosis of deterioration of the catalyst, means for detecting an inversion state value relating to a state of inversion of the output signal of the first air-fuel ratio sensor, means for setting a decision standard value in accordance with the inversion state value from the inversion state value detecting means, and means for judging the deterioration of the catalyst by comparing the inversion ratio value from the inversion ratio value calculating means with the decision standard value from the decision standard value setting means.

REFERENCES:
patent: 5177959 (1993-01-01), Schnaibel et al.
patent: 5307626 (1994-05-01), Maus et al.
patent: 5317868 (1994-06-01), Blischke et al.
patent: 5335538 (1994-08-01), Blischke et al.
patent: 5533332 (1996-07-01), Uchikawa
patent: 5557929 (1996-09-01), Sato et al.
patent: 5568725 (1996-10-01), Uchikawa

Affiliated with

Also associated with

Rating

Catalyst deterioration diagnosis system for internal combustion does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Catalyst deterioration diagnosis system for internal combustion , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Catalyst deterioration diagnosis system for internal combustion will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-144355