排気管直挿型NOxセンサによるNOx吸蔵還元触媒の劣化検知(J25-2 交通機械と進化するエネルギー技術,J25 交通機械と進化するエネルギー技術)  [in Japanese] Detection of Deteriorated NOx Storage-Reduction Catalyst by Thick Film Zr02 NOx Sensor  [in Japanese]

The NOx storage-reduction catalyst installed in the exhaust system of a direct injection gasoline engine has the function which reduced the NOx in the catalyst under the lean combustion. However, deterioration of NOx storage-reduction performance causes increase of NOx emission and unburnt gas. slip. In this study, we found that it is possible to evaluate the performance of the NOx storage-reduction catalyst by effectively using both of the air-fuel ratio signal and NOx concentration signal from two NOx sensors that were placed upstream and downstream of the catalytic converter. In addition, the effectiveness of this method was verified by carrying out a chassis dynamometer test with various deteriorating catalysts.