| 摘要 |
<p>To provide an exhaust gas purification device for an internal combustion engine with which the amount of SOx having accumulated on a NOx catalyst can be precisely calculated using a comparatively simple configuration, whereby fuel efficiency and exhaust gas characteristics of the internal combustion engine can be improved. During EGR operation, a portion of exhaust gas discharged from an engine (3) into an exhaust pipe (5) flows into a NOx catalyst while the remaining portion is circulated to an intake pipe (4) via an EGR pipe (6a). A CO2 sensor (22) having BaCO3 included in a detection electrode (22a) is provided downstream of a merging part (4a) of the intake pipe (4). According to this exhaust gas purification device (1), the amount of SOx having accumulated on the catalyst SOxLNT is calculated according to the EGR rate rEGR and the amount of SOx having accumulated on the sensor SOxSNS (Step 39), the calculation being performed on the basis that the relationship between the amount of SOx having accumulated on the catalyst SOxLNT and the amount of SOx having accumulated on the sensor SOxSNS as detected by the CO2 sensor (22) is determined according to the EGR rate rEGR.</p> |
