| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a deterioration determination device of an exhaust emission control device capable of improving deterioration determination accuracy of a catalyst to be determined in the case that another catalyst is arranged at an upstream side of the catalyst to be determined. <P>SOLUTION: In the exhaust emission control device 10 provided with an upstream side catalyst 11 and a downstream side catalyst 12, the deterioration determination device 1 for determining deterioration of the downstream side catalyst 12 is provided with an ECU 2. The ECU 2 controls the exhaust gas flowing to the upstream side catalyst 11 to switch from oxidative atmosphere to reductive atmosphere (steps 1, 3), calculates a basic value OSCbase of a catalyst oxygen storage ability by using a second equivalence ratio KACT2 and a third KACT3 after this switch when the upstream side catalyst 11 is in an activated state (a step 60), calculates a catalyst oxygen storage ability OSC by correcting this base value OSCbase in accordance with a catalyst temperature TCAC and an exhaust gas flow rate QGAS (a step 63) and deterioration of the downstream side catalyst 12 is determined by using the catalyst oxygen storage ability OSC (steps 64-66). <P>COPYRIGHT: (C)2010,JPO&INPIT |
