| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for internal combustion engine including an SOx retaining member to hold sulfur oxides (SOx) in exhaust gas, in which SOx can be removed from the SOx retaining member while preventing acceleration of degradation of the SOx retaining member. <P>SOLUTION: The exhaust emission control device includes the SOx retaining member arranged in an exhaust passage, an air-fuel ratio sensor, a reducing agent supply means for supplying a reducing agent to the SOx retaining member, an air-fuel ratio control means which controls the air-fuel ratio of the internal combustion engine according to the learned value of air-fuel ratio, a control means which controls the reducing agent supply means so that the exhaust gas flowing into the SOx retaining member may have desired air-fuel ratio, and a learned value reset means which resets the air-fuel ratio learned value to the initial value before the control means starts controlling the reducing agent supply means in order to remove SOx from the SOx retaining member. Thus, because the reducing agent is never added to the SOx retaining member based on the erroneously learned value of air-fuel ratio, it is possible to prevent acceleration of degradation of the SOx retaining member. <P>COPYRIGHT: (C)2004,JPO |
