| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust gas purification device of an internal combustion engine, capable of suppressing progress of degradation in a reducing agent and improving fuel economy of an internal combustion engine, and appropriately melting the reducing agent. <P>SOLUTION: In the exhaust gas purification device, NOx in exhaust gas is purified by using a reducing agent supplied in a liquid state by an NOx selective reducing catalyst provided in an exhaust passage of an internal combustion engine. A defrosting control is carried out (steps 5, 12) to melt a frozen reducing agent by heating; a degradation degree DTEG of the reducing agent is estimated in accordance with the temperature TU of the reducing agent detected during the defrosting control (step 8) is carried out; and the defrosting control is carried out in accordance with the estimated degradation degree DTEG of the reducing agent (step 12). <P>COPYRIGHT: (C)2013,JPO&INPIT |
