EXHAUST GAS PURIFICATION DEVICE FOR INTERNAL COMBUSTION ENGINE

摘要

Disclosed is an exhaust gas purification device for an internal combustion engine. The exhaust gas purification device is equipped with a selective reduction catalyst that is provided in the exhaust passage of the internal combustion engine, captures the reducing agent NH3, and uses the captured NH3 to reduce NOx flowing through the aforementioned exhaust passage; a reducing agent supply means that supplies the reducing agent upstream of the selective reduction catalyst in the exhaust passage; and a reducing agent supply setting means that sets the amount of the reducing agent supplied by the reducing agent supply means. In cases in which it is necessary to set a shorter supply period than the minimum supply period that can be controlled by the reducing agent supply means, the reducing agent supply setting means sets the supplied amount of the reducing agent on the basis of said minimum supply period while lengthening the intervals between the supply of said reducing agent.