| 摘要 |
The present invention resides in that in case where a reducing agent addition valve is arranged in a position in which at least part of a reducing agent added to an exhaust gas in an exhaust passage at a location upstream of a precatalyst reaches the precatalyst in the state of liquid, the reducing agent is supplied in a more suitable state to an exhaust gas purification device which is arranged in the exhaust passage at a downstream side of the precatalyst. In the present invention, when the addition of the reducing agent is performed by the reducing agent addition valve (S107), the flow rate of the exhaust gas flowing into the precatalyst is decreased so that at least part of the reducing agent, which has reached the precatalyst and has vaporized in the precatalyst, is caused to flow back (S106). |
