| 摘要 |
<P>PROBLEM TO BE SOLVED: To strike a balance between the exhaust emission cleaning performance and the output performance of an internal combustion engine, by sufficiently mixing reducing agent and exhaust gas, and also by suppressing pressure loss in an exhaust passage. <P>SOLUTION: The exhaust emission control device of the engine arranged in the exhaust pipe 2 of the engine, having a reducing agent injection valve for injecting urea water and an SCR catalyst for cleaning the exhaust gas by subjecting the injected reducing agent and nitrogen oxide in the exhaust gas to the catalytic reduction reaction, and controlling the injection of the reducing agent from the reducing agent injection valve based on the operating state of the engine has the mixer 10 arranged in the upstream of the SCR catalyst of the exhaust pipe 2 and generating swirling flow in the exhaust gas passing through the exhaust pipe 2, the mixer 10 has the fins 22 capable of changing the angle of the exhaust gas in the exhaust pipe 2 to the flowing direction, generates the swirling flow when the urea water is injected from the reducing agent injecting valve, the angle of the fins 22 to the exhaust gas flowing direction is changed based on the engine operating state such that the swirling flow is stopped when the injection of the urea water is stopped. <P>COPYRIGHT: (C)2012,JPO&INPIT |
