| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system capable of efficiently purifying an exhaust emission from immediately after the start of an engine, while precisely controlling an exhaust emission flowing passage, and a method thereof. <P>SOLUTION: The exhaust emission control system includes a main catalyst provided in a main passage, a bypass passage branching once from the main passage located in an upstream of the main catalyst to again join to the main passage in the upstream of the main catalyst, a bypass passage catalyst provided in the bypass passage, a flow control valve which is provided in the main passage and specifically on more downstream side than a portion where the bypass passage branches and more upstream side than a portion where the bypass passage l joins the main passage and can regulate the exhaust emission volume flowing through the main passage. Further, the exhaust emission control system includes a gas temperature estimating means (steps S2, S3, S5) for estimating exhaust emission temperature based on an engine operational status, and a valve control means (steps S8, S9) for performing opening and closing control of the flow control valve based on the estimated exhaust emission temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT |
