| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a technology for selecting a plurality of modes including a single mode, a dual mode, a tandem mode and a by-pass mode, with simple constitution in an exhaust emission control system combining a plurality of exhaust emission control devices. <P>SOLUTION: In this exhaust emission control system, an exhaust passage 5 of an internal combustion engine 1 is branched into a first branch passage 10a provided with a first filter 11a, a second branch passage 10b provided with a second filter 11b, and a third branch passage. The first branch passage 10a and the second branch passage 10b join to form a communicating line 10d, and the communicating line 10d joins the third branch passage 10c. The attitude positions of a first selector valve 12a capable of selecting three attitude positions and a second selector valve 12b capable of selecting two attitude positions, are suitably controlled to select the plurality of modes including the single mode, dual mode, tandem mode and by-pass mode. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
