| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine efficiently removing noxious gas three components (CO, HC, NOx) in exhaust gas. <P>SOLUTION: Two catalytic converters 16, 36 having three-way conversion catalysts 17, 37 built therein are arranged in an exhaust gas passage of the engine 1 in the exhaust emission control device. An O2 sensor 34 is arranged in a downstream of the catalytic converter 36 arranged in a back stage. When time passing from a moment when output voltage Vr of the O2 sensor 34 exceeds a predetermined value V1 reaches predetermined time T1 (S5: Yes), VVT mechanism 40 is operated to advance open timing of an intake valve 48 and to reduce emission of NOx by internal EGR effect. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
