| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device maintaining sufficient exhaust emission control performance and reducing use quantity of noble metal. <P>SOLUTION: The exhaust emission control device 10 includes an exhaust manifold 30 including a collecting part where a plurality of branched pipes merge, and a catalytic converter 40 provided right downstream of the exhaust manifold 30. The catalytic converter 40 includes an upstream catalyst 43 held at an upstream side and a downstream catalyst 45 held at a downstream of the upstream catalyst 43. The upstream catalyst 43 includes a carrier, an upstream first layer positioned above the carrier and containing Pd, an upstream second layer positioned above the upstream first layer and containing Rh, and an upstream third layer positioned above the upstream second layer and containing Pd. The downstream catalyst 45 includes a carrier, a downstream first layer positioned above the carrier and containing Pd, a downstream second layer positioned above the downstream first layer and containing Pt and Rh. The collecting part communicates to the catalytic converter 40 through a prescribed length straightening channel 35 of which width gets narrower in sequence from an upstream to a downstream, and a neck 33 provided at the straightening channel 35. <P>COPYRIGHT: (C)2010,JPO&INPIT |
