EXHAUST EMISSION CONTROL DEVICE

PROBLEM TO BE SOLVED: To provide an exhaust emission control device capable of maintaining appropriate exhaust emission control efficiency of an exhaust emission control means in a downstream side casing by suppressing a degree of unevenness of an exhaust gas flow by a bending part of a communication path low. SOLUTION: An upstream side casing 42, connected with an exhaust gas pipe 20 of an engine 1, for storing a front step oxidation catalyst 38 and a particulate filter 40 and the cylindrical downstream side casing 36, arranged at a downstream side of the upstream side casing 42, for storing an ammonia selective reduction type NOx catalyst 42 and a rear step oxidation catalyst 44 are communicated by a communication path 34. The communication path 34 has a first bending part 48 in a middle part and its end is connected with a side face part of the downstream side casing 36. The first bending part 48 has a predetermined bending form which is set to have a bending angle θ not larger than 120° and a ratio R/r of the bending radius R in a center axis of the communication path 34 for the radius r of the communication path 34 is 0.8 or larger. COPYRIGHT: (C)2009,JPO&INPIT