To provide an exhaust emission control device, capable of avoiding the problems of thermal deterioration of a DeNOx catalyst and misfire of an engine, in an exhaust emission control device for an internal combustion engine equipped with a DeNOx catalyst and DPF.
The exhaust emission control device is equipped with a fuel reformer (8) which is separately provided with a DPF (43); an exhaust pipe 4 and a DeNOx catalyst (42) for absorbing NOx in exhaust gas from an engine 2 under coexistence with hydrogen and which generates reformed gas containing at least hydrogen through reform of fuel; a first introduction passage (52) for introducing the reformed gas into the exhaust pipe 4 on the upstream side of the DeNOx catalyst (42); and first introduction control means (7, 51) for controlling a flow rate of the reformed gas introduced via the first introduction passage (52). The first inlet control means (7, 51) suppresses or stops the introduction of reformed gas via the medium of the first introduction passage (52), when regenerating the DPF 43 for burning and removing PM collected and deposited on the DPF 43 by supplying high temperature exhaust gas to the DPF 43.
SHIRAISHI RYUSUKE
MIKAMI HITOSHI
MOTOHASHI TAKESHI
IWAMOTO ATSUSHI
Hayashi Ichiyoshi