Exhaust gas purification device for internal combustion engine

Abstract

An exhaust gas purification device for an internal combustion engine, in which a catalyst installed in an exhaust passage is quickly heated to the activation temperature of the catalyst. The exhaust gas purification device has a NOx purification catalyst () for adsorbing or occluding NOx in exhaust gas and reducing the NOx, a catalytic converter () installed at that position of an exhaust pipe () which is upstream of the NOx purification catalyst (), a fuel reformer () installed separately from the exhaust pipe (), producing a reformed gas, and supplying the reformed gas, as a reducing gas, into the exhaust pipe () from an introduction opening () formed in that portion of the exhaust pipe () which is upstream of the NOx purification catalyst () and the catalytic converter (), and an ECU () which, while the exhaust gas air-fuel ratio is being set to be lean, supplies the reducing gas into the exhaust pipe () and controls at least one of a throttle valve (), an EGR valve (), and a turbocharger () to regulate the flow rate of the exhaust gas flowing in the exhaust pipe ().