| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control device, an internal combustion engine and a recovering method of catalysts, when recovering the emission control performance of the catalysts, desorbing sulfur components adsorbed to the catalysts by changing an exhaust path of exhaust gas to raise a temperature of the catalyst arranged on a downstream side to a higher temperature than that of the catalyst arranged on an upstream side. <P>SOLUTION: The exhaust emission control device applied in an engine 11 of the embodiment has the upstream catalyst 27 and the downstream catalyst 29 arranged in an exhaust passage 26 and controlling the emission of exhaust gas and an exhaust path control means which controls the exhaust path of the exhaust gas by changing the flow direction of the exhaust gas to an upstream catalyst device 28 and a downstream catalyst device 30 to the forward direction from one end sides of the upstream catalyst 27 and downstream catalyst 29 to the other end sides or to a reverse direction from the other end sides to one-end sides. The exhaust emission control device has a secondary air supply means 33 supplying secondary air 32 to the exhaust gas and an air-fuel control means enriching an air-fuel ratio to the engine 11 so that an air-fuel ratio of the exhaust gas after supply of the secondary air 32 becomes rich. <P>COPYRIGHT: (C)2010,JPO&INPIT |
