| 摘要 |
PROBLEM TO BE SOLVED: To provide an exhaust emission control device for an internal combustion engine reducing moisture effect of a catalyst by using superheated steam formed from water adsorbed by an adsorption catalyst during engine start, and effectively cleaning NO<SB>X</SB>by remarkably improving response of a NO<SB>X</SB>adsorption catalyst. SOLUTION: The adsorption catalyst 59 is provided in a first exhaust pipe 57 connected to a bank 12, a three-way catalyst 60 is provided in a second exhaust pipe 58 connected to a bank 13, and a NO<SB>X</SB>purification catalyst 62 is provided in an exhaust gas collecting passage 61. Exhaust gas is fed to the exhaust passage 57 side to make the adsorption catalyst 59 adsorb water while catalyst temperature of the adsorption catalyst 59 is not higher than predetermined temperature at which steam is not formed, feed of exhaust gas is changed over to the exhaust passage 58 side from the exhaust passage 57 side after catalyst temperature of the adsorption catalyst 59 gets to temperature not less than the predetermined temperature, and feed of exhaust gas is changed over to the exhaust passage 57 side from the exhaust passage 58 side after load gets high. Consequently, superheated steam is formed from water adsorbed by the adsorption catalyst 59 and temperature of the NO<SB>X</SB>purification catalyst 62 is raised. COPYRIGHT: (C)2009,JPO&INPIT
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