Patent ID: 6729122
Filing Date: 2004-05-04
Classification: F01N,F02M,Y02T

Abstract:
A system for purifying exhaust gas of an internal combustion engine, the system comprising:an exhaust pipe for discharging exhaust gas generated by the engine to exterior of the engine through a catalytic converter; a branch pipe coupled to the exhaust pipe through a flange at a location downstream of the catalytic converter and having a main exhaust gas passage and a bypass exhaust gas passage; a switch-over valve for selectively connecting the exhaust pipe to the main exhaust gas passage or the bypass exhaust gas passage, the switch over valve is housed in a switch-over valve body which is coupled to the exhaust pipe through a first flange and to the flange of the branch pipe through a second flange having a first hole; an adsorbent installed in the bypass exhaust gas passage for adsorbing unburned components of the exhaust gas; a recirculation pipe for recirculates the exhaust gas including the unburned components at a location upstream of the catalytic converter; and an inlet of the recirculation pipe for introducing the recirculated gas is formed integrally with the branch pipe flange; and the branch pipe is provided with a second hole in such a way that a distal end of the recirculation pipe is fixed to the first hole which is mated to the second hole formed at the branch pipe such that the inlet of the recirculation pipe is formed integrally with the branch pipe flange.