Exhaust apparatus for internal combustion engine

Abstract

An exhaust apparatus for an internal combustion engine comprises: an exhaust heating device ( 40 ) provided in an exhaust passage ( 12 ) of an internal combustion engine ( 1 ) for increasing a temperature of an exhaust gas; an exhaust purification catalyst ( 13 ) provided in the exhaust passage ( 12 ) downstream from the exhaust heating device ( 40 ); an EGR passage ( 30 ) for connecting the exhaust passage ( 12 ) downstream of the exhaust purification catalyst ( 13 ) and an intake passage ( 6 ) of the internal combustion engine ( 1 ); a bypass passage ( 31 ) for connecting the EGR passage ( 30 ) and a point downstream from the exhaust heating device ( 40 ) and also upstream from the exhaust purification catalyst ( 13 ) in the exhaust passage ( 12 ); a bypass valve ( 39 ) operable to open/close the bypass passage ( 31 ); and a controller ( 50 ) for controlling the control valve. When a temperature of the EGR passage ( 30 ) is lower than a predetermined reference value, the controller ( 50 ) controls the bypass valve ( 34 ) to be opened for a supply of an exhaust gas heated by the exhaust heating device ( 40 ) through the EGR passage ( 30 ) to the intake passage ( 6 ).

1 . An exhaust apparatus for an internal combustion engine, comprising:
 an exhaust heating device provided in an exhaust passage of the internal combustion engine for increasing a temperature of an exhaust gas;   an exhaust purification catalyst provided in the exhaust passage downstream from the exhaust heating device;   an EGR passage for connecting the exhaust passage downstream of the exhaust purification catalyst and an intake passage of the internal combustion engine;   a bypass passage for connecting a point downstream from the exhaust heating device and also upstream from the exhaust purification catalyst in the exhaust passage and the EGR passage;   a bypass valve operable to open/close the bypass passage; and   a controller configured to control the bypass valve,   wherein, when a temperature of the EGR passage is lower than a predetermined reference value, the controller controls the bypass valve to be opened for a supply of an exhaust gas heated by the exhaust heating device through the EGR passage to the intake passage.   
     
     
         2 . The exhaust apparatus for an internal combustion engine according to  claim 1 , wherein
 the EGR passage is provided with an EGR cooler for cooling the exhaust gas, and   the bypass passage is connected to the EGR passage in a position closer to an intake side than a position of the EGR cooler.   
     
     
         3 . The exhaust apparatus for an internal combustion engine according to  claim 2 , wherein
 the EGR passage is provided with an EGR valve for opening/closing the EGR passage, said EGR valve being located closer to the intake side than a connection point of the bypass passage, and   the controller controls the EGR valve to be closed such that the exhaust gas, having flown through the bypass passage, is supplied to an exhaust side of the EGR passage.   
     
     
         4 . The exhaust apparatus for an internal combustion engine according to  claim 3 , wherein the controller controls the EGR valve to increase the temperature in the intake side of the EGR passage after temperature of the EGR cooler is increased. 
     
     
         5 . The exhaust apparatus for an internal combustion engine according to  claim 1 , wherein the EGR passage is provided with an EGR cooler for cooling an exhaust gas, and the bypass passage is connected to the EGR passage in a position closer to an exhaust side than a position of the EGR cooler.