Exhaust gas purifying device for internal combustion engine, and swirl generating device

Abstract

An exhaust gas purifying device for an internal combustion engine, provided with a swirl generating means for generating a swirl which has a strong swirl force and applying reduced resistance to the swirl. A swirl generating device for generating a swirl which has a strong swirl force and applying reduced resistance to the swirl is also provided. An exhaust gas purifying device ( 100 ) for an internal combustion engine is provided with an exhaust pipe ( 1 ), a reduction catalyst ( 2 ), a reducing agent supply means ( 3 ), and a swirl generating means ( 40 ). The swirl generating means ( 40 ) has two blades ( 410, 420 ) formed by dividing a substantially elliptic plate into two in the direction of the major axis thereof. The two blades ( 410, 420 ) are integrated together such that the two blades are rotated relative to each other about the minor axis of the plate so as to cross each other, and the two blades are mounted such that the direction of the major axis is parallel to the direction of flow of exhaust gas.

1 . An exhaust gas purifying device for an internal combustion engine, the exhaust gas purifying device comprising:
 an exhaust pipe through which exhaust gas exhausted from the internal combustion engine flows;   a reduction catalyst provided in the exhaust pipe and reducing and purifying an oxynitride contained in the exhaust gas;   reducing agent supply means for supplying a reducing agent by injecting the reducing agent into the exhaust gas flowing upstream of the reduction catalyst; and   swirl generating means provided upstream of the reduction catalyst in the exhaust pipe and generating a swirl in the exhaust gas,   wherein the swirl generating means has two blades formed by halving a substantially elliptic plate along the direction of a major axis thereof, the two blades so integrated together that the blades are rotated relative to each other about a minor axis of the plate so as to cross each other, the two blades so mounted that the direction of the major axis is parallel to the direction in which the exhaust gas flows.   
     
     
         2 . The exhaust gas purifying device for an internal combustion engine according to  claim 1 ,
 wherein the two blades are so configured that arcuate portions of outer edges of the blades are in contact with an inner wall of the exhaust pipe.   
     
     
         3 . The exhaust gas purifying device for an internal combustion engine according to  claim 1 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are cut in the direction parallel to the minor axis.   
     
     
         4 . The exhaust gas purifying device for an internal combustion engine according to  claim 1 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.   
     
     
         5 . Swirl generating means provided in an exhaust pipe, the swirl generating means comprising:
 two blades formed by halving a substantially elliptic plate along the direction of a major axis thereof, the two blades so integrated together that the blades are rotated relative to each other about a minor axis of the plate so as to cross each other, the two blades so mounted that the direction of the major axis is parallel to the direction in which the exhaust gas flows.   
     
     
         6 . The swirl generating means according to  claim 5 ,
 wherein the two blades are so configured that arcuate portions of outer edges of the blades are in contact with an inner wall of the exhaust pipe.   
     
     
         7 . The swirl generating means according to  claim 5 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are cut in the direction parallel to the minor axis.   
     
     
         8 . The swirl generating means according to  claim 5 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.   
     
     
         9 . The exhaust gas purifying device for an internal combustion engine according to  claim 2 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are cut in the direction parallel to the minor axis.   
     
     
         10 . The exhaust gas purifying device for an internal combustion engine according to  claim 2 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.   
     
     
         11 . The exhaust gas purifying device for an internal combustion engine according to  claim 3 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.   
     
     
         12 . The swirl generating means according to  claim 6 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are cut in the direction parallel to the minor axis.   
     
     
         13 . The swirl generating means according to  claim 6 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.   
     
     
         14 . The swirl generating means according to  claim 7 ,
 wherein the two blades are so configured that both ends thereof in the direction of the major axis are integrated together by connecting portions, and   one of the connecting portions, the connecting portion disposed on the upstream side in the exhaust pipe, is configured to connect upstream ends of the two blades with each other.