Exhaust gas purification apparatus for internal combustion engine

Abstract

The present invention resides in an exhaust gas purification apparatus for an internal combustion engine, comprising an exhaust gas purification catalyst which is arranged in an exhaust gas passage of the internal combustion engine for a reducing agent added from a reducing agent addition valve, the reducing agent addition valve which adds the reducing agent to an exhaust gas allowed to flow upstream from the exhaust gas purification catalyst, and a dispersion member which disperses the reducing agent added from the reducing agent addition valve, wherein a task or object thereof is to form fine particles of the reducing agent and improve the dispersibility while suppressing the increase in the exhaust resistance caused by the dispersion member to be small. In order to solve the task or achieve the object, in the present invention, the dispersion member is arranged only on a flight route of a coarse reducing agent which is included in the reducing agent added from the reducing agent addition valve and which has relatively large particle diameters.

1 . An exhaust gas purification apparatus for an internal combustion engine, comprising:
 an exhaust gas purification catalyst which is arranged in an exhaust gas passage of the internal combustion engine;   a reducing agent addition valve which adds a reducing agent to an exhaust gas allowed to flow upstream from the exhaust gas purification catalyst; and   a dispersion member which is a member for allowing the reducing agent added from the reducing agent addition valve to collide therewith and which is arranged on a flight route of a coarse reducing agent, the coarse reducing agent being included in the reducing agent added from the reducing agent addition valve and the coarse reducing agent being the reducing agent having relatively large particle diameters.   
     
     
         2 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 1 , wherein:
 the reducing agent addition valve is an injection valve for forming a cone-shaped spray; and   the dispersion member is arranged on a route along which a circumferential edge portion of the cone-shaped spray flies.   
     
     
         3 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 2 , wherein the dispersion member is a member having a protruding portion which is formed on one end surface of a cylindrical member and which extends in a radial direction. 
     
     
         4 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 2 , wherein the dispersion member is a plate member which is formed to have an annular form. 
     
     
         5 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 4 , wherein protrusions and recesses are formed on a surface of the plate member. 
     
     
         6 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 4 , wherein a plurality of through-holes are provided through the plate member. 
     
     
         7 . The exhaust gas purification apparatus for the internal combustion engine according to  claim 2 , wherein the dispersion member is a member in which a plurality of plate members are arranged in an annular form.