Patent ID: 6769247
Filing Date: 2004-08-03
Classification: F01N,F02D

Abstract:
An exhaust gas valve device in an internal combustion engine, said exhaust gas valve device being disposed to change over the course of an exhaust gas flow between a plurality of exhaust gas passages of an exhaust system located downstream of said exhaust gas valve device, said exhaust gas valve device comprising:a valve body provided in said exhaust system in the internal combustion engine and defining a flow passage through which the exhaust gas flows; a valve shaft mounted traverse to said flow passage; a valve member mounted to said valve shaft within said valve body; a bottomed cylindrical first bearing member mounted between said valve shaft and said valve body with one end of said valve shaft turnably fitted into said first bearing member; a cylindrical second bearing member mounted between said valve shaft and said valve body with the other end of said valve shaft passing through said second bearing member; and an actuator connected to the other end of said valve shaft protruding from said second bearing member for driving said valve shaft to turn, wherein said valve body, said valve shaft and said first and second bearing members are each formed of a form of steel having equivalent thermal expansion coefficients; wherein said first and second bearing members are press-fitted into said valve body; and wherein a skin of a graphite-based solid lubricant is formed by coating on a surface of said valve shaft in regions corresponding to said first and second bearing members.