| 摘要 |
<p>PURPOSE:To surely maintain sliding performances of rotary shafts of butterfly valves in an exhaust emission control device arranged in an exhaust system for an automobile. CONSTITUTION:An exhaust pipe line 47 in which an auxiliary catalyst converter 45 is arranged is connected to an exhaust manifold 43 of an engine 41, the exhaust pipe line 47 is bypassed so as to form a bypass pipe line 49, and a main exhaust pipe line 55 in which a main catalyst converter 53 is arranged is connected to the lower stream side of a connection part 51 of the exhaust pipe line 47 in the lower stream side end of the bypass pipe line 49. The first butterfly valve 57 is arranged in the upper stream side of the connection part 51 of the exhaust pipe line 47 and the second butterfly valve 59 is arranged in the upper stream side of the connection part 51 of the bypass pipe line 49. The bearing member of the first butterfly valve 57 is formed from a material superior in low temperature sliding performance and the bearing member of the second butterfly valve 59 is formed from a material superior in high temperature sliding performance.</p> |
