| 摘要 |
PURPOSE:To eliminate tar or the like attached to an exhaust path while improving the durability of catalyst by forming the upstream side of the exhaust path of a perforated inner tube and a non-perforated outer tube and sandwiching a catalyst layer and an adiabatic permeable material in the laminated form between these tubes. CONSTITUTION:An exhaust pipe 1 has in the upstream side an exhaust path 2 which is a thin pipe having approximately equal diameter and curvedly formed, and the downstream side of the exhaust path 2 are connected sequentialy an expansion chamber and silencing portion having the diameter expanded gradually toward the downsteram. Thus, the upsteam side exhaust path 2 has in the inside an inner tube 6 provided with a plurality of through holes 5 and in the outside a non-perforated outer tube 7 to form a doubled structure. And between the inner and outer tubes 6, 7 are sandwiched a catalyst layer 8 and a permeable adiabatic material 9 in the laminated form. Thus, when exhaust gas passes through the exhaust path 2, a portion of unburnt gas passes through the through holes 5 in the inner tube 6 and contacts the catalyst layer 8 for exothermic reaction. Accordingly attachment of tar or the like to the exhaust path can be obviated. |
