| 摘要 |
PURPOSE: To obtain high exhaust purifying performance, preventing thermal damage, by storing a porous inner tube molded corresponding to an outer covering tube and is cover with catalyst within the outer covering tube partially having an expansion chamber and demarcating an annular chamber of roughly constant cross section between both of the outer covering tube and the porous inner tubes. CONSTITUTION: An outer covering tube 1 which partially has an expansion chamber and is formed into an arbitrary shape and porous inner tube 3 stored in the outer covering tube 1 and molded corresponding to the outer covering tube 1 are provided. Between both of the outer covering tube 1 and the porous inner tube 3, an annular chamber 5 having roughly constant cross section is demarcated. In this inner tube 3, one surface or both the surfaces are covered with exhaust gas purifying catalyst. The rate of an inner diameter of the outer covering tube 1: an outer diameter of the inner tube 3 is set to the range of 1.01 to 1.20. A porous hole provided on the inner tube 3 is formed as expansion of upward and/or downward deep drawing and the inner tube 3 is constituted of two half shells which are joined each other as occasion. |
