| 摘要 |
PURPOSE: To lengthen a heat transfer passage, to suppress the radiation of heat from a honeycomb body and to reduce the quantity of heat radiated by fixing the upper stream side of a protective tube on the upper stream side or downstream side of an exhaust passage and joining the downstream side of the honeycomb body to the inner wall of the downstream side of the protective tube. CONSTITUTION: A flat sheet 113 is superposed on a corrugated sheet 112 and they are spirally wound to form the honeycomb carrier 11 of a catalytic converter 10. At this time, slits 111 are formed in the sheets 113, 112 from the central part of the carrier 11 in the longitudinal direction toward the end on the upper stream side of exhaust gas. The inside diameter of a protective tube 12 covering the periphery of the carrier 11 on the upper stream side of exhaust gas is made larger than that on the downstream side and a gap 100 is ensured around the slits 111. The positional relation between the honeycomb carrier 11 and the protective tube 12 is decided so that the tube 12 protrudes from the end 11a of the carrier 11 on the upper stream side in the axial direction. The tube 12 is then irradiated with laser beams from the outside of the tube 12 except the notches 121 to fix the corrugated sheet 112 and the tube 12 by welding. |
