| 摘要 |
PROBLEM TO BE SOLVED: To solve the trouble of leakage of exhaust gas by setting the thermal expansion coefficient of the part contact with a catalyst carrier and the long edge of a casing of a mat member larger than the thermal expansion coefficient of the part contact with the short edge thereof. SOLUTION: A mat member for retaining a catalyst carrier within a casing is interposed in the clearance between the inside surface of the casing and the outside surface of the catalyst carrier so that it is closely fitted to both the inside surface of the casing and the outside of the catalyst carrier over the whole circumference of the catalyst carrier. The mat member is formed by alternately arranging a highly thermally expansible fiber 5a contact with the long edge 3e of the casing and a low thermally expansible fiber 5b contact with the short edge 3f thereof in the circumferential direction of the catalyst carrier. The clearance is increased in a hot time where the internal temperature of a catalytic converter 1 is sufficiently increased by exhaust gas. According to such a structure, even if the increase quantity is varied in the parts 3e, 3f, the catalyst carrier can be retained regularly at a fixed pressure to prevent the leak of the exhaust gas. |
