PREPARATION OF CATALYST EXHAUST TREATING DEVICE

摘要

PURPOSE: To protect a mat from the erosion by fitting an expansion mat to a center part of a cylindrical surface of a catalytic substrate, and fitting a support seal to each end part of the catalytic substrate to fit a catalyst close to an engine. CONSTITUTION: A catalytic conversion device 10 is provided with a container 22 to accommodate a totally cylindrical substrate 12. The substrate 12 has one cylindrical surface 14 and two cylindrical end parts 16. An expansion mat 20 is attached to the substrate 12 before accommodated in the container 22 by the coating. The expansion mat 20 occupies a center part of the cylindrical surface 14. Not only the expansion mat 20 but also a plurality of support seals 18 are attached to the substrate 12 before the substrate is inserted in the container 22. The support seals comprise rings extending in the axial direction along the cylindrical surface 14 from the end parts of the cylindrical surface 14 to the center part. A catalyst unit which is free from leakage and durable can thus be formed.