Exhaust processing device and manufacturing method thereof

An exhaust processing device comprising:

• a main body tube portion, a closing tube portion, and an annular member, the main body tube portion including an opening in an axial end thereof, and the main body tube portion housing a main body exhaust path in an inside thereof to allow an exhaust gas to pass therethrough;
• the closing tube portion including a plate portion covering the opening of the axial end of the main body tube portion, and a tubular portion radially outwardly protruding from an outer peripheral surface of the main body tube portion, the tubular portion being integrated with the plate portion, the tubular portion housing an exhaust path in an inside thereof, the exhaust path communicating with the main body exhaust path, and the tubular portion including a first split half portion integrally molded with the plate portion and having a first joint surface, and a second split half portion having a second joint surface and joined to the first split half portion such that the second joint surface engages with the first joint surface of the first split half portion, one of the first joint surface and the second joint surface including one of a convex portion and a concave portion, and the other of the first joint surface and the second joint surface including the other of the convex portion and the concave portion, the convex portion and the concave portion being configured to be engaged for appropriately positioning the first and second split half portions;
• and the annular member being fitted onto the tubular portion with the annular member abutting an end of a flange portion disposed along an edge of the first split half portion and an end of a flange portion disposed along an edge of the second split half portion for integrating the first split half portion and the second split half portion.