Exhaust muffler combining components made of different materials

An exhaust muffler comprising:

• an outer shell consisting of two halves made of synthetic resin material abutting each other at a brim portion of each of said two halves, each of said two halves being provided with a hollow semi-cylindrical extension extending from said brim portion of the corresponding half so as to form a completely tubular extension by the cooperation of said two hollow semi-cylindrical extensions;
• an inner pipe made of metallic material extending through said outer shell and out of said tubular extension of said outer shell;
• a sleeve member fitted onto said tubular extension at one end thereof and fitted in a substantially airtight fashion onto a part of said inner pipe extending out of said tubular extension of said outer shell at the other end thereof;
• and
• fastening means for securing said sleeve member fitted on said tubular extension and producing a radial securing force which urges said semi-cylindrical extensions toward each other, wherein said other end of said sleeve member is securely welded to the inner pipe, and is provided with means for accommodating relative movement between the outer shell and the inner pipe.

An exhaust muffler comprising:

• an outer shell consisting of two halves made of synthetic resin material abutting each other at a brim portion of each of said two halves, each of said two halves being provided with a hollow semi-cylindrical extension extending from said brim portion of the corresponding half so as to form a completely tubular extension by the cooperation of said two hollow semi-cylindrical extensions;
• an inner pipe made of metallic material extending through said outer shell and out of said tubular extension of said outer shell;
• a sleeve member fitted onto said tubular extension at one end thereof and fitted in a substantially airtight fashion onto a part of said inner pipe extending out of said tubular extension of said outer shell at the other end thereof;
• and
• fastening means for securing said sleeve member fitted on said tubular extension and producing a radial securing force which urges said semi-cylindrical extensions toward each other, wherein said other end of said sleeve member is securely welded to the inner pipe, and a part of the inner pipe is provided with means for accommodating relative movement between the outer shell and the inner pipe.