Patent ID: 8327633

Claim:
A exhaust pipe for a vehicle-mounted engine comprising: an outer pipe including an inner peripheral surface; an inner pipe inserted in the outer pipe, wherein the inner pipe includes an end and a plurality of communication holes; an expansion chamber that is formed between the outer pipe and the inner pipe by contacting the inner pipe with the inner peripheral surface of the outer pipe at the end of the inner pipe and contacting the outer pipe with the inner pipe at the position different from the contact position of the inner pipe with the inner peripheral surface of the outer pipe in the axial direction of the outer and inner pipes, wherein the expansion chamber communicates with the interior of the inner pipe via the plurality of communication holes to form a muffler; an exhaust gas purification catalyst provided within the outer pipe adjacent to the expansion chamber; and a weir for stopping the flow of condensed water provided on the inner peripheral surface of the outer pipe between the end of the inner pipe and the exhaust gas purification catalyst so as to protrude inward the outer pipe.