Patent ID: 7971682

Claim:
An exhaust device for an engine, said exhaust device including: an exhaust pipe having a curved portion; a flow rectifying means for rectifying a flow of an exhaust gas, said flow rectifying means being disposed in an upstream end of an inner pipe, said flow rectifying means comprising protrusions projecting inwardly, and being attached to an inner surface of the inner pipe, said inner pipe being connected to an end of the exhaust pipe, wherein the exhaust gas engaging said flow rectifying means has passed through the curved portion of the inner pipe, and wherein the inner pipe also includes a muffler having a plurality of vent holes disposed in an inner portion thereof, and an outer pipe surrounding the inner pipe, defining an angular chamber therebetween, and wherein said flow rectifying means comprises a first flow rectifying member attached to the inner surface of the inner pipe, outwardly of a curved direction of the curved portion of the exhaust pipe, and a second flow rectifying member attached to the inner surface of the inner pipe, downstream of the first flow rectifying member, said first and second flow rectifying members having the protrusions projecting integrally therewith, inwardly from an inner surface of the upstream end of the inner pipe, wherein the flow rectifying means uniformizes exhaust gas pressure in the inner pipe.