Abstract: A valve device includes a valve seat, a valve body, a buffer, and a non-overlapping portion. The valve seat has an opening that communicates with an exhaust flow path. The valve body is configured to open and close at least a part of the opening. The buffer is disposed between the valve seat and the valve body and is more flexible than the valve seat. The non-overlapping portion is configured so that the valve seat and the valve body do not overlap each other in an opening and closing direction of the valve body at at least a part of an outer periphery of the valve body in a state where the valve body is closed.

Abstract: An exhaust silencer device which is interposed in an exhaust passage in a vehicle to reduce exhaust noise comprises a sub-muffler which is interposed in the exhaust passage and has an expansion chamber formed therein; an inlet pipe which is airtightly inserted through an inlet opening of the sub-muffler; and an outlet pipe which is airtightly inserted through an outlet opening of the sub-muffler, wherein the inlet pipe and the outlet pipe are formed with openings (small apertures, non-joined portions) only in their upper half area and their lower half area is sealed without having the openings.

Abstract: A muffler includes an inner pipe and an outer pipe which, along with the inner pipe, forms a double-wall pipe. A cavity is provided between the inner and outer pipes. A first end of the double-wall pipe is closed between the inner and outer pipes, and a second end of the double-wall pipe has an opening between the inner and outer pipes. The cavity communicates with an exhaust channel via the opening. The cavity is formed as a result of the inner pipe being shaped in a manner such that a portion of an outer-circumferential surface of the inner pipe is positioned on an inner-circumferential side relative to a reference, the reference being a position of an outer-circumferential surface of the outer pipe.

Abstract: An exhaust silencer device which is interposed in an exhaust passage in a vehicle to reduce exhaust noise comprises a sub-muffler which is interposed in the exhaust passage and has an expansion chamber formed therein; an inlet pipe which is airtightly inserted through an inlet opening of the sub-muffler; and an outlet pipe which is airtightly inserted through an outlet opening of the sub-muffler, wherein the inlet pipe and the outlet pipe are formed with openings (small apertures, non-joined portions) only in their upper half area and their lower half area is sealed without having the openings.

Abstract: A muffler includes an inner pipe and an outer pipe which, along with the inner pipe, forms a double-wall pipe. A cavity is provided between the inner and outer pipes. A first end of the double-wall pipe is closed between the inner and outer pipes, and a second end of the double-wall pipe has an opening between the inner and outer pipes. The cavity communicates with an exhaust channel via the opening. The cavity is formed as a result of the inner pipe being shaped in a manner such that a portion of an outer-circumferential surface of the inner pipe is positioned on an inner-circumferential side relative to a reference, the reference being a position of an outer-circumferential surface of the outer pipe.