An exhaust structure for a straddle-type vehicle includes a muffler having an outer tube constituting an outer circumferential member of the muffler; first and second separators defining expansion chambers in the outer tube; a body end member arranged at the downstream end of the outer tube; and glass wool provided on the inner circumference of the outer tube. The muffler further includes a resonator chamber provided in the most downstream portion of the muffler. The resonator chamber is formed by the outer tube, the body end member and the second separator situated closest to the body end member. The surroundings of the resonator chamber are surrounded by the glass wool. Such exhaust structure of a straddle-type vehicle is capable of taking measures against exhaust heat and exhaust sound even with a configuration where there is only one, single resonator chamber.

An exhaust structure for a straddle-type vehicle includes a muffler having an outer tube constituting an outer circumferential member of the muffler; first and second separators defining expansion chambers in the outer tube; a body end member arranged at the downstream end of the outer tube; and glass wool provided on the inner circumference of the outer tube. The muffler further includes a resonator chamber provided in the most downstream portion of the muffler. The resonator chamber is formed by the outer tube, the body end member and the second separator situated closest to the body end member. The surroundings of the resonator chamber are surrounded by the glass wool. Such exhaust structure of a straddle-type vehicle is capable of taking measures against exhaust heat and exhaust sound even with a configuration where there is only one, single resonator chamber.

An air blower has an inlet muffler and an outlet muffler to reduce the noise of the air blower during operation. Each of the mufflers may have two sections. One section is configured to attenuate high frequency noise and the other section is configured to attenuate lower frequency noise. A tubular internal wall in each of the mufflers defines the through passage for each of the mufflers. A noise absorbent material may be fitted about the tubular wall within each muffler. A plurality of holes are formed along the tubular wall of each through passage to expose the through passage to the noise absorbent material. A heater plenum may be interposed between the blower plenum and the outlet muffler to heat the air from the blower plenum. A filter at the input muffler filters the air sucked into the air blower.

A vehicle exhaust system includes a tubular component having an inner surface and an outer surface such that the inner surface defines a primary exhaust gas flow path and wherein the tubular component extends along a central axis from an inlet end to an outlet end. The tubular component comprises at least one ridge along the central axis. The at least one ridge extends at least partly along a circumference of the tubular component. Each ridge includes a first portion angularly devoid of apertures and extending inwardly from the tubular component and a second portion disposed downstream of the first portion. The second portion is angularly devoid of apertures and extends inwardly from the tubular component. The tubular component also includes a plurality of spaced apertures positioned along a portion of the circumference of the tubular component and downsteam of the second portion.

A muffler assembly unit for an exhaust system of an internal combustion engine, especially in a vehicle, includes a muffler (42) with a muffler housing (10). The muffler housing (10) is elongated along a longitudinal axis of the housing. A housing jacket (40) encloses the muffler housing (10). At least one air guiding bulge (34) is provided on the housing jacket (40).

A sound suppression apparatus for installation inside a gas transport duct is provided. The sound suppression apparatus comprises a resistive sound-absorbing element (110) and a housing providing a reactive sound-attenuating element (130) communicating with a surrounding of the apparatus via opening in an outer surface of the housing. An outer surface of the sound suppression apparatus comprises an outer surface of the resistive sound-absorbing element and the outer surface of the housing. A gas transport duct comprising the sound suppression apparatus is also provided.

A muffler may include a main body, a perforated tube assembly disposed within the main body, inlet and outlet end cap assemblies connected to opposite ends of the main body, and inlet and outlet expansion chambers defined in opposite ends of the main body by the perforated tube assembly, the inlet and outlet end cap assemblies, and portions of the main body. The perforated tube assembly may include a plurality of perforated tubes with tube supports connected to opposite ends of the perforated tubes. Portions of each perforated tube located between the tube supports may be individually wrapped with insulating material and collectively wrapped with an additional layer of insulating material. Unwrapped portions of each perforated tube may extend into the inlet and outlet expansion chambers defined in the main body.

A muffler may include a main body, a perforated tube assembly disposed within the main body, inlet and outlet end cap assemblies connected to opposite ends of the main body, and inlet and outlet expansion chambers defined in opposite ends of the main body by the perforated tube assembly, the inlet and outlet end cap assemblies, and portions of the main body. The perforated tube assembly may include a plurality of perforated tubes with tube supports connected to opposite ends of the perforated tubes. Portions of each perforated tube located between the tube supports may be individually wrapped with insulating material and collectively wrapped with an additional layer of insulating material. Unwrapped portions of each perforated tube may extend into the inlet and outlet expansion chambers defined in the main body.

An engine-driven working machine capable of favorably reducing exhaust sound (that is, noise) is provided. An engine-driven working machine 10 is a generator in which an engine 15 and a muffler 67 are housed in an inside 13 of an outer case 12. The generator 10 includes a tail pipe 68 that is provided at a lower portion 67a of the muffler 67, a discharge port 37 that is disposed above the tail pipe 68, and a baffle plate 84 that is disposed to face the discharge port 37. The discharge port 37 is formed in the outer case 12. Further, cooling air that is sent from a cooling fan 17 is guided to below the muffler 67 with the baffle plate 84.

An engine-driven working machine capable of favorably reducing exhaust sound (that is, noise) is provided. An engine-driven working machine 10 is a generator in which an engine 15 and a muffler 67 are housed in an inside 13 of an outer case 12. The generator 10 includes a tail pipe 68 that is provided at a lower portion 67a of the muffler 67, a discharge port 37 that is disposed above the tail pipe 68, and a baffle plate 84 that is disposed to face the discharge port 37. The discharge port 37 is formed in the outer case 12. Further, cooling air that is sent from a cooling fan 17 is guided to below the muffler 67 with the baffle plate 84.