A muffler devised particularly for a small, reciprocating-piston two-stroke internal combustion engine of the type used on unmanned aerial vehicles. The muffler comprises a body incorporating an inlet, an outlet, and a plurality of chambers for exhaust gas flow from the inlet to the outlet. The body is configured to present a compact profile for installation on the engine. The chambers are so configured that adjacent chambers communicate to facilitate exhaust gas flow from the inlet to the outlet via flow passages. The various chambers comprise an inner chamber, an outer chamber, and one or more intervening chambers disposed between the inner and outer chambers. The various chambers are disposed one about another in annular formation. This arrangement creates a long flow path from the inlet to the outlet incorporating various directional changes.

A muffler for an exhaust system of an internal combustion engine includes a housing with a circumferential wall. At least one resonator chamber (48) is defined by the circumferential wall and two base walls (28, 22), that are provided in the housing. At least one resonator pipe (50), with a first pipe end (51) and with a second pipe end (56), is connected to one of the base walls (28) in the area of a first opening (52) in the one of the base walls (28). In the alternative or in addition the one of the base walls (28) traverses an interior space such that the first pipe end (51) lies outside of the resonator chamber (48), with the second pipe end (56) being fixed to the other base wall (22).

A noise suppressor is removably installed in power generator equipment including an enclosure and a power generator unit. The enclosure includes at least one of an air intake port and an air discharge port that are vents. The power generator unit is covered with the enclosure. The noise suppressor includes a tubular member having a first opening that opens to a direction different from the vent and a second opening that opens to the vent, forming a channel for gas leading from the first opening to the second opening, and provided with an acoustic liner inside the channel. The tubular member has such a shape that the channel bends at a plurality of points.

An exhaust device structure for a rocking vehicle includes: a front side exhaust device and a rear side exhaust device muffling exhaust gas noise from an engine; the front side exhaust device and the rear side exhaust device including a front side exhaust pipe and a rear side exhaust pipe having upstream ends connected to exhaust ports of the engine and a first muffler and a second muffler connected to downstream ends of the front side exhaust pipe and the rear side exhaust pipe, the first muffler and the second muffler being disposed on a lower side of the vehicle, the first muffler and the second muffler being arranged to be separated from each other in a forward-rearward direction of the vehicle, and the first muffler and the second muffler being arranged so as to be separated from each other in a left-right direction with respect to a vehicle center.

A silencer having an outer housing; and a central perforated tube through which air flows. The silencer further includes an additional perforated structure located between the central perforated tube and the outer housing, a first chamber is formed between the central perforated tube and the additional perforated structure, and the additional perforated structure is configured such that at least one second chamber is formed, which is at least partially located radially outside of the first chamber, where the second chamber is communicated with the first chamber by perforates. The disclosure further relates to a vehicle engine having the silencer. The silencer is compact in structure, and has a better broadband silencing effect.

An exhaust-gas system for a vehicle having an internal combustion engine includes a Helmholtz resonator and two exhaust-gas lines extending toward the resonator. The resonator has two neck openings to a resonator volume. Each neck opening is coupled to one of the exhaust-gas lines, and the resonator is tuned to damp a dominant engine order.

An exhaust device structure for a rocking vehicle includes: a front side exhaust device and a rear side exhaust device muffling exhaust gas noise from an engine; the front side exhaust device and the rear side exhaust device including a front side exhaust pipe and a rear side exhaust pipe having upstream ends connected to exhaust ports of the engine and a first muffler and a second muffler connected to downstream ends of the front side exhaust pipe and the rear side exhaust pipe, the first muffler and the second muffler being disposed on a lower side of the vehicle, the first muffler and the second muffler being arranged to be separated from each other in a forward-rearward direction of the vehicle, and the first muffler and the second muffler being arranged so as to be separated from each other in a left-right direction with respect to a vehicle center.

A silencer includes conduit with a downstream end portion configured from a tubular member which includes a conduit discharge port extending through a silencer main body and discharges exhaust gas to the outside therethrough. The tubular member includes a resonance communication hole communicating with a resonance chamber and an upstream side communication hole and a downstream side communication hole communicating with a second chamber. A barrier wall serving as a throttle portion for throttling an exhaust path at an intermediate location of the tubular member is provided in the inside of the tubular member and between the upstream side communication hole and the downstream side communication hole.

A muffler for an exhaust system of an internal combustion engine includes a housing with a circumferential wall. At least one resonator chamber (48) is defined by the circumferential wall and two base walls (28, 22), that are provided in the housing. At least one resonator pipe (50), with a first pipe end (51) and with a second pipe end (56), is connected to one of the base walls (28) in the area of a first opening (52) in the one of the base walls (28). In the alternative or in addition the one of the base walls (28) traverses an interior space such that the first pipe end (51) lies outside of the resonator chamber (48), with the second pipe end (56) being fixed to the other base wall (22).

A muffler for an exhaust system of an internal combustion engine, comprises a housing comprising a shell having an inner wall, an inlet pipe and an outlet pipe, the inlet pipe and the outlet pipe extending into an inner space of the housing, for conveying an exhaust gas stream into and out of the inner space of the housing, at least one baffle arranged in the inner space of the housing, the baffle comprising a baffle plate, the baffle plate having a circumference, and a baffle lip arranged at the circumference of the baffle plate, the baffle lip engaging the inner wall of the shell and having an end portion, wherein the end portion of the baffle lip is curved inwardly away from the inner wall of the shell.