A muffler, for an internal combustion engine exhaust system, includes a muffler housing (12) with a housing jacket (14) elongated in a housing longitudinal axis (A) direction and with an outer panel (16) connected to the housing jacket at both axial end areas thereof to define a muffler interior (18). An inner panel (20) is arranged in and divides the muffler interior. A muffling unit (24) includes an exhaust-gas-carrying inner pipe (26), an outer pipe (28) enclosing the inner pipe and muffling material (32) arranged between the inner pipe and the outer pipe. The inner pipe is accommodated in an opening (48) of an inner panel and in an opening (40) of one of the outer panels or of an additional inner panel. The outer pipe is permanently connected to the inner panel or/and to one of the outer panels or to the additional inner panel.

A sound isolation window includes a frame and a plurality of sound blocking bars. The frame has an upper frame portion and a lower frame portion. The frame further has a first sidewall and a second sidewall connected to the upper and lower frame portion. The upper frame portion, the lower frame portion, the first sidewall and the second sidewall form a first opening and an opposite second opening. Each sound blocking bar includes a plane perpendicular to the upper frame portion and the lower frame. The sound blocking bars are arranged along the first direction from the first opening to the second opening and spaced apart from each other. Projections along the first direction of the sound blocking bars over the first opening cover the first opening. The width of each sound blocking bar is less than one-half of the width of the first opening.

A sound isolation window includes a frame and a plurality of sound blocking bars. The frame has an upper frame portion and a lower frame portion. The frame further has a first sidewall and a second sidewall connected to the upper and lower frame portion. The upper frame portion, the lower frame portion, the first sidewall and the second sidewall form a first opening and an opposite second opening. Each sound blocking bar includes a plane perpendicular to the upper frame portion and the lower frame. The sound blocking bars are arranged along the first direction from the first opening to the second opening and spaced apart from each other. Projections along the first direction of the sound blocking bars over the first opening cover the first opening. The width of each sound blocking bar is less than one-half of the width of the first opening.

A reduction device includes a housing defining an input chamber configured to receive exhaust from a power source, an output chamber, an exhaust channel configured to direct the exhaust from the input chamber to the output chamber, and a longitudinal axis. The reduction device also includes a treatment unit disposed in the exhaust channel and along the longitudinal axis. The treatment unit is configured to at least partly remove pollutant species from the exhaust. The reduction device also includes an attenuation component disposed in the housing and radially outward of the treatment unit. The attenuation component is fluidly connected to the exhaust channel, and is configured to attenuate a range of frequencies corresponding to operation of the power source. Additionally, the exhaust channel prohibits exhaust entering the input chamber from exiting the housing without passing through the treatment unit.

A reduction device includes a housing defining an input chamber configured to receive exhaust from a power source, an output chamber, an exhaust channel configured to direct the exhaust from the input chamber to the output chamber, and a longitudinal axis. The reduction device also includes a treatment unit disposed in the exhaust channel and along the longitudinal axis. The treatment unit is configured to at least partly remove pollutant species from the exhaust. The reduction device also includes an attenuation component disposed in the housing and radially outward of the treatment unit. The attenuation component is fluidly connected to the exhaust channel, and is configured to attenuate a range of frequencies corresponding to operation of the power source. Additionally, the exhaust channel prohibits exhaust entering the input chamber from exiting the housing without passing through the treatment unit.

There is provided a method for filling a silencer with glass fiber, for filling an internal space between a case and an inner pipe with glass fiber in a silencer in which a porous inner pipe penetrates through a pair of through holes in the case, the method including shifting the inner pipe in a penetrating direction from a normal position where the inner pipe is secured to the case, inserting a nozzle auxiliary portion into an interior of the case from a through hole opened by the inner pipe being shifted, supplying glass fiber into the interior of the case from a nozzle of a glass fiber supply machine connected to the nozzle auxiliary portion, and filling the internal space between the case and the inner pipe with glass fiber.

There is provided a method for filling a silencer with glass fiber, for filling an internal space between a case and an inner pipe with glass fiber in a silencer in which a porous inner pipe penetrates through a pair of through holes in the case, the method including shifting the inner pipe in a penetrating direction from a normal position where the inner pipe is secured to the case, inserting a nozzle auxiliary portion into an interior of the case from a through hole opened by the inner pipe being shifted, supplying glass fiber into the interior of the case from a nozzle of a glass fiber supply machine connected to the nozzle auxiliary portion, and filling the internal space between the case and the inner pipe with glass fiber.

A muffler structure contains: a body, a first cover unit, and a second cover unit. The body includes an accommodation tube, fiber cotton, and a first mesh portion. The accommodation tube has an accommodating space and an internal fence. The first cover unit includes a manifold connection portion, a first polygonal cap, a hollowly tubular mesh having multiple orifices, a second mesh portion, and a stainless steel mesh. The second cover unit is fixed on a rear end of the accommodation tube of the body opposite to the first cover unit, and the second cover unit includes a second polygonal cap and a silencer. The second polygonal cap is covered on the accommodation tube of the body, and the second polygonal cap has a receiving portion defined in a free end thereof and configured to accommodate the silencer.

A muffler structure contains: a body, a first cover unit, and a second cover unit. The body includes an accommodation tube, fiber cotton, and a first mesh portion. The accommodation tube has an accommodating space and an internal fence. The first cover unit includes a manifold connection portion, a first polygonal cap, a hollowly tubular mesh having multiple orifices, a second mesh portion, and a stainless steel mesh. The second cover unit is fixed on a rear end of the accommodation tube of the body opposite to the first cover unit, and the second cover unit includes a second polygonal cap and a silencer. The second polygonal cap is covered on the accommodation tube of the body, and the second polygonal cap has a receiving portion defined in a free end thereof and configured to accommodate the silencer.

A silencing apparatus is provided with a shell, ventilation pipes communicating with the inside of the shell, insertion holes which are respectively formed in the shell so as to have sizes smaller than surrounding skirt parts and allow the ventilation pipes to be loosely inserted in, and partitions partitioning the inside of the shell. In the silencing apparatus, at least, a sound-absorbing chamber partitioned by the partition and positioned adjacent to the insertion hole is filled with a sound-absorbing fiber material, and a sound-absorbing fiber material filling gap between the insertion hole and the ventilation pipe is closed by an annular closing member. To provide a silencing apparatus allowing a sound-absorbing chamber to be filled with sound-absorbing fiber material without a gap, even in a complicated configuration having the inside of a shell partitioned by a partition.