A sound generation assembly unit, for an exhaust system of an internal combustion engine, includes a sound generation module (16) with a sound generation module housing to be arranged at an exhaust gas guide element (12) of the exhaust system (14). At least one loudspeaker unit (20) is arranged in the sound generation module housing (18). A rear volume module (30) includes a rear volume module housing (32) and a rear volume (34) formed in the rear volume module housing (32). The rear volume module housing (32) is connected or can be connected to the sound generation module housing (18) for the acoustic coupling of the rear volume (34) to the at least one loudspeaker unit (20).

An internal combustion engine includes an exhaust conduit having an exhaust port fluidically coupled to ambient fluid and having an internal cross-sectional area and an engine cylinder fluidically coupled to the exhaust conduit. A fluidic amplifier is disposed within the exhaust conduit and is fluidically coupled to the engine cylinder. The amplifier is further fluidically coupled to a source of primary fluid and is configured to introduce the primary fluid and at least a portion of fluid from the engine cylinder to the exhaust port.

A self-cleaning duct assembly. The self-cleaning duct assembly includes a hollow member having an inner surface, the inner surface defining a central axis and a flow passage for directing a fluid flow along the central axis. The self-cleaning duct assembly also includes a resilient member including a plurality of arcuate segments disposed along the central axis, each of the arcuate segments spaced from the inner surface. The arcuate segments intermittently contact the inner surface as the resilient member is induced to move within the hollow member.

A timbre scaled internal combustion exhaust system includes: an inlet collector including a single entrance duct at a first end of the collector in fluid communication with an exhaust flow from an internal combustion engine and an exit duct at a second end of the collector; a plurality of non-perforated parallel tuning tubes in fluid communication with the plurality of exit ducts of the inlet collector, the plurality of tuning tubes having lengths and diameters selected based on a desired note of the timbre scaled exhaust system; an outlet collector including a plurality of entrance ducts in fluid communication with the at least first and second tuning tubes and a single exit duct in fluid communication with an outlet of the exhaust system. The inlet collector splits the exhaust flow through the plurality of tuning tubes to create individual notes, and wherein the outlet collector combines the split exhaust flow to create a desired sound of internal combustion engine exhaust.

An exhaust muffler includes a first muffler section connected to an exhaust pipe and a second muffler section connected to the first muffler section. Exhaust gases delivered from the exhaust pipe are discharged from the first muffler section and the second muffler section out of the exhaust muffler. The first muffler section includes a tubular member made up of an inner pipe to which the exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and the second muffler section to each other. The first muffler section has a first expansion chamber defined therein between the inner pipe and the outer pipe. The inner pipe houses therein a valve for changing an amount of exhaust gases passing through the inner pipe. The first muffler section includes a curved portion that is curved vertically as viewed in side elevation of the vehicle. The exhaust muffler has a second expansion chamber defined in the second muffler section rearward and upward of the first muffler section, the second expansion chamber having a cross-sectional area larger than a cross-sectional area of the first expansion chamber. There is thus provided an exhaust device for an internal combustion engine, which includes a muffler compact in a longitudinal direction thereof.

To facilitate the vaporization of additives added upstream of a selective catalytic reduction device and to suppress their precipitation.

A mixing device includes: a case surrounding a blowing section, through which an exhaust gas is blown out, of a filter or a catalyst; an upper pipe segment having an opening formed therein, the opening facing a direction facing the blowing section, the upper pipe segment being tilted relative to the vertical direction so that the more the upper pipe segment goes vertically downward, the closer it gets to the blowing section in a region facing the blowing section within the case; a lower pipe segment bent from a lower end of the upper pipe segment, the lower pipe segment being tilted relative to the vertical direction so that the more the lower pipe segment goes vertically downward, the further away it gets from the blowing section, the lower pipe segment extending out from the case and being connected to a selective catalytic reduction device; and an injector attached to the case, the injector injecting a liquid additive toward an area faced by the opening, the area being located outside the upper pipe segment in the case.

Provided is a tail pipe in which a silencing effect at a discharge port is obtained. One aspect of the present disclosure is a tail pipe including: an inner tube including a discharge port configured such that an exhaust gas is discharged therefrom; an outer tube arranged so as to form a space between the outer tube and the inner tube by surrounding an outer peripheral surface of the inner tube, an upstream end of the outer tube in a flow direction of the exhaust gas being closed; and at least one communication hole allowing communication between an interior of the inner tube and the space.

The present disclosure provides a method for molding a pipe body that can inexpensively mold a pipe body having a tapered portion radially outwardly projecting relative to a large-diameter portion. The method for molding a pipe body comprises: molding of a tubular body by bending an unfolded stock so as to wrap a core metal; and removal of the core metal from inside the tubular body. The core metal comprises a first core metal piece for molding a projecting portion of the tapered portion. During the molding of the tubular body, the first core metal piece at least partly abuts on an inner surface of the projecting portion of the tapered portion, and does not abut on an area of the inner surface of the large-diameter portion located in an opposite side of a central axis of the large-diameter portion from the projecting portion.

The present invention relates to a manifold for receiving exhausts from a multi-cylindrical internal combustion engine. The internal combustion engine has such a firing order that the riser in the manifold receives exhausts from two cylinders during an overlapping stage, simultaneously via an inlet opening arranged upstream and from an inlet opening arranged downstream in the riser. The riser comprises a substantially constant cross sectional area, except in one area, which is located in a position in connection with the inlet opening arranged downstream of the two inlet openings, receiving exhausts simultaneously. Said area has a geometry facilitating receipt and flow of exhausts in the predetermined direction in the riser, on occasions when the two inlet openings receive exhausts simultaneously.

A mix box for an exhaust system of an internal combustion engine, the mix box being used to incorporate additives into an exhaust gas flow and including at least one inlet tube, at least one outlet tube and a housing for accommodating the inlet tube and the outlet tube, wherein: the housing delimits a volume of the mix box in relation to the surroundings; the inlet tube has an inflow section located inside the housing, which inflow section is provided with at least one inflow opening for introducing the exhaust gas into the housing; the outlet tube has a metering device designed as an injection nozzle at the end of the outlet tube and has an outflow section located inside the housing, which outflow section has a length (La) and is provided with at least one outflow opening for discharging the exhaust gas from the housing; a flow zone is provided between the inlet tube and the outlet tube and the flow zone, over at least 30% of its length (La), is free of flow guiding elements which deflect the flow in a circumferential direction and which have an outer face and an inner face inside the volume.