A breather device for an outboard motor engine, the outboard motor engine including a breather chamber formed in an engine main body, and an intake passage guiding air into the engine main body, in which an intake port of the intake passage is open inside an engine cover that covers the engine main body, the breather device includes a resonator chamber communicating with an upstream side of the intake passage, and a breather passage extending from the breather chamber and communicating with the resonator chamber.

A resonator (1, 1′, 1″) for reducing airborne noise has at least one first ring-shaped chamber (2, 2′, 2″) arranged between an inlet piece (6, 6′) and an outlet piece (7, 7′). An inner tube (3) or inner tube pieces (4, 4″, 5) are arranged between the inlet piece (6, 6′) and outlet piece (7, 7′) and have wall apertures (18, 19, 28, 28″, 29, 29″, 30, 30″) as a connection to the adjacent ring-shaped chamber (2, 2′, 2″). The first ring-shaped chamber (2, 2′, 2″) is divided by at least one radially encircling dividing rib (13, 13′, 13″) into at least two sub-chambers (14, 14′, 14″, 15, 15′, 15″). The dividing rib (13, 13′, 13″) has a free end that, relative to the wall that is adjacent in a radial direction, forms an encircling annular space (16) for receiving an air layer that co-resonates in steady-state.

A high frequency attenuating device for an air flow induction system of a vehicle employing a thermoformed fibrous mat of any shape that fits robustly inside the duct. The dissipative nature of the fibrous mat helps in achieving broadband attenuation in the high frequency regime. The ability to manufacture the fibrous mat into any shape helps with restriction, targets different attenuation bands, and makes it more feasible to manufacture. Hybrid solutions are possible when combined with low frequency perforated silencers or high frequency QWT arrays injection molded onto them.

A method for producing a damper for an air line of an internal combustion engine includes the following steps: providing a temperature-controlled inner part having passages; producing a tubular preform of an outer jacket from a thermoplastic melt; and attaching the temperature-controlled inner part to a blowing mandrel of a blow mold, which is open. The blowing mandrel has outlet openings and the passages are positioned over the outlet openings. The method further includes bringing the temperature-controlled preform over the inner part and closing the blow mold such that the preform is blown against the walls of the blow mold, whereby an outer jacket is obtained. Simultaneously, local connections between the inner part and the outer jacket are obtained by pressing the preform and the inner part against each other in some regions. Finally, the blow mold is opened and the damper is removed.

An air duct of an internal combustion engine has an inner pipe providing a flow channel and a housing with a first housing part and a second housing part, wherein the inner pipe is arranged in the housing. The first housing part and the second housing part enclose a chamber between the inner pipe and the housing. The inner pipe has at least one section with perforations in a wall of the inner pipe, wherein the perforations completely penetrate the wall of the inner pipe. A cylindrical acoustic component at least partially encloses the at least one section of the inner pipe at an outer side of the inner pipe. A wall of the cylindrical acoustic component is provided, at least in sections thereof, with continuous openings. The flow channel is acoustically connected via the perforations and via the continuous openings to the chamber.

An attenuation device for attenuating sound waves, and a corresponding system and method, generated by a source emitting sound waves having frequencies between f1 and f2 and wherein the pressure levels are between n1 and n2. The attenuation device comprising at least one acoustic absorber comprising at least one non-linear membrane; the attenuation device being configured in such a way that the first face of the absorber is in acoustic communication with the source. The attenuation device also comprises at least one coupling element for coupling the second face with the source, the coupling element being configured to transmit to the second face sound waves according to the sound waves emitted by the source, and of which the phase and/or the amplitude leads to a pressure differential of the sound waves arriving respectively on the first and second face at the same time.

A resonator divides and forms a sound attenuation space and maintains airtightness without external force. The resonator includes a tubular cover body and having a hollow portion with different diameters, a tubular insert inserted into the cover body and having second hollow portion that turbocharger air is introduced into the second hollow portion, the air being guided into the first hollow portion on an outer surface of the insert body; and one or more space partition members coupled to the outer surface of the insert body to form airtight noise attenuation spaces. The partition members are ring shaped, and each space partition member is formed of a resilient material, and each space partition member has a contact portion formed by an inclined surface to be in contact with the inner surface of the cover body in a direction in which the insert body is inserted into the cover body.

An engine cover covers an engine; and an intake pipe through which the air is introduced into the engine. An intake silencer is provided adjacent to the intake pipe and suppresses air pressure fluctuations of air in the intake pipe to reduce intake sound. A portion of the intake silencer is covered with the engine cover, and a remaining portion is exposed with respect to the engine cover. An advantage is that secondary noise generated by the intake silencer and a temperature increase of air suctioned into the engine are simultaneously suppressed.

A supercharger assembly comprises a housing, a rotor bore with an outer wall, an outlet in an outlet plane, an inlet in an inlet plane perpendicular to the outlet plane, and an outlet divider wall. The supercharger assembly comprises a first recess, a first perforated material covering the first recess, and an outlet resonator. The first recess is separated from the outlet by the outlet divider wall. The first recess is located between the outer wall and the first perforated material.

A vehicle air filter housing having a broad band tuner. The housing is formed from a tray having a divider wall defining an unfiltered air induction chamber and a tuner chamber. A cover securable to the tray includes a second divider wall defining a filtered air chamber and a flow path chamber. A filter member provides a seal between the tray and the cover, and holds an air filter between the unfiltered air chamber and the filtered air chamber. A plate securable to the flow path chamber has a plurality of perforations. Air inducted through the inlet passes through the air filter and flows through the flow path chamber at a velocity whereby the filtered air passes over the perforated plate and predetermined frequencies pass through the plate perforations for attenuation in the tuner chamber. The tuners in the tuner chamber may be sized to attenuate different frequencies.