Abstract: A device for reducing airborne and structure-borne sound has a flow channel with a flow channel wall (22, 22?, 22?) and at least one resonator chamber (40, 40?, 40?) adjacent the flow channel wall (22, 22?, 22?). The flow channel wall is formed by a sound absorber (30, 30?, 30?) at least in a part bordering the resonator chamber (40, 40?, 40?). The sound absorber (30, 30?, 30?) is covered towards the resonator chamber (40, 40?, 40?) by an acoustically reflecting inner wall (42, 42?, 42?) of the resonator chamber with at least one wall aperture (44, 44?, 44?). Openings (32, 32?, 32?) completely covers the wall aperture (44, 44?, 44?) of the inner wall (42, 42?, 42?) of the resonator chamber such that sound waves flowing through the flow channel must pass the sound absorber (30, 30?, 30?) to enter the resonator chamber (40, 40?, 40?).

Abstract: A control flap (1) has a flap body (2) and a circumferential seal (3) capable of sealing upon abutting to a sealing surface (7) of an opening (8). The flap body (2) and the seal (3) are made of elastomers. The seal (3) is joined to the flap body (2) by a pressure plate (4) made of a thermoplastic. The control flap may be made by a method that includes: producing the flap body (2) from a thermoplastic by injection molding; producing the pressure plate (4) from a thermoplastic by injection molding; producing the seal (3) from an elastomer by injection molding; introducing the pressure plate (4) into the undercut (10) of the seal (3); inserting the pressure plate (4) with the seal (3) into the recess (16) of the flap body (2) and bonding the pressure plate (4) and flap body (2).

Abstract: A sound attenuator has an inner pipe (12) with expansion sections (121) of enlarged diameter corresponding to the constriction sections (141) of an outer pipe (14). The expansion sections (121) in pairs axially delimit an intermediate inner pipe section (122) containing a wall opening (18) and having a reduced diameter relative to the expansion sections (121). The inner surface of the outer pipe (14) in each of its constriction sections (141) is connected to the outer surface of the inner pipe (12) in its respective corresponding expansion section (121). A method of manufacturing such a sound attenuator (10) also is provided and uses internal high-pressure forming.

Abstract: A device (1) for lowering flow noises has opposed first and second connection pieces (2, 3), and outer and inner sleeves (4, 5) between the connection pieces. A radial collar (6) is between the sleeves (4, 5) and forms separated volume chambers. Openings (11) in the inner sleeve (5) connect the volume chambers to a line space (13) enclosed by the inner sleeve (5). A sealing ring (15) at the free end (14) of the collar (6) defines a ring cap with a lateral surface (21) that reaches over the collar (6) and seals against the sleeve (4, 5) adjacent the free end (14) of the collar (6) and that has a surface (23, 26) that seals against either an end face (25) of the collar (6) or a side surface (28) of the collar (6) extending parallel to the radial collar (6).

Abstract: 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.

Abstract: A resonator (1) has at least first and second annular chambers (2, 3, 17) arranged between inlet and outlet pieces (22, 21). An inner pipe (4) extends between the inlet piece (22) and the outlet piece (21) and has wall holes (23) that connect to the annular chambers (2, 3, 17). The first annular chamber (2) has a U-shaped circumferential wall (6) coaxial to the resonator longitudinal axis (5) and transitions at both ends to engage the inner pipe (4). The second annular chamber (3) has an L-shaped circumferential wall (12) coaxial to the resonator longitudinal axis (5). An end of the L-shaped circumferential wall remote from the first annular chamber (2) transitions into a cylindrical end piece (13), and an opposite end of the L-shaped circumferential wall lies on part of the outer wall (9) of the first annular chamber (2) extending parallel to the resonator longitudinal axis (5).

Abstract: 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.

Abstract: 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.