A vacuum clear and an electric motor module (100) therefor are provided. The electric motor module (100) includes an outer casing (1) provided with an air inlet (10) at a front side thereof and an air outlet (11) at a rear side thereof; an electric motor assembly (2) arranged in the outer casing (1), and cooperating with the outer casing (1) to define an air passage in communication with the air inlet (10) and the air outlet (11); and a silencer (3) arranged at the air inlet (10), defining at least one resonant cavity therein, and the at least one resonant cavity having a side wall provided with a throat in communication with the resonant cavity.

Provided is a flow modification component for use with a muffler, which can be a Helmholtz resonator muffler, a side branch muffler, or a Y-pipe. The flow modification component includes a porous plate adapted for incorporation into a passage to a sound muffling portion connected to a through passage pipe of the muffler or Y-pipe. One or more openings are formed on the porous plate to allow low frequency acoustic waves to pass through into the passage to the sound muffling portion while reducing large-scale turbulent eddies that produce undesirable resonant tones within the aperture tube to small-scale turbulent eddies. The openings having sufficient porosity such that the resulting sound frequency is determined by size, shape, number, and spacing of the openings. The flow modification component can also include a dissipative material component in an internal port passage of the muffler to further reduce resonant tones.

Provided is a flow modification component for use with a muffler, which can be a Helmholtz resonator muffler, a side branch muffler, or a Y-pipe. The flow modification component includes a porous plate adapted for incorporation into a passage to a sound muffling portion connected to a through passage pipe of the muffler or Y-pipe. One or more openings are formed on the porous plate to allow low frequency acoustic waves to pass through into the passage to the sound muffling portion while reducing large-scale turbulent eddies that produce undesirable resonant tones within the aperture tube to small-scale turbulent eddies. The openings having sufficient porosity such that the resulting sound frequency is determined by size, shape, number, and spacing of the openings. The flow modification component can also include a dissipative material component in an internal port passage of the muffler to further reduce resonant tones.

The present invention aims to provide a sound-absorbing material having sound absorption performance with an average sound absorption coefficient of 0.65 or more in the frequency domain of 800 to 2000 Hz. The present invention relates to a sound-absorbing material including: a fiber layer including a plurality of holes open to a surface thereof and having a thickness of 3 mm or more; and an inorganic material layer formed on the surface of the fiber layer, the holes being blind holes each penetrating through the inorganic material layer and having a bottom inside the fiber layer.

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 valve assembly for an exhaust system includes a conduit, a valve flap disposed within an exhaust passageway for controlling exhaust flow through the exhaust passageway, a shaft supporting the valve flap in the exhaust passageway for rotation about a pivot axis, and a mass damper disposed external to the conduit and coupled to the shaft. The mass damper includes a longitudinal segment coupled to the shaft. The mass damper also includes a first damping mass that is disposed proximal to a first end of the longitudinal segment and is linearly movable along a centerline axis to a first distance with respect to the pivot axis. The mass damper further includes a second damping mass that is disposed proximal to a second end of the longitudinal segment and is linearly movable along the centerline axis to a second distance with respect to the pivot axis.

A valve assembly for an exhaust system includes a conduit, a valve flap disposed within an exhaust passageway for controlling exhaust flow through the exhaust passageway, a shaft supporting the valve flap in the exhaust passageway for rotation about a pivot axis, and a mass damper disposed external to the conduit and coupled to the shaft. The mass damper includes a longitudinal segment coupled to the shaft. The mass damper also includes a first damping mass that is disposed proximal to a first end of the longitudinal segment and is linearly movable along a centerline axis to a first distance with respect to the pivot axis. The mass damper further includes a second damping mass that is disposed proximal to a second end of the longitudinal segment and is linearly movable along the centerline axis to a second distance with respect to the pivot axis.

A muffler generates a sporty and rhythmic sound for a vehicle. The muffler includes a housing, first and second baffles, an inlet pipe, and left and right exhaust pipes. The first and second baffles the housing interior into left, intermediate, and right chambers. The left and right chambers include a sound absorber and the inlet pipe extends from a front of the housing into the intermediate chamber. A first end of the left exhaust pipe is in the intermediate chamber, a second end of the left exhaust pipe penetrates the left chamber and extends out of the housing, and a plurality of first through-holes is in a portion of the left exhaust pipe in the left chamber. A first end of the right exhaust pipe is in the intermediate chamber, a second end of the right exhaust pipe penetrates the right chamber and extends out of the housing, and a plurality of second through-holes is in a portion of the right exhaust pipe in the right chamber. Exhaust gas introduced through the inlet pipe is discharged from the housing through the left and right exhaust pipes.

A muffler generates a sporty and rhythmic sound for a vehicle. The muffler includes a housing, first and second baffles, an inlet pipe, and left and right exhaust pipes. The first and second baffles the housing interior into left, intermediate, and right chambers. The left and right chambers include a sound absorber and the inlet pipe extends from a front of the housing into the intermediate chamber. A first end of the left exhaust pipe is in the intermediate chamber, a second end of the left exhaust pipe penetrates the left chamber and extends out of the housing, and a plurality of first through-holes is in a portion of the left exhaust pipe in the left chamber. A first end of the right exhaust pipe is in the intermediate chamber, a second end of the right exhaust pipe penetrates the right chamber and extends out of the housing, and a plurality of second through-holes is in a portion of the right exhaust pipe in the right chamber. Exhaust gas introduced through the inlet pipe is discharged from the housing through the left and right exhaust pipes.

An engine assembly for a vehicle includes an internal combustion engine and an exhaust system. The exhaust system includes a catalytic converter, a main muffler, a hydrocarbon trap, a pre-muffler disposed upstream from the main muffler and the hydrocarbon trap, and an exhaust path valve. The exhaust path valve is movable between first and second exhaust path positions. The exhaust path valve obstructs a second exhaust path in the first exhaust path position such that exhaust gas flows from an exhaust port of an engine cylinder to the catalytic converter to the main muffler and to the atmosphere. The exhaust path valve obstructs a first exhaust path in the second exhaust path position such that exhaust gas flows from the exhaust port of the engine cylinder to the catalytic converter to the hydrocarbon trap and to the atmosphere.