An apparatus for engine exhaust sound attenuation includes a housing, a plurality of baffle plates arranged within the housing. The baffle plates are disposed apart from each other to define a plurality of intermediate chambers. The plurality of intermediate chambers includes a first resonant chamber proximate to the outlet chamber, a second resonant chamber proximate to the inlet chamber, a first intermediate chamber proximate to the second resonant chamber, and a second intermediate chamber proximate to the first intermediate chamber and the first resonant chamber. An inlet tube and an outlet tube are included. A first tube directs a flow of exhaust from the inlet chamber to one of the plurality of intermediate chambers via an interior of the first tube. Additionally, a second tube directs the flow of exhaust from a second one of the plurality of intermediate chambers to the outlet chamber via an interior of the second tube.

An exhaust muffler has an outer cylinder into which an exhaust gas from an engine is introduced and a muffling member made of a foamed ceramic material. The outer cylinder has an inner cylinder through which the exhaust gas passes, a part of the muffling member is supported by an outer wall of the inner cylinder via a holding member. The inner cylinder includes, in an area where the inner cylinder overlaps with the muffling member with respect to axial direction of the inner cylinder, a porous wall portion formed with communication holes communicating an inside and an outside of the inner cylinder. The holding member is arranged at a position where it does not overlap with a part of the porous wall portion, so that muffling effect is enhanced, and the muffling member having a low resistance to impact forces can be supported stably by the inner cylinder.

A muffler for an engine includes a muffler body, at least one partition wall, and at least one reinforcing plate. The muffler body has an inner space formed by a shell. The partition wall includes a flange portion which is in tight contact with an inner surface of the shell, and the partition wall divides the inner space of the muffler body into a plurality of chambers. The reinforcing plate is welded on an outer surface of the shell at a position facing the flange portion of the partition wall.

A high-frequency resonator forming a flow passage for an air induction system, includes an outer shell having a cylindrical inner surface at a first radial distance from a centerline, and an inner shell positioned within the outer shell and forming a volume therebetween. The inner shell includes a first cylindrical outer surface positioned at a second radial distance from the centerline, the first cylindrical outer surface forming an inner surface of the volume and having a first plurality of resonator openings, and a cylindrical support structure having a second cylindrical outer surface positioned at a third radial distance from the axial centerline, and having hydrocarbon adsorber openings. The resonator includes a hydrocarbon adsorber positioned over the cylindrical support structure, such that an inner surface of the hydrocarbon adsorber is exposed to the flow passage through the hydrocarbon adsorber openings. The third radial distance is less than the first radial distance.

A high-frequency resonator forming a flow passage for an air induction system, includes an outer shell having a cylindrical inner surface at a first radial distance from a centerline, and an inner shell positioned within the outer shell and forming a volume therebetween. The inner shell includes a first cylindrical outer surface positioned at a second radial distance from the centerline, the first cylindrical outer surface forming an inner surface of the volume and having a first plurality of resonator openings, and a cylindrical support structure having a second cylindrical outer surface positioned at a third radial distance from the axial centerline, and having hydrocarbon adsorber openings. The resonator includes a hydrocarbon adsorber positioned over the cylindrical support structure, such that an inner surface of the hydrocarbon adsorber is exposed to the flow passage through the hydrocarbon adsorber openings. The third radial distance is less than the first radial distance.

A muffler for a vehicle includes: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve includes: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve arm connected to the valve plate; and a valve actuator to move the valve arm by variations in pressure of the exhaust gas. The valve plate is capable of rotating in a plane parallel to a plane of the baffle.

An exhaust system includes a housing comprising a first housing portion and a second housing portion separated by a common wall. The first housing portion has a first exhaust passage therethrough. The first exhaust passage has a first inlet receiving exhaust gasses from a turbocharger. The second housing portion has a second exhaust passage therethrough. The second exhaust passage has a second inlet receiving gasses from an exhaust bypass valve. The first passage and the second passage are non-intersecting within the housing.

A muffler for receiving exhaust gas from a combustion engine is disclosed. The muffler includes a casing and a pipe. The casing includes a shell coupled to first and second end caps that cooperate to define an internal volume. The pipe is disposed within the internal volume and extends substantially a length of the shell. Each of the first and second end caps includes a circumferentially extending flange engaging an outer surface of the pipe to provide support for the pipe. Each circumferentially extending flange extends at an acute angle relative to a shell axis of the shell. Each circumferentially extending flange is coaxial along a pipe axis of the pipe.

A vehicle muffler may include first to third baffles to partition the internal to a housing into first to fourth chambers; a suction tube penetrating the housing, the first to third baffles in series, having an inlet at outside of the housing and an outlet in the fourth chamber, and having through-holes in the section locating in the first to third chambers; a first discharge tube penetrating the first and second baffles and the housing in series, having an inlet on the first baffle, and an outlet at outside of the housing; a second discharge tube penetrating the second and third baffles, and the housing in series, having an inlet in the second chamber, and an outlet at the outside of the housing; and a connection tube penetrating the second and third baffles in series, having an inlet in the second chamber, and an outlet in the fourth chamber.

Apparatuses and methods for tuning a muffler. An apparatus comprises a housing for a muffler, a first inlet pipe, and a second inlet pipe. The housing includes a coupling chamber. The first inlet pipe has a first set of physical features and carries exhaust to the coupling chamber. The second inlet pipe has a second set of physical features and carries the exhaust to the coupling chamber. The first set of physical features varies from the second set of physical features with respect to at least one physical feature such that a first sound waveform passing through the first inlet pipe and a second sound waveform passing through the second inlet pipe are uniquely tuned to thereby tune an overall sound waveform emitted by the muffler.