Abstract: A pneumatic system includes a passage to discharge compressed air and a sound attenuator including a first chamber in fluid communication with the passage and defined by a first wall through which the passage opens into the first chamber, a first surface of a second wall spaced from and opposite the first wall, and a sidewall extending between the first and second walls. The first chamber has a volume and includes a first opening in the sidewall. A second chamber is in fluid communication with the first opening and partially surrounds the first chamber. The second chamber is partially defined by a second surface of the second wall opposite the first surface and by the sidewall, and the second chamber has a volume and includes a second opening to exhaust air from the second chamber. The volume of the first chamber is less than that of the second chamber.

Abstract: A valve assembly for a vehicle exhaust system includes at least one pipe enclosing an exhaust gas flow path, the pipe defining a central axis, and at least one flexible flap positioned within the exhaust gas flowpath. The at least one flexible flap has one fixed edge held fixed to the pipe and extends to a distal edge that is free to bend in response to an increase in exhaust gas flow pressure to provide a variable restriction to flow through the pipe that varies in response to a pressure difference upstream and downstream of the at least one flexible flap.

Abstract: An aftertreatment module is disclosed. The aftertreatment module may include a housing and a mounting plate within the housing that forms an inlet chamber and an outlet chamber. The aftertreatment module may include an inlet for exhaust gas from a combustion engine to flow into the inlet chamber and an outlet through a top plate of the housing for the exhaust gas to flow from the outlet chamber, wherein the outlet comprises a plurality of perforations. The aftertreatment module may include an outlet sensor mounted on the outlet to obtain information relating to the exhaust gas as the exhaust gas flows from the outlet chamber and a set of catalysts mounted to the mounting plate to treat the exhaust gas as the exhaust gas flows from the inlet chamber to the outlet chamber. The aftertreatment module may include a drain port through a side plate of the housing.

Abstract: A muffler (4) for motor vehicles comprising an intake pipe (8) of the exhaust gases that separates, at a fork (10), into a main pipe (12) and a secondary pipe (16), a muffler body (24) which delimits an expansion volume (28) and houses at least partly the main pipe (12) and the secondary pipe (16), wherein the intake pipe (8) of the exhaust gas is in fluid continuous connection with the main pipe (12) through the secondary pipe (16), and wherein the main pipe (12) comprises, downstream of the fork (10), a throttle valve (32) which allows or prevents a further fluidic connection of the intake pipe (8) of exhaust gas with the main pipe (12), and an output of the exhaust gases (40), for the expulsion of the gases from the muffler pipe (4).

Abstract: An electric valve may include a valve housing, a valve plate disposed in the exhaust gas passage of the valve housing by a rotation shaft, a heat shield being connected to the valve housing by a bracket and forming a penetration opening to be penetrated by an upper end portion of the rotation shaft, an actuator assembled on the heat shield to decelerate torque of a drive actuator and then to output the decelerated torque, a power delivering member transferring torque of the drive actuator, wherein damping is performed by a power delivering spring disposed between a spring seat mounted the rotation shaft and the worm wheel of the actuator, to the rotation shaft, and a rotation limiting member mounted between the penetration opening of the heat shield and the spring seat corresponding with the penetration opening to limit a rotation angle of the rotation shaft.

Abstract: An exhaust muffler device for an combustion engine includes: a first expansion chamber into which exhaust gas from a combustion engine flows; a second expansion chamber disposed downstream of the first expansion chamber; a resonance chamber that is disposed adjacent to the first expansion chamber and communicates with an exhaust passage; a discharge passage through which the exhaust gas that flows into the resonance chamber is discharged to the outside; and an exhaust valve disposed in a second partition wall between the first expansion chamber and the resonance chamber. The exhaust valve opens when pressure in the first expansion chamber attains a value greater than a predetermined value.

Abstract: A very compact Selective Catalytic Reduction (SCR) system with a very low footprint comprising an SCR reactor, an inlet flow system, and a vaporizer module is described. The SCR reactor comprises at least one SCR catalyst which is in communication with the inlet flow system and the vaporizer module. The inlet flow system is configured to provide an approximately uniform flow of the exhaust gas through the catalyst and to provide heat to the vaporizer module. The vaporizer module is configured to allow for the conversion of urea to ammonia and to contact the ammonia with the exhaust gases in the SCR reactor upstream of the SCR catalyst.

Abstract: To present an injection head having silencing function for gas type fire extinguisher capable of reducing the noise generated upon release of fire extinguishing gas. In a gas type fire extinguisher using a fire extinguishing gas, a silencer 3A is disposed in an injection head 1A installed for releasing a fire extinguishing gas into a fire extinguishing area.

Abstract: An exhaust gas treatment device (1) includes a combustion waste gas inlet pipe (2), an outlet pipe, an essentially gas-tight inner housing (7) fluidically connected with the inlet pipe and fluidically connected with the outlet pipe. The inner housing receives a particle filter (4). A connection element (9) is arranged in a connection area (8) of the inner housing. The connection area fluidically faces the outlet pipe (3), for mechanically connecting the particle filter with the inner housing. An oxidation catalytic converter (5) is arranged upstream of the particle filter in the inner housing for catalyzing an oxidation reaction of the combustion waste gas. A counterpressure monitoring point (10, 11, 12) is provided fluidically between the oxidation catalytic converter and the connection element for measuring a counterpressure exerted by the particle filter during the operation of the treatment device. An internal combustion engine (24) is provided with the treatment device.

Abstract: A motorcycle includes a second silencer separate from a first silencer. A first exhaust pipe connects an exhaust port and the first silencer. A connecting pipe portion connects the first silencer and the second silencer. A first expansion chamber of the first silencer is located downstream from the first exhaust pipe in the exhaust flow. A second expansion chamber of the first silencer is partitioned from the first expansion chamber. The second expansion chamber is located downstream from the first expansion chamber. The connecting pipe portion includes a second exhaust pipe, an exhaust control valve, and a third exhaust pipe. The second exhaust pipe is connected to the first expansion chamber. The exhaust control valve is disposed in the second exhaust pipe. The exhaust control valve controls the flow passage area of the second exhaust pipe. The third exhaust pipe is connected to the second expansion chamber.

Abstract: A device for manipulating the exhaust outlet noise of a motor vehicle, having an exhaust flap which can be positioned in an exhaust pipe and which can be displaced in oscillatory fashion about an exhaust flap basic position in a defined angle range about the exhaust flap basic position in order to manipulate the exhaust outlet noise, wherein the exhaust flap basic position can be actively adjusted as a function of an engine rotational speed and/or an engine load, and wherein the angle range can be actively adjusted as a function of a frequency to be eliminated or attenuated, or a frequency to be generated or enhanced, of the exhaust outlet noise.

Abstract: A vehicle exhaust system includes at least one exhaust component that defines an exhaust passage from an engine to an exhaust outlet. An active noise attenuation component is associated with the exhaust component. A valve is positioned within the exhaust component downstream of the engine and upstream of the active noise attenuation component. The valve and active noise attenuation component cooperate with each other to control noise generated by the exhaust system.

Abstract: A housing with a first end wall and second end wall with a first baffle and second baffle spaced apart and positioned between end walls with a cover attached to form a first chamber, an intermediate chamber and a third chamber. An intake tube is inserted through the first end wall, first baffle and second baffle to terminate at an exit end in the third chamber. An exhaust tube is inserted through the second end wall, second baffle and first baffle to terminate at an intake end in the first chamber. The intake tube and exhaust tube each have openings in an intermediate tube wall. The exhaust tube has openings in a second tube wall portion. There is an intermediate port in the first baffle. A threaded shaft of a valve is threadably engaged in a fitting attached in the second end wall to be positioned opposed the exit end.

Abstract: An exhaust system for an internal combustion engine having a first exhaust tract assigned to a first group of cylinders of the internal combustion engine, and a second exhaust tract assigned to a second group of cylinders of the internal combustion engine, the first exhaust tract and the second exhaust tract being coupled to one another by a connecting line. A common bypass line branches off from the connecting line coupling the exhaust tracts.

Abstract: An exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit includes a valve plate rotatable between open and closed positions. An axle is adapted to pivotally couple the valve plate to the exhaust conduit about a longitudinal axis of the axle. The axle axis is adapted to extend in a direction substantially perpendicular to a direction of exhaust flow through the conduit. A cantilevered spring pad has a first portion coupled to the valve plate and a second portion spaced apart from the valve plate. The second portion is oriented to contact an inner surface of the conduit as the valve plate moves toward the closed position to dampen vibration.

Abstract: A muffler for a vehicle may include a main muffler in front of a rear suspension when viewing from a front of the vehicle, a plurality of baffles dividing an interior of the main muffler into a plurality of chambers, an inlet pipe installed substantially at an center of one side of the main muffler and passing through the plurality of the baffles, a discharge pipe installed at a lower side of the other side of the main muffler and passing through the plurality of the baffles, wherein the discharge pipe exhausts an exhaust gas flowed in the inlet pipe to an exterior of the main muffler, an intermediate pipe in fluidic communication with an outlet port of the inlet pipe, and a variable valve selectively opened or closed in response to a back pressure of the exhaust gas from an outlet port of the intermediate pipe.

Abstract: A silencer for a two-stroke motor of a power tool, including a silencer inlet to which adjoins a flow channel of channel length so that the flow channel can be connected to an outlet of a combustion chamber of the two-stroke motor, whereby the flow channel at the channel end opposite the silencer inlet opens out into a first chamber of depth, between the silencer inlet and the first chamber the flow channel is so flow-beneficially designed, that due to its mass inertia the exhaust gas flowing into the silencer inlet predominantly flows into the first chamber and after filling the first chamber flows back again thereby creating a counterpressure in the direction of the combustion chamber, so that in spite of small geometric dimensions it provides a periodically actin counterpressure on the outlet of the combustion chamber of the two-stroke motor.

Abstract: A muffler for an internal combustion engine exhaust system includes a housing having an inlet and outlet headers enclosing opposite ends of an outer shell. A partition divides a housing interior into first and second chambers, the first chamber having sound absorbing material positioned therein. The partition has an aperture allowing fluid communication between the first and second chambers. A through pipe extends through the inlet and outlet headers and the partition and has a plurality of perforations enabling fluid communication between the through pipe and the first chamber. A valve assembly has a valve flap positioned inside the through pipe for rotation with an axle pivotally coupled to the pipe between a closed position and an open position. The valve is positioned downstream of the pipe perforations such that all of an exhaust gas flowing through the muffler passes through the valve regardless of the valve flap position.

Abstract: A plastic muffler is configured to provide a controlled mode for releasing exhaust gas pressure during an over-pressurization event. The plastic muffler has a plastic casing that includes at least one pressure relief feature. The pressure relief feature allows exhaust gas to escape from the plastic casing when internal exhaust gas pressure exceeds a predetermined pressure level.

Abstract: A muffler having an inlet and an outlet, through which exhaust gas flows; a tubular main body; a heat exchanger inside the main body; a noise-deadening first conduit, which extends at least partly inside the main body, from a fork region located directly downstream from the inlet, to a converging region directly upstream from the outlet; a second conduit, which extends through the heat exchanger and at least partly inside the main body, from the fork region to the converging region and parallel to the first conduit; and a regulating valve located outside the main body, to selectively direct exhaust gas flow along the first conduit or the second conduit.

Abstract: An aftertreatment module for use with an engine is disclosed. The aftertreatment module may have a first chamber with an inlet, and at least one catalyst substrate disposed in the first chamber in a flow path through the inlet and having a flow direction from an inlet face to an outlet face in general alignment with the flow path. The aftertreatment module may also have a second chamber with at least one outlet in general alignment with the flow direction through the inlet. The aftertreatment module may further have at least one noise attenuation passage fluidly connecting the first chamber with the second chamber. The at least one noise attenuation passage may be oriented generally orthogonal to the inlet and the at least one outlet and be located between the inlet and the outlet face of the at least one catalyst substrate.

Abstract: The invention relates to a retainer device for retaining a reducing agent metering valve. The retainer device at least partially surrounds an interior space which is provided for holding the reducing agent metering valve. According to the invention, the retainer device has a sound dampening device which dampens sound vibrations emerging from the interior space.

Abstract: A valve suitable for closing an orifice (36) of a structure (10) of a silencer (1) for a motor vehicle exhaust line, includes a closing component (44) which is connectable to the structure (10) and capable of adopting a position for closing the orifice (36). The closing component (44) is capable of rising by bending from its closure position. The closing component (44) includes a closure plate (54) capable of closing the orifice (36) and at least one connection plate (56) capable of connecting the closure plate (54) to the structure (10), the closure plate (54) and the or each connection plate (56) having differing thicknesses and/or being made of materials having differing mechanical characteristics.

Abstract: A condensed water discharge apparatus is capable of smoothly excreting residual condensed water in a muffler. The device may include a through hole formed at the bottom of a muffler case, an inflow pipe communicated to the muffler case and in which exhaust gas flows, an exhaust pipe communicated to the atmosphere so that exhaust gas is exhausted from the muffler case thereto, a thermoelement, and a control valve mounted at the through hole so as to selectively open/close the through hole when driving or stopped by sliding about the through hole.

Abstract: A muffler is disclosed. In the muffler a throttling device that is controlled by the energy of the airflow to be muffled is provided in a pipeline of the airflow that needs to be muffled. The muffler is adjusted by itself according to random variety of the pulsing airflow, and can eliminate or reduce effectively the pulsation of the airflow and the related noise in the range of the low frequency and the middle frequency. The muffling effect of the muffler has no correlation with the volume of the muffler, and therefore the volume of the muffler can be reduced.

Abstract: A muffler that is externally mounted to a housing shell of a compressor. To externally mount the muffler to the housing shell and prevent unnecessary vibration of the muffler during compressor operation, an attachment device connects an essentially central portion of the muffler to the housing shell. The attachment device may also be adapted to house a pressure- or temperature-related sensor device.

Abstract: Disclosed are apparatus and methodology for reducing noise and wear in a flapper configured exhaust tip for a marine exhaust system. A metallic flapper is located at an end portion of an exhaust tip of the exhaust pipe. An elastomeric flapper assembly is provided covering the exhaust tip and includes a lip portion configured to provide noise reduction by functioning as a stop for a tip portion of the metallic flapper. The metallic flapper is positioned such that a tip thereof contacts the elastomeric flapper assembly rather than the metallic exhaust pipe. Such contact with an elastomeric flapper assembly reduces noise previously produced by flapper contact with the hot exhaust pipe.

Abstract: An intake sound adjusting device includes an intake passage, a tubular branch passage branched from the intake passage, and an oscillating member disposed within the branch passage, in which the oscillating member has an oscillating portion disposed so as to close an interior of the branch passage and a controlling portion extending from the oscillating portion in a direction along an extending direction of the branch passage.

Abstract: A damping device and a method of damping a structural element of a vehicle body are disclosed. The damping device generally includes a carrier material, a separating material, and a damping material disposed on the carrier material. The damping material is one of a material forming an open cell structure and a material having an absorption coefficient for sound waves greater than about 0.5. The method generally includes fixing a damping device on a structural element of a vehicle, the damping device including a carrier material, a separating material, and a damping material, and one of expanding and dilating at least one of the separating material and the damping material, the damping material having one of an open cell structure and an absorption coefficient for sound waves greater than 0.5 after expansion.

Abstract: A muffler apparatus for a vehicle, may include a muffler housing; baffle plates that are disposed in the muffler housing and divides an internal space of the muffler housing; an intake pipe that is supported by at least one of the baffle plates and takes in exhaust gas; and an exhaust pipe that is supported by at least one of the baffle plates and takes in the exhaust gas discharged from the intake pipe and discharges the exhaust gas outside the muffler housing, and of which a pipe line of the exhaust pipe circulates through the internal space of the muffler housing.

Abstract: A variable resonation chamber valve includes an outer valve seat and a rotatable plunger. The outer valve seat defines an inlet opening into an associated resonation chamber. The rotatable plunger is movable into the inlet opening of the valve seat for varying a tuner area of the inlet opening.

Abstract: A muffler for an internal combustion engine featuring two flowpaths for exhaust through the muffler. A first serpentine pathway is substantially longer than a second pathway through the muffler, thereby providing increased sound attenuation. Temperature activated internal valves operate to change the exhaust flowpath from the first flowpath to the second flowpath through the muffler as exhaust gasses warm the muffler and the temperature actuated valves.

Abstract: Disclosed are apparatus and methodology for reducing noise and wear in a flapper configured exhaust tip for a marine exhaust system. A flapper, normally located within an exhaust tip of a marine exhaust system, is relocated upstream of the point in the exhaust system where cooling water normally contacts the exhaust pipe. An exhaust tip is coupled to the upstream portion of the exhaust system by way of an elastomeric coupling device. The flapper is positioned such that a tip thereof contacts the elastomeric coupling rather than the metallic exhaust pipe. Such contact with an elastomeric coupling device reduces noise previously produced by flapper contact with the hot exhaust pipe occasioned by destruction and/or heat degeneration of elastomeric material generally associated with the flapper device.

Abstract: A high-performance muffler assembly for exhaust system of an internal combustion engine. The muffler assembly comprises an elongated casing having an inlet port and an exit port, a first pipe disposed within the casing and having an inlet end in fluid communication with the inlet port and an outlet end selectively fluidly connected to the exit port of the casing, and a first valve mounted within the casing. The first valve is selectively movable between a closed position and an open position for regulating an exhaust gas flow through the first pipe. The muffler assembly is operable in a number of different modes of operation including a high-performance mode, an exhaust braking mode, a reverse-flow mode, etc., determined by the positions of the first valve of the muffler assembly.

Abstract: An exhaust valve and a catalyst can be easily disposed of in a simple manner. The interior of a triangular muffler is partitioned into three expansion chambers. A manifold pipe is connected to the second, middle expansion chamber sideways from a lower portion thereof and is accommodated therein so as to face upward. A catalyst is accommodated in the interior of the manifold pipe. Exhaust gas flowing out from an open end of the manifold pipe expands into the second chamber. A short-circuiting aperture is formed in a second separator and is opened and closed with an exhaust valve installed within the third chamber. The exhaust valve is normally closed by a spring. When the exhaust pressure reaches a predetermined magnitude, the exhaust valve opens automatically, allowing the exhaust gas to flow out into the third chamber through the short-circuiting aperture, thereby controlling the exhaust pressure.

Abstract: Snap action valve assemblies for use in conduits of automotive exhaust systems have their operation controlled by use of inertia damper elements coupled to an axle of a rotatable valve plate of the valve assembly.

Abstract: A system and method for reducing concentrations of reactants in gases flowing through an exhaust system are disclosed. Briefly described, one embodiment comprises creating a turbulent flow of gases along a periphery region of an exhaust pipe, the turbulent flow created by the gases transported over a wire mesh residing in the periphery region; and mixing the gases in the periphery region with a reactant gas being transported in a flow-through region, the mixing caused by the turbulent flow of gases, such that concentration of the reactant gas is reduced as the reactant gas is transported through the exhaust system.

Abstract: A vehicle (1) is provided with an exhaust pipe (2) extending from an engine mounted in the front part of the vehicle to a branch part (24) in the rear part of the vehicle, and right and left branch pipes (25, 26) extending from the branch part to mufflers (5, 6) on both right and left sides. The branch part (24) is arranged so as to be offset to the side of either one muffler (5) of the right and left mufflers with respect to the center in the vehicle width direction; the exhaust pipe has an upstream part (2, 21) laid linearly to a bend part (22) positioned in the center in the vehicle width direction near the rear end of a fuel tank, and an oblique part (23) laid slantwise from the bend part toward the branch part; and the length of the branch pipe (25) having a longer distance to the muffler is approximately equal to the length of the oblique part (23).

Abstract: A muffler for efficiently reducing noise. Front side exhaust pipes and rear side exhaust pipes extend from front cylinders and rear cylinders, respectively, of a V-type water-cooled 4-cylinder engine and are operatively connected to a catalyst chamber disposed below a crankcase. The catalyst chamber is connected to an exhaust chamber located to the rear thereof in which exhaust gas is expanded. An outlet pipe laterally projects from a lateral surface of a rear end portion of the exhaust chamber and is connected to a front pipe projecting from the lateral surface of the front portion of a muffler. The front pipe is transversely inserted into the muffler to increase a cross-section ratio, thereby efficiently reducing noise.

Abstract: The diffuser can be used at an end of a vehicle exhaust system. The diffuser can have a generally hollow body with an inlet for receiving exhaust gasses from a substantially vertically-extending component of the vehicle exhaust system, and a substantially flat outlet grate through which the exhaust gasses are to be released to the atmosphere, the outlet grate being configured and adapted for use in a roof of the vehicle, in an aligned position therewith, with the hollow body of the diffuser positioned inside the vehicle and below the outlet grate.

Abstract: A muffler is disclosed. In the muffler a throttling device that is controlled by the energy of the airflow to be muffled is provided in a pipeline of the airflow that needs to be muffled. The muffler is adjusted by itself according to random variety of the pulsing airflow, and can eliminate or reduce effectively the pulsation of the airflow and the related noise in the range of the low frequency and the middle frequency. The muffling effect of the muffler has no correlation with the volume of the muffler, and therefore the volume of the muffler can be reduced.

Abstract: A passive, exhaust pressure actuated valve assembly for placement inside a tubular exhaust conduit is pivotally mounted to an off-center axle for rotation between fully closed and fully opened positions. A bias element forces the valve flap toward the fully closed position. The valve flap is shaped in a manner enabling use of the interior surface of the exhaust conduit to define stops at the full closed and full opened positions. The valve flap shape, in conjunction with the bias element arrangement, enables the flap to lie substantially parallel to a longitudinal axis of the conduit in the fully opened position, which provides for minimum back pressure in the conduit. The valve assembly finds particularly advantageous use inside a bypass through pipe of a muffler assembly.

Abstract: A muffler has a casing with a plurality of sound-muffling chambers, exhaust pipes that pass through at least two sound-muffling chambers and to pass through exhaust from an engine, a plurality of apertures provided in each exhaust pipe, and a plurality of valves provided in each of the apertures. In this muffler, the plurality of apertures are provided at the locations at which an exhaust flow from one aperture and an exhaust flow from another aperture do not interfere with each other. When there are two apertures, the apertures are provided at positions in the exhaust pipes at which the apertures do not face each other. For this reason, by avoiding interference between exhaust flows from the two apertures, it is possible to suppress an abnormal sound caused by the interference.

Abstract: A high-performance muffler assembly for exhaust system of an internal combustion engine. The muffler assembly comprises an elongated casing having an inlet port and an exit port, a first pipe disposed within the casing and having an inlet end in fluid communication with the inlet port and an outlet end selectively fluidly connected to the exit port of the casing, and a first valve mounted within the casing. The first valve is selectively movable between a closed position and an open position for regulating an exhaust gas flow through the first pipe. The muffler assembly is operable in a number of different modes of operation including a high-performance mode, an exhaust braking mode, a reverse-flow mode, etc., determined by the positions of the first valve of the muffler assembly.

Abstract: Acoustic noise from relatively high pressure gas flows as a result of opening for example a bypass valve in a gas turbine engine can cause problems. By provision of an acoustic apparatus incorporating an inner chamber where there is a pressure reduction and then a chamber divider surface incorporating small apertures with a wide spacing distribution an upward shift in acoustic frequency of the gas flow is achieved beyond normal human comprehension. An outer chamber is provided to receive the fine gas flow jets from the apertures in the chamber divider surface for further pressure reduction and low pressure release through wider apertures in an exit surface.

Abstract: The present invention relates to an acoustic baffle device for sealing a cavity of a vehicle body at a predetermined cross section of the cavity, comprising a piece of sealing material that is formed in a shape corresponding to but being smaller than the shape of the cross section of the cavity. The acoustic baffle device of the invention is characterized in having a flap assembly having a lower neck defining a passage for a flexible tube or a similar device, said lower neck having a flap secured in closed position by a locking device and being connected preferably to the lower end of the lower neck through means that permit the reversible opening of the above-defined passage. Furthermore, the present invention relates to a flap assembly useful for such an acoustic baffle device, and to a process for sealing a cavity of a vehicle body at a predetermined cross section of the cavity.

Abstract: A high-performance muffler assembly for exhaust system of an internal combustion engine. The muffler assembly comprises an elongated casing having an inlet port and an exit port, a first pipe disposed within the casing and having an inlet end in fluid communication with the inlet port and an outlet end selectively fluidly connected to the exit port of the casing, and a first valve mounted within the casing. The first valve is selectively movable between a closed position and an open position for regulating an exhaust gas flow through the first pipe. The muffler assembly is operable in a number of different modes of operation including a high-performance mode, an exhaust braking mode, a reverse-flow mode, etc., determined by the positions of the first valve of the muffler assembly.

Abstract: A flow-through muffler includes a plurality of heat conducting walls, baffles, or partitions that together define a plurality of passages arranged to form acoustic waveguides, attenuators, and/or cancellation chambers, the walls, baffles, or partitions increasing a surface area exposed to the exhaust gases to facilitate extraction of heat while attenuating or canceling the resulting sound pressure waves. The muffler may have a cooling arrangement mounted thereon, and thermoelectric generator elements or other heat-powered device, such as a reformer, connected across the heat differential between the cooling arrangement and an exterior surface of the muffler housing that is in thermal contact with the heat conducting walls, bafflers, or partitions. In addition, the muffler may be made tuneable by providing a device for varying a length of one of the passages relative to another passage, and by including a sound cancellation chamber at an intersection of the passages.

Abstract: A compressor muffler includes a housing having an inlet end and an outlet end. A baffle arrangement extends from an interior surface of the housing. The baffle arrangement includes a surface capable of reflecting compressed fluid to attenuate noise. A valve assembly is disposed inside the baffle arrangement. The valve assembly is positionable between a first position and a second position. The valve assembly also includes a valve surface that at least partially prevents flow of fluid through the housing from the outlet end when the valve assembly is in the first position.

Abstract: An exhaust flow rate control valve includes an on-off valve which is switched between a closed state in which a flow passage area of an exhaust pipe is decreased, and an opened state in which the flow passage area is increased. A notch is formed in the on-off valve, and a recess is formed in an inner pipe member of the exhaust pipe to correspond to the notch. A resilient member, for biasing the on-off valve in a closing direction, is disposed in a space formed between the recess and an outer pipe member of the exhaust pipe. Thus, the degree of freedom is improved in setting the operating characteristic of the on-off valve, without increasing the size of an exhaust structure.