Abstract: A muffler having a movable baffle may include a housing where an input pipe into which exhaust gas is flowed from an engine and an output pipe through which the exhaust gas is expelled to atmosphere are disposed, a baffle which is configured to be slidable along the longitudinal direction of the housing and divides the space of the housing, baffle moving means for moving the baffle to an arbitrary position within a predetermined range along the longitudinal direction of the housing, and a controller which data for determining whether to move the baffle or not is input thereto when the engine is driven, determines whether to move the baffle or not by use of the input data and controls the baffle moving means when the baffle is determined to be moved.

Abstract: A selective acoustic soundproofing device for a vehicle includes a housing that is configured to couple to an exhaust system of the vehicle so that an internal space defined by the housing is in fluidic communication with the exhaust system. A wall that is coupled to the housing extends from proximate to the first end to proximate to the second end of the housing to define a first passage and a second passage through the housing. A selector that is coupled to the housing is configured to selectively direct sound pressure from the engine through the first and second passages. A baffle positioned in the first passage is configured for acoustic quieting of loudness of the sound pressure when the selector is positioned to direct the sound pressure from the engine through the first passage relative to when the selector is positioned to direct the sound pressure through the second passage.

Abstract: An acoustic absorber cell (1) for mounting on a turbojet wall in contact with a fluid flow, the cell (1) having a resonant cavity (2) presenting a wall (30) having at least one orifice (4) associated with a neck (5) having a tube (51) extending inside the resonant cavity (2) and projecting from the wall (30). The neck (5) also having a tubular ring (52) coaxial with the tube (51) and movable relative to the tube (51), and the cell (1) includes electromagnetic actuator (6) for moving the ring (52) along the tube (51), and controller (7) for controlling the electromagnetic actuator (6) and configured to control movement of the ring (52) along the tube (51) as a function of the operating speed of the turbojet between at least first and second positions defining respective first and second resonant frequencies of the resonant cavity (2).

Abstract: A sound deadening device has an introducing and damping section. The introducing and damping section includes an introduction section that introduces fluid, an expansion chamber, and a lead-out section. The expansion chamber is communicated with the introduction section, has a flow passage cross-section larger than a flow passage cross-section of the introduction section, and has protrusions along a travelling direction of a sound wave, resonance of the sound wave being to be suppressed. The lead-out section is communicated with the expansion chamber, has a flow passage cross-section smaller than that of the expansion chamber, and leads out the fluid in a direction different from an introduction direction of the fluid. Accordingly, it is possible to weaken the resonance of the sound wave, suppress rise of inner sound pressure of the sound deadening device, and prevent reduction in a sound deadening effect.

Abstract: Provided is an expansion-chamber muffler as a downsized sound muffler while keeping a function of noise reduction, comprising: a tube (A) which supplies and evacuates a gas having a noise, wherein the tube (A) in the midway has a cavity with a cross-sectional area larger than that of the tube (A); and at least two or more ports for inflow or outflow of the gas on the lateral side of a tube (B) extending from the expansion-chamber muffler, on the opposite side of the noise source generating the noise.

Abstract: A system and method automatically controls exhaust sound of a vehicle according to music chosen by a driver for the pleasure of driving. The system may include a media reproducing device which plays music and outputs a music playback signal, a control unit which analyzes a frequency of the music playback signal output from the media reproducing device and generates a drive signal according to the frequency, and a variable valve of a muffler installed in the muffler which adjusts the exhaust sound according to the drive signal output from the control unit.

Abstract: A damper arrangement (10) has a first Helmholtz damper (11) connected in series to a second Helmholtz damper (12). The resonance frequency of the first Helmholtz damper (11) and the resonance frequency of the second Helmholtz damper (12) are shifted from one another in an amount producing a synergic damping effect.

Abstract: An exhaust system component for a motor vehicle has a first exhaust passage, an attachment flange, which encloses the first exhaust passage, for the connection of the component to an adjacent component, the attachment flange defining an attachment plane for the contact with the adjacent component and having fastening holes for the connection to the adjacent component, and a second exhaust passage, which is spaced apart from the first exhaust passage in a longitudinal direction of the component. A normal line on the attachment plane extends at a non-negligible angle to the longitudinal direction, and the fastening holes are elongated in a direction parallel to the attachment plane.

Abstract: The invention relates to a method for damping thermo-acoustic oscillations via a resonator having a resonator volume with thermo-acoustic oscillations induced in a cavity inclined to thermo-acoustic oscillations, and at least some of the thermo-acoustic oscillations being output from the cavity and being input into the resonator volume, with damping oscillations produced in the resonator volume, which are matched to the thermo-acoustic oscillations, with at least some of the damping oscillations being input into the cavity such that the damping oscillations and the thermo-acoustic oscillations overlap in an overlap area, and the oscillations being largely cancelled out. The invention relates to an apparatus for damping thermo-acoustic oscillations in a cavity, comprising a resonator with a resonator volume and a cavity. The invention also relates to a combustion chamber together with a method and an apparatus according to the invention, and to a gas turbine having a combustion chamber.

Abstract: A muffler for a vehicle is provided, including: a muffler housing having a first housing body and a second housing body that are divided in two parts and form an internal space with an inlet opening and an outlet opening when combined; and an internal structure inserted and forced into the internal space of the muffler housing to be detachable from the muffler housing, and allowing an exhaust gas discharged from an engine to flow into the internal space and to be discharged out of the muffler housing through a predetermined path.

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: A Helmholtz damper, including an enclosure, a neck extending from the enclosure, and a pipe for inserting into the neck. The portions of the pipe inserted into the neck is adjusted to regulate a resonance frequency of the Helmholtz damper.

Abstract: The expandable chamber acoustic silencer may be installed at the inlet or outlet of virtually any mechanism that processes air or other gas flow therethrough, to reduce the audible output of the gas flow. The silencer may be used to reduce the noise produced in an air conditioning system, in the inlet or outlet side of an air compressor, or as a muffler for an internal combustion engine, among other applications. The device includes an expansion chamber having adjustable walls driven by actuators installed within the walls to adjust the cross-sectional area of the chamber, with a portion of the walls being formed of a flexible or resilient material to enable such expansion and retraction. One or more microphones are installed at the outlet and/or inlet ends of the silencer and communicate with a controller that operates the actuators in accordance with a predetermined algorithm.

Abstract: An attenuating apparatus for use with a positive displacement compressor. The device includes a bore formed in a housing of the compressor, the bore being positioned at an angle to a discharge chamber of the compressor and in fluid communication with the compressor discharge chamber. A plug is positioned within the bore, the plug movable within the bore to a preselected position. The plug has a first end in contact with a gas from the compressor discharge chamber and a second, opposite end being accessible from an exterior of the housing. A seal is positioned between the plug and the bore to seal an interface between the plug and the bore to prevent leakage of a gas from the compressor discharge chamber along the interface. The plug is lockable within the bore at the preselected position.

Abstract: The present invention relates to a muffler (8) for an exhaust system (6) of a combustion engine (1), more preferably of a motor vehicle, with a housing (14) comprising at least one exhaust gas inlet (18) and at least one exhaust gas outlet (19), with a pipe arrangement (20) for conducting exhaust gas arranged in the housing (14), which comprises at least one pipe section (21) running within the housing (14), and with a hollow space (22) formed in the housing (14), which is present in addition to the pipe arrangement (20) and is connected to said pipe arrangement at least for the airborne sound transmission.

Abstract: The present invention relates to a sliding fit for the axially movable bearing of a thermally loaded pipe on a component, in particular on an exhaust system of an internal combustion engine, having a wire mesh which is radially supported on the outside of the pipe and is secured directly or indirectly to the component.

Abstract: An engine intake air tuning assembly may include a housing assembly and an air flow control member. The housing assembly may include an air inlet, an air outlet, and a body portion extending therebetween. The body portion may define an air flow passage and a tuning chamber. The air flow passage may provide fluid communication between the air inlet and outlet. The air flow control member may be located within the body portion and may be displaced between first and second positions relative to the air flow passage. The air flow control member may provide a first communication path from the air flow passage to the tuning chamber when in the first position and a second communication path from the air flow passage to the tuning chamber when in the second position. The second communication path may define a greater number of openings than the first communication path.

Abstract: An exhaust system of an internal combustion engine and provided with: at least one first high acoustic attenuation path having a first inlet opening; at least one second low acoustic attenuation path having a second inlet opening; and at least one control valve, which is arranged at the second inlet opening of the second path to control the flow of the exhaust gases along the second path.

Abstract: A muffling device has a muffling piece that is placed in an airflow path and muffles sound caused by airflow, and a drive unit that performs one of rotation and movement of the muffling piece.

Abstract: A silencer cover adapts to a heat expansion of a silencer even when, for example, the silencer cover has a large size and is attached to the silencer over an area from the front to the rear. A silencer cover is provided for a silencer connected to a downstream end of an exhaust pipe of an engine. The silencer cover is fixed to a fixing support provided to the silencer. The silencer is heat-expanded with the fixing support part fixed as a base. The fixing support part is provided at a front end portion, in a vehicle front-rear direction, of the silencer. With a tail pipe constituting a rear end portion of the silencer, the rear end portion of the silencer is provided with a slide structure in which the silencer cover is slidably supported.

Abstract: A method and system for reducing pulsation in a gas compressor system. A pulsation control device, such as a filter bottle or side branch absorber, is installed at a port into some location on the compressor system. The pulsation control device has a choke tube with a variable cross-sectional area, such as by having multiple conduits that may be opened or closed or a diameter that may be varied. In operation, the cross sectional area of the choke tube is varied depending on the compressor speed.

Abstract: A motorcycle includes a spark arrester having an increased surface area without any undue increase in the length of a silencer or the width of the motorcycle. The motorcycle includes a rear wheel and a silencer provided on a side of the rear wheel. The silencer includes an outer tube and a spark arrester which is tubular and is disposed inside the outer tube, the longitudinal axis of the spark arrester being oriented in a longitudinal direction of the outer tube. In a sectional plane which is perpendicular or substantially perpendicular to the longitudinal direction of the outer tube and the spark arrester, the outer tube has an outside dimension in a height direction greater than an outside dimension of the outer tube in a lateral direction, and the spark arrester has an outside dimension in the height direction greater than an outside dimension of the spark arrester in the lateral direction.

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 system for reducing an acoustic load of a fluid flow includes a first pipe to carry the fluid flow; a standpipe connected to the first pipe at an opening in the first pipe; and a standpipe flow tripper provided in the standpipe. The flow tripper includes an edge extending through the opening into the flow on a downstream side of the opening. A method of reducing an acoustic load of a standing wave in a standpipe connected to a first pipe configured to carry a flow includes disrupting the flow in the first pipe at a downstream side of an opening in the first pipe to which the standpipe is connected.

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 selectively removable exhaust baffle which can be placed within an exhaust pipe to muffle the emitted sound. The removable baffle preferably includes a frame having a pair of legs joined by a spring portion. One or more transverse occluding plates are mounted on the frame. The frame is sized so that when it is pushed into the exhaust pipe it must be compressed. This compression holds the frame in place. The transverse occluding plate or plates lie against the interior wall of the exhaust pipe. The gas flow must therefore pass around the plate or plates, thereby attenuating the sound.

Abstract: A selectively removable exhaust baffle which can be placed within an exhaust pipe to muffle the emitted sound. The removable baffle preferably includes a frame having a pair of legs joined by a spring portion. One or more transverse occluding plates are mounted on the frame. The frame is sized so that when it is pushed into the exhaust pipe it must be compressed. This compression holds the frame in place. The transverse occluding plate or plates lie against the interior wall of the exhaust pipe. The gas flow must therefore pass around the plate or plates, thereby attenuating the sound.

Abstract: An exhaust-gas muffler (1) has a housing (2) through which at least one sleeve (11) projects. At one end, the sleeve (11) has an attachment opening (10) and at the opposite-lying end has an access opening (14). To avoid a contamination of the sleeve (11) during operation, a plug (15, 25, 35, 40, 45, 55) of a pressed metal wire is arranged in the access opening (14).

Abstract: A method and system for reducing pulsation in lateral piping associated with a gas compressor system. A tunable side branch absorber (TSBA) is installed on the lateral piping. A pulsation sensor is placed in the lateral piping, to measure pulsation within the piping. The sensor output signals are delivered to a controller, which controls actuators that change the acoustic dimensions of the SBA.

Abstract: A system for reducing an acoustic load of a fluid flow includes a first pipe. The first pipe includes a first end and a second end and a first aperture and a second aperture, the first and second apertures being intermediate the first and second ends. A second pipe includes a first end and a second end and a third aperture intermediate the first and second ends. The second pipe is connected at its first end to the first pipe at the first aperture. A bypass pipe includes a first end connected to the second aperture of the first pipe and a second end connected to the third aperture of the second pipe. A method of reducing an acoustic load of a flow in a standpipe connected to a first pipe configured to carry a main flow includes providing a bypass flow from the first pipe to the standpipe.

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: The present invention relates to a balance pipe assembly for a vehicle exhaust system including at least a pair of exhaust pipes or pipe shaped portions, and a further pipe or pipe shaped portion extending between the exhaust pipes or pipe shaped portions so as to act as a balance pipe. The assembly further includes at least one of the exhaust pipes or pipe shaped portions including means adapted to reduce the pressure of exhaust gasses passing there through at a position downstream of the balance pipe or pipe shaped portion.

Abstract: The insert for an engine exhaust system has at least one conical section of flexible mesh or rovings of metallic or other high temperature resistant fiber or tape. Each section includes a rigid anchor or attachment ring having an outer diameter closely conforming to the inner diameter of the exhaust pipe, with the anchor ring being welded to the mesh or roving or tape material or the mesh or roving or tape being crimped between two concentric rings. A smaller diameter support ring may be provided at the opposite end of the conical mesh, with the support ring braced by a series of radial arms. The device may serve to reduce the sound output of the exhaust system, and/or may serve as a spark arrestor as well.

Abstract: An auto-sensing, automatic adjusting exhaust baffle; for reducing noise emissions produced by internal combustion engines, while improving overall engine performance, i.e., torque and horsepower. The design uses a spherical shape to evacuate spent exhaust gas, thus scavenging the surrounding exhaust gases to adjust the backpressure, while reducing the noise exiting the exhaust pipe at lower rpm's. The device uses a sphere with an internal bearing; sliding linearly on a shaft and said sphere and bearing being acted upon by exhaust gasses and a compression spring mounted axially over the diameter of the shaft. The purpose of this device is to reduce noise while improving tuning of the air/fuel intake system, by adjusting backpressure of the exhaust system. The lesser amount of exhaust pressure, the less the sphere moves, as in idle to just off of idle, this results in a quiet operational mode of the invention.

Abstract: An intake assembly, such as a supercharger assembly, is provided for an internal combustion engine. The intake assembly includes a housing having a wall defining an inlet passage through which intake air enters the intake assembly. A plurality of stiffening ribs is provided on the wall opposite the inlet passage and at least partially defines at least one cavity. A plate is mounted to the wall of the housing and further defines the at least one cavity. The wall defines at least one orifice configured to provide communication between the inlet passage and the at least one cavity. The at least one cavity and the at least one orifice cooperate to form at least one resonator. A method of forming the intake assembly having integral resonators is also provided.

Abstract: A noise reduction system for a device having a noise generating subsystem includes a Helmholtz resonator and a controller. The Helmholtz resonator is disposed in fluid communication with the noise generating subsystem, and includes an active material responsive to a control signal that adjusts a dimensional characteristic of the Helmholtz resonator in such a manner as to affect a resonance characteristic of the Helmholtz resonator. The controller is responsive to an operational characteristic of either the device or the noise generating subsystem to produce the control signal. In response to the operational characteristic, the control signal serves to affect the resonance characteristic of the Helmholtz resonator in such a manner as to reduce a noise arising from the noise generating subsystem, or create a desirable sound quality alteration.

Abstract: A resonator for a vehicle air intake system is disclosed, wherein the resonator is variable tuned to militate against the emission of sound waves caused by the engine and other sources at a wide range of engine speeds.

Abstract: A dual-mode exhaust system includes a housing with an input port attached to the existing muffler exhaust system and positioned downstream thereof. The system further includes a mechanism for selectively distributing vehicle exhaust from the input port to the first and second output ports, upper and lower chambers vertically stacked within the housing, and first and second vertically spaced pendulum arms disposed within the upper and lower chambers respectively and anchored at respective distal ends thereof respectively. First and second vehicle exhaust pipes are coupled to the first and second output ports.

Abstract: A variable geometry muffler for an exhaust system of an internal combustion engine; the muffler displays: a tubular body, which displays an inlet opening, an outlet opening and a labyrinth which determines a path for the exhaust gases from the inlet opening to the outlet opening; and a bypass valve, which is arranged within the tubular body to modify the geometry of the labyrinth according to the exhaust gas pressure; the bypass valve displays a lid, which is coupled to a bypass opening and is mobile from a closed position of the bypass opening to an opening position of the bypass opening by effect of the exhaust gas pressure and against the bias of an elastic body which tends to maintain the lid in the closed position; the elastic body consists of an elastic foil, which is folded as a “U” and displays a mobile end which supports the lid and a fixed end which is opposite to the mobile end and which is integral with a fixed part of the muffler.

Abstract: An adjustable Helmholtz resonator assembly is provided having an active state and an inactive state. In the active state the Helmholtz resonator assembly is operable to attenuate pressure pulsations within air passing therethrough. In the inactive state the Helmholtz resonator assembly does not attenuate pressure pulsations within air passing therethrough. The Helmholtz resonator assembly is preferably configured to be mounted within an intake system of an internal combustion engine.

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: The invention uses tubes for the reduction of radiated duct noise. The tubes may be used to attenuate narrow band noise by diverting a portion of the acoustic energy through the tubes back into the duct. Upon reintroducing the diverted flow out of phase with the primary flow, acoustic cancellation is achieved. The frequency at which this occurs is dependent on the difference in the path lengths through the tubes and the separation distance—the distance separating the inlet and outlet of the tube. This invention can be used over varying frequency ranges by using an arrangement of flexible, constant length tubes. The effective frequency range is tailored by varying the separation distance and also allows the varying the angular arrangement of the tubes for more effective attenuation of spinning modes having varying propagation angle.

Abstract: An exhaust system is provided with a muffler with reversible end-caps, which allow a tailpipe to be switched over from one side of the muffler to the other before or after it is attached to an engine and mounted on an application.

Abstract: A switchable exhaust system apparatus. The switchable exhaust system apparatus is switchable between a quiet or normal mode and a loud mode when desired.

Abstract: The invention uses tubes for the reduction of radiated duct noise. The tubes may be used to attenuate narrow band noise by diverting a portion of the acoustic energy through the tubes back into the duct. Upon reintroducing the diverted flow out of phase with the primary flow, acoustic cancellation is achieved. The frequency at which this occurs is dependent on the difference in the path lengths through the tubes and the separation distance—the distance separating the inlet and outlet of the tube. This invention can be used over varying frequency ranges by using an arrangement of flexible, constant length tubes. The effective frequency range is tailored by varying the separation distance and also allows the varying the angular arrangement of the tubes for more effective attenuation of spinning modes having varying propagation angle.

Abstract: An apparatus for sonic coupling between an intake tract or engine compartment and a vehicle interior of a motor vehicle has a housing into which sound enters from the intake tract via a first line, and out of which sound exits into the vehicle interior via a second line. A transmission body is arranged in the housing, the transmission body having a gas-tight separating wall between a sound inlet into the housing and a sound outlet out of the housing. The position of the separating wall is held essentially constant by a positioning device. A transmission wall between the separating wall and the housing provides an acoutis transfer function that is adjustable. The separating wall runs generally perpendicular to the longitudinal axis of sound propagation and the transmission wall runs at an angle ? to the longitudinal axis of sound propagation.

Abstract: A muffler outlet part for a muffler to be used in exhaust systems of motorcycles has at least one main body disposed transversely to an outflow direction of exhaust gas and having a center axis, the main body having a centrical first outlet opening disposed concentrically relative to the center axis for the outflow of exhaust gas from an outlet chamber of the muffler, and at least one second outlet opening disposed eccentrically relative to the center axis for the outflow of exhaust gas from an expansion chamber of the muffler, said expansion chamber enclosing the outlet chamber. It further has at least one closing member that is swivel-mounted about the center axis for an at least partial closing of the at least one second outlet opening, and at least one adjustment element for swiveling of the closing member via an adjustment means, which cooperates in a torque-transmitting manner with the at least one adjustment element.

Abstract: A muffler system includes a housing having two pipes perforated with holes or other shapes that slide or rotate on top of each other. The sliding or rotating pipes allow for varying degrees of alignment of the holes and thereby allow more or less sound dampening. The control of the sound dampening is actuated by an operator via an electric switch that activates at least one of the pipes inside the muffler system to rotate or slide on each other thereby aligning the holes.

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.

Abstract: A powertrain control system is provided that includes an engine having multiple cylinders. A controller selectively activates the cylinders to provide a cylinder combination having a desired power displacement. In one example powertrain control system, the controller selectively activates the cylinders between a V-8 and V-4 mode. An exhaust system having a valve and an electrical actuator selectively electrically actuates the valve in response to the controller between multiple positions. The electrical actuator moves the valve from an open position in V-8 mode to a partially closed position in V-4 mode to increase back pressure and reduce NVH issues in V-4 mode. A muffler includes a housing having an exhaust passage. The valve is supported by the housing and arranged in the exhaust passage. The valve is moveable between multiple positions for tuning the muffler. The electrical actuator is supported by the housing to actuate the valve between the multiple positions.