Abstract: A muffler assembly, for an exhaust system of an internal combustion engine has an exhaust gas inlet tube projected into the muffler to feed the muffler with the exhaust gas of the engine. First and second flow passages are defined through which the exhaust gas from the muffler flows independently before discharged to the open air. The controller has a pneumatic actuator that has a piston rod and a work chamber. The piston rod is adapted to reciprocate linearly in accordance with the magnitude of pressure developed in the work chamber. The pressure of the exhaust gas of the engine is fed to the work chamber of the pneumatic actuator. The actuator controls a valve assembly which includes a valve plate and a pivot shaft through which the valve plate is pivotally installed in the second flow passage of the first means.

Abstract: A plurality of chambers are partitioned in a muffler by a baffle board. The muffler is provided with an exhaust gas passage for discharging exhaust gas outside the muffler via these chambers and a valve that bypasses a part of the exhaust passage. This valve opens according to the exhaust gas pressure. Also provided are a mechanism for pushing the valve in a closing direction, and a mechanism for damping the shock when the valve closes. Thus, valve closing noise is suppressed, and exhaust gas noise is further suppressed.

Abstract: An exhaust system in an internal combustion engine includes a flow rate regulating valve which is positioned in an intermediate portion of an exhaust gas flow passage. The flow rate regulating valve has a rotary shaft rotatably supported in a valve housing, and a rotationally biasing spring mounted between the rotary shaft and the valve housing which provides a spring force to rotationally bias the rotary shaft. In the exhaust system, an axially biasing spring is mounted separately from the rotationally biasing spring between the valve housing and the rotary shaft for biasing the rotary shaft in an axial direction. The rotary shaft is provided with an abutment surface which faces in the one axial direction, and the valve housing is provided with a limiting portion which abuts against the abutment surface to limit the axial movement of the rotary shaft.

Abstract: An inlet tube leads exhaust gas from an automobile engine to an expansion chamber inside a muffler housing. Exhaust gas from the expansion chamber is discharged to the atmosphere via a first tail tube. A dead space chamber and volume chamber are disposed on either side of the expansion chamber in the housing, and a first internal tube connects the volume chamber and expansion chamber. A second internal tube having a valve which opens under pressure of the exhaust gas connects the volume chamber and dead space chamber. Exhaust gas from the dead space chamber is discharged to the atmosphere via a second tail tube. As the dead space chamber and volume chamber are not adjacent, pressure waves in the volume chamber do not cause a volume change of the dead space chamber, and emission noise from the second tail tube due to excitation of a resonance system comprising the dead space chamber, is reduced.

Abstract: A first and second noise suppressing mechanism are provided inside the muffler. Each mechanism is provided with a discharge pipe for discharging exhaust gas to outside the muffler. The first noise suppressing mechanism reduces exhaust noise in the low engine speed region. The second noise suppressing mechanism reduces noise in the medium and high engine speed regions. A valve is provided that connects the first noise suppressing mechanism and second noise suppressing mechanism according to the engine exhaust pressure. In the low speed region, the valve is closed and exhaust gas is discharged via the first noise suppressing mechanism where mainly low frequency noise is eliminated. In the medium and high speed regions, the valve is opened and exhaust gas is also discharged via the second noise suppressing mechanism where high frequency noise specific in these regions is also eliminated.

Abstract: An improved exhaust cutout device is provided for an engine having a collector pipe from a header and an exhaust pipe to a muffler. The device consists of a mechanism for diverting exhaust gases. Elements are for fluidly coupling the diverting mechanism between the collector pipe and the exhaust pipe. A structure is for operating the diverting mechanism. In a first operable position, the exhaust gases can pass between the collector pipe and the exhaust pipe to pass through the muffler for a quiet exhaust for city and restricted areas. In a second operable position, the exhaust gases can exit directly into the atmosphere for open road, racing purposes and country driving when more speed, more power and gas economy is required.

Abstract: An intake silencer of the variable type is for reducing noise generated coming from the difference between the inner pressure and the outer pressure of a combustion chamber when an intake valve being opened or closed. The present invention for reducing noise comprises a signal processing part, a signal comparing part and a valve driving part. In the signal processing part, a RPM sensor modulates a waveform obtained by detecting the revolution number of the engine and a F/V converter changes it thereafter emitting a signal to the signal comparing part. In the signal comparing part, a plurality of comparators emit the opened and closed signal to a valve driver by comparing a output signal emitted from the signal processing part with a basic signal. In the valve driving part, when the corresponding valve driver turns on or off by virtue of the signal emitted from the corresponding comparator, a corresponding actuator opens or closes the corresponding valve dividing the inside of the side branch.

Abstract: A weight biased check valve is located in a reflective muffler at the entrance thereof. As a result, both the check valve and muffler are located proximate to a compressor which minimizes both the package size and the volume trapped upon shutdown. The axis of the weight biased check valve is skewed whereby the weight biasing effect is reduced.

Abstract: A resonance detection device is provided for detecting resonance in an exhaust passage of an automotive vehicle. The detection device employs a temperature sensor in combination with an arrangement which enables the sensor to be exposed to a flow of exhaust gas the temperature of which is different from the temperature of the bulk of the flow, when resonance occurs. In given embodiments the arrangement takes the form different diameter conduits and/or vessels, while others it takes the form of a heat exchange device which either heats or cools the gases, and which is disposed proximate the temperature sensor. When no resonance occurs in the passage, the output of the temperature sensor remains stable. When resonance occurs the fluid flow characteristics in the passage change in a manner wherein the gas which has been either heated or cooled by the heat exchange device is induced to flow against the temperature sensor.

Abstract: There is provided a method for controlling an exhaust system of a vehicle including a controller for controlling an open-close operation of an on-off valve which is provided at an intermediate portion of one of a pair of exhaust pipes arranged in parallel and communicating with an exhaust port of an engine depending upon running condition of the vehicle. The control method includes three control patterns different from each other, i.e., a first control pattern during an accelerated running condition of the vehicle, a second control pattern during a constant-speed running of the vehicle, and a third control pattern during a decelerated running condition of the vehicle.

Abstract: An engine exhaust apparatus in which an exhaust passageway of the engine is provided with a plurality of sound deadening passsages. One common exhaust passageway from the engine is branched into first and second exhaust passageways. Each of the first and second exhaust passageways has a silencer or muffler including first and second exhaust outlet tubes with a shift valve mounted in one of these exhaust outlet tubes. A control unit controls the shift valves to close both when engine speed is in a low region, to open one of them when engine speed is in a medium region and to open both when engine speed is in a high region.

Abstract: A muffler for an internal combustion engine comprises: a communicating passage constituting member allowing a plurality of chambers formed by partitioning walls inside an outer shell to be communicated with each other; and a butterfly-type valve provided in the communicating passage. The communicating passage constituting member is formed into the shape of a gutter so as to face either an inner surface of the outer shell at an open side of the constituting member or an outer surface of the outer shell at an open side of the constituting member. Alternatively, the communicating passage constituting member is constituted by a pipe and is provided in the outer shell. The arrangement makes it possible to improve the engine output, reduce the back pressure, and enhance the sound-damping effect.

Abstract: Disclosed is an engine-control apparatus in which an exhaust passageway of the engine is provided with plural sound deadening passages. A portion of the plural sound deadening passages is designed to be opened or closed by a shift valve on the basis of a predetermined switching characteristic, and the pressure of the exhaust gases is changed upon the switching of the shift valve. In order to prevent torque shock to the driven wheels which may occur attendant upon operation of the shift valve to open or close or in order to reduce probability that torque shock would occur, there is provided a torque regulating apparatus which permits an adjustment of torque generator by the engine, of a transmission efficiency of power to the driven wheel, or of a switching speed at which the shift valve is switched to open or close, or a change in the switching characteristic.

Abstract: An exhaust gas purifying apparatus comprising a first and a second casings having expansion chambers, respectively, a third casing arranged between the first and second casings to form a passage therebetween, an inlet pipe introducing the exhaust gas into the first expansion chamber, and an outlet pipe discharging the exhaust gas from the second expansion chamber, whereby a muffler is constituted. The apparatus also comprises a filter arranged in the third casing to trap particulates in the exhaust gas, and a heater arranged adjacent to the filter on the side of the second expansion chamber to burn the particulates deposited on the filter, to regenerate the filter. A flow control unit, comprising a bypass and a valve therein, is arranged such that the exhaust gas normally flows through the filter and the heater, and when the filter is regenerated, at least a part of the exhaust gas flows in reverse through the heater and the filter. This exhaust gas purifying apparatus is built-in to the muffler.

Abstract: A gas silencing system for controlled sound attenuation of the exhaust gas in a motor vehicle comprises a sound attenuation muffler for exhaust gases. The system also includes means providing a bypass passage for gas to flow around at least part of the muffler. Bypass control valve is provided to allow selective regulation of the flow of exhaust through the muffler and the pass-pipe. The bypass control valve is responsive to a modulated pressure signal controlled by the driver of the vehicle. The invention also includes circuits for visually indicating the amount of bypass flow and the sound level of gas leaving the system.

Abstract: A muffler responsive to exhaust flow rate is provided for an internal combustion engine. The muffler includes a body having a variable restrictor located downstream from an inlet port and upstream from an outlet port of the muffler. The variable restrictor includes a valving element with an operative position which varies as a function of engine exhaust flow rate to occlude exhaust gas flow. The variable restrictor is formed with a solid wall disposed about the valving element to define a constricting annular passageway having a cross section that varies with distance from the inlet port and from the outlet port. The passageway cross section for some mufflers will increase in a direction proceeding from the inlet port toward the outlet port, and will decrease proceeding in that same direction in other mufflers, depending upon the type of internal combustion engine employed.

Abstract: In an automotive vehicle installed with a V-6 engine, engine revolution speed and engine load are detected and a selector valve provided in a silencer is normally closed but it is opened when the engine revolution speed exceeds a predetermined engine revolution speed value when the 3rd order component of exhaust sound coincides with a longitudinal resonance frequency within a vehicle cabin when the vehicle is at acceleration. The selector valve which is normally closed is opened when the engine revolution speed exceeds a second predetermined engine revolution speed value when the 1.5th order component of the exhaust sound coincides with the longitudinal resonance frequency.

Abstract: An exhaust silencer for a car includes a housing, a partitioning diaphragm plate, a conduction pipe for conducting therethrough an exhaust gas from the car engine, an exhaust pipe exhausting thereout the exhaust gas to the atmosphere, an exhaust conduit capable of exhausting therethrough the exhaust gas, a valve mounted in the conduit, and a controlling device responsive to the rpm of the car engine for enabling the valve to/not to block up the conduit so that the exhaust gas can be exhausted to the atmosphere in a quicker manner, if desired.

Abstract: Disclosed is an automobile muffler having a drain pipe communicating with the upperstream, upper half inside sound-deadening area of its outer pipe, thereby allowing the moisture of the air drawn into the sound-deadening space to leave for the surrounding atomosphere via the drain pipe prior to condensation of the moisture to water in the sound-deadening space, thus making it unnecessary to drain water from the muffler.

Abstract: A tail pipe structure of a control type muffler having a first outlet pipe and a second outlet pipe provided with a control valve inserted therein, wherein the first outlet pipe is in communication with the downstream side of the control valve of the second outlet pipe. The mechanism of the muffler is such that when the control valve is opened, the exhaust gases flow into the atmosphere from the first and second outlet pipes. Further, even when the control valve is closed, the exhaust gases in the first outlet pipe flow into the atmosphere therethrough while a part of the exhaust gases flow into the second outlet pipe from the first outlet pipe through the communication pipe and is then discharged into the atmosphere.

Abstract: A pneumatic impact tool comprising a casing having an interior space in which is mounted a piston for reciprocations under the action of compressed air for delivering useful blows, and ports of at least two exhaust passages opening into the interior space, one of the exhaust passages permanently communicating with atmosphere and the other with a chamber for preliminarily reducing the exhaust pressure. The chamber for preliminarily reducing the exhaust pressure is permanently connected through at least one passage to the exhaust passage communicating with atmosphere.

Abstract: The invention relates to a fuel supply device for model aircraft. To produce an excess pressure in the fuel tank in order to force the fuel into the engine, the fuel tank is connected to an excess pressure chamber (4) of an exhaust constructed in the form of a silencer. The casing (1) of the exhaust is subdivided by partitions (5, 6) into a number of chambers lying axially one behind the other. The excess pressure chamber (4) and the chamber (3) disposed therebehind in the direction of flow and directly connected to the exhaust gas outlet (9) are interconnected via a valve arrangement (16-18) which so operates after the fashion of a non-return valve that the valves are throttled in dependence on the inclined position of the exhaust. During climbing throttling is particularly heavy, so that a heavier excess pressure is formed in the chamber and therefore higher delivery pressure acts on the fuel in the tank. In this way the engine is supplied with enough fuel even during climbing.

Abstract: The invention relates to an exhaust silencer device for an internal combustion engine, for placement in the exhaust pipe of the engine. The device according to the invention comprises a damper plate disposed in the exhaust pipe and pivotably about a shaft substantially perpendicular to the longitudinal axis of the exhaust pipe between a closed position, in which the damper plate covers the major portion of the exhaust pipe flow area, and an open position, in which it permits substantially free flow through the exhaust pipe. An operating device is arranged to actuate the damper plate to adjust its position dependent on the exhaust flow through the exhaust pipe.

Abstract: An exhaust control system for use in an internal combustion engine for controlling the flow of exhaust gases discharged from the engine to the atmosphere. The apparatus determines a first condition representing the engine speed being higher than a predetermined value, a second condition representing the transmission being not in neutral, and a third condition representing the throttle valve being not at or near its closed position. A control circuit generates a command signal only upon simultaneous occurrence of the first, second and third conditions. The apparatus includes a device responsive to the command signal from the control circuit for increasing the effective area of the exhaust passage.

Abstract: An exhaust gas silencing assembly or unit of the wet-type receives the exhaust gases from a water cooled internal combustion engine used to power a water-going vehicle, such as a speed boat, and the coolant water from the water jacket of the engine. The exhaust gas and water mixture may be expelled through a downwardly directed combined exhaust gas and water outlet of the silencing unit, or in response to opening a valve in an exhaust flow tube of the unit, exhaust gases and some of the water may be expelled directly out an outlet opening of the silencing unit. When the water and exhaust gases are expelled downwardly into the turbulent waters and foam of the wake of the boat the level of sound emanating from the silencing unit is substantially minimized. Upon opening of the valve at an outlet end of the silencing unit to provide straight through fluid flow the sound level of the engine is at a maximum, but the back pressure imposed on an engine is at a minimum for providing maximum engine performance.

Abstract: A small arm having a barrel (11) with at least one transverse bore (14) and a detachable silencer (62) including an expansion chamber (58) communicating with the transverse bore, comprising selectively operable closure means (34) arranged in the path of the combustion gases between the interior of the barrel and the expansion chamber is characterized by an arrangement in which the closure means (34) is prevented from opening or remaining in the open position when the silencer (62) is not in place. Thus, any risk of injury to the shooter is excluded.

Abstract: An exhaust diffusion apparatus positionable between noise level control and performance modes defining a restricted diffusion passage and an unrestricted exit port for performance operation which may be closed to effect noise level control operation.

Abstract: A device for attenuating noise of fluid in non-axisymmetric turbulent flow which comprises a conduit and a plurality of parallel aligned nested tubes in said conduit. The nested tubes are of varying cross-sectional size and have approximately the same cross-sectional shape. The tubes are eccentrically aligned with respect to each other such that a lower surface of each tube is in closely spaced relationship or is in substantially line contact with a surface of an adjacent tube along their longitudinal lengths, the line contact between all of the tubes being substantially at a common line, allowing for the thickness of the tube walls. A brace extends through and interconnects the nested tubes. In one embodiment, the noise attenuating device is spaced closely downstream from a reverse flow ball valve to provide a smooth transition from the non-axisymmetric flow discharging from the valve to substantially axisymmetric flow (or fully developed pipe flow) in the conduit downstream of the valve.

Abstract: When exhaust gases reach an abnormally high temperature, a bimetal valve opens and the muffler operates abnormally to produce a loud noise.