Abstract: The device for attenuation of noise in a tube intended to transport a gas includes a branch tube having two ends which open into said tube by two connections, and at least one tube referred to as quarter wave tube having a closed end referred to as the free end and another end which is connected to said tube at the level of the connections of the branch tube, thus forming three sections of circulation of gas entering into said tube. The invention can be applied in the field of motor vehicles.

Abstract: The present invention relates to an apparatus for controlling exhaust noise in an internal combustion engine by using the length difference between the exhaust pipe and the bypass pipe. The apparatus comprises an exhaust pipe for outwardly releasing exhaust gas from the engine; a bypass pipe variable in length which diverges from said exhaust pipe with a distance and has U-shaped and reverse U-shaped sections formed alternately; an actuator having an actuating rod connected to said bypass pipe to vary the length of said bypass pipe; and a control unit for controlling said actuator. The bypass pipe has the U-shaped and reverse U-shaped sections arranged alternately so that the variable length of the bypass pipe can be extended while minimizing the space for installing the bypass pipe, and thereby noise in the low frequency band can be suitably reduced.

Abstract: An exhaust processor includes a housing formed to include an interior region and a partition or first spark arrester that partitions the interior region into chambers and includes a wool filter formed to include an opening. The wool filter is positioned to filter unburned carbon particles from combustion product generated by a vehicle engine. The exhaust processor further includes an outer conduit that extends through the opening formed in the wool filter and is formed to include a passage and an inner conduit that extends into the passage and is formed to include an opening through which unburned carbon particles flow from inside the inner conduit to impinge against the outer conduit so that the outer and inner conduits operate as a second spark arrester.

Abstract: A silencer for an idle air bypass valve in an internal combustion engine includes a grid disposed between the outlet of the idle air bypass valve and the intake manifold. The grid acts to reduce the air velocity entering into the intake manifold which dampens the vibration of a plastic manifold, thereby reducing noise generated.

Abstract: An exhaust assembly for use with a motor vehicle having a combustion engine. The exhaust assembly includes an exhaust and a muffler having first and second gas flow routes. A control device controls the damping characteristic of the exhaust assembly by selectively dividing the gas flow by different amounts between the different gas flow routes. The control device, which may include a valve or a sliceable sleeve, is selectively operable by a user manually or electronically while the combustion engine is operating.

Abstract: An automatic compression brake muffler is provided including a muffler pipe. An auxiliary pipe is connected to the muffler pipe and defines passages which are offset from the muffler pipe. Next provided is a mechanical valve having an open orientation for allowing the passage of air through the entire muffler pipe and a closed orientation for precluding the passage of air through the entire muffler pipe and further forcing air through the auxiliary pipe. Finally, a mechanism is included for transferring the mechanical valve to the closed orientation only when a compression brake is actuated.

Abstract: A silencer for an idle air bypass valve in an internal combustion engine includes a grid disposed between the outlet of the idle air bypass valve and the intake manifold. The grid acts to reduce the air velocity entering into the intake manifold which dampens the vibration of a plastic manifold, thereby reducing noise generated.

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: A muffler disposed close to the atmospheric discharge end of the exhaust system, consisting of an accelerating part (4) which accelerates the exhaust gas flow and a negative pressure chamber (5) which generates negative pressure in association with the acceleration thereof. Said negative pressure acts to connect the negative pressure chamber (5) with the flow-distributing chamber (2) disposed on the exhaust pipe (1) at the upper stream of the silencing part (19) by means of the bypass (9), in order to promote suction of the exhaust gas flow. The flow-distributing chamber (2), which has a larger cross-sectional area than that of the exhaust pipe (1), contains at its center an exhaust port (3) which is opened to the accelerating part (4), and flow-distributing holes (7) that are opened to the bypass (9) in the peripheral area.

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: The apparatus would include a body portion positionable intermediate the exhaust manifold and the muffler or the catalytic converters if the car is adapted with such, so that exhaust gases, under a first condition, can flow through the body portion and into the muffler prior to exiting to atmosphere, and under a second condition, via the removal of a plate member, a greater portion of the exhaust gases would be exhausted directly out to atmosphere bypassing the remainder of the exhaust system including the muffler and/or catalytic converter.

Abstract: An exhaust silencer system for piston type internal combustion engines hag a wet-exhaust, having a muffler and a muffler bypass which contains water at slow and moderate engine speeds, the water being expelled by the exhaust gas pressure at high engine speed, opening said bypass to the flow of exhaust gases thus reducing the exhaust back pressure occurring in the muffler.