An exhaust muffler includes a first muffler section connected to an exhaust pipe and a second muffler section connected to the first muffler section. Exhaust gases delivered from the exhaust pipe are discharged from the first muffler section and the second muffler section out of the exhaust muffler. The first muffler section includes a tubular member made up of an inner pipe to which the exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and the second muffler section to each other. The first muffler section has a first expansion chamber defined therein between the inner pipe and the outer pipe. The inner pipe houses therein a valve for changing an amount of exhaust gases passing through the inner pipe. The first muffler section includes a curved portion that is curved vertically as viewed in side elevation of the vehicle. The exhaust muffler has a second expansion chamber defined in the second muffler section rearward and upward of the first muffler section, the second expansion chamber having a cross-sectional area larger than a cross-sectional area of the first expansion chamber. There is thus provided an exhaust device for an internal combustion engine, which includes a muffler compact in a longitudinal direction thereof.

A damper valve assembly for an exhaust system of a vehicle includes a valve housing and a valve flap. The valve housing is adapted to be attached to a pipe of the exhaust system and defines an opening. The valve flap is rotatable relative to the valve housing and about a pivot axis between a first position whereat fluid flow through the opening of the valve housing is restricted and a second position whereat fluid flow through the opening of the valve housing is allowed. The valve flap includes a body and a mass damper. The mass damper is integral with the body and includes a plurality of segments that are folded so that the plurality of segments are in a stacked arrangement.

A system for regulating performance characteristics of a vehicle includes an engine configured to output an exhaust gas. The system further comprises an emissions system in fluid communication with the engine, the emissions system configured to clean the exhaust gas. The system further comprises a valve system in fluid communication with the emissions system, the valve system configured to regulate a flow of the exhaust gas. The valve system comprises a vane movable between a forward open position, a closed position, and a rear open position. The valve system further comprises a biasing member configured to bias the vane in the forward open position. The valve system further comprises a bypass channel configured to provide a bypass flow path for the exhaust gas to control a backpressure on the vane.

An exhaust gas flap, especially for the exhaust gas stream of an internal combustion engine, includes a flap tube (24), a flap diaphragm (26). The flap diaphragm (26) is carried in the interior of the flap tube (24) on a pivot shaft (18), rotatable about a pivot axis (A). The flap diaphragm (26) has at least one flap diaphragm part (28, 30) and a mounting area (40) enclosing the pivot shaft (18) in at least some areas. A wing stop (42, 44) is provided at an inner circumferential area of the flap tube (24) in association with at least one flap diaphragm part (28, 30). A recess (60, 62, 64, 66) at the flap diaphragm (26), receiving a circumferential end area (48, 50) of a wing stop (42, 44), is provided in at least one axial end area of the mounting area (40).

A device for reducing total hydrocarbon (THC) contained in exhaust gas in a CNG-diesel dual fuel engine system, includes: an engine providing power for the diesel and outputting exhaust gas due to operation; a MOC (Methane Oxidation Catalyst) oxidizing and discharging CH.sub.4 contained in exhaust gas discharged from the engine; an exhaust valve disposed in a pipe connecting the rear end of the engine and the front end of the MOC, and discharging the exhaust gas produced by the engine; a first temperature sensor disposed at the front end of the exhaust valve and measuring the temperature of exhaust gas coming from the engine; a second temperature sensor disposed at the rear end of the exhaust valve and measuring the exhaust gas discharged from the exhaust valve and flowing into the MOC; and an exhaust valve control unit increasing the temperature of exhaust gas flowing into the MOC.

An adaptive valve assembly includes a pipe defining a passageway for conducting engine exhaust gases, a pivot shaft supported by the pipe, and a valve body coupled to the pivot shaft. The valve body is moveable between an open position where exhaust gas flow through the passageway is increased and a closed position where exhaust gas flow through the passageway is reduced. A spring biases the valve body toward the closed position. The spring includes a plurality of coils that have torsional displacement relative to each other as the valve body moves between the open and closed positions. A torsional damper feature is associated with at least one coil of the plurality of coils to provide torsional spring damping.

An exhaust valve device includes a valve body, a valve seat, a support shaft, a coil spring, and a cushion member. The valve body is placed in an exhaust passage in a silencer, and configured to open and close the exhaust passage. The valve body abuts against the valve seat when the valve body is closed. The support shaft is fixed to the valve seat, and supports the valve body to be able to swing freely. The support shaft is inserted in the coil spring. The coil spring biases the valve body. The cushion member is interposed between the coil spring and the support shaft. The cushion member is rotatable relative to the support shaft.

A vehicle exhaust system includes an exhaust pipe defining an exhaust gas flow path, a heat recovery device connected to the exhaust pipe, and a diverter valve that controls exhaust gas flow between the exhaust pipe and heat recovery device. The diverter valve is moveable between at least a heat recovery mode where the diverter valve blocks flow through the exhaust pipe and directs flow into the heat recovery device, a full bypass acoustic mode where the diverter valve blocks flow through the heat recovery device and directs flow through the exhaust pipe, a transition mode where the diverter valve partially blocks flow through the heat recovery device and partially blocks flow through the exhaust pipe, and a partial bypass acoustic mode where the diverter valve blocks flow through the heat recovery device and partially blocks flow through the exhaust pipe.

An article of manufacture includes a rigid plate, first and second tab members defined by a pair of substantially diametrically-opposed U-shaped apertures within the plate, and a third tab member defined by a U-shaped aperture proximal to the first and the second tab members. The article of manufacture can be used as an active exhaust defeat device, providing the capability of locking a butterfly valve of a vehicle active exhaust system in a desired orientation. Although the butterfly valve is locked, which may be a non-standard exhaust configuration, the article of manufacture provides that vehicle error codes specific to an exhaust valve actuator are avoided.

A snap-action valve assembly for an exhaust system and a method for manufacturing the same is provided. The valve assembly includes a first conduit and a second conduit that is partially received in the first conduit. A valve flap is disposed within the first conduit for controlling exhaust flow. A shaft supports the valve flap in the first conduit for rotation between open and closed positions. The first conduit has first and second slots, each extending from an open slot end to a closed slot end. First and second bushings supporting the shaft are disposed within the slots between the second conduit and the closed slot ends. A pad made of wire mesh is attached to the valve flap. The pad includes an end portion that contacts the first conduit in the closed position to dampen vibration and reduce valve flap flutter.