An apparatus and method are provided for a drone elimination muffler to attenuate drone exhibited by engine exhaust systems. The drone elimination muffler comprises a hollow canister having a length and a diameter, and a tuned port comprising a first end connected to the canister and a second end connected to the exhaust system. The canister operates in concert with the tuned port as a dampener configured to substantially attenuate exhaust drone, or resonance, at one or more frequencies of engine operation. A valve is configured to switch the drone elimination muffler between a closed state in which the exhaust system operates without acoustic influence due to the drone elimination muffler, and an open state in which the drone elimination muffler directly influences the acoustic properties of the exhaust system.

The valve includes a valve body that inwardly defines a passage for circulation of a fluid, a drive shaft, and a bearing to guide the rotation of the drive shaft. The bearing comprises a chamber surrounding a segment of the drive shaft and a plurality of balls filling the chamber. The balls are free inside the chamber, and the chamber is completely filled with balls. The balls are in contact with the drive shaft along all or part of the segment.

A snap-action valve assembly for an exhaust system is provided with a conduit that defines an exhaust passageway. A valve flap is disposed within the exhaust passageway for controlling exhaust flow. A shaft supports the valve flap in the exhaust passageway and allows the valve flap to rotate between closed and open positions. A mass damper, positioned outside the conduit, includes a longitudinal segment that is rotatably coupled to the shaft and that extends between first and second coiled ends. The longitudinal segment includes an inboard side and an outboard side. The first and second coiled ends include a series of overlapping layers arranged in either a folded serpentine shape or a spiral shape.

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.

Gas flow and sound control valve for an exhaust system of an internal combustion engine comprising a housing including an inlet, a first outlet, and a second outlet, and a valve member arranged within the housing for forming a first conduit connecting the inlet to the first outlet and/or a second conduit from the inlet to the second outlet, wherein the valve member can be moved relative to the housing between a first predetermined position in which the valve member closes the second conduit and a second predetermined position in which the valve member closes the first conduit, whereby the valve member is rotatable around a valve axis aligned parallel, in particular coaxial, to a centerline of the inlet.

A changeover valve includes: a valve body portion that closes an opening formed at a switching position of an exhaust flow path; a fixing portion that rotatably fixes the valve body portion; a first raised portion protruding at one of a flow path forming portion and the fixing portion; a cushion portion; a second raised portion protruding at the valve body portion; and a biasing portion that biases the valve body portion. The first raised portion has an inclined portion inclined relative to a valve closing direction and the second raised portion has an inclined portion inclined relative to the valve closing direction. Both of the inclined portions are contactable with each other at the time of valve closing.

A muffler for an exhaust system of an internal combustion engine, especially for vehicles with hybrid drive, includes a muffler housing (12), a heat exchanger unit (48), arranged in the muffler housing (12), for transferring heat from combustion exhaust gas to a heat transfer medium, an inlet pipe (38), a first outlet pipe (52) and a second outlet pipe (40). A first exhaust gas flow path (54), in the muffler housing, routs exhaust gas through the heat exchanger unit (48) to the first outlet pipe (52). A second exhaust gas flow path (56), in the muffler housing, routs exhaust gas to a second outlet pipe (40), bypassing the heat exchanger unit (48). A flow path blocking/releasing device (58) for blocking and releasing at least one exhaust gas flow path (54, 56), of the first exhaust gas flow path (54) and of the second exhaust gas flow path (56).

A muffler for a vehicle, where the muffler comprises a partition wall that divides the interior in a first chamber and a second chamber, where an inlet pipe comprising a perforated section arranged in the first chamber and a closed section arranged in the first chamber, where the outlet opening of the inlet pipe is arranged in the second chamber, a first outlet pipe comprising an inlet opening arranged in the first chamber and an outlet opening arranged outside of the muffler, where the muffler comprises a second outlet pipe having an inlet opening arranged in the second chamber, and where the second outlet pipe is provided with an exhaust valve adapted to open or close the exhaust gas flow through the second outlet pipe. The advantage of the invention is that a muffler with an improved low frequency noise attenuation and low backpressure is provided.

A vehicle is provided with an engine having an exhaust gas system comprising a muffler body containing a valve controlling exhaust gas flow through a tuning tube. The vehicle has an expander, a condenser, a pump, and an evaporator in sequential fluid communication in a closed loop containing a working fluid. The evaporator is positioned within the body and supports the valve and tuning tube therein, with the evaporator in thermal contact with exhaust gas and the working fluid.

One aspect of the present disclosure provides an exhaust unit including a housing, a wall member, a catalyst, and a muffler chamber. The housing includes a feed inlet and a discharge outlet. The housing is configured such that an exhaust gas of an internal combustion engine is introduced from the feed inlet, and the exhaust gas is discharged from the discharge outlet. The wall member is disposed in the housing, and forms a cylindrical flow path that guides a flow of the exhaust gas introduced from the feed inlet to curve along an outer circumference of an interior of the housing. The catalyst is disposed in the flow path. The muffler chamber communicates with the flow path in a downstream side of the catalyst in the flow path. The wall member serves as a part of a wall that defines an inside and an outside of the muffler chamber.