An exhaust system noise reduction device of a vehicle enables an exhaust system to contribute to an increase in engine output while reducing engine exhaust noise. The exhaust system noise reduction device includes a muffler housing formed to airtightly surround a rear end section of an exhaust pipe; a branch pipe branched from a front end section of the exhaust pipe while having a rear end section of the branch pipe extend through the muffler housing; a barrier wall disposed at a peripheral surface of the rear end section of the exhaust pipe to divide an inner space of the muffler housing into a first chamber and a second chamber; and a punched portion formed at the rear end section of the branch pipe and disposed in the first chamber. A resonance chamber structure for reducing exhaust noise is formed in the first chamber, thereby reducing exhaust noise.

A muffler for a vehicle includes: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve includes: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve arm connected to the valve plate; and a valve actuator to move the valve arm by variations in pressure of the exhaust gas. The valve plate is capable of rotating in a plane parallel to a plane of the baffle.

An exhaust heat recovery system may include a muffler including a muffler case, a pipe through which exhaust gas flows, a baffle partitioning an internal space of the muffler case into a first space and a second space, and a valve mounted on an end portion of the pipe to change a direction in which the exhaust gas flows, and a heat exchanger mounted outside the muffler to fluidically-communicate with both the first and second spaces, allowing the exhaust gas to be introduced thereinto and to be discharged therefrom, the heat exchanger including a cooling channel through which cooling water flows, and heat exchange between the exhaust gas and the cooling water being performed in the heat exchanger.

The present disclosure provides a muffler, a compressor assembly, and a refrigerator. The muffler includes a housing and a partition member. The housing includes a cavity, a gas inlet, and a gas outlet. The gas inlet and the gas outlet are respectively in communication with the cavity. The partition member is disposed in the housing. The partition member partitions the cavity into a resonant cavity and a muffling cavity that are isolated from each other. The resonant cavity is in communication only with the gas inlet. The muffling cavity is in communication with both the gas inlet and the gas outlet. The technical solutions of the present disclosure effectively resolve the problem in prior art that a muffler having a simple chamber structure cannot effectively, simultaneously reduce noise in different frequency ranges.

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.

An exhaust heat recovery system may include a muffler including a muffler case, a pipe through which exhaust gas flows, a baffle partitioning an internal space of the muffler case into a first space and a second space, and a valve mounted on an end portion of the pipe to change a direction in which the exhaust gas flows, and a heat exchanger mounted outside the muffler to fluidically-communicate with both the first and second spaces, allowing the exhaust gas to be introduced thereinto and to be discharged therefrom, the heat exchanger including a cooling channel through which cooling water flows, and heat exchange between the exhaust gas and the cooling water being performed in the heat exchanger.

A mixer for a vehicle exhaust system includes an outer housing that defines an internal cavity, an inlet pipe that directs exhaust gas into the internal cavity, and an outlet baffle. The outer housing includes a doser opening configured to receive a doser. The outlet baffle directs a mixture of the exhaust gas and a reducing agent injected by the doser into a downstream exhaust component. A deflector deflects exhaust gas exiting the inlet pipe to mix with the reducing agent prior to entering the downstream exhaust component.

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 method of manufacturing a subassembly for an exhaust treatment device includes providing a metal sheet including first and second apertures having respective first and second sizes, and a one-piece pipe including first and second linear portions having respective third and fourth sizes. The method further includes defining the first size based on a first difference between the first size and the third size being less than or equal to a predetermined value, and defining the second size based on manufacturing tolerances of the pipe to assure that the second linear portion will pass through the second aperture while the first linear portion passes through the first aperture. The method further includes fixing the first linear portion to the sheet, expanding the second linear portion from the fourth size to an enlarged size less than or equal to the predetermined value, and fixing the second linear portion to the sheet.

An inlet for an SCR device including a tube having an upstream end for receiving exhaust gases and a downstream end terminating in a porous wall. A plurality of openings are spaced around the circumference of the tube adjacent the porous wall and a plurality of vanes are formed at a connection junction adjacent one edge of the opening to form vanes extending inward at an acute angle relative to a plane between the connecting junction and the longitudinal axis of the tube. Preferably, the vanes are concave on the surface extending inward to promote more effective mixing.