Provided is a tail pipe in which a silencing effect at a discharge port is obtained. One aspect of the present disclosure is a tail pipe including: an inner tube including a discharge port configured such that an exhaust gas is discharged therefrom; an outer tube arranged so as to form a space between the outer tube and the inner tube by surrounding an outer peripheral surface of the inner tube, an upstream end of the outer tube in a flow direction of the exhaust gas being closed; and at least one communication hole allowing communication between an interior of the inner tube and the space.

Disclosed is a silencer for fuel cell vehicles. The silencer for fuel cell vehicles includes a housing having an inlet configured to receive air and hydrogen flowing into the housing therethrough, an outlet, and a condensation water drain hole configured to discharge condensation water to the outside therethrough, a distribution plate disposed in the housing and having distribution holes to distribute air and hydrogen flowing into the housing, a rotary plate disposed in the housing closer to the outlet than the distribution plate, a motor connected to the rotary plate to rotate the rotary plate, and an anti-freezing unit extending from one end of the rotary plate to the condensation water drain hole.

Apparatuses and methods for tuning a muffler. An apparatus comprises a housing for a muffler, a first inlet pipe, and a second inlet pipe. The housing includes a coupling chamber. The first inlet pipe has a first set of physical features and carries exhaust to the coupling chamber. The second inlet pipe has a second set of physical features and carries the exhaust to the coupling chamber. The first set of physical features varies from the second set of physical features with respect to at least one physical feature such that a first sound waveform passing through the first inlet pipe and a second sound waveform passing through the second inlet pipe are uniquely tuned to thereby tune an overall sound waveform emitted by the muffler.

A muffler includes a first tube defining a first inlet for receiving exhaust and a first outlet. The muffler includes a housing defining a tuning chamber. The muffler includes a second tube at least partially received within the first tube. Further, the second tube defines a second inlet disposed within the first tube and a second outlet disposed in fluid communication with the tuning chamber. The muffler further includes a muffler outlet for discharging exhaust from the muffler. Moreover, the first tube and the second tube define an annular passage therebetween. The annular passage is disposed in fluid communication with the first outlet of the first tube and the muffler outlet.

A muffler for receiving exhaust gas from a combustion engine is disclosed. The muffler includes a casing and a pipe. The casing includes a shell coupled to first and second end caps that cooperate to define an internal volume. The pipe is disposed within the internal volume and extends substantially a length of the shell. Each of the first and second end caps includes a circumferentially extending flange engaging an outer surface of the pipe to provide support for the pipe. Each circumferentially extending flange extends at an acute angle relative to a shell axis of the shell. Each circumferentially extending flange is coaxial along a pipe axis of the pipe.

A muffler structure contains: a body, a first cover unit, and a second cover unit. The body includes an accommodation tube, fiber cotton, and a first mesh portion. The accommodation tube has an accommodating space and an internal fence. The first cover unit includes a manifold connection portion, a first polygonal cap, a hollowly tubular mesh having multiple orifices, a second mesh portion, and a stainless steel mesh. The second cover unit is fixed on a rear end of the accommodation tube of the body opposite to the first cover unit, and the second cover unit includes a second polygonal cap and a silencer. The second polygonal cap is covered on the accommodation tube of the body, and the second polygonal cap has a receiving portion defined in a free end thereof and configured to accommodate the silencer.

There is provided a muffler structure of a saddle-type vehicle. The muffler structure is disposed at a downstream side of an exhaust pipe extending from an exhaust port of a cylinder head. A pipe is connected to the exhaust pipe and inserted into a muffler main body. The pipe is provided with an expansion chamber having an inner diameter that is larger than an inner diameter of the exhaust pipe. At least a part of the expansion chamber is disposed in the muffler main body, and a plurality of through holes are formed on an outer peripheral surface of the expansion chamber disposed in the muffler main body.

An exhaust gas purification device includes a pre-oxidation catalyst disposed in an exhaust gas passage and a muffler that is provided in such a manner as to surround the pre-oxidation catalyst, and discharges exhaust gas while reducing noise. The muffler has an inlet which is connected to an upstream side exhaust pipe and an outlet which is connected to a downstream side exhaust pipe. The exhaust gas purification device includes a downstream side purification device that is disposed in the exhaust gas passage, and accommodates a second oxidation catalyst and a particulate matter removing filter. The exhaust gas is discharged to the atmosphere after the exhaust gas flows through the downstream side purification device.

An exhaust muffler includes a first muffler section having a tubular member made up of an inner pipe to which an exhaust pipe is connected and an outer pipe covering the inner pipe, and a connector connecting the tubular member and a second muffler section to each other, and the second muffler section having an outer shell, a first partition wall, a second partition wall, and a third partition wall. 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 second muffler section has a cross-sectional area larger than a cross-sectional area of the tubular member. The exhaust muffler includes a first expansion chamber, a second expansion chamber, and a third expansion chamber. The second muffler section includes a fluid communication pipe extending through the first partition wall and the second partition wall for leading exhaust gases from the first expansion chamber into the second expansion chamber, and an exhaust passage pipe held in fluid communication with the third expansion chamber and extending through the second partition and the third partition wall. The second partition wall has a fluid communication hole defined therein that provides fluid communication between the second expansion chamber and the third expansion chamber. There is thus provided an engine exhaust device capable of increasing a silencing capability by increasing the length of a route through which the exhaust gases flow while maintaining the length of the exhaust device.

A muffler for an exhaust system of an internal combustion engine includes a housing, a through pipe that conducts exhaust gas during operation of the muffler and is guided through the housing, and a branch pipe fluidically branching off from the through pipe within the housing. The branch pipe has an upstream end at the through pipe and ends freely and open at an end face with a downstream end within the housing. The branch pipe has a length from the upstream to the downstream end or up to a lateral recess which has a cross-sectional area which is greater than half a pipe cross-section of the branch pipe. The branch pipe has downstream perforations in a section from ⅜ of the length as measured from the upstream end A total area of the downstream perforations is smaller than half the pipe cross-section of the branch pipe, and no perforations or upstream perforations have a total area of at most 10% of the pipe cross-section of the branch pipe being present in a section before ⅜ of the length.