An exhaust gas purification system comprises an exhaust gas purification device which is arranged in an exhaust gas route of an engine, renewing devices for burning and removing a particulate matter within the exhaust gas purification device, renewal advance notifying means which is actuated in the case that a clogged state of the exhaust gas purification device becomes equal to or more than a prescribed level, and renewal informing means which informs of a fact that the renewing devices are under operation. The renewal advance notifying means is actuated before actuating the renewing devices.

An aftertreatment system (100) connected downstream an internal combustion engine arrangement (102) for receiving exhaust gases conveyed from the internal combustion engine arrangement (102) during operation thereof, wherein the aftertreatment system comprises first and second catalytic devices in series, wherein a gap is there between.

An exhaust duct assembly for conveying exhaust gases emanating from a combustion zone to atmosphere is disclosed. The assembly includes: an exhaust gas outlet for exhausting exhaust gas into the atmosphere; and an acoustic duct portion located upstream of the exhaust gas outlet, the acoustic duct portion having a peripheral wall defining a through-passage arranged and constructed to promote propagation of sound there-through. The acoustic duct portion has a length in a flow direction that is at least 50% of an average hydraulic diameter of the through-passage.

A vehicle exhaust system includes an upstream exhaust component comprising at least a first catalyst having a first outer dimension, a downstream exhaust component comprising at least a second catalyst having a second outer dimension, and a mixer that connects the upstream and downstream exhaust components. The mixer comprises a first portion associated with an outlet from the first catalyst and a second portion associated with an inlet to the second catalyst. The first portion includes a swirl component having a first length and the second portion includes an additional component having a second length. A connection interface between the first and second portions allows the upstream and downstream exhaust components to be arranged in different positions relative to each other. A combined length of the first and second lengths is adjusted relative to the first and second outer dimensions to achieve a desired position of the upstream and downstream exhaust components relative to each other.

An aftertreatment component includes an inlet connector tube, an outlet connector tube, a chamber, a flow dissipater, and a substrate. The inlet connector tube receives exhaust gasses. The chamber is between the inlet connector tube and the outlet connector tube. The flow dissipater is positioned around the inlet connector tube and within the chamber. The flow dissipater receives the exhaust gasses from the inlet connector tube and includes a plurality of perforations. The plurality of perforations defines an open area of the flow dissipater. The open area of the flow dissipater is greatest proximate to the inlet connector tube and progressively decreasing proximate to the outlet connector tube. The substrate is positioned within the chamber and receives the exhaust gasses from the flow dissipater and provides the treated exhaust gasses to the outlet connector tube. The exhaust gases are expelled through the flow dissipater via the plurality of perforations.

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 muffler main body includes a cylindrical portion and a reduced diameter portion joined to a downstream side end portion of the cylindrical portion and having a diameter reduced toward the downstream side thereof. The pipe includes a center pipe passing through the cylindrical portion, and a tail pipe disposed in the reduced diameter portion. An expansion chamber is formed by a space in the reduced diameter portion in the vicinity of the tail pipe.

An exhaust muffler includes first and second pipes which extend through a casing, and which are disposed so that a downstream end of the first pipe faces an upstream end of the second pipe, wherein the downstream end of the first pipe and the upstream end of the second pipe are disposed so as to be spaced from each other in an axial direction, one end part of a support member having a circular cross section that has a smaller diameter than those of the first and the second pipes is fixed to one of a first lid member covering an opening at the downstream end of the first pipe and a second lid member covering an opening at the upstream end of the second pipe, and the other end part of the support member is slidably fitted to the other of the first and the second lid members.

An exhaust system assembly including a catalyst housing, a catalyst core, and a swirler tube positioned inside the catalyst housing. The swirler tube has a plurality of openings that permit radial exhaust flow into an inner volume of the swirler tube from the catalyst housing. One end of the swirler tube has blades that extend inward and include oblique surfaces arranged at oblique angles relative to a centerline axis of the swirler tube. These blades induce a vortex in the exhaust gases exiting the first swirler tube end. The swirler tube is arranged inside the catalyst housing such that a sequential flow path is created where the exhaust gases flowing through the catalyst housing must first pass through the openings in the swirler tube and then by the blades at the first swirler tube end.

A structure is provided for installing a pipe fixing clamp installed in a sound absorber. A part of a curved pipe portion of an internal structural pipe of the sound absorber is cut to form an exhaust gas flow space. The pipe fixing clamp having multiple holes is connected to the exhaust gas flow space.

A muffler unit includes: an inner cylinder connected with a first exhaust pipe; a first outlet pipe that is connected with a downstream end of the inner cylinder and through which exhaust gas is discharged; an outer cylinder that houses thereinside the inner cylinder and defines, between the outer cylinder and an outer surface of the inner cylinder, an expansion chamber communicating with the second exhaust pipe; and a second outlet pipe that houses thereinside the first outlet pipe and defines, between the second outlet pipe and an outer surface of the first outlet pipe, a path connected with the expansion chamber to thereby be used for discharging the exhaust gas. Accordingly, there is provided the muffler unit having a size reduced compared with a configuration including two mufflers disposed in parallel with each other.