Provided acoustic devices include an external housing defining an expansion chamber and a wall extending through and partitioning the expansion chamber into a central chamber and a peripheral chamber adjacent the central chamber, wherein an inlet and outlet communicate with the central chamber, and wherein the wall includes a plurality of apertures formed therethrough to allow air movement to and from the central and expansion chambers, the plurality of apertures sized to provide an average flow resistance ranging from 100 MKS Rayls to 5000 MKS Rayls. The acoustic devices advantageously show significant sound attenuation while streamlining air flow to reduce pressure drop across the expansion chamber.

An internal combustion (IC) power plant includes an IC engine and an exhaust system carrying exhaust gasses from the IC engine to an outlet communicating to the atmosphere.

An internal combustion (IC) power plant includes an IC engine and an exhaust system carrying exhaust gasses from the IC engine to an outlet communicating to the atmosphere.

An exhaust muffler is made up of a plurality of layers including an exhaust passage pipe and expansion chambers, and includes a front assembly and a rear assembly sub-assembled separately from the front assembly. The front assembly includes a front exhaust passage pipe, a front muffler body disposed in covering relation to the outside of the front exhaust passage pipe and cooperating with the front exhaust passage pipe in making up double-walled pipes, and an exhaust valve disposed in the front exhaust passage pipe. The rear assembly includes a rear exhaust passage pipe and a rear muffler body disposed in covering relation to the outside of the rear exhaust passage pipe and cooperating with the rear exhaust passage pipe in making up double-walled pipes. There is thus provided an exhaust device for an internal combustion engine in which the accuracy of a position where the exhaust valve is installed is high.

An exhaust muffler is made up of a plurality of layers including an exhaust passage pipe and expansion chambers, and includes a front assembly and a rear assembly sub-assembled separately from the front assembly. The front assembly includes a front exhaust passage pipe, a front muffler body disposed in covering relation to the outside of the front exhaust passage pipe and cooperating with the front exhaust passage pipe in making up double-walled pipes, and an exhaust valve disposed in the front exhaust passage pipe. The rear assembly includes a rear exhaust passage pipe and a rear muffler body disposed in covering relation to the outside of the rear exhaust passage pipe and cooperating with the rear exhaust passage pipe in making up double-walled pipes. There is thus provided an exhaust device for an internal combustion engine in which the accuracy of a position where the exhaust valve is installed is high.

An exhaust gas aftertreatment system for an internal combustion engine is disclosed. In one embodiment, the system has a first aftertreatment element including a first inlet region and a first outlet region, and a second aftertreatment element including a second inlet region and a second outlet region The first outlet region is connected to the second inlet region via at least one connection section, and the at least one connection section extends outside the first aftertreatment element. At least parts of the first inlet region and of the second inlet region are arranged in a common distributor housing.

An exhaust pipe includes a tubular portion and a space forming portion. The tubular portion forms an exhaust flow path in an exhaust system of an internal combustion engine. The tubular portion has a tubular shape. The space forming portion is provided along at least one of an inner surface and an outer surface of the tubular portion and forms at least one branch space between the space forming portion and the tubular portion. The at least one branch space communicates with the exhaust flow path and has a function as a side-branch muffler. The at least one branch space includes a space with a length that is one third or more of an entire length of the exhaust system.

An exhaust pipe includes a tubular portion and a space forming portion. The tubular portion forms an exhaust flow path in an exhaust system of an internal combustion engine. The tubular portion has a tubular shape. The space forming portion is provided along at least one of an inner surface and an outer surface of the tubular portion and forms at least one branch space between the space forming portion and the tubular portion. The at least one branch space communicates with the exhaust flow path and has a function as a side-branch muffler. The at least one branch space includes a space with a length that is one third or more of an entire length of the exhaust system.

An exhaust system includes a housing comprising a first housing portion and a second housing portion separated by a common wall. The first housing portion has a first exhaust passage therethrough. The first exhaust passage has a first inlet receiving exhaust gasses from a turbocharger. The second housing portion has a second exhaust passage therethrough. The second exhaust passage has a second inlet receiving gasses from an exhaust bypass valve. The first passage and the second passage are non-intersecting within the housing.

An exhaust system includes a housing comprising a first housing portion and a second housing portion separated by a common wall. The first housing portion has a first exhaust passage therethrough. The first exhaust passage has a first inlet receiving exhaust gasses from a turbocharger. The second housing portion has a second exhaust passage therethrough. The second exhaust passage has a second inlet receiving gasses from an exhaust bypass valve. The first passage and the second passage are non-intersecting within the housing.