A muffler for receiving exhaust gas from a combustion engine comprises a shell, first and second inlet pipes each having outlets providing exhaust gas to a mixing chamber within the shell, a first chamber and a second chamber positioned within the shell and a pair of communication pipes each including an inlet receiving exhaust gas from the mixing chamber. Each communication pipe includes an outlet providing exhaust to the second chamber. Each of the communication pipes further includes a Helmholtz opening positioned downstream of the mixing chamber. The Helmholtz openings are open to the first chamber.

A two-stroke engine exhaust resonator with an exhaust gas catalytic converter comprising an inlet opening, wherein the inlet opening is followed by the first end of a stabilizing tube with a catalytic converter mounted thereon, characterized in that the other end of the stabilizing tube is directed towards the primary reflective surface, the primary reflective surface is followed by the first end of a resonator casing, which is surrounding the stabilizing tube, wherein the resonator casing exceeds at least over a part of the catalytic converter on the stabilizing tube, wherein a resonator outlet opening is arranged in the resonator casing between its first and second end or in the primary reflective surface, and at least a part of the resonator casing surrounding the stabilizing tube is surrounded by a cooler.

A decomposition chamber for an aftertreatment system includes: a body comprising: an inlet configured to receive exhaust gas, an outlet configured to expel the exhaust gas, a thermal management chamber in fluid communication with the inlet, the thermal management chamber configured to receive an exhaust gas first portion from the inlet, an exhaust assist chamber in fluid communication with the inlet, the exhaust assist chamber configured to receive an exhaust gas second portion from the inlet, and a main flow chamber in fluid communication with the inlet, the main flow chamber configured to receive an exhaust gas third portion from the inlet, receive the exhaust gas first portion from the thermal management chamber, and receive the exhaust gas second portion from the exhaust assist chamber.

A decomposition chamber for an aftertreatment system includes: a body including: an inlet configured to receive exhaust gas; an outlet configured to expel the exhaust gas, a thermal management chamber in fluid communication with the inlet, the thermal management chamber configured to receive a first portion of the exhaust gas from the inlet, and a main flow chamber in fluid communication with the inlet, the main flow chamber configured to receive a second portion of the exhaust gas from the inlet and to receive the first portion of the exhaust gas from the thermal management chamber; and a diffuser positioned within the main flow chamber, the diffuser including: a diffuser inlet portion including a plurality of diffuser perforations, the diffuser inlet portion configured to receive the exhaust gas from the main flow chamber, and a diffuser flange portion configured to receive the exhaust gas from the diffuser inlet portion and provide the exhaust gas to the outlet.

The invention relates to an annular catalytic converter, having a first, tubular flow path, having a diverting region (4) and having a second, annular flow path, wherein the tubular flow path is formed by an inner pipe (1), wherein the annular flow path is formed between the inner pipe (1) and an outer pipe (2) surrounding the inner pipe, and the diverting region (4) is of pot-shaped form for the purposes of diverting the exhaust-gas flow from the tubular flow path into the annular flow path, wherein the inner pipe (1) and/or the outer pipe (2) has a conical cross section (D1, D2, D1, D4) that widens or narrows along the flow direction of the exhaust gas.

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 straddled vehicle having an engine unit supported by a vehicle body frame. The engine unit includes an engine body, a turbocharger, and an exhaust device. The exhaust device includes an exhaust pipe and a muffler that are connected to each other to form a portion of an exhaust passage, to allow the exhaust gas passed through the turbocharger to pass therethrough, and a first catalyst and a second catalyst that are arranged in this order along a direction in which the exhaust gas flows through the exhaust pipe. The exhaust pipe has an upstream end thereof connected to the turbocharger, a downstream end thereof connected to the muffler, and a corner section that is bent in at least a part thereof between a downstream end of the first catalyst and an upstream end of the second catalyst, the catalysts not being arranged in the corner section.

A decomposition chamber for an aftertreatment system includes a body and a diffuser. The body includes an inlet, an outlet, a thermal management chamber, and a main flow chamber. The inlet is configured to receive exhaust gas. The outlet is configured to expel the exhaust gas. The thermal management chamber is in fluid communication with the inlet. The thermal management chamber is configured to receive an exhaust gas first portion from the inlet. The main flow chamber is in fluid communication with the inlet. The main flow chamber is configured to receive an exhaust gas second portion from the inlet and to receive the exhaust gas first portion from the thermal management chamber. The diffuser is positioned within the main flow chamber. The diffuser includes a diffuser inlet portion and a diffuser flange portion. The diffuser inlet portion includes a plurality of diffuser perforations.

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.

A two-stroke engine exhaust resonator with an exhaust gas catalytic converter comprising an inlet opening, wherein the inlet opening is followed by the first end of a stabilizing tube with a catalytic converter mounted thereon, characterized in that the other end of the stabilizing tube is directed towards the primary reflective surface, the primary reflective surface is followed by the first end of a resonator casing, which is surrounding the stabilizing tube, wherein the resonator casing exceeds at least over a part of the catalytic converter on the stabilizing tube, wherein a resonator outlet opening is arranged in the resonator casing between its first and second end or in the primary reflective surface, and at least a part of the resonator casing surrounding the stabilizing tube is surrounded by a cooler.