A device for controlling an exhaust sound of a vehicle includes a sound tunnel mounted near a muffler and an exhaust pipe so as to transmit exhaust sound to an interior of a vehicle, a sound introduction hole formed in the sound tunnel, and a catalytic assembly mounted in the sound tunnel so as to clog the sound introduction hole, the catalytic assembly functioning to reduce high-frequency noise and to filter exhaust gas, thereby reducing high-frequency noise included in the exhaust sound transmitted to the interior of the vehicle and thereby filtering the exhaust gas so as to prevent introduction of the exhaust gas into the interior of the vehicle.

A working vehicle according to an embodiment includes an exhaust pipeline and a cover. The exhaust pipeline includes an exhaust gas purification device provided to stand on one of left and right sides of a running vehicle body. The cover is provided to cover at least a peripheral surface of the exhaust gas purification device of the exhaust pipeline and has an opening in a bottom thereof. The cover has a plurality of vent holes with a diameter less than that of the opening that are formed above the opening.

Switchable radiative energy harvesting systems and methods of harvesting radiation are disclosed. A system includes an optical filter that includes at least one of an active material and a passive material. The optical filter is switchable between a shield mode and a harvesting mode such that the at least one of the active material and the passive material is in a reflecting state during the shield mode such that the optical filter blocks passage of radiation from a thermal emitter to a thermophotovoltaic cell and a transmitting state during the harvesting mode such that that the optical filter allows the radiation to pass from the thermal emitter to the thermophotovoltaic cell.

A muffler for an exhaust gas system of an internal combustion engine. The muffler has a muffler housing having at least two interconnected housing shells delimiting a muffler interior. Each housing shell has a connecting edge extending away from the muffler interior. The housing shells are mutually connected by material bonding in the region of their mutually adjacent housing shell connecting edges. An insulating arrangement covers at least regions of the inner side of one of the housing shells. The insulating arrangement has an insulating shell with an insulating shell connecting edge extending away from the muffler interior and the insulating shell is arranged with the insulating shell connecting edge between the mutually adjacent connecting edges of the housing shells and is connected by material bonding to the connecting edges of the housing shells in the region of the insulating shell connecting edge.

A muffler heat protection system for a vehicle includes a muffler heat shield configured to extend circumferentially around a portion of a muffler, the muffler heat shield having a first end and a second end; a heat shield extension secured to the first end of the muffler heat shield; a double wall exhaust pipe including an inner exhaust pipe and an outer covering pipe disposed over the inner exhaust pipe, the outer covering pipe having a first end portion and a second end portion, and the inner exhaust pipe having a first end portion and a second end portion; wherein the second end portion of the outer covering pipe is welded to the muffler at a welded connection seam; and wherein the heat shield extension projects outward from the muffler heat shield over the welded connection seam.

A valve assembly for an exhaust system of a vehicle comprises a housing defining an inlet, an outlet, and a longitudinally extending exhaust gas passageway in fluid communication with the inlet and the outlet. The valve assembly further comprises a valve flap disposed in the housing and rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is less restricted. A mass damper is disposed within the exhaust gas passageway and attached to the valve flap. The mass damper includes end portions and an intermediate portion disposed between the end portions with the intermediate portion having a thickness that is greater than a thickness of the end portions. The mass damper is positioned proximate an inner surface of the housing and positioned between the valve flap and the housing when the valve flap is at the second position.

A heat management system for air-cooled engines suitable to power yard care equipment or vehicles. The system may generally comprise an engine, a blower configured to blow ambient cooling air across the engine, and an exhaust system comprising an exhaust header and a muffler. The exhaust header has an inlet end which receives heated exhaust gas from the engine and an outlet end fluidly coupled to the muffler. An air control baffle is configured to redirect a portion of the cooling air from the blower towards the exhaust header and the muffler to enhance cooling the exhaust system. The system may further include an outermost protective shield exposed to equipment operators and an inner heat barrier or shield located between the muffler and protective shield. The system is designed to ameliorate both radiative and convective sources of heat transfer to maintain the protective shield at temperatures below established industry standards.

An exhaust gas system for an internal combustion engine includes at least one component which delimits an exhaust gas flow volume via an outer wall and, on an inner side of the outer wall which faces the exhaust gas flow volume, supports at least one shielding element. An intermediate space is formed between the outer wall and the shielding element. At least one connecting molding on the shielding element is directed toward the outer wall and is connected fixedly to the outer wall.

A multi-pass catalytic converter can divide a catalyst block into several catalytic volumes and enable the exhaust gas to flow through each volume in two or more passes consecutively. As the exhaust gas in an early pass can emit sensible thermal energy and chemical reaction energy to preheat the remaining catalytic volumes via conductive heat transfer, it can shorten the catalyst light-off time for the later passes and the whole catalyst block. By recouping the previously lost dissipating heat from the early catalytic volume, the present disclosure can significantly reduce the catalyst light-off time and emission concentration. Furthermore, one or more mixing chambers can be utilized to thoroughly mix the exhaust gas.

A reducing agent supply device for supplying a reducing agent to a portion of a passage for a flue gas upstream of a SCR catalyst includes at least one header pipe extending in the passage and configured to allow the reducing agent to pass through; a plurality of injection nozzles disposed on the header pipe at intervals along an extension direction of the header pipe and configured to inject the reducing agent into the passage; a heat shield plate disposed on an upstream side of the header pipe with respect to a flow direction of the flue gas and having a longitudinal direction along the extension direction of the header pipe; and at least one fixing part contacting each of the heat shield plate and the header pipe and fixing the heat shield plate to the header pipe.