A hedge trimmer has at least one cutting blade and an internal combustion engine operatively connected to the at least one cutting blade so as to drive the at least one cutting blade reciprocatingly. The internal combustion engine has an exhaust gas muffler with an outlet for discharging exhaust gases from the exhaust gas muffler. A multi-part exhaust gas pipe is connected seal-tightly to the outlet of the exhaust gas muffler and connects the outlet of the exhaust gas muffler to an outlet opening where the exhaust gases exit from the hedge trimmer. The multi-part exhaust gas pipe has a plurality of pipe sections, including at least a first pipe section and a second pipe section, wherein the second pipe section is embodied separate from the first pipe section. At least one of the plurality of pipe sections is made of plastic material.

An exhaust gas treatment device, which includes an outer layer, an inner layer that is at least in part disposed within the outer layer, and a loose-fill insulation disposed in the volume between the outer layer and the inner layer, where a piece of fiber mat is disposed between the outer layer and the inner layer and forms a barrier that at least partially prevents the loss of the loose-fill insulation from the volume between the outer layer and the inner layer and a manufacturing method that includes placing a loose-fill insulation into the volume of space between an inner layer and an outer layer and positioning a piece of fiber mat between the outer layer and the inner layer to form a barrier that at least partially prevents the loss of the loose-fill insulation from the volume of space between the outer and inner layers.

An exhaust gas duct system for an internal combustion engine includes an upstream, first exhaust gas pipe area (30), a downstream, second exhaust gas pipe area (34) adjoining the first exhaust gas pipe area (30) in a transition area (38) in an exhaust gas flow direction (G), and a liquid drain channel area (60) in the transition area. The drain channel area is open from the exhaust gas flow volume (78) in the first exhaust gas pipe area (30) or/and in the second exhaust gas pipe area (34) to a liquid collection volume (80).

A catalytic converter includes at least one heating element that is configured to disrupt the direction of flow of exhaust gases which contain harmful toxic gases and pollutants and aid in removing and/or reducing said toxic gases and pollutants.

Methods and systems are provided for a mixer. In one example, the mixer may include a plurality of projections spatially separated from one another along an exhaust conduit.

An exhaust handling system comprising: an exhaust pipe having an exhaust outlet, said exhaust outlet having a nozzle arranged to vent exhaust gas; at least one acceleration jet arranged to project an air flow at a velocity head greater than that of the vented exhaust gas; wherein the at least one acceleration jet and exhaust outlet are positioned to project the air flow so as to impinge on a path of said vented exhaust gas, and consequently transfer velocity head to the vented exhaust gas.

An abnormality detection device determines abnormality in an exhaust gas sensor, disposed in an exhaust passage of an engine to detect a component in exhaust gas. The abnormality detection device includes: a responsiveness determination unit configured to calculate responsiveness of the exhaust gas sensor on the basis of a timewise change of output values of the exhaust gas sensor; and an abnormality determination unit configured to determine that the exhaust gas sensor has abnormality when the responsiveness calculated by the responsiveness determination unit is lower than a predetermined responsiveness threshold. The abnormality determination unit determines if the exhaust gas sensor has abnormality, excluding an excluded period during which a slope of the output values becomes zero or is inversed with respect to a preceding trend of the timewise change while the output values of the exhaust gas sensor timewisely change between a predetermined first and second determination values.

A modular exhaust manifold 1 for a motor vehicle, with multiple adjoining manifold pipe modules, having: at least one engine flange, via which an inlet connection pipe of the manifold pipe modules can be connected to a cylinder head of the motor vehicle; at least one manifold pipe module, configured as a collector pipe module and having a contact flange, via which the exhaust manifold can be connected to an exhaust system of the motor vehicle, the respective manifold pipe modules having an overlap contour of a length a that permits the telescoping of two manifold pipe modules to an insertion depth t for coupling purposes, at least two manifold pipe modules being identical in shape, and a variation of the insertion depth t of at least 5 mm to 30 mm or 10 mm or 15 mm or 20 mm or 25 mm being obtained by the formation of length a of the overlap contour. A method for producing a manifold formed from multiple adjoining manifold pipe modules.

A muffler assembly unit for an exhaust system of an internal combustion engine, especially in a vehicle, includes a muffler (42) with a muffler housing (10). The muffler housing (10) is elongated along a longitudinal axis of the housing. A housing jacket (40) encloses the muffler housing (10). At least one air guiding bulge (34) is provided on the housing jacket (40).

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.