Andreas Stihl Ag & Co.

Uwe Janoske

Johannes Menzel

Jörg Schlossarczyk

Peter Linsbauer

J&ouml;rg Schlossarczyk

Markus Keller

A muffler arrangement includes an exhaust-gas muffler, which is subdivided into an inlet space and an outlet space. An exhaust-gas stub of an internal combustion engine opens into the inlet space. Exhaust gas is conducted from the outlet space into an air channel via an exhaust-gas outlet. The air channel is formed between the housing of the exhaust-gas muffler and an outer cover and extends along a side of the exhaust-gas muffler. A cooling-air component flow is branched from a cooling-air flow of a cooling-air blower and enters at a first end of the air channel. The cooling-air component flow exits again at the second end of the air channel. In order to reduce the discharge temperature of the exhaust gas (especially with the arrangement of a catalytic converter), it is provided that the exhaust-gas jet is conducted in the air channel in spaced relationship to the air channel walls and is essentially surrounded on its path to the air channel outlet window by the supplied cooling-air component flow so that the exhaust-gas jet forms a core flow and the cooling-air component flow forms a cover flow surrounding the core flow.

Muffler arrangement for an internal combustion engine

The cleaning arrangement ( ) is provided for the combustion air ( ) of an internal combustion engine ( ) in a portable handheld work apparatus such as a cutoff machine. The cleaning arrangement is formed from a filter housing ( ) which contains an air filter ( ) in order to ensure a disturbance-free operation especially for a dust-laden ambient air of the work apparatus. The air filter ( ) partitions the filter housing ( ) into a contaminant space ( ) and a clean space ( ). The clean space side ( ) is connected to a carburetor ( ) of the engine ( ). To minimize the dust deposit on the contaminant space side of the air filter ( ), a centrifugal-force separator ( ) is arranged in the filter housing ( ) and is charged with combustion air ( ) which is supplied under pressure by a cooling air fan ( ) via a feed channel ( ) to the separator ( ). In the centrifugal-force separator ( ), the combustion air ( ), which is laden with dust ( ), is divided into a tangential flow ( ) having a higher particle density ( ) and a core flow ( ) having a low particle density ( ). The core flow ( ) is supplied to the contaminant chamber ( ) of the filter housing ( ).

Cleaning arrangement for the combustion air of an internal combustion engine

The invention relates to an intake system ( ) for the combustion air ( ) of an internal combustion engine ( ) in a portable handheld work apparatus ( ). The intake system ( ) includes a filter housing ( ) having an air filter ( ) for purifying the combustion air ( ). The clean space ( ) of the air filter ( ) is fluidly connected to an outlet opening ( ) of the filter housing ( ). The outlet opening ( ) communicates with a carburetor ( ) of the engine ( ). A centrifugal-force separator ( ) is mounted forward of the air filter ( ) for separating large amounts of dust in the inducted combustion air ( ). The separator ( ) is so positioned ahead of the filter housing ( ) that a central core flow ( ) of the separator has a lower particle density ( ) and is supplied to the filter ( ). A tangential flow ( ) surrounds the central core flow ( ) in the interior of the separator ( ). The tangential flow ( ) has a great amount of dust or dirt and is conducted away via the suction side ( ) of a blower ( ), especially of a cooling-air blower ( ) of the engine ( ) having vanes on the back side thereof.

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Michelfeld, Germany

Uwe Janoske