Andreas Stihl Ag Co. Kg

Fritz Kiesewetter

Georg Maier

Axel Klimmek

Andreas Bähner

Ralf Tuckermann

An exhaust gas muffler for an internal combustion engine, especially the engine of a manually-guided implement such as a power saw, a cut-off machine, or the like. The muffler has a housing having an inlet for exhaust gases and an outlet out of the housing. The housing has an outer wall over which the exhaust gases from the outlet flow. To achieve an adequate cooling of the exhaust gas muffler and the discharging exhaust gases, the exhaust gases out of the outlet draw in atmospheric air between the exhaust gases and the outer wall of the housing.

Exhaust gas muffler

A fan arrangement of a portable handheld work apparatus is driven by an internal combustion engine and includes a radial fan () which includes a fan wheel () and a spirally-shaped fan housing () which encloses the fan wheel () at least partially. A take-out opening () is provided in the radial fan () in the region of the moved air flow () for diverting a combustion air flow () for the engine. The combustion air flow () is branched off from the air flow (). In the radial direction outside of the fan wheel (), there is an aerodynamically formed guide ramp () provided in the air flow () which rises in the axial direction. The take-out opening () is arranged downstream of the guide ramp ().

Fan arrangement of a portable handheld work apparatus driven by an internal combustion engine

An intake system for preparing combustion air () is for an internal combustion engine of a portable handheld work apparatus. The intake system includes: a carburetor (); an air filter () which is connected upstream of the carburetor (); and, a filter case () which closes the air filter () from the outside. A combustion air channel () leads from a take-up opening () in a cooling air fan () of the engine to an inlet opening () in the filter case (). The filter case () includes at least one defined ventilation opening () for connecting an inner space () of the filter case () to the ambient air. The flow cross section of the ventilation opening () is so designed that the airflows through the inlet opening (), the intake opening () of the carburetor () and the ventilation opening () are compensated at the rated rpm of the engine and that a uniform pressure level adjusts in the inner space () of the filter case ().

Intake system

A fan arrangement of an internal combustion engine, especially of a portable handheld work apparatus, includes a fan wheel () and a spirally-shaped fan housing at least partially enclosing the fan wheel. A take-out opening () is provided in the fan arrangement at the region of the moved air flow for diverting a combustion air flow for the engine. The combustion air flow is branched-off from the air flow. The take-out opening () is arranged in radial direction directly outside of the fan wheel () and is so configured that the take-out opening () defines a window () which, referred to the flow direction (S), has a small width at a forward edge and that the width as well as the depth of the window () increases to a rearward edge.

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Stuttgart, Germany

Fritz Kiesewetter