Andreas Stihl Ag Co. Kg

Andreas Lingen

Andreas Bähner

Predag Ostojic

Hans Nickel

Georg Maier

Claus Naegele

Heinrich Leufen

Sebastian Friedrich

Axel Klimmek

Hans Holderle

Michael Joos

Matthias Hehnke

Jörg Amann

Stanislaw Cichon

Jan Borchardt

Daniel Diepolder

Bärbel Nickel, Legal Representative

Michael Schmid

Jens Knauss

Joachim Baumhauer

Christian Schmidt

Leo Kieβling

Nils Kunert

Christina Escher

Juergen Bernert

A handheld work apparatus has at least one tool which is driven by a combustion engine. A portion of an intake channel of the combustion engine is formed by an elastic connecting piece which has a first section and a second section between which an expansion fold is arranged. The expansion fold has a first side wall and a second side wall arranged downstream of the first side wall. A peripheral wall, which extends in the region of the largest outside diameter (a) of the expansion fold, is arranged in flow direction between the first side wall and the second side wall. The connecting piece has a stop for the expansion fold which prevents a segment of the first side wall adjoining the peripheral wall from bearing against the second side wall.

Handheld work apparatus and elastic connecting piece for a handheld work apparatus

A handheld work apparatus has an internal combustion engine (&#x2033;) and a starter device (). The internal combustion engine has a piston (&#x2033;) which has at least one piston ring (). In order to avoid a delay when starting the engine, at least one recess is provided in the cylinder bore () which bridges the at least one piston ring () in at least one position of the piston (') and which has a distance (n, o, p) to all function openings of the engine (&#x2033;) configured in the cylinder bore (). To reduce the compression in the combustion chamber (), the piston (&#x2032;) has only one piston ring () or two piston rings () are provided having respective piston ring gaps () defining an angle (&#x3b2;) which is up to approximately 45&#xb0;.

Handheld work apparatus

A two-stroke engine has a cylinder with a combustion chamber delimited by a reciprocating piston, wherein the piston drives in rotation a crankshaft, and wherein a spark plug projects into the combustion chamber and ignites a fuel/air mixture. The two-stroke engine further has devices for supplying fuel and combustion air to the combustion chamber and a control unit that determines the ignition timing based on an ignition map. The ignition map indicates the ignition timing as a function of the engine speed for at least one first and one second operating states and for at least one first and one second engine speed ranges. The engine is controlled in that for an engine cycle the ignition timing is set in the second operating state at least within the first engine speed range based on the engine speed and on the number of engine cycles since the last combustion.

Method for operating a two-stroke engine

An internal combustion engine includes a cylinder () wherein a combustion chamber () is formed. The engine also includes devices for metering fuel and combustion air as well as an ignition device for igniting the mixture in the combustion chamber (). A method for operating the internal combustion engine provides that fuel and combustion air are supplied to the engine and the mixture is ignited in the combustion chamber (). The combustion chamber () is delimited by a piston () which drives a crankshaft () rotatably journalled in a crankcase (). A control is provided which controls the supply of fuel and the ignition of the mixture in the combustion chamber (). The internal combustion engine is so controlled in at least one operating state that the number of combustions is less than the number of engine cycles in the same time span. To avoid the formation of self ignitions, the operating state is a high rpm range wherein the rpm lies above the rated rpm and below the rpm in a regulating range.

Method for operating an internal combustion engine

A carburetor () has an intake channel () wherein a throttle element and a choke element are arranged with the choke element being upstream of the throttle element. The choke element is displaceable between an operating position () and at least one starting position (). A first fuel path is provided which supplies fuel to the intake channel section () in dependence upon the underpressure present therein. A first controllable valve () for controlling the supplied fuel quantity is mounted in the first fuel path. In order to achieve an adapted fuel supply in different operating states, a second fuel path is provided which defines a bypass line to the first valve (). A second valve () is mounted in the second fuel path. A method for operating the carburetor () provides that the second valve () is actuated in dependence upon at least one operating parameter of the carburetor ().

Carburetor and method of operating the same

A two-stroke engine () has a combustion chamber () disposed in a cylinder (). The combustion chamber () is delimited by a reciprocating piston (). The piston () drives a crankshaft () via a connecting rod () and the crankshaft () is rotatably journalled in a crankcase (). The two-stroke engine () has an intake channel () for the supply of fuel into the crankcase (), an outlet () for exhaust gases from the combustion chamber () and an air channel () for the supply of substantially fuel-free air. A throttle element () is mounted in the air channel (). At pregiven positions of the piston (), the crankcase () is connected via at least one transfer channel () to the combustion chamber (). In order to prevent air from being drawn by suction into the air channel because of leakages during idle or at low rpm, a fluid connection is provided between the air channel () downstream of the throttle element () and the crankcase () for underpressure compensation which connection is present at least partially for a position of the piston from 90&#xb0; ahead of bottom dead center to 90&#xb0; after bottom dead center. A connection between the crankcase () and the intake channel () can be provided in lieu of, or in addition to, the connection to the air channel ().

Two-stroke engine

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Althütte, Germany

Andreas Lingen