Andreas Stihl Ag Co. Kg

Karsten Schmidt

Florian Hoche

Klaus Geyer

Michael Raffenberg

Friedrich Hollmeier

Michael Dietenberger

Andreas Hägele

Frederik Herrmann

Jochen Gantert

Jörg Elfner

Martin Kiesner

Steffen Bantle

Fevronia Konstantinidou

Jan-Philipp Banzhaf

Andreas Baehner

Friedrich Holmeier

The invention relates to a method for operating a work apparatus having a combustion engine. An ignition device is provided for triggering an ignition spark at a spark plug for igniting a fuel/air mixture in a combustion chamber of the combustion engine. The combustion chamber is bounded by a piston which drives a crankshaft in a rotating manner. In order to avoid the combustion engine stopping in rich mode, the speed (n) of the combustion engine is monitored over the period of time (t, &#x394;T) and the ignition point (ZZP) of the ignition device is advanced if the speed (n) of the combustion engine lies within a predefined speed range (n; n) within a predefined period of time (t, &#x394;T) and then the speed n drops below a speed limit value (n).

Method for operating a work apparatus having a combustion engine

The invention relates to a method for adapting the composition of a mixture of fuel and combustion air. The mixture is supplied to a combustion chamber of a mixture-lubricated combustion engine in a work apparatus. The fuel is supplied to the combustion engine via a controlled fuel valve. In an operating state (I) of the combustion engine, the quantity of fuel is metered by the fuel valve. For the purpose of adapting the composition of the mixture, the combustion engine is shifted into a special operating state (II) which differs from the normal operating state (I). After starting, the combustion engine is operated in a first rotational speed range (B) for a prespecified operating time (T), wherein, after the prespecified operating time (T) has elapsed, the operating state (II) for adapting the composition of the mixture is initiated by a prespecified user action.

Method for adapting the composition of a mixture of fuel and combustion air

The invention relates to a fuel-metering arrangement for the mixture-forming unit () of an internal combustion engine () in a portable handheld work apparatus. The mixture-forming unit comprises a fuel store (), a switchable valve () and a fuel channel () which opens into an intake region of the engine (). The valve () has an inflow port () which is connected to the fuel store () and an outflow port () which is connected to the fuel channel (). A fuel column is mechanically moved by the switching of the valve. In order to compensate for this fuel column, the outflow port () is connected via a bypass channel () to the inflow port () and a flow valve () is mounted in the bypass channel (). The flow valve () opens in flow direction () from the outflow port () to the inflow port () and blocks in the direction opposite thereto.

Fuel-metering arrangement having an electromagnetic fuel valve

A two-stroke engine has an intake arrangement including a carburetor. An intake channel divides into a mixture channel and an air channel. An intermediate flange is mounted between the carburetor and the cylinder. This flange has a carburetor connecting surface, which faces toward the carburetor, and a cylinder connecting surface which faces toward the cylinder. Referred to the flow direction in the intake channel, the air channel divides upstream of the cylinder connecting surface into two branches. The first branch has a first longitudinal center axis and the second branch has a second longitudinal center axis. The intersect points of the center axes with the connecting surfaces are mutually connected via an imaginary connecting line in the carburetor connecting surface or the cylinder connecting surface. The two connecting lines conjointly define an angle &#x3b2; in the carburetor connecting surface with this angle being greater than 0&#xb0;.

Two-stroke engine having an intake arrangement

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Waiblingen, Germany

Karsten Schmidt