Andreas Stihl Ag Co. Kg

Robert Koehli

Tobias Deigendesch

Jan Pawlowski

Tilman Seidel

Michael Grether

Ulrich Kapinsky

Bernd Engel

Matthias Maier

Richard Wirt

Guenter Wolf

A two-stroke engine includes a cylinder having a combustion chamber. The combustion chamber is delimited by a piston guided in a reciprocating manner in the cylinder and drives a crankshaft. A first intake channel opens into the crankcase interior. A transfer channel opens into the crankcase interior via a transfer window on a cylinder bore of the cylinder and via a passage opening. A second intake channel is provided for supplying scavenging air to the transfer channel. The first intake channel and the second intake channel are configured for supplying air. An injection valve configured for injecting the entire quantity of fuel to be supplied to the engine directly into the crankcase interior is disposed on the crankcase. A method for operating a two-stroke engine provides that the entire quantity of fuel to be supplied to the engine via a metering installation is supplied directly to the crankcase interior.

Two-stroke engine and method for operating a two-stroke engine

A two-stroke engine possesses a cylinder, in the cylinder bore of which a combustion chamber is formed. The combustion chamber is bounded by a reciprocating piston, which drives a crankshaft rotatably mounted in a crankcase. A crankcase interior is fluidically connected to the combustion chamber across at least one transfer channel in at least one position of the piston. The at least one transfer channel emerges with a discharge opening in the crankcase interior and with at least one transfer window on the cylinder bore. It is proposed that all transfer channels have an average length as measured from the discharge opening to the transfer window, the average length being at least 1.5 in relation to the stroke, and that the volume of the crankcase interior including all transfer channels is at most 3.1 in relation to the piston displacement.

Two-stroke engine

A handheld work apparatus has a combustion engine for driving a tool of the work apparatus and further has an air filter unit for filtering the intake air of the combustion engine. The work apparatus defines a vertical direction. The air filter unit includes an air filter and a filter housing enclosing the air filter. The air filter extends along a filter axis and has a filter element disposed peripherally around the filter axis, wherein the filter axis forms an angle of inclination (&#x3b1;) with the vertical direction. The filter element has an upper filter section in relation to the vertical direction. The filter housing has, remotely from the upper filter section, at least one air intake window and, in addition thereto, a further upper, permanently open cold air intake window in the region of the upper filter section.

Handheld work apparatus

Growing community of inventors

Winnenden, Germany

Robert Koehli