Maximum speed limitation for a two-cycle engine

摘要

A method of limiting the maximum speed of a two-cycle engine in a manually-guided implement such as a hedge trimmer is provided. Via a unit for controlling the ignition time point in a crankshaft angular range prior to the upper dead center position of a reciprocating piston, the ignition is interfered with above an operational speed to keep the speed below the maximum speed. To ensure a rapid onset of the speed regulation along with good exhaust gas values, in the range between the operational speed and the maximum speed, the ignition time point is shifted in the direction toward the upper dead center position of the piston in such a way that in the vicinity of the maximum speed, the ignition time point is close to the upper dead center position of the piston and the engine output is reduced to a prescribed value that corresponds approximately to the frictional horsepower for the driving of the tool.