Maschineinstabilitäten

Maschineinstabilitäten, also known as machine instabilities or chatter, refer to self-excited vibrations that occur during machining operations. These vibrations arise from a complex interaction between the cutting tool, the workpiece, and the machine tool structure. When the dynamic properties of these components lead to a regenerative effect, where the cutting action at any point in time is influenced by the surface left by the previous passes, instability can occur. This regenerative effect amplifies vibrations.

The onset of machine instabilities is often characterized by a sudden increase in vibration amplitude and can manifest as a characteristic chattering noise. These instabilities can lead to a degradation of surface finish on the workpiece, reduced tool life due to increased wear and potential fracture, and diminished accuracy of the machined part. In severe cases, they can also cause damage to the machine tool itself.

Factors contributing to machine instabilities include low stiffness of the machine structure and cutting tool, poor damping characteristics, high cutting speeds, high depth of cut, and inappropriate cutting tool geometry. Understanding and mitigating these instabilities is crucial for efficient and high-quality machining. Strategies for prevention and control include increasing the stiffness of the machine and tool, improving damping, using specialized tooling, optimizing cutting parameters, and employing active vibration control systems. Analyzing the dynamic response of the machine tool system is a common approach to predict and address potential instability issues.