Entwicklung und Anwendung eines adaptiven Schwingungsdämpfers für das Einlippentiefbohren

(Development and Application of an Adaptive Vibration-Damping system for Single-Lip Deep-Hole Drilling)

Kersting, M.

Deep-hole drilling processes are often affected by dynamical instabilities. When machining with high process parameter values, the instabilities can cause chatter vibrations. These vibrations are torsional oscillations, which may lead to shortened tool life and poor bore quality. Within this thesis the development and application of an adaptive chatter damping system is presented. Adaptive systems, also referred to as adaptronics, are characterized by their capability to react to certain process situations. They consist of sensor and actuator components and feature a control unit for self adaptivity.

For the development, experimental and simulative investigations were conducted. Thereby, torque, feed force, amplitude of twist and oscillation frequencies could be determined. Taking these values into account, a requirement specification was devised. Based on this specification several solution approaches were obtained. The approaches were evaluated and based on procedures for construction a decision was made. The most promising approach based on a magnetorheological fluid for torque transmission and chatter damping was designed and build.

The new adaptive damping system was applied to a horizontal deep-hole drilling machining center as a tool holder. During the tests, more than 62 % of the torsional oscillations could be damped compared to a regular tool holder. In addition, a 60 % increase in feed rate was possible without increasing the level of process instability. These results show the high potential of adaptive systems for chattering processes in production engineering.

Published as

Dissertation, Technische Universität Dortmund, Vulkan Verlag, Essen, 2009, ISBN 978-3-8027-8749-2