Development of a magnetic reluctance force actuator for chatter suppression in boring bars

Inhalt:
The productivity of boring processes is limited by chatter vibrations, which are related to the flexibility of the boring bar. The introduction of tuned mass dampers (TMD) is a well-known industrial solution that offers excellent results in middle size boring bars, but since TMDs must be tuned to a certain frequency, each bar requires its own damper and their performance is limited by possible changes of the natural frequency of the bar. The present article deals with the development of an reluctance force based electromagnetic active damper, which can overcome the limitations of TMDs and can increase the cutting capacity of slender boring bars. The actuator has been designed according to the specific requirements of the boring operation, followed by a complete experimental validation. Finally, experimental cutting tests have been performed in a real machining environment by means of a test bench which allows to test different overhangs and where the actuator is embedded in a modular way.