ABSTRACT
Fixtures are used to locate and hold workpieces during machining. Because workpiece surface errors and fixture set-up errors (called source errors) always exist, the fixtured workpiece will consequently have position and/or orientation errors (called resultant errors) that will definitely affect the final machining accuracy.
It is estimated that fixturing could constitute 15-25% of the total manufacturing costs, assuming that the fixtures are amortized over relatively small batches.
This paper illustrates a novel adaptive fixturing based on active clamping forces for smart micro-positioning of thin walled precision parts.The proposed adaptive fixturing device can lead to the following advantages:
- to perform an automatic errors-free workpiece clamping and then drastically reduce the overall fixturing
set up time;
- to recover unwanted strains induced to the workpiece, in order to limit the amplitude of elastic strain
recovery;
- to perform, if necessary, active vibration control (AVC) in order to limit vibration/chatter effects
induced by the cutting tool.
Moreover the proposed device has been designed with the aim of obtaining a modular unit, reusable and exploitable to different industrial applications.
Keywords: Micromachining, Fixturing, Adaptronics, Smart actuators.
