INFLUENCE OF CLAMPING STRATEGIES ON ROUNDNESS DEVIATIONS OF TURNED RINGS

Abstract

During turning of rings, shape deviations occur due to clamping. These deviations can be minimized by using optimized clamping fixtures. However, for small batch production with varying ring diameters the application of simple clamping techniques, e.g., three-jaw-chucks, is favorable from an economic point of view. In this paper, strategies for reducing the roundness deviations of turned rings by using a three-jaw-chuck (hard jaws for external clamping and segment jaws for internal clamping) will be introduced. Within this study results from finite element analyses and roundness measurements are presented and discussed. The simulations and measurements agree reasonably well and show that the minimal out-of-roundness strongly depends on the interaction of the angular shift between external and internal clamping with the deviation between segment jaw diameter and inner ring diameter.

Keywords:

• clamping
• distortion
• rings
• shape deviation
• simulation
• turning

ACKNOWLEDGMENT

This work was carried out within the “Sonderforschungsbereich 570, Distortion Engineering”. The authors would like to thank the Deutsche Forschungsgemeinschaft (DFG) for the financial support. This paper has in parts been presented at the 12th CIRP Conference on Modelling of Machining Operations from May 7–8, 2009 in Donostia – San Sebastián, Spain.