Accurate and fast measurement of specific cutting force coefficients changing with spindle speed

Niccolò Grossi1
1Department of Industrial Engineering, University of Firenze, Firenze, Italy

Tóm tắt

Prediction of cutting forces is essential to simulate dynamic effects of the milling process, and optimize process parameters to reduce detrimental vibrations. Cutting forces are conventionally modeled by assuming a dependence on uncut chip thickness using dedicated coefficients, to be experimentally identified. These coefficients are proven to vary significantly with spindle speed, causing the need of a time-consuming experimental phase to achieve an accurate simulation of cutting forces in a wide range of spindle speeds. This paper presents a method to efficiently identify the specific cutting force coefficients in the entire speed range by a single milling test, in which spindle speed is ramped-up. During the test, the forces signals are acquired and then processed to identify the speed-varying cutting force coefficients. The method was applied to the identification of Aluminum 6082-T4 coefficients in a wide range of speeds and results were validated through traditional approach, proving the efficiency and effectiveness of the proposed technique. In addition, an application of the obtained coefficients to chatter prediction is presented and validated through chatter tests.

Tài liệu tham khảo

Altintas, Y., “Manufacturing Automation: Metal Cutting Mechanics, Machine Tool Vibrations, and CNC Design,” Cambridge University Press, 2000. Ko, J. H. and Shaw, K. C., “Chatter Prediction Based on Frequency Domain Solution in CNC Pocket Milling,” Int. J. Precis. Eng. Manuf., Vol. 10, No. 4, pp. 19–25, 2009. Dotcheva, M., Dotchev, K., and Popov, I., “Modelling and Optimisation of Up-and Down-Milling Processes for a Representative Pocket Feature,” Int. J. Precis. Eng. Manuf., Vol. 14, No. 5, pp. 703–708, 2013. Scippa, A., Montevecchi, F., Grossi, N., Sallese, L., and Campatelli, G., “Time Domain Simulation Model for Active Fixturing in Milling,” Proc. of International Conference on Leading Edge Manufacturing in 21st Century: LEM21, 2015. Scippa, A., Grossi, N., and Campatelli, G., “FEM Based Cutting Velocity Selection for Thin Walled Part Machining,” Procedia CIRP, Vol. 14, No. pp. 287–292, 2014. Hong, Y.-C., Ha, S.-J., and Cho, M.-W., “Predicting of Cutting Forces in a Micromilling Process Based on Frequency Analysis of Sensor Signals and Modified Polynomial Neural Network Algorithm,” Int. J. Precis. Eng. Manuf., Vol. 13, No. 1, pp. 17–23, 2012. Kienzle, O. and Victor, H., “Spezifische Schnittkräfte bei der Metallbearbeitung,” Werkstattstechnik und Maschinenbau, Vol. 47, No. 5, pp. 224–225, 1957. Lee, T. H., “Development of a Theoretical Model to Predict Cutting Forces for Hard Machining,” Int. J. Precis. Eng. Manuf., Vol. 12, No. 5, pp. 775–782, 2011. Budak, E., Altintas Y., and Armarego, E. J. A., “Prediction of Milling Force Coefficients from Orthogonal Cutting Data,” Journal of Manufacturing Science and Engineering, Vol. 118, No. 2, pp. 216–224, 1996. Gonzalo, O., Beristain, J., Jauregi, H., and Sanz, C., “A Method for the Identification of the Specific Force Coefficients for Mechanistic Milling Simulation,” International Journal of Machine Tools and Manufacture, Vol. 50, No. 9, pp. 765–774, 2010. Rubeo, M. A. and Schmitz, T. L., “Mechanistic Force Model Coefficients: A Comparison of Linear Regression and Nonlinear Optimization,” Precision Engineering, Vol. 45, pp. 311–321, 2016. Grossi, N., Sallese, L., Scippa, A., and Campatelli, G., “Speed-Varying Cutting Force Coefficient Identification in Milling,” Precision Engineering, Vol. 42, pp. 321–334, 2015. Wang, M., Gao, L., and Zheng, Y., “An Examination of the Fundamental Mechanics of Cutting Force Coefficients,” International Journal of Machine Tools and Manufacture, Vol. 78, pp. 1–7, 2014. Chae, J. and Park, S., “High Frequency Bandwidth Measurements of Micro Cutting Forces,” International Journal of Machine Tools and Manufacture, Vol. 47, No. 9, pp. 1433–1441, 2007. Grossi, N., Scippa, A., Sallese, L., Sato, R., and Campatelli, G., “Spindle Speed Ramp-Up Test: A Novel Experimental Approach for Chatter Stability Detection,” International Journal of Machine Tools and Manufacture, Vol. 89, pp. 221–230, 2015. Kumanchik, L. M. and Schmitz, T. L., “Improved Analytical Chip Thickness Model for Milling,” Precision Engineering, Vol. 31, No. 3, pp. 317–324, 2007. Altintaş, Y. and Budak, E., “Analytical Prediction of Stability Lobes in Milling,” CIRP Annals-Manufacturing Technology, Vol. 44, No. 1, pp. 357–362, 1995. Scippa, A., Sallese, L., Grossi, N., and Campatelli, G., “Improved Dynamic Compensation for Accurate Cutting Force Measurements in Milling Applications,” Mechanical Systems and Signal Processing, Vol. 54, pp. 314–324, 2015. Sallese, L., Grossi, N., Scippa, A., and Campatelli, G., “Investigation and Correction of Actual Microphone Response for Chatter Detection in Milling Operations,” Measurement and Control, Vol. 50, No. 2, pp. 45–52, 2017. Shin, B.-C., Ha, S.-J., Cho, M.-W., Seo, T.-I., Yoon, G.-S., and Heo, Y.-M., “Indirect Cutting Force Measurement in the Micro End-Milling Process Based on Frequency Analysis of Sensor Signals,” Journal of Mechanical Science and Technology, Vol. 24, No. 1, pp. 165–168, 2010.