Off-line feedrate optimization with multiple constraints for corner milling of a cavity

High quality and high efficiency are very important factors in the mold industry and must be considered in machining technology development. Corners are one of the typical features in a cavity mold that can cause low accuracy, tool wear, cutter defection, and vibration. Therefore, off-line feedrate optimization in a corner-milling process has been proposed as a means for avoiding these drawbacks. The corner-milling process could be divided into five stages according to the contact conditions between the cutter and workpiece. An improved chip thickness model based on the actual trajectory of the cutter was presented to predict the movement of the cutter along a curved path. Various feedrate optimizations were presented with varying control parameters. In this paper, three feedrate optimizations were implemented using three control parameters, relative volume, milling force, and cutter deflection, based on the differential element method (DEM). A corner-milling force experiment indicated that the simulation results using a modified milling force model agreed well with actual experimental milling results. Following this, a feedrate optimization with multiple constraints was built, according to a combination of three feedrate optimizations and then consider the acceleration and deceleration limitation. The simulation by using the method in this paper demonstrated that the machining time of rough milling, semi-finish milling, and finish milling could be reduced. In addition, it was found that the resulting milling force varies within a narrow range.

[1]  Minjie Wang,et al.  Cutting forces prediction in generalized pocket machining , 2010 .

[2]  Lv Miao.  PREDICTION OF THE CUTTING FORCE IN END MILLING OF DIFFICULT-TO-MACHINE MATERIAL POCKETS , 2009 .

[3]  Kwangsoo Kim,et al.  Voxel-Based Virtual Multi-Axis Machining , 2000 .

[4]  Hsi-Yung Feng,et al.  Geometry of chip formation in circular end milling , 2012 .

[5]  Zhang Yidu,et al.  Corner-milling of Thin Walled Cavities on Aeronautical Components , 2009 .

[6]  K. P. Karunakaran,et al.  A solid model-based off-line adaptive controller for feed rate scheduling for milling process , 2008 .

[7]  Kwok Wah Chan,et al.  Machining Tactics for Interior Corners of Pockets , 2002 .

[8]  Li Zheng,et al.  Prediction of cutting forces in end milling of pockets , 2005 .

[9]  Yusuf Altintas,et al.  Prediction of ball-end milling forces from orthogonal cutting data , 1996 .

[10]  Li Kai-zhu.  Analysis report about research on high speed milling at pocket corner of complex mould , 2010 .

[11]  Siti Zaiton Mohd Hashim,et al.  Evolutionary techniques in optimizing machining parameters: Review and recent applications (2007-2011) , 2012, Expert Syst. Appl..

[12]  Mariana Dotcheva,et al.  The application of tolerance analysis to the theoretical and experimental evaluation of a CNC corner-milling operation , 2005 .

[13]  W. P. Wang,et al.  Solid modeling for optimizing metal removal of three-dimensional NC end milling , 1988 .

[14]  Xue Yan,et al.  Cutting force prediction for circular end milling process , 2013 .