Feedrate Scheduling Based On Predictive Force Model For NC Machining

The simulation is an important part in NC machining. Compared with ball-end cutter, it is high accuracy, short manufacturing cycle and lower cost for NC machining die/mold surface with other millings. So ball-end milling has become more and more important in the digitized manufacturing technology and especially in aviation. Therefore, the simulation of milling force has an important direction to machining, and it can greatly increase efficiency and create more profit. For freeform surface machining, the simulation of milling force is introduced to the classical method in this paper. Comparing with the classical method, high feedrate can be achieved and dynamics of the machine is improved.The establish of the cutting forces model, machining parameter optimization in the physical simulation fields are made more research on the basis of the above research contents. The main achievements are as follows:Firstly, the theoretical basis of the simulation of milling force is introduced. The relevant force models are researched, and a milling force model for ball-end mill in which ploughing force and shearing force is presented is gained based on the relation of milling force and chip, which meets any advance direction.Secondly, considering the deformation of the tool in NC machining, the iterative relation of milling force and chip is studied. The milling force model of ball-end mill is obtained and the machining error is researched due to the deformation of the cutter. The ploughing coefficients and the shearing coefficients are regressed from orthogonal cutting tests. Then the instantaneous milling force can be predicted by inputting the geometric parameters from geometric simulation to the milling force prediction model.Thirdly, according to the instantaneous milling force from the milling force prediction model, the relevant feedrates on different cutter-location points are evaluated by its cutting load. Then the cutter-location points are divided into pieces due to close feedrates. The lowest federates of each piece are adopted and rounded up to be the whole pieces feedrates. Finally, an efficient and rational NC program can be gained by rewriting the optimized feedrates back to the original NC program.Finally, Experimental results show that the proposed method can effectively reduce machining time while ensuing machining quality. So it is proved that the feedrate optimization means presented in this paper is efficient and rational.