Study On Milling Of Inner Cooling Based On Cutting Force

In machining,cooling is necessary for eliminating cutting heat from tool and workpiece,improper cooling method would reduce process quality and tool life.Usually outer cooling is used,but sometime cooling liquid cannot attach cutting face well,especially in hole milling.Then inner cooling is developed to improve cooling effect.A kind of inner cooling mill was developed by author's team,with which this research was to test the merits of inner cooling to outer cooling,and to explore the features of cutting force in hole milling by experiments.Main works and results of this research were:(1)Zig-zag milling experiments were done with different spindle speed and tools,while feed,cutting width and cutting depth remained same.The results were that the cutting forces of outer cooling were significantly greater than those of inner cooling,and the bigger of the cutter,the more significant of their comparison.(2)Theoretical analysis of cutting force in hole milling was done,the results showed that the component forces in x and y directions should be about some sine functions.(3)Hole milling experiments were completed with variable diameters of cutter and hole at different spindle speed.The results showed that,the cutting forces of inner cooling milling were less than that of outer cooling milling;component force in z direction was the largest among three dimensional component forces;and with the cutter going down,milling forces increased,in outer cooling,forces increased significantly,while in inner cooling,they increased a little,the component forces in z direction increased more significantly than that in x and y directions.From these results,conclusions can be gotten that:(1)The performance of the inner cooling tool that newly developed by author's team is outstanding.(2)Inner cooling is better than outer cooling,and is more valuable in hole milling than in zig-zag milling.(3)As for hole milling,the cutting force is relevant to the diameters of hole and cutter;the component force in z direction is much greater than other component forces;with the cutter descending,the force will increase,the reason might be that the chip can not flow out of the hole easily,in outer cooling this phenomenon would be more obvious,which implies that the inner cooling condition should be better than the outer cooling condition when the milled position is deep.This results of this research might be referred by practical processes and researches where inner cool milling might be used.