介观尺度铣削工艺分析

设计了面向介观尺度零件制造的微型三轴数控铣床,并进行了黄铜微铣削实验.当加工特征在介观尺度范畴时,微铣削工艺现象和力学特点受到尺度效应的强烈影响,与常规尺度铣削不同.较大的刀具切削刃圆弧半径和主轴跳动度与单齿进给量比成为影响介观尺度铣削机理和切削力特点的重要因素,导致低进给率条件下产生间断性切屑成形现象.给定切削条件下,单齿进给量不再是一个常量,而是主轴跳动度、最小切削厚度和切削条件的函数.

Technology Analysis on Mesoscale Milling

A three-axis micro CNC milling machine was developed for manufacturing mesoscale components and products,and the experiments of end-milling brass were performed on the developed machine.The experimental results show that:when the machined feature range is at mesoscale,the process phenomena and mechanical characteristics in milling operations can heavily differ from conventional scale milling due to the size effects;the relatively large ratios of cutting edge radius and spindle's runout to feed per tooth,which induce the intermittency of the chip formation at a low feedrate,have an important influence on the mesoscale milling mechanism and forces characteristics;the feed per tooth is not a constant in the given cutting condition,but a function of the spindle's runout,the minimum chip thickness and the cutting condition.