扁钻加工过程的分析模型　1.基本钻削模型和流屑角的计算(英文)

ANALYTICAL PREDICTION OF SPADE DRILLING PROCESS Part 1 Basic Spade Drilling Model

大直径镶片式扁钻与传统的扁钻相比，结构上有了很大的改进，切削性能获得了较大的提高，已开始批量地应用于CNC机床．扁钻加工中主切削刃为沿半径方向前角，刃倾角和切削速度均变化的斜角切削．把主切削刃的斜角切削看作是一系列宽度狭窄的斜角切削排列起来，从而推导出主切削刃的总切削功率为包含切屑流屑角的函数表达式．应用切屑沿切削功率最小方向流出的原理和数值分析的方法求出流屑角．计算的流屑角与试验测量结果是相吻合的．

The paper proposes first the spade drilling process in which the cutting action of lips is modelled as oblique machining process with inclination angle, rake angle and the cutting velocity varying along the edges. Then, a model for calculating the cutting power along the lips in spade drilling of ductile metals is described in detail. The model enables to predict the chip flow angle, which is based on the principle that the material removal in cutting process flows up along the direction of minimal cutting power consumption. The calcu1ated and experimental results are well consistent.