中文摘要：

为进行高速切削切屑折断界限变化规律研究，采用具有代表性的三维复杂槽型车刀片进行11种常速、高速断屑试验。在分析试验数据基础上，得到切屑折断界限曲线及其共性切屑折断界限曲线。在对三次样条函数插值方法进行分析，以及应用二次、三次多项式拟合方法建立切削速度与极限进给量、断屑范围之间变化规律的数学模型的基础上，优选出误差小、计算简单的数学模型。发现在各种切削速度下极限背吃刀量是定值，并且极限背吃刀量曲线是垂直直线，为此建立新的极限背吃刀量数学模型。结合具有代表性的三维复杂槽型车刀片，研究极限进给量变化规律，并推导出极限进给量理论预报公式。三维复杂槽型切屑折断界限曲线及其数学模型的建立，可为今后高速切削领域里三维复杂槽型车刀片断屑机理及其预报系统的研究打下理论与试验基础。

英文摘要：

In order to study the change rule of chip breaking limits in high speed machining, chip breaking experiments are performed by using the representative turning insert with 3D complex groove at eleven normal and high cutting speeds. Based on the analysis of the experimental data, the chip-breaking limit curve and the common-character chip-breaking limit curve are obtained. The relationship between cutting speed and critical feed rate and the relationship between cutting speed and chip breaking region are analyzed by the method of cubic spline function interpolation and their mathematical models are built by the method of quadratic polynomial fitting and cubic polynomial fitting. Then, the mathematical model with least error and easy calculation is chosen. The results of the cutting experiments show that the critical depths-of-cut is a constant value at various cutting speeds, and the curve of critical depths-of-cut is a perpendicular line. Therefore, the new mathematical model of the critical depth-of-cut is built. Combining with the representative turning insert with 3D complicated groove, the change rule of the critical feed rate is studied and the predictive model is deduced. The establishment of the chip breaking limit curve and the mathematical model of 3D complicated grooved insert lays a theoretical and experimental basis for the future investigation of the chip breaking mechanism of turning insert with 3D complicated groove in the field of high speed machining.