基于斜角切削的曲线端铣切削力建模  

Cutting Force Modeling in End Milling of Curved Geometries Based on Oblique Cutting Process

作　　者：罗智文[1] 赵文祥[1] 焦黎[1] 高守锋[1] 刘志兵[1] 颜培[1] 王西彬[1] 

机构地区：[1]北京理工大学先进加工技术国防重点学科实验室,北京100081

出　　处：《机械工程学报》2016年第9期184-192,共9页Journal of Mechanical Engineering

基　　金：国家自然科学基金资助项目(51105035;51375055)

摘　　要：切削力预测是制定与优化加工工艺的重要环节。针对曲线端铣加工过程,提出一种基于斜角切削的切削力建模方法。将刀具沿轴向微分,以曲线微分几何计算微元刃上的工作基面。在微元刃的工作法平面参考系中,应用最小能量原理,构建微元刃中力矢量、速度矢量、流屑角、法向摩擦角、法向剪切角及剪应力等切削参数之间的约束。以单齿直线铣削试验对切削参数进行标定,其中法向摩擦角、法向剪切角及剪应力等可表示为瞬时未变形切屑厚度的函数。选取高强度钢PCrNi3MoVA试件,分别进行圆弧和Bézier曲线端铣加工试验。试验结果表明,曲线端铣时切削力的变化与瞬时进给方向和曲线曲率相关。切削力预测值的幅值大小和变化趋势与试验值一致,验证了该切削力建模方法的有效性。Cutting force prediction is the key issue for planning and optimizing the machining process. Based on an oblique cutting process, a novel method for modeling cutting force is proposed in end milling of curved geometries. Differentiating cutter along the axil, the working reference plane for an infinitesimal cutter element is calculated by utilizing differential geometry of curves. In the reference system of working normal plane, the connection between cutting parameters, e.g., force vectors, velocity vectors, chip flow angle, normal friction angle, normal shear angle and shear stress, is established by the minimum energy principle. Single-tooth straight milling tests are utilized for calibrating the cutting force coefficients, in which normal friction angle, normal shear angle and shear stress can be characterized by the dual-exponential function of instantaneous unreformed chip thickness. Two PCrNi3MoVA components with circular and B＆#233;zier curved geometries are machined. The experimental results show that variation of cutting force is influenced with the instantaneous feed direction and the curvature of the curve. Validity of the cutting force model is demonstrated by comparing predicted cutting forces with the experimental results.

关 键 词：切削力 曲线端铣 斜角切削 最小能量原理 

分 类 号：TG506[金属学及工艺—金属切削加工及机床]