整体叶轮五轴侧铣加工的铣削力预测模型研究

A Cutting Force Prediction Model for Five-axis Flank Milling of an Integral Impeller' Blade Surface

为了对整体叶轮等复杂曲面的半精或精加工过程进行仿真和铣削力预测,提出了采用锥度球头铣刀五轴侧铣加工叶片型面的刀轴运动和铣削力计算模型。将锥度球头铣刀沿刀轴方向分解成一定数量的微元,为每个微元创建独立的进给坐标系,并将各微元的总进给速度朝垂直刀轴和平行刀轴等两个方向进行分解,进而得到水平和垂直方向的进给量,由此精确建立微元的总切屑厚度模型。通过斜角切削的正交实验计算相应的摩擦角、剪切应力和剪切角等参数,得到各微元被作用的铣削力,即可预测刀具和工件接触的总铣削力。仿真计算和实验结果对比表明:所建立的铣削力预测模型仿真计算结果与实测一致性好,基本符合实际加工规律。

Tool movement model and milling force calculation model is presented for five-axis flank milling blade with tapered,helical,ball-end mills,and then geometrical simulation and milling force prediction are carried out for the semi-finishing or finishing process of complex surface such as integral impeller.The cutter is divided axially into a number of differential elements,each with its own feed-coordinate system.The total velocity is split into horizontal and vertical feed components.It can obtain the horizontal and vertical direction of the feed,which accurately establish the total chip thickness model.The cutting forces for each element are calculated by transforming friction angle,shear stress,and shear angle from an orthogonal cutting database to the oblique cutting plane.The distributed cutting load is digitally summed to obtain the total forces acting on the cutter and blade.Simulation and experimental results show that the mathematical model of milling force prediction is basically accorded with the actual machining rule.