中文摘要：

针对模具型腔拐角铣削过程,提出一种考虑刀具变形及铣削力变化的基于载荷控制的进给量优化方法。根据拐角的铣削中刀具与工件接触情况的不同,将铣削过程分为五个阶段,分别分析拐角铣削时刀具切削刃真实运动轨迹,建立拐角圆弧运动轨迹下瞬时切屑厚度模型,提高切屑厚度模型在拐角加工中的预测精度。修正铣削力预测模型,使其满足拐角加工过程不同阶段的要求。选取刀具变形量为约束条件,计算不同阶段的允许最大载荷,利用二分迭代法得到该载荷下对应的进给量值。考虑到数控机床的运动加速度限制,对得到的优化进给量值进行二次优化,以满足实际加工的要求。仿真结果表明,在进给优化后的拐角铣削过程中,载荷变化趋于平稳,加工时间缩短。进行拐角加工验证试验,数值仿真计算和试验测量结果表明,建立的铣削力模型能够很好地预测拐角铣削过程。所建立的优化模型为模具型腔的高精、高效加工提供理论支持。

英文摘要：

An approach of feedrate optimization is presented for corner-milling process through controlling the load. According to the actual trajectory model of cutting edge of ball-end mill, the mathematical model of the instantaneous chip thickness for corner-milling is proposed, which increases the forecasting accuracy. The milling force model is modified to meet the characteristic of corner-milling, which can be divided into five stages. The allowable load under the cutter deformation limitation is used for optimizing the feedrate by the dichotomy. To meet the machining requirements, second optimization for the optimized feedrate value is carried out in consideration of the restrictions on dynamics of the machine tools. By simulation computation, the variation of the load maintains stably with the optimized feedrate, and machining time decreases slightly. An experiment for corner-milling with ball-end mill is operated. Both the results of the milling force by simulation and measurement are well matched in magnitude and variation tendency. The method provides theoretic support for high efficiency and high precision processing in pocket machining.