面向铣削力控制的凸曲面拼接模具硬态铣削工艺优化

Optimization of Hard Milling Processing for Convex Surface Joining Die with Milling Force Control

机械加工对于模具结构的要求日益复杂,导致在模具自由型面上存在大量沟槽、凸凹等结构,容易出现磨损严重、拉毛拉裂等问题。对于模具不同位置所需要的应力特征不同,多采用镶块式模件拼接后整体铣削加工。而拼接处存在铣削力的突变导致刀具磨损过快和型面精度不高问题。本文通过阐述球头刀铣削凸曲面拼接模具表面形成机理,分析了铣削过程中不同位置的刀具-工件的接触关系;并且以球头铣刀加工不同硬度的淬硬钢Cr12MoV凸曲面拼接模具试验为对象,揭示切削深度、切削速度、每齿进给量及刀具铣削方向对拼接处铣削力突变的影响规律;以铣削力突变最小为目标进行正交试验研究,得到考察指标的主次影响规律和最优参数组合。

In machining for mold structural requirements become more complex,resulting in the existence of a large number of grooves and convex concave structure in the free type mold surface,prone to severe wear and galling cracking. The stress characteristics of different positions of the die are different,adopting the whole milling process of insert type module after splicing. However,the splicing is mainly caused by the milling force mutation,which leads to the problem of high tool wear and low precision. In this paper,the forming mechanism of the surface of the convex surface splicing die is formed by the tool of the ball end milling,and the contact relationship between the cutting tool and the workpiece in the milling process is analyzed; The hardened steel Cr12MoV convex surface splicing die experiment of ball end milling cutter of different hardness as the object,to reveal the effects of depth of cut,cutting speed,feed per tooth and milling directions on milling force mutation of splicing area. The orthogonal experiment was carried out with the minimum milling force mutation as the target,then the primary and secondary influence law and the optimal parameter combination were obtained.