复杂曲面加工广泛应用于模具行业. 由于加工参数缺乏科学的选择工具,数控加工的进给率常根据加工经验设定. 通常必须创建切削体积模型或矢量力模型来优化刀具路径各段的进给率. 鉴于模具型腔粗加工常采用2.5维加工,提出一种通过正交切削试验建立切削力曲面模型用于模具型腔粗加工进给率优选的新策略. 基于切削力曲面模型,采用多项式拟合的方法构建刀具在许可切削力下的侧向切深和进给率的方程,根据建立的方程计算每个刀位点处的进给率并反写到初始的G代码文件中. 通过典型模具型腔的粗加工试验验证,证明该进给率优化策略不仅可以缩短加工时间,而且可以使加工载荷均匀. 该策略对切削力载荷要求尽量均匀的模具型腔高速加工更有意义.%Sculptured surface machining is a critical process commonly used in die and mold industries. Since there is a lack of scientific tools in practical process planning stages, feedrates of NC machining are selected based on previous experiences. Usually, volumetric models or vector force models used for optimization of feedrate must be created to get the variable feedrate along the tool path. Considering the die-cavity roughing being a 2.5D cutting, a novel cutting force surface model is created based on orthogonal cutting tests. Based on the cutting force surface model, a polynomial equation of side cutting depth and feedrate is created to calculate the feedrate of each CL data and the calculated feedrate value is written out with the G-code position data block to an updated version of the die-cavity. The model is tested by a typical die-cavity roughing, and shortening machining time and balancing cutting-load can be attained. The presented feedrate scheduling characterized by balancing the cutting-loads in die-cavity roughing will be more significant in high speed machining.
展开▼
