中文摘要：

针对数控加工中最佳刀具组合方式的选择问题，提出了一种适用于2．5维腔槽类零件加工的多刀具组合方式的评价策略，并建立了相应的加工成本计算模型。在该模型中，不仅考虑了刀具的切削时间、空走刀时问和换刀时间，还综合考虑了刀具磨损和机床折旧等因素的影响。为简化计算且便于管理，采用有向图表示法枚举和表示所有可能的刀具组合形式。同时，在扫描线填充算法的基础上，提出了刀具有效加工区域的计算新方法。实践证明，该方法简单可行，为数控程序设计和优化开辟了一条新途径。

英文摘要：

Aiming at determining optimal tool sequences, a new evaluation strategy was proposed for multiple tool sequences of 2.5 dimensional pockets machining, and the corresponding machining cost model was also presented. In this model, not only the cutting time, air cut time and time spent on changes of tools were considered, but also cutting tool wear and depreciation of the machine tool usage were taken into account. To simplify the computation, directed graph was used to represent all possible tool sequences. And an approach based on scan line filling algorithm was introduced to compute the accessible region of every tool and remaining uncut regions. The proposed method was proved to be simple and feasible, which provided a new way for optimization of Numerical Control （NC） machining.