基于切削刃空间分布对加工特性影响的侧铣工艺参数优选

As one of effective ways, high performance peripheral machining (HPPM) is used to mill workpieces made of aerospace alloy. The negative change of machining properties, which is induced by improper selection of side edge spatial distribution and process parameters, have negative influence on the milling accuracy and efficiency when the frame shape workpiece accuracy is severely required. So, this project takes the high performance HPPM as a study focus. Though analyzing the key machining properties of the milling process and based on the effect rules of the side edge’s spatial distribution on the key milling properties, the optimization method of process parameters is presented. Then, the effects of the side edge spatial distribution on the key milling properties i.e. milling forces, milling stability and surface finish are mainly studied. Using the study research results, the optimization model of process parameters is built. The achievement of this project could extend the theory of the peripheral machining from classical end mill to new mill with non-uniform helix and pitch angle. Simultaneously, these researches can provide the theory basis and technology support for high performance milling to give full play to technical advantage, ensure the machining accuracy and improve milling efficiency greatly.

航空合金框类零件的侧铣加工是高性能加工的主要应用对象之一。在对框类零件精度有较高要求的场合，因螺旋立铣刀侧刃空间分布状态及与之配合的加工工艺参数选择不当引起切削特性消极变化对框类零件侧铣加工的精度、效率有严重的负面影响。本项目以螺旋立铣刀高性能侧铣加工为研究对象，通过对铣削过程中关键加工特性的分析，进而基于铣刀侧刃空间分布状态变化对关键加工特性影响规律，提出一种框类零件的加工工艺参数优选方法。重点研究螺旋立铣刀切削刃空间分布状态变化对侧铣加工的静态铣削力、铣削稳定性以及表面几何精度等关键加工特性的影响规律及在此基础上着力解决高性能侧铣加工工艺参数优选模型的建立等关键问题。研究结果可以将现有的传统螺旋立铣刀侧铣加工理论拓展到新型螺旋立铣刀侧铣加工领域，为变螺旋刃立铣刀高性能侧铣加工提供必要的理论基础与技术支撑，以充分发挥高性能侧铣的技术优势，保证框类零件的加工精度且最大限度地提高加工效率。

在对框类零件精度有较高要求的场合，因螺旋立铣刀侧刃空间分布状态及与之配合的加工工艺参数选择不当引起切削特性消极变化对框类零件侧铣加工的精度、效率有严重的负面影响。针对硬质合金圆周螺旋立铣刀侧铣航空合金框类零件这一典型工艺过程，研究了变螺旋铣刀铣削稳定性预测方法，从理论上探明了螺旋角、顺铣与逆铣、不同径向切削深度对稳定性的影响规律；讨论了变螺旋铣刀在五轴加工过程中铣削力的预测，为了提高计算效率与考虑变螺旋铣刀切削刃各不相同对切削力的影响，采用未变形切削厚度补偿模型来预测铣削力，结果与预期吻合；基于此优化了变螺旋铣刀螺旋角的组合，采用优化后的变螺旋铣刀，使得框类零件的加工效率提高50%以上。从而可以理论上指导和优化框类零件加工，充分发挥了高性能侧铣的技术优势，保证框类零件的加工精度且最大限度地提高加工效率。基本完成研究目标所预期的任务。