摘要
在薄壁零件加工过程中,工件材料的连续切除会造成工艺系统动力学特性的不断变化,并对工艺系统的颤振稳定性产生显著影响。以航空发动机机匣为对象,研究了其铣削过程中工件材料切除以及切削位置变化对工件动力学特性与颤振稳定性的影响规律。首先,根据机匣的几何结构与铣削工艺特点,提出了按切削行及切削段进行材料切除过程细分的方法。其次,建立了工艺系统动力学特性演化的快速计算方法和颤振稳定性极限的频域预测方法,并在单个切削行内和不同切削行间分析了材料切除过程对工艺系统的影响。结果显示,在单个切削行内工艺系统的动力学特性会小幅度减小,稳定性极限图会向左下方小幅度偏移;在不同切削行间工艺系统的动力学特性变化幅度较大,稳定性极限图呈现出交错排列现象,难以针对整个铣削过程进行切削参数优选,因此提出了基于单行刀位轨迹的切削参数优选方法,保证了整个材料切除过程的稳定切削。最后,进行了机匣铣削与模态试验,验证了所提方法的正确性与有效性。
During the milling of thin-walled parts,the dynamic characteristics of the process system constantly vary with the material removal,which also have a significant impact on the chatter stability of the process system.The influence of material removal effect on the dynamics and stability in end milling of aero-engine casings is studied.Firstly,the material removal process is divided into several cutting lines and several cutting segments by analyzing the geometry and processing technology of the workpiece.Secondly,the calculation methods of the dynamic evolution and stability limits are developed.And the material removal effect is investigated in one single cutting line as well as in different cutting lines.The results show that the dynamic characteristics of the workpiece have a small reduction in a single cutting line but have a big change in different cutting lines,and the stability lobe diagram will have a small offset towards the left inferior side in a single cutting line but present a staggered case in different cutting lines.Then it is difficult to optimize the cutting parameters for the entire milling process.Therefore,an optimal selection approach of cutting parameters based on single line toolpath is proposed to suppress cutting chatter in the whole material removal process.Finally,several milling and hammer impact tests are carried out to validate the feasibility and effectiveness of the presented method.
出处
《航空学报》
EI
CAS
CSCD
北大核心
2016年第4期1352-1362,共11页
Acta Aeronautica et Astronautica Sinica
基金
国家"973"计划(2013CB035802)
国家自然科学基金(51475382)~~
关键词
材料切除
机匣
铣削
动力学特性
颤振稳定性
material removal
aero-engine casings
milling
dynamic characteristics
chatter stability
