立式铣床刀尖频响函数预测方法研究

摘要

由于对机械加工精度和效率影响较大,切削颤振一直是制造领域的研究热点之一.为了避免颤振的发生,通常利用稳定性Lobe图确定合适的加工参数,而机床刀尖频响函数是绘制稳定性Lobe图的先决条件.基于模态叠加法、激振实验和响应耦合子结构耦合方法(Receptance Coupling Substructure Analysis, RCSA),提出了一种新的机床刀尖频响函数计算方法.首先通过模态叠加法计算刀柄和刀具的各个端点频响函数,通过锤击法得到机床主轴的端点频响函数,最后利用RCSA耦合各个子结构,获取机床刀尖频响函数.对比实验结果,本文作者提出的方法能够得到精确的立式铣床刀尖频响函数.%Because of its significant impact on the precision and efficiency of mechanical machining,cutting chatter is one of the hot topics in the manufacturing regions.In order to prevent chatter,stability Lobe chart is usually used to choose appropriate machining parameters,and tool point frequency response functions (FRFs) of machine tools are essential in calculating the stability Lobe.Based on mode superposition method,excitation experiment and Receptance Coupling Substructure Analysis (RCSA),a new calculation method of tool point FRFs of machine tools was proposed.Firstly,superposition method and excitation experiment were used to get the end FRFs of the holder,the tool and the spindle part.Finally,RCSA was employed to obtain the tool point FRF by coupling the three substructures.Compared with the measured results,the proposed calculation method can obtain precise tool point FRF of vertical milling machine.