基于锰铜薄膜的新型MEMS切削力传感器研究

In the background of intelligent manufacturing and industry 4.0, a novel, practical and reliable cutting condition monitoring system is urgently needed for the intelligent control of high grade CNC machine. Cutting force measurement is considered to be the most direct, effective and promising method for cutting condition monitoring. In view of the problems of complex structure, large volume, poor compatibility and difficult to measure cutting force directly in the cutting position, this project focuses on the idea of "the cutting tool is a sensor", making the cutting tool qualified with both cutting and sensing function at the same time and proposes a kind of novel MEMS cutting force sensor research program based on manganin thin film. Analyzing the force and heat generated during cutting process theoretically, choosing manganin to develop modularized sensing unit for cutting force measurement duo to its high pressure stability and low temperature coefficient of resistance. The sensing unit is embedded into the cutting position in order to measure cutting force directly. The developed cutting force sensor has the advantages of high precision, fast response, high sensitivity and wide frequency band. It satisfies the requirement of compatibility and interchangeability, and possesses the characteristics of corrosion resistance, anti-interference and anti-shock, which can provide effective data support for the prediction of cutting faults, the study of cutting mechanism, the extension of tool life and the improvement of machining precision. This research is of great value and practical significance for cutting condition monitoring and intelligent machining, it has great development and application potential.

在智能制造和工业4.0背景下，高档数控机床的智能化迫切需要新型、实用、可靠的切削状态监测系统，切削力测量被认为是最直接、有效且具有应用前景的切削状态监测方法。针对目前切削力传感器结构复杂、体积大、兼容性差以及难以在切削位置直接测量切削力的问题，本项目围绕“刀具即传感”的研究思路，使刀具兼具切削和测量功能，提出一种基于锰铜薄膜的新型MEMS切削力传感器研究计划。通过对刀具受力和受热的理论分析，选择具有耐高压和低电阻温度系数的锰铜合金研制用于切削力测量的模块化敏感单元，并将其嵌入刀具切削位置直接测量切削力。该传感器具有精度高、响应快、灵敏度高和频带宽的优点，满足兼容性和互换性要求，并且具有耐腐蚀、抗干扰和防冲击的特点，能够为预报切削故障、研究切削机理、延长刀具寿命、提高加工精度提供有效的数据支持，对进行切削状态监测和实现智能化加工具有重要研究价值和现实意义，有较大的发展和应用潜力。

切削状态监测是高档数控机床实现智能制造的必备功能，而切削力与切削热、切削振动、刀具磨损等切削现象密切相关，切削状态的任何微小变化都能通过切削力反映出来，因此切削力测量是进行切削状态监测最直接、有效的一种方法。目前商业化切削力传感器在体积、价格和兼容性等方面尚不能满足在高档数控机床上批量装配使用的要求。针对该问题，本项目提出了一种基于刀具本身的切削力测量技术。研制了一种基于锰铜薄膜的小型化切削力传感器，该传感器形状和机械特性与车刀的刀垫相似，可以代替刀垫安装到刀具中进行切削力在线检测，形成具有切削加工和状态监测功能的智能刀具。本项目对切削力传感器的工作原理、结构设计、制作工艺和封装技术进行了深入研究，并对所研制的切削力传感器进行了静态和动态性能测试。实验结果显示，所研制的切削力传感器线性度达2.6%，灵敏度为0.0018mV/N，固有频率达1633Hz，能够满足机床主轴转速不超过24496r/min条件下的动态测量需求。同时，为了满足高速精密切削加工过程中对微小切削力的检测需求，本项目还进一步探索了基于SiAlCO陶瓷的高灵敏度切削力传感器，使传感器的测量灵敏度得到极大提高（219.38mV/N）。后续将针对传感器综合性能一致性和长期稳定性开展更加深入的研究。本项目旨在为高档数控机床进行切削状态监测提供准确可靠的测试技术，部分研究成果已经实现在机械制造企业的转化应用，该研究在智能制造和高端装备领域具有良好的发展前景，对于促进高性能传感器技术和智能制造装备研发具有重要意义。