Monitoring and Analysis of Vibration and AE Signals in Hard Milling of Mold Steel

硬切削作为绿色切削的重要组成部分,已成为金属切削的一个研究热点。为了对硬切削过程进行监测,建立了一套信号采集系统,通过该系统采集模具钢铣削过程中的振动信号和声发射信号,并从时域、频域对其进行了分析研究。研究结果表明:模具钢硬铣削过程的振动信号和声发射信号的时域波形呈现不同的特点;振动信号和声发射信号的均方根值随切削速度的增大均呈明显的增大趋势,而受每齿进给量和铣削深度影响很小;随着切削速度的提高,振动信号各频段的幅值均增大,但频谱分布基本不变;随切削速度的提高,声发射信号的频谱成分增多,并导致了均方根值的增大。Hard milling is one of the main green machining processes,and it has become a research hot-point.In order to monitoring hard milling process,a signal acquisition system was built.Vibration signals and AE signals were sampled in mold steel milling process.Analysis of sampled signals was conducted through time domain and frequency domain.The research shows that the time domain waveforms are different between vibration signals and AE signals in milling process; higher cutting speed results in bigger RMS values,feed per tooth and cutting depth have less effect on vibration and AE signals; higher cutting speed results in increase of amplitude in all frequency bands of vibration signals; higher cutting speed results in increase of component of frequency,which results in increase of RMS values.国家自然科学基金资助项目(50875120

A Comparative Study of Dry Milling and Little Quantity Lubricant Milling of Aeronautic Aluminum Alloy Based on AE Signals

为了揭示少量润滑的机理,在建立切削液供应系统和数据采集系统实验平台的基础上,采集航空铝合金7050-T7451干铣削和少量润滑铣削过程中的声发射信号,并对信号从时域、能量角度进行了分析研究。研究结果表明:(1)航空铝合金铣削过程中使用切削液可以加速声发射信号的衰减;(2)主轴转速的提高使得AE信号的强度随之提高,且AE信号的能量成分向高频区域增加;(3)切削液的加入使得AE信号能量向低频区域移动,随着切削液流量的增大,这种作用将逐渐减弱。In order to reveal the mechanism of little quantity lubricantion,an experimental platform of cutting fluid supply system and signal aquasition system was established.AE signals in dry milling and LQL milling of aeronautic aluminum alloy 7050-T7451 were sampled and analyzed through time domain and energy distribution.The results show that:(1)cutting fluid can speed the attenuation of AE signal in milling process;(2)the increase of main spindle speed results in the increase of AE signal intensity,and results in the increase of energy of AE signal in high frequency band;(3)the introduction of cutting fluid in milling process makes the energy ratio of AE signal increase in low frequency band,and this function will gradually weaken with the increase of the flow rate of cutting fluid.国家自然科学基金(50875120