PCBN刀具切削中锯齿形切屑形态的动态切削力识别

精密硬态切削过程锯齿形切屑对动态切削力、切削温度波动、PCBN刀具寿命和已加工表面质量有重要作用。本文依据锯齿形切屑锯齿的形成和终了过程可以在动态切削力高频信号中体现出来的特征，采用小波分析硬态切削力的高频信号，分析结果表明不同形态的锯齿形切屑形态对应不同的切削力高频信号。从切削力高频信号的切削速度、进给量、采样频率和时间可以定性描述锯齿形切屑形态和剪切失稳的特征参数。依据Shaw建立的锯齿形生成频率模型。在精密硬态切削条件下，锯齿形切屑的生成频率要远小于切削力高频信号的频率，高速切削条件下两者频率逐渐趋于相等。实验及分析结果表明可以采用动态切削力的小波分析来判别锯齿形切屑的基本特征。

In-process recognition of chip forms using dynamic component of cutting force in hard turning with PCBN tool

Saw-tooth chip has great effect on the dynamic cutting forces,cutting temperature fluctuation,PCBN tool life and surface integrity during precision hard part machining.The forming and ending process of saw-tooth chip could be observed through different high frequencies of dynamic cutting forces by wavelet analysis.According to the cutting speed,feed rate,sampling frequency and time,the characteristic parameters of saw-tooth chip type and shear instability could be calculated based on the saw-tooth chip forming frequency formula supported by M.C.Shaw theory.The forming frequency of saw-tooth chip was far smaller than high frequency of cutting forces under the normal cutting parameters during precision hard part machining process,and will be moved similarly equal to each other under the high cutting speed.Experimental results and analysis show that the basic characteristics of saw-tooth chip could be calculated through dynamic cutting forces wavelet analysis.