【作者】 黄秀珍；

【导师】 王维；

【作者基本信息】 沈阳工业大学 ， 机械电子工程， 2002， 硕士

【摘要】 在变切削参数加工中，铣刀很容易发生破损，给生产带来极大危害，在线检测刀具破损就成为一个非常重要的课题。 本文研究了实际加工条件下的刀片破损机理，得到刀片参与切削概率最大的切削刃的长度及切削刃位置，发现刀片的刀尖部分承受了大部分的切削任务，是磨损最严重的区域，而且刀尖也是实际刀片破损发生最频繁的地方。因而得出刀片破损与其磨损存在内在联系。 在变切削参数的加工工况下，通过对振动信号的采集和频域处理，发现采用单一的自功率谱方法难以有效检测出刀片破损。针对这种情况，结合频域和统计理论，提出了一种新的刀具破损检测方法：频谱—方差分析法。得到的破损状态特征值为破损方程的建立提供了辨识的依据。 基于小波理论的特点，将其应用于刀具破损状态的检测。通过对振动信号的处理，提取出能体现刀具破损状态的特征向量。所得结果与应用频谱—方差法的结果吻合，因此从另一方面验证了频谱—方差法。 以工件加工的时间间隔为输入量，以破损状态特征值为输出量，研究了对工件—刀具这一非线性系统进行系统辨识的方法。并应用这种方法得出刀具破损模型的方程。方程的确定为刀具破损状态的预报监控奠定了基础。 论文最后一章将检测、建模、预报等部分结合在一起，提出了刀具破损状态监控的方案，并对刀具破损状态监控进行了实例应用。更多还原

【Abstract】 During the process of variable cutting parameter,the milling cutter is easyly disrepaired.It will bring great damage to manufacture.So monitoring tool failure online becomes an important task.The reason of tool breakage in the practical producing condition is studied.The length of the cutting edge which most frequently participates in the cutting is calculated.The result shows that the point of the cutter takes on the most part of cutting task. As the point is also the place where tool breakage mostly taken place, the tool breakage has inner relation with tool wear.Through collecting vibration signal and analyzing it in the frequency domain in the condition of changing parameter cutting, a single self power spectrum is hard to detect tool breakage effectively.Combined methods of frequency domain and statistic analysis, a spectrum-standard deviation method of detecting breakage of disc cutter is advanced.This method can be used to detect breakage of disc cutter with displaceable blades.The eigenvalue of tool breakage is picked up and can be used to build tool breakage equation.Wavelet theory is applied in the measurment of tool breakage status and the eigenvector which embodied the status of tool is picked up.It validate the method of spectrum-standard deviation on the other side,for results of the two methods are similar.System differentiation of the nonlinear system of workpiece and tool is investigated.Time distance of cutting is taken as input value and the tool breakage eigenvalue as output value.At last, the equation of tool breakage model is achieved.The last chapter gives out the scheme of detecting tool status in milling by uniting measuring and modeling with predicting .更多还原