Tool Failure Monitoring Techniques For Milling Of Variable Cutting Parameters

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 .