The Noise Study Of Machining 6N01 Thin-walled Structure Aluminum Alloy Plate For High-speed Train

Thin-walled structure aluminum alloy plate,which has the advantages of prominent modeling characteristics,light-weight,high-strength,stable mechanical properties and good performance of sound insulation,has been widely used in the manufacture of the body of high-speed train.However,vibration and loud noise which can do harm to the health of workers would generated in high-speed machining of this material because of its special structural characteristics,such as thin-wall,hollow,weak rigidity.6N01 thin-walled structure aluminum alloy plate was researched in this paper and milling model was established.The results show that the vibration and noise caused by elastic deflection of the weak section stiffness in the process of milling.Partial differential equation was established and the main factors including cutting tool parameters(handle diameter,helix angle)and milling parameters(the speed of spindle,the cutting width in radial direction and the feed)and itself structure were analyzed.Orthogonal experimental test system and hybrid programs about different milling parameters,including the speed of spindle,the cutting width in radial direction and the feed,and single factor test about tool structural parameters were designed with the help of DAQ assistant in Lab VIEW to collect vibration and noise signals.The noise signals' time-domain eigenvalues were extracted to study influence law between the noise and milling parameters.The results show that,with the increase of spindle speed and the cutting width in radial direction,the SPL of noise shoMw a trend of first increase then decrease.With the increase of the feed,the SPL of noise show a trend of descrease.Frequency domain analysis and wavelet packet energy analysis conducted by the program written by LabVIEW and MATLAB software.The results indicate that the main frequencies of the noise are the basic frequency and the frequency multiplication,especially the frequency doubling,caused by the speed of spindle and energy of the noise is mainly concentrated in the high-frequency phase.Aiming at decreasing the noise of high-speed machining of hollow aluminum alloy according to generation mechanism of the vibration and noise,this paper designs the measure of filling damping rubber in the inner cavity of' hollow structural aluminum alloy and conducted validated experiment contrasting the results of the controlled trial.It shows that the noise reduction effect is very obvious.