Research On Reduction Effect Of Noise And Vibration During Sheet Metal Blanking Based On Servo Press

Stamping has an important position in mechanical manufacturing industry, and blanking process accounts for about 50% ~ 60% of the whole stamping process.The noise and vibration which influence the sheet forming quality of the part and reduce working life of the press and die set occurred in the blanking process is bad for worker's health. Comparing with mechanical press, the servo press has a programmable function that allows fully control of the position and velocity of the press slide. The blanking noise and vibration by using servo press is lower than using mechanical press. The research subject is supported by Guangdong Province & Chinese Academy of Sciences Comprehensive strategic cooperation project(No.2009B091300019)—"Development and Application of Multi-Field Integrated Design and Simulation for New Forging Equipment".The vibration and noise occurred in the blanking process under different parameters based on servo press were mainly studied by the numerical simulation, the theoretical analysis, the engineering simulation and the experimental study; the following works were carried out:1 The valid finite element model is builded and equivalent stress, equivalent strain and mean stress during blanking is analysised. And the variation regulation of blanking force curve and the maximum blanking force under different processing parameter which is the foundation of the research on reduction effect of noise and vibration is discussed. The results show that the maximum blanking force increases with increasing in the material shear strength and sheet thickness;the maximum blanking force increase with increasing in the blanking speed but increase barely wit the ration of punch stroke for Q235.2 The forecast model of noise pressure level during fracture separating stage of blanking on servo press was established through the theoretical analysis, and the mathematical formula to calculate the noise pressure level was deduced. The variation regulation of noise pressure level under the different material, sheet thickness and blanking speed were obtained based on the deduced theoretical formula. The results show that the noise level increases with increasing in the material shear strength, sheet thickness and blanking speed.3 Three degrees of freedom (TDOF) vibration system based on software Matlab/Simulink during sheet blanking on servo press was established through the theoretical analysis. The variation regulation of press vibration under the different material, sheet thickness, blanking speed and the ratio of punch stroke were obtained. The results show that with the increasing of material shear strength, sheet thickness and the blanking speed, the trend of the press vibration increases; however, with the increasing of the ration of punch stroke before the fracture of sheet, the trend of the press vibration decreases, and the vibration is lowest when the ration of punch stroke is 65%.Finally,blanking experiment was done and the result shows that the validity of the forecast model of noise pressure level and TDOF vibration system .