Design And Accuracy Of Rotating Station Drive System For CNC Turret Punch

Numerical control turret punch press is the key equipment used for 0.5-6mm sheet blanking process; compared with the common numerical control press, its mold library can automatically change mold; the rotating position in mold library can automatically rotate mold, greatly improving the processing ability of punch; but due to these features, compared with the common punch, the machining accuracy of numerical control turret punch press is affected, and some problems exist in the design of the drive system of rotating position, thus the mold often locks or mismatches. This project takes a type of numerical control turret punch press as the research object, designs a set of rotating position drive system, and analyses the precision of rotating position drive system.This project analyzes the machining precision of rotating position, points out that the transmission accuracy of rotating position drive system influences its angular precision and blanking clearance; builds the kinematic error model of rotating position mold by using the theory of multi-body kinematics, according to the structural parameters of the existing model, arrive at the conclusion that the transmission accuracy of rotating position is ±0.01°.According to the design requirements of rotating position and the advantages and disadvantages of the existing rotating position drive model, determine the transmission scheme of rotating position drive system; select the appropriate drive motor, carry out gear ratio distribution as well as designing and calculating the important parts. Carry out physical design for all parts of the drive system, and have virtual assembly on the basis of the existing numerical control turret punch press.Carry on the theoretical calculation of the transmission chain error of designed rotating position drive system, analyze the influence of part precision of transmission chain on rotating position transmission accuracy, and thus make a conclusion that the transmission accuracy of worm and worm wheel is the major factor to influence the transmission accuracy of rotating position. Analyze the assembly error that causes the worm and worm wheel return difference; carry out the mesh simulation of worm and worm wheel using the ADAMS software; analyze the influence of three factors, namely center distance error, mid-plane error and shaft angle error, on its angular precision, come to a conclusion that the shaft angle error influences the angular precision most, mid-plane error comes second, and center distance error influences least.Establish the finite element analytical model of body and turret parts using ANSYS software, analyze the influence of the first eight vibration modes on machining precision, and thus find that the rigidity of work platen, joint of connecting base and base plate is lower, and needs to be strengthened. Carry out exciter test for rotating parts of this machine tool using excitation device to get the vibration mode and inherent frequency of turret parts. Compare the result between finite element analysis and modal test, thus confirm the accuracy of finite element model. Analyse the transient response of body and turret parts to get the vibration conditions of body and turret parts at typical operating conditions under four cycles of punching load.