Design And Research Of The Four Rollers Plate Bending Machine CNC System

Plate bending machine belongs to the bending correction machine in eight categories of forgingmachinery products. With the developing of manufacturing industry, the need of square-circle，elliptic, multi-curvature cylinder increases rapidly. At present，the mainly methods of producingmulti-curvature cylinder are as follows:(1)for cylinder with thin wall, by reaming in mould ofdiameter enlarging machine to reach the desired shape;(2)for cylinder with thick wall，by splicing andwelding with different curvature and arc plate. The above production process is cumbersome anddifficult to ensure the quality of workpieces. Therefore，combined with the particularity of four rollerbending machine, a set of bending machine CNC system used for rolling curvature tube is designed inthis paper.Firstly, the working principle and rolling process of the four roller bending machine arediscussed in this paper. Based on the elastic-plastic theory，the plate bending process of sheet metal isanalysed deeply and the springback after unloading is deduced. With the geometry of bendingmachine’s work-roller，the model of side roller’s stroke and plates’ bending radius is established，applied to the control system. Secondly，according to the four roller bending machine’s mechanicalstructure and control demand，the open-bus-structure control system based on "Industrial PersonalComputer (IPC)+board" is adopted，and at last，the software and hardware of CNC system aredesigned on this structure.Finally，to realize the main functions of bending machine CNC system, the spindle drive servosystem with precise plate feeding is designed. The electro-hydraulic proportional synchronous controlsystem for the side roller position synchronous is introduced."Synchronous mode"+"master-slavemode" strategy and expert adaptive PID algorithm are used in the synchronization control of sideroller’s hydraulic cylinder. The result of the algorithm is simulated and analysed.