Wire Wire Drawing Machine Tension Control System Research And Development

The aluminum welding loop mode wire-drawing machine is the key equipment in the production of Beijing Nonferrous Metal Material Co.LTD. It mainly relys on friction generated by the reel which is driven by motor, and pull the wire into cold-finished products after raw silk (aluminum or steel) passing through the multi-Level wire-drawingdie. The Original Equipment was imported from board as second-hand equipment, lagging technique,poor controlled resolution and poor reliability of the equipment has influenced seriously surface quality of production on active duty.The loop mode continual wire-drawing machine is one advanced type in the wire-drawing equipment.It uses the direct current motor to drag, realizes the wide range stepless speed regulation, and expands the elongation ratio to the selected scope between the reel.In the process of drawing each reel is produced a rally or counter-rally, which can reduce the pull-out force,extend life and reduce energy consumption.This article explains the basic work principle about wire-drawing, uses SIEMENS Corporation's top-end S7-318-2DP of S7-300 series PLC, fully digital DC speed control device 6RA70 and man-machine interface TP177B, and designes cocurrent velocity modulation control system including the rotational speed and torque double-closed loop based on the Profibus-DP bus.It could solve the electric motor starting process and the stable state movement well, and guarantee non-static error about electrical machinery rotational speed on theoretically.This system can display the superiority of the fully digital cocurrent velocity modulation,and improved the quality and speed of the pull-out.The prime task is as follows:(1) Combined the processing technology of aluminum wire and the structure features of the wire-drawing machine, the paper introduces the widespread tensity control key formula as well as the control flow which is adopted,uses the tension-rotational speed-torque three-closed loop cocurrent velocity modulation plan, studies the tension control as well as the speed control principle thoroughly, and completes the incremental numeral PI regulator design about tension closed loop as well as the rotational speed closed loop, and gives the system diagram.(2) This paper designs the hardware circuits, including the main circuit and control circuit,based on SIEMENS Corporation's top-end S7-318-2DP of S7-300 series PLC, fully digital DC speed control device 6RA70 and man-machine interface TP177B.At same time the paper introduced the he flow chart of system software and the concrete realization about each sub-module by used the tension-speed-torque three closed-loop DC speed control algorithm, the Profibus-DP bus communication, the logical control software between various operation. (3) On the basis of the original equipment,it realizes the entire equipment's build of the electrically controlled system, completes the whole machine debugging, protects the security and stability of the efficient operation, and gives the application result and the conclusion.This system has already been applied successfully to the aluminum welding loop mode wire-drawing machine in Beijing Nonferrous Metal Material Co.LTD.The application result indicates that this control system's hardware architecture is simpler, the service is easier, the movement is stabler, the operation was more convenient, and it enhances the work rate, and realizes the real-time automatic control completely.