Research On Application Of S7-400 PLC In The Reform Of Tyre Manufacturing Extrusion Line

In the tire manufacturing extrusion line,there are many production equipment and the manufacturing process is complicated.Automated control and stability of production equipment will affect the production efficiency and the final quality of tire directly.In the original production line,the programmable logic controller(PLC)have been eliminated.If the production equipment failure occurred or damaged,we will lack of parts.Besides,the system of direct-current speed control and PLC control part have been old in the original extrusion line,the whole system is unstable,the production equipment failure occurred frequently,the rate of shutdown is high,production efficiency and accuracy of control is low.We decided to reform the original tire manufacturing extrusion line,increasing the production efficiency and improving the quality of product.We mainly studied the following contents:We elaborated the operation mode and principle of programmable logic controller(PLC),combining the equipment condition in the tire manufacturing extrusion line and we designed the structure of direct-current speed control system based on PLC.We analysed the control point of mathematical model in the speed and current double-loop control system,introducing the characteristic of typical Ⅰ type and typical Ⅱ type.Finally,we built simulation model of the speed and current double-loop control system under the simulation platform Simulink,making simulation experiments of no-load operation,operation with rated load,operation with voltage noise.In the light of the problems in original production line,we studied and projected the reform plan of the double compound extrusion line.We chose series S7 PLC of SIEMENS to take the place of series S5 PLC of SIEMENS and series FX PLC of MITSUBISHI.We also chose all digital direct-current speed controller of series 6RA70 to take the place of the old controller.We used new PROFIBUS to link the whole production line.We provided the new industrial control equipment and designed human-computer interactive interface.Meanwhile,according to production process requirements,we projected the speed requirement of DC-motor.We used programming function of PLC to write the program,which is of the double compound extrusion line,line speed,weight control and position controller of cutting.Using PLCSIM simulation software,we simulated the program of each segment data block to proof the practicability of S7-400 PLC applicaton in the double compound extrusion line theoretically.Finally,we tested the 6RA70 series direct-current speed controller and system of PLC at the scene.We used built-in function of direct-current speed controller 6RA70 to optimize the parameter manually,using software Drivemonitor to optimize the parameter further.We can get the best parameter of direct-current speed controller 6RA70.Using industrial control equipment Win CC,we tested the speed of DC-motor.Meanwhile,we monitored the whole tire manufacturing extrusion line by on-site monitoring software.The results show that expected effect of equipment reform was achieved.