Design & Research Of Control Systems For I.S. Forming Machine

Traditional bottle forming machine implements timing relation of mechanical movements through mechanical cam.However the precision of the mechanical cam is not too high and it is difficult to modulate.How to innovate control technology of forming machine and how to shorten the distance between us and foreign countries are uegent problem to solve for bottle forming machine factories.An electronic timing system and synchronization control system are designed based on computer control technology and field bus technology.The electronic timing system is composed of PC,section control board and main control board.The control boards of the electronic timing system and synchronization control system are connected by using CAN bus.The section control boards detect switch signals from fields and drive electromagnetic valves to work according to the set starting or stopping time.So mechanics of the forming machine oPerate in a specific sequence.Meanwhile the operating sequence of section control boards is managed by main control board.And the synchronization between section control boards and feeder machine is also operated by main control board.Main control board distributes synchronous signals to section control boards through CAN bus after a time delay,when main control board gets synchronous signals,in order to realize the synchronization between section control board and feeder machine.PC which is a supervisor realizes to supervise and administer through CAN bus.The system of synchronous control makes feeder,divider and dialing bottle machine operate in same speed and a certain phase in order to ensure machine to work harmoniously.In this thesis,the system is developed by the following steps.Firstly,the thesis discusses the general design plan of control system for I.S.forming machine on the basis of analyzing requirement of I.S.forming machine.Secondly,the design of hardware circuit,which is around the PIC microcontroller,is discussed.Finally,the software of electronic timing system is designed according to the thought of foreground/background system.The main thought and flow chart of the program are provided.The method of distributing synchronous signals,which delivers signals though CAN bus,is proposed.And the feasibility of this method is analyzed.In this way,not only investment and the complexity of system are lowered and the capability of anti-interrupt is enhanced,but also the hardware need not modify when the section number of the forming machine is changed.It's very convenient to modify the parameter which represents the section number of the forming machine.Having been put into several companies,the results show the electronic timing system and synchronization control system operate steadily,and the passing rate of bottle can reach 90%.