Study Of Die Spotting Hydraulic Presses System In PLC Control

The development of modem hydraulic technology is mainly embodied in the combination of hydraulic power technology, electronics technology and computer technology .It aims at improving the automation degree of hydraulic system and control accuracy. This thesis is derived from a practical project, which produces a kind of machine to repair mould with high precision. It mainly deals with the control of the Die Spotting Hydraulic Press (DSHP) synchronous system of high accuracy position, which integrates good control method of PLC to master the whole action, then equips it with high accuracy and good quality.On the base of large amount of materials, this text studies such problems as follows. It gives brief introduction to the principle of the DSHP. Comparing and analyzing the synchronous control strategy, which brings up the new method to control the double un-symmetry jars proceed synchronously with the combination of proportional valve and servo valve, which forms closed loop control; Basing on the above methods, models are made to get mathematics models of position control system and to analyze system model theoretically by using PID controller, we can realize regulating parameters, minimizing synchronous errors and enhancing the dynamic performances; The Simulink tool box in MATLAB software is used to imitate the system according to the model, which not only makes the result visual and easy to adjust the parameters in interactive way but also lets us understand the effects of different parameters and optimizes the dynamic properties.The theory of PLC control in DSHP is discussed after advanced understanding of the system movements. Hardware design and general regulation are given on the base of SIEMENSCompany products S7-200 PLC. Action control programs are made by the use of softwareMicro Win/step7. During programming, three parts are paid great attention to. These are communication between distance sensors and PLC, the realization of PID control in PLC and the data-input of BCD dial plate.Applying the PLC in the Spotting Hydraulic Presses, which enhances the reliability and anti-interference greatly, buildups the position control accuracy, promotes the spotting quality, realizes the combination of machine, hydraulic and electronics.