Research And Design Of Electrostatic Spraying System Based On PLC

In the manufacturing industry, spraying is a very important and indispensable process, especially in the automotive field. However, manual spraying is widely applied in small and medium-sized enterprises, which has a great impact on the human body, the quality and efficiency of spraying, and the level of automation is low. Therefore, in this thesis, by using the widely used in automatic spraying key equipment in the field of electrostatic spraying, namely high speed rotating cup electrostatic spraying machine to spray the wheel hub, design a set of automatic electrostatic spraying system has very important significance.In this thesis, a series of control behavior of the electrostatic spraying system, such as the detection of the workpiece, the movement of the spray gun, and the spraying of the spray gun, is completed. First, by measuring the speed, size and position of the wheel, PLC determines the range of motion of the gun according to these parameters, and then control the spraying gun to spray. The whole system is based on the Profibus-DP field bus S7-300 PLC control system.First of all, this thesis describes the background and significance of the research, reviews the domestic and foreign development status, points out the gap between China and the coating equipment and puts forward the research content of this paper. Then through the research of the existing spraying process, puts forward the simplified automatic spraying method and by adopting PLC control system based on Profibus-DP field bus, the overall control scheme based on PLC is established, also design the motion control system and rotary cup control system. Secondly, the performance of the main hardware used in the control system is briefly introduced and a variety of hardware integration methods are studied. The monitoring system of the PLC control system is designed and the preparation process of PLC program and the design method of automatic spraying monitoring system are introduced in detail. Finally, summarizes the results achieved by the system in this thesis and the improved method of imperfect system are put forward.