Research And Apply On Control System Of Multiple Automatic Electroplating Line

Electroplating technology is an important surface treatment technology, which has been used widely and linked with people's daily life closely. In China, the scale of electroplating industries is generally small. Most small and medium enterprises are still using outdated technologies and equipments. A large number of production lines are semi-automatic, even some of them are manual, so that product quality is poor, and production efficiency is extremely low. All of these lead to a bad economic efficiency to enterprise. Competition in market is more and more fierce, which causes enterprises urgently to improve production efficiency and stability of product quality, that is why improving the automation of an electroplating production line is great importance.In this paper, research and apply on the control system of multiple automatic electroplating line has been taken as a target. After the analysis of the production process requirements of zinc, copper, nickel plating and oxidation surface treatment of an enterprise in our country, considering the actual situation of the workshop, all kinds of plating were integrated into one production line, and the distributed hierarchical control system with PROFIBUS was developed.After the electrical system design, the emphasis focused on the multi-channel temperature detection and control system of electroplating solution, where taken PID control method instead of the traditional fixed-point switch control method. In this method, not only increased temperature to target value stably, but also temperature overshoot at the end of heating process and fluctuation in holding process was greatly reduced. Furthermore, multi-machine instant communication programs between rectifiers, inverters and PLC were developed.Practical experience of the multiple automatic electroplating line indicates that precision of electroplating solution temperature control is high, which is up to±0.5℃, and multi-machine communication works well. Practice proves that control system of multiple automatic electroplating line by means of distributed hierarchical control structure has high reliability and strong practicality, besides that it fully meets the needs of actual production. Not only did product quality and production efficiency improved, but also realized integrated automation of electroplating.