Design On The Control System Of Friction Plug Pull Welding Equipment And Study On The Welding Experiment

In this paper,the control system for friction plug pull welding(FPPW)equipment is designed.This work contains the design and development of both the hardware and software.According to the characteristics of FPPW,the welding experiments are designed.The core of the control system in this FPPW equipment is the S7-300 PLC.The FPPW process was controlled based on the CPU 314C-2DP,analog input modele SM331 and analog output module SM332.The speed sensor was installed in the spindle unit to detect rotational speed,which was controlled and adjusted by the variable pump and the hydraulic motor.The pressure sensors were installed in the hydraulic circuit to detect the cylinder pressure,which was controlled and adjusted by the the proportional relief valves.The displacement sensor was installed in the spindle unit to detect the cylinder displacement,which was controlled and adjusted by the the proportional reversing valve.All of the signals are transmitted to the PLC system.Then these signals are collected by the data acquisition system and displayed on the human machine interface(HMI)of the industrial personal computer(IPC).The software design includes writting the programm of control system and HMI based on the software STEP7 and WinCC,respectively.According to the characteristics of the FPPW,the basic controlling demands on each components of the equipment are proposed.The program is designed for both manual operation and automatic welding operation.The operation of the rotational speed of the spindle and the pressure and movement of the hydraulic cylinder can be achieved manully by the manullay operation programme.The automatic welding operation can achieve the process of FPPW automatically.All of the operation can be controlled through the HMI.The welding tests have shown that this control system has high reliability and stability.The welds with high quality can be obtained in this equipment.The experiment of FPPW is carried out on this independent development FPPW equipment.The welding results show that the welding defects in FPPW are top unbonded,middle unbonded and bottom defects.The welding quality will be improved by controlling the moving speed of the spindle.The welds with high quality can be obtained with 6000 rpm rational speed,20 kN welding pressure,20 kN forging pressure and 2 mm/s moving speed.