Design Of Multi Machine Power Freguency Resistance Welding System

With the continuous improvement of the degree of automation of industrial production,welding equipment develop into the direction of network,integrated,digital and high efficiency gradually.Today's power frequency resistance welding equipment,is generally a welding controller to control a transformer,for the multi-point welding materials,multiple welding transformer needs to work at the same time to complete the welding task.However,when the welding parameters are more,the adjustment process is very complicated,which leads to low welding efficiency.According to the welding equipment to multi-point welding,parameter setting tedious and low efficiency of welding,this paper proposes a multi machine power freguency resistance welding system,it can be achieved on multiple welding equipment parameter setting,state monitoring,welding parameters and fault alarm record through a touch screen.The main welding equipment of multi machine power freguency resistance welding system choesed single-phase power frequency resistance welding machine,the output current of the secondary side of the welding transformer is adjusted by adjusting the trigger angle of the thyristor.The system use the touch screen as the host computer,through the touch screen and the welding controller(centralized control center)'s man-machine exchange,while the centralized control center communicate to a number of drive controller(drive module),so as to achieve the purpose of control of group welding machine and welding work.The touch screen,the driver module and the centralized control center adopt RS485 communication modes.In the system hardware design,the use of ATmegal28 mcu and ATmega8 mcu composed of dual control chip to design digital control circuit,it takes full storage capacity,strong control ability of the ATmega128 microcontroller and the low cost advantage of ATmega8 mcu.The hardware design circuit of the centralized control center mainly includes the power module,the network voltage sampling module,the RS485 communication module,the zero crossing detection circuit,the alternate input and output ports,and the relay output interface.The driver module focuses on the design of silicon driving circuit,RS485 communication module,foot switch circuit,valve circuit,operation panel module and more.The touch screen as a man-machine exchange interface,introduced the touch screen interface preparation process,the touch screen interface programming of touch screen program using a specific language provided by Weilong Tong.In software,this paper introduced the working flow chart of the system,the centralized control center and the drive module,and complete the program debugging.The welding parameters are sent to the centralized control center by the touch screen,the centralized control center for processing parameters,and the processed data is stored in EEPROM,when given the welding command,sends the processed data to the corresponding drive module,control the welding transformer for welding work,reduce the workload and improve the efficiency of the drive controller.Finally,the paper has carried on the experiment test to this design,has carried on the system test under the welding mode and the system test under the monitoring mode separately,has carried on the writing and the analysis to the touch screen interface,and has given the waveform of the secondary output current.After repeated long-term testing,it shows that the test system is stable and can achieve the desired design goals.