Study On Monitoring System For Twin-wire High Speed Submerged Arc Weld

Improving the welding quality and productivity has been the focus during the welding research, twin-wire Submerged Arc Welding(SAW), as a efficient welding method, widely used in the industrial production such as shipbuilding, boiler and pressure vessel. However, because of lacking of the timing control and the managing about the parameter, and low level of automation, the further development of twin-wire SAW has been hindered. To slove the problems above, funded by the National Natural Science Foundation, the dissertation designed a new style twin-wire high speed monitoring system based on the Programmable Logic Controller(PLC) and KINGVIEW.Firstly, the dissertation introduces the overall plan and function about the monitoring system of twin-wire SAW. It chooses MZ-2000A-IGBT DC and MZE-1800A-IGBT AC square wave power source, two high power inter power source, as the host and slave power source for the twin-wire SAW. It also analyses the function about them and then leads to the two key PLC and KINGVIEW for monitoring system.Human-machine interface, in the use of the KINGVIEW software, has been designed including the function about parameter setting, parameter displaying and real-time curve viewing. Command language also has been used to program the timing control during the arc starting and arc ending process about the host and salve power source, and to control the current and voltage sampling from the basic equipment with the PID method. Based on the KINGVIEW and Microsoft Access, a welding parameter database could be designed conveniently, it has been used to store, add or delete parameters that belong to the good welding quality.PLC as a bridge between the PC and basic equipment about the twin-wire SAW, has chosen basic and special module for the lower machine designing. The basic module is used to control the switch at the basic equipment. The special module contains four parts, on the one hand, it transmits the datas that the host machine setting to the basic machine for parameters setting. On the other hand, contrast with the previous, it transmits the datas that sampling from the basic machine to the host machine for displaying. Owing to the poor conditions and serious interference during the twin-wire SAW, some optical isolation circuits have been designed to reduce the interference at the term of setting or sampling about current and voltage. The monitoring system has the functions of surveying, controlling and data managing.The experiments done by the monitoring system of the twin-wire high speed SAW show that the monitoring system designed stable and reliable, and the welding sharp during the arc starting and arc dending process shows eximious.The expected achievement has come true. What's more, the technology of twin-wire welding has also been used in the actual production of a shipyard, where the welding speed has been improved obviously and a highly efficient welding has been carried out.