Study On Controlled System For Pulse MIG Welding

The pulse MIG welding is a high-efficiency and high-quality welding method. The welding technique has many advantages such as good arc axial property, low spatter and good weld beam shape. In recent years, it is developed rapidly. Simple analogously controlled system cannot satisfy higher and higher requirement welding technology. Microcomputer controlled arc welding inverter power source can raises greatly controlled level of pulse MIG welding for its flexible control, high accuracy, high system response.A simple chip microcomputer controlled inverter pulse MIG welding machines is developed in this paper. Power circuit of arc inverter power source is consisted of IGBT full bridge inverter circuit. Conduction width of IGBT in full bridge inverter circuit is controlled by means of PWM. The PWM circuit and the driving circuit of IGBT are composed of the SG 3525 chip and EXB 841 chip. It has the welding current feedback circuit and the welding voltage feedback circuit. The wire feeder timing system consists of MOSFET switch control circuit, PWM circuit and control circuit.The pulse MIG welding process is controlled by simple chip microcomputer controlled system in which unit 80C196KC plays a key part. On the basis of the hardware of control system, the control system can put out different acquired welding parameters by the flexible design of the software in order to control the pulse welding current waveform in welding. The control system can realize welding sequential control and 2 beats or 4 beats sequential control mode. As the good man-machine interface the control system, the operators can preset and regulate the welding parameters conveniently.Because welding machine works in the awful condition of high-current and intense magnetic field, variable interrupt factors are likely to make the computer system working abnormal so that effect the stability in welding process, even make the control system paralytic.Anti-interfering technology is applied in the design of software and hardware to improve anti-interfering ability of system.