Main parts of electric welding machine

The main component of the electric welding machine is a step-down transformer. The two ends of the secondary coil are the welded workpiece and welding rod. During operation, the arc is ignited and the welding rod is fused in the gap of the workpiece at the high temperature of the arc. Because the iron core of welding transformer has its own characteristics, it has the characteristics of sharp voltage drop, that is, the voltage drops after the electrode is ignited; When the electrode is stuck and short circuited, the voltage drops sharply. During welding operation, although the current in the circuit is equal everywhere, due to the different resistance everywhere, the resistance at the unfixed contact is large (this resistance is called contact resistance). According to the law of thermal effect of current (also known as Joule's law), i.e. q = IR. T, when the current phase is equal, the greater the resistance, the higher the heating. Therefore, during welding, The contact resistance of the contact of the electrode, that is, the contact of the connected metal body, is large, so there will be more electric heating at this part. In addition, the electrode is an alloy with low melting point, which is naturally easy to melt. The melted alloy electrode core is bonded to the welded object, and the welded object is bonded together after cooling.