The main component of the electric welding machine is a step-down transformer. The two ends of the secondary coil are the workpiece to be welded and the electrode. When working, the arc is ignited, and the electrode is fused into the gap of the workpiece at the high temperature of the arc. Because the iron core of the welding transformer has its own characteristics, it has the characteristics of a sharp drop in voltage, that is, the voltage drops after the electrode is ignited; when the electrode is stuck and short-circuited, the voltage drops sharply.
During the welding operation, although the current in the circuit is equal everywhere, because the resistance is different everywhere, the resistance at the non-fixed contact is the largest (this resistance is called contact resistance), according to the law of thermal effect of current (also called Joule's law) , that is, Q=IRt: when the current is equal, the higher the resistance is, the higher the heat will be. Therefore, during welding, the contact of the electrode, that is, the contact of the metal body to be connected, has the largest contact resistance. The electric heat generated is naturally the most, and the welding rod is an alloy with a lower melting point, which is naturally easy to melt. The molten alloy electrode core is bonded to the object to be welded, and after cooling, the object to be welded is bonded together.
Generally, there is an output DC current adjustment knob on the panel of the DC inverter welding machine. The inverter DC welding machine first performs bridge rectification and filtering of single-phase AC 220V voltage or three-phase AC 380V voltage, and then supplies power switching devices for inverter processing.
Main feature
1. Reasonable design and free adjustment. Different discharge frequencies can be selected according to different metal materials to achieve the best repair effect.
2. The heat affected area is small. There is no heat input during the instant of stacking, so there is no deformation, undercut and residual stress. No partial annealing occurs, and no reheat treatment is required after repair.
3. The impact of welding repair is extremely small. This welding machine overcomes the phenomenon that ordinary argon arc welding produces impact on the periphery of the workpiece in the process of welding repair. Repairs can be performed with confidence even on the machined surface of the workpiece with no allowance.
4. The repairing precision is high. The thickness of surfacing welding is from a few microns to a few millimeters, just grinding and polishing.
5. High welding strength. Due to the full penetration of the material into the workpiece surface, it produces a very strong bonding force.
