Working principle of spot welding machine

Spot welding machine is a common metal welding equipment, mainly used to weld two metal workpieces through current and pressure. The working principle of spot welding machine is based on the principles of resistance heating and heat conduction.
Principle of Resistance Heating
The spot welding machine uses the resistance generated by the current at the contact point to heat and melt the surface of the workpiece, thereby achieving welding. The specific working principle is as follows:
1. Power supply: Spot welding machines usually use AC power, which is reduced to an appropriate voltage through a transformer. The current magnitude is usually adjusted through the spot welding machine control system.
2. Current conduction: Current is transmitted from the power source to the electrodes of the spot welding machine through cables.
3. Current passes through the workpiece: Current flows through the electrode through the workpiece, and due to the high resistance of the workpiece, the current generates local heating at the contact point.
4. Resistance heating: Resistance heating at the contact point causes the surface temperature of the workpiece to rise, reaching a state of melting or thermal softening.
5. Pressure application: At the same time, the electrodes of the spot welding machine will apply a certain amount of pressure, causing the workpiece to be compressed while heating.
6. Cooling: After a certain period of heating and pressure, the current stops and the workpiece cools down, forming a welding point.
 

Principle of heat conduction
The heat conduction principle of spot welding machine refers to the process of transferring heat from the heated surface of the workpiece to the interior of the workpiece, thereby forming welding. The specific working principle is as follows:
1. Heating the surface: The electrode of the spot welding machine heats the surface temperature of the workpiece through resistance heating.
2. Heat conduction: Heat is conducted from the surface of the workpiece to the interior, gradually heating the entire cross-section of the workpiece.
3. Thermal softening: As the temperature increases, the metal of the workpiece begins to soften, forming a molten area on the surface of the workpiece.
4. Pressure application: The electrodes of the spot welding machine apply a certain amount of pressure to compress the workpiece while heating.
5. Cooling: After a certain period of heating and pressure, heat is transferred to the hand, and a welding point is formed after the workpiece cools down.