To understand a spot welding machine, it's essential to understand its core components:
1. Transformer (Core Component)
The mains power (220V) is stepped down and boosted by the transformer, resulting in approximately:
2-5V ultra-low voltage
800A-3000A ultra-high current
This is crucial for the spot welding machine to instantly create a melting point.
2. Welding Electrode
Typically made of copper or chromium-zirconium copper, its characteristics include:
Excellent conductivity
High temperature resistance
High hardness and non-deformation
The electrode is responsible for directly transmitting the high current to the metal welding point.
3. Control Circuit (Pulse Control)
Modern spot welding machines are equipped with a control board that adjusts:
Electrification time (1-20 ms)
Welding force
Number of pulses (single pulse, double pulse)
Power intensity
The more precise the current and timing control, the more stable the weld.
4. Pressure Mechanism (Manual/Pneumatic)
During welding, the electrode needs to apply pressure to the metal to ensure a tight weld.
Practical Applications of Spot Welding Machines
Spot welding machines are widely used in:
Lithium-ion battery nickel sheet welding (most common)
Sheet metal processing
Stainless steel structure welding
Factory automated production
Automotive manufacturing (body spot welding)
Battery spot welding has the highest equipment requirements because:
The battery must not overheat
Precise weld joints are required
Low-voltage, high-current pulsed current is needed