The laser spot welding machine, also known as the resistance welding machine, is usually classified into three categories based on the properties of the welding power supply:
- AC spot welding machine;
- Energy storage spot welding machine;
- DC spot welding machine.
AC spot welding machine
Precision AC spot welding machines generally refer to spot welding machines with power below 16KVA, mostly in tabletop form, usually divided into foot pedal and pneumatic types. This type of welding machine uses AC discharge and various control methods such as single pulse, multiple pulse, frequency, time, and program are employed.
It can perform single spot welding, continuous welding automatic control, and manual control, with complete specifications. It is mainly used for welding various metal sheets, wires, and rods of tungsten, molybdenum, iron-nickel, aluminum, stainless steel, silver, and other materials.
High-power AC spot welding machines generally refer to spot welding machines with power above 16KVA, mostly in vertical pneumatic form. The performance characteristics of high-power AC spot welding machines include a direct pressurization mechanism, good follow-up performance, fast welding speed, long service life, low noise, safety, and easy to use.
It adopts a water-saving forced cooling method, a high firmness and strength body structure, and a simple and practical upper insulation. The main circuit uses high-power SCR non-contact switch with high conductivity and low power loss.
In the secondary current circuit of domestic AC spot welding machines, the secondary output of the main transformer adopts multi-layer high-toughness and high-conductivity copper soft straps, and is connected in a U-shape, which greatly improves the service life. The next-stage output uses an integrated direct connection mechanism, and the current loss is minimized.
The Weld King AC spot welding machine adopts water-cooled high-power thyristor elements in the main circuit, with strong, stable, and reliable output power. It has the rigidity to resist impact and vibration, can prevent electrode head sliding during pressure application, and achieve stable welding.
It is mainly used in the hardware, electromechanical, and automotive industries. The precision and welding performance of AC machines are higher than that of energy storage machines.
Energy storage spot welding machine
The precision energy storage spot welding machine in this series adopts capacitor energy storage for charging and discharging welding, which has the characteristics of low impact on the power grid, concentrated welding current, fast discharge speed, strong penetration, and small heat-affected zone on the welded surface.
It is suitable for welding various metal sheets, wires, bars of copper, nickel, stainless steel, iron, etc., as well as various small relays, low-voltage electrical appliances, and spring sheets, silver contacts, and copper wires.
A high-power energy storage spot welding machine generally refers to an energy storage spot welding machine with a power above 800J (joules). Its characteristics are: wide application range, able to weld stainless steel, copper, aluminum, alloys, and general non-ferrous metals besides general soft iron, and has excellent welding performance. Due to the complete separation of output and input, it is not affected by external power supply changes and maintains constant power output.
Compared to DC and AC machines, the product performance is slightly inferior, but the appearance of the weld and the firmness of the welding are still acceptable, suitable for processing products with lower appearance requirements. The disadvantage is that the device requires energy storage, which means that the electricity needs to be stored in the device’s capacitors before each discharge, and the capacitors need to be replaced after the device is used for a period of time.
Inverter DC spot welding machine
The principle of DC spot welding machine is to invert AC electricity into DC electricity for welding purposes.
As is well known, the electricity we use, whether it is for household or industrial purposes, is all AC electricity. This is because the advantages of AC electricity are ease of transportation and low cost, while its advantages are the disadvantages of DC electricity, and vice versa. They are complementary.
DC electricity is relatively more stable and safe for use in equipment than AC electricity. Like AC machines, DC machines are mostly tabletop, and usually come in two types: foot-operated and pneumatic.
Welding machines use DC electricity for discharge and can use various control methods such as single pulse, multiple pulse, frequency, time, etc. They can also implement single-point welding, continuous welding automatic control, manual control, and have a complete range of specifications.
They are mainly used for welding various metal sheets, wires, and rods made of tungsten, molybdenum, iron, nickel, aluminum, copper, stainless steel, silver, and other materials.
The advantages of DC welding machine over AC and energy storage welding machine are: compact structure, smaller size, strong overload capacity, low energy consumption, superior performance, and higher welding precision. The disadvantage is that it is more expensive than the first two types of welding machines in terms of cost.