Spot welding in accordance with the use of points, a universal (general-purpose), special-purpose; according to the number of welding points at the same time points, there are single-point, double-point, multi-point; Bilateral; in accordance with the transmission mechanism of the pressure mechanism points, a pedal, the motor - cam, pneumatic, hydraulic, complex (gas hydraulic type); in accordance with the characteristics of the operation, there is non-automation, automation; The method of installation points, there are fixed, mobile or portable (hanging); according to the welder (IF spot welder) active electrode (usually the upper electrode) of the moving direction points, a vertical stroke (the electrode for linear motion ), Arc travel; in accordance with the supply of energy points, there are frequency welder (using 50 Hz AC power supply), pulse welding machine (DC pulse welding machine, energy storage welding machine, etc.), variable frequency welding machine ).

When the workpiece and the electrode is fixed, the resistance of the workpiece depends on its resistivity. Therefore, the resistivity is an important property of the material to be welded. High resistivity metal poor conductivity (such as stainless steel) Low resistivity of the metal conductivity good (Such as aluminum). Therefore, the spot welding stainless steel easy to produce heat and heat difficult, spot welding aluminum alloy heat difficult and heat dissipation. Spot welding, the former available smaller current (thousands of amps), which must use a very large current Million amperes). Resistivity depends not only on the type of metal, but also the state of heat treatment, processing methods and temperature.

In order to ensure nugget size and solder joint strength, welding time and welding current can complement each other within a certain range. In order to obtain a certain degree of strength of the solder joints, you can use high current and short time (strong conditions, also known as hard norms), can also use small current and long time (weak conditions, also known as soft specifications). The choice of hard or soft specifications, depending on the performance of the metal, the thickness and the power of the welder used. For different performance and thickness of the metal current and time required, there is an upper and lower limits, when used as the standard.

The electrode pressure has a significant effect on the total resistance R between the two electrodes. With the increase of the electrode pressure, R decreases significantly, while the welding current does not increase greatly, which can not affect the reduction of heat production due to the decrease of R. Therefore, the total solder joint strength decreases with increasing welding pressure. The solution is to increase the welding pressure, while increasing the welding current.

Welder's daily inspection - spot welding machine manufacturers for everyone to his right

The first point:

Ground (zero) screw intact and terminal well conductive.

Second point:

Ground (zero) line insulation intact.

The third point:

Power, cable terminals solid, reliable, good electrical conductivity.

fourth point:

Power thumb and cable insulation intact.