In the actual intermediate frequency spot welding machine, adjusting the electrode pressure is one of the key parameters of spot welding. The nature of the workpiece adjusts the parameters and pressure. Excessive or too small electrode pressure will reduce the load-bearing capacity and dispersion of the solder joints, especially for tensile loads.

　　When the electrode pressure is too small, the contact resistance increases, the current density is too high, and the heating speed is too fast, resulting in splashing; when the electrode pressure is too high, the contact area of ​​the welding area increases, the contact resistance decreases, and the resistance heat decreases, resulting in non-fusion and disconnection. Defects such as welding. When the nugget is cooled and crystallized, proper pressure can avoid defects such as shrinkage holes and cracks. Therefore, online monitoring of dynamic electrode pressure is of key significance to ensure the quality of spot welding.

　　While increasing the electrode pressure, appropriately increase the welding current or welding time to keep the heating of the welding area consistent. At the same time, due to the increase in pressure, the negative influence of the weldment assembly gap and uneven rigidity on the strength of the solder joint can be eliminated. At this time, the strength of the solder joints not only remains consistent, but the stability can also be greatly improved.

　　The force that the electrode adds to the workpiece can be divided into two parts, one part overcomes the elastic deformation of the workpiece and makes the workpiece contactable. The other part is used to compress the welding contact surface. The force to overcome the deformation of the workpiece and the pressure on the electrode are related to the thickness of the workpiece. As the thickness of the workpiece increases, the pressure increases at the same time.

　　If the other parameters are the same, as the electrode pressure increases, the strength of the solder joints will slowly decrease. As the electrode pressure increases, the current density decreases, and the heat loss increases. The more difficult it is to heat the welding area, the weld core size and welding quality will inevitably decrease.

　　If the welding current is increased while the electrode pressure is increased, or the welding time is appropriately extended while the electrode pressure is increased, so that the strength of the solder joints is consistent, as the electrode pressure increases, the strength of the solder joints becomes more and more stable.