The basic principle of resistance spot welder is to pressurize and heat fusion at the joint, so it plays a very important role in the power generator. If the electrode is not pressurized correctly, it will produce bad joints, scalp shavings, indentation marks, bubbles, etc. Generally you can use human power (hand and foot) or lever to pressurize directly, and compressed air cylinder or oil cylinder can be pressurized with motor thread.

The most common method is to use compressed air cylinder pressurization. Convert the power source into the output part of the force and the guide part. In the air compression output part, according to the air sealing method, there is the use of O-ring, U-shaped pad and other sliding seals of the piston cylinder, there is also the use of flexible rubber-like divider, no words of that part of the diaphragm cylinder or waveform diaphragm cylinder.

Diaphragm cylinder or waveform diaphragm cylinder has good immediate responsiveness, but its disadvantage is that it cannot obtain longer pressurization stroke and is more expensive, so it is rarely used except for large welding machines and other special applications.

The guiding part has the function of guiding the direction of pressurization and stopping to reduce the friction on the structure as much as possible so that the force can be transferred to the electrode top forging effectively, especially in the convex welder and capacitor machine, a spring is installed between the cylinder and the guiding part to reduce the friction when guiding and improve the immediate response and follow-through when pressurizing.