Spot welding machines are widely used in metal processing across various industries. During operation, if the welding frequency is high, a cooling water system (water chiller) must be used in conjunction with the machine. This article will explain why cooling water is necessary when using a spot welding machine.
Most welding equipment on the market requires cooling, with low-power models using air cooling and high-power models typically using water cooling. The primary purposes of cooling are twofold: first, to cool the electrode components, as the welding process generates a significant amount of heat; second, to cool the power supply components, as high-power switching elements also generate heat during operation; Air-cooled systems are typically equipped with heat sinks and fans to dissipate heat through airflow. Water-cooled systems use water as a medium to remove heat, with the goal of protecting the electrodes and switching components, preventing failure due to high temperatures, and extending their service life.
Some spot welding equipment does not require cooling water, such as precision spot welders and capacitor storage discharge welders. Precision spot welders with currents below 6KA typically do not require cooling water, as their welding currents are low, welding times are short, and the temperature rise of the electrodes is controllable. The load duty cycle of the welder generally does not exceed 5%, and the switching components inside the power supply can operate normally under air cooling conditions, so cooling water is unnecessary; The discharge time of capacitor storage welders is generally between 5 and 15 milliseconds, so the temperature rise of the discharge transformer under normal operating conditions is very low. The heating of the electrode section is also controllable. However, in high-power capacitor storage welders, during welding, the melting of the workpiece generates significant heat, which can cause excessive temperature rise in the electrodes through diffusion and conduction. Therefore, cooling water is required to cool the electrode section. This leads to an interesting phenomenon: large-capacity storage welders are equipped with only a small cooling water tank because they do not need to cool the welder body itself, only the upper and lower electrode sections.
More welding machines require cooling water, such as power-frequency or medium-frequency spot welders, seam welders, diffusion welders, and butt welders. In some cases, external water spraying is also needed in addition to internal cooling water, as several areas generate significant heat during welding that requires cooling: first, the welding transformer; second, the power supply components, such as thyristors or IGBTs; third, the secondary connections, such as the joints between copper plates and copper strips; fourth, the electrode sections, including the electrode handles and electrode tips; these sections generate a significant amount of heat during prolonged welding operations and all require cooling water to dissipate the heat.
Cooling water plays a dual role in the welding process: first, it protects the power supply and extends the lifespan of components; second, it facilitates the welding process by quickly dissipating heat after welding to prevent electrode overheating, thereby protecting the electrodes, extending their service life, and preventing burns to operators; Second, it rapidly removes heat from the product to prevent excessive indentation and high temperatures from causing the product and electrodes to form compounds. For example, aluminum plate spot welding requires strong water cooling to maintain welding quality and stable production. Similarly, during galvanized plate spot welding, if the temperature rises too high, the proportion of oxides formed between the copper electrodes and the zinc layer increases, leading to accelerated electrode wear and electrode adhesion.
The above explains why cooling water is used in spot welding machines. As a manufacturer of resistance spot welding machines, Agera specializes in the production of resistance welding machines and also provides customers with appropriately matched industrial chillers to ensure normal welding operations.
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