Impact of Mechanical Characteristics of Capacitor Energy Storage Spot Welders on Welding

How do the stiffness characteristics of capacitor energy storage spot welders affect welding? Here are some key points we tested and summarized:

 

Influence on Weld Formation

Influence on Welding Strength

Influence on Electrode Alignment

Let’s take a closer look:

 

1、Influence on Weld Formation

The mechanical stiffness of a capacitor energy storage spot welder directly affects the electrode force, which in turn influences the welding process. Therefore, it naturally connects the stiffness of the welder to the weld formation process. Experiments clearly show the relationship between weld formation and welder stiffness. Welders with different stiffness may have significantly different actual electrode pressures during welding. This difference can affect the welding process in terms of spatter occurrence and nugget formation (nugget structure). Increasing the welder’s stiffness can delay spatter. Modifying the mechanical structure to increase stiffness resulted in a higher spatter limit (spatter current). High stiffness frames exert greater constraint on the workpiece, reducing spatter. This effect is more pronounced in thin sheet welding, allowing higher welding currents to be used without spatter, resulting in larger welds.

2、Influence on Welding Strength

Comparative tests demonstrate the impact of welder stiffness on welding quality. The stiffness of the welder base was varied between its original and a higher stiffness. Increased stiffness slightly improved the tensile shear strength of the welds by about 3%, though the data ranges overlapped.

3、Influence on Electrode Alignment

Capacitor energy storage spot welders must ensure electrode alignment, as electrode misalignment negatively affects the welding process and quality. Axial or angular misalignment can lead to irregularly shaped welds and smaller weld sizes due to asymmetric pressure and current distribution. The stiffness of the welder frame influences electrode alignment, with lower stiffness welders experiencing more axial and angular misalignment under electrode force. Therefore, high stiffness frames are generally preferred, though excessively high stiffness may be unnecessary and uneconomical.

 

Suzhou Agera Automation Equipment Co., Ltd. specializes in the production of welding equipment, focusing on the research, development, and sales of efficient and energy-saving resistance welding machines, automated welding equipment, and industry-specific non-standard welding equipment. Agera is dedicated to improving welding quality, efficiency, and reducing welding costs. If you are interested in our capacitor energy storage spot welders, please contact us：leo@agerawelder.com