The shape, size, and cooling conditions of the electrode end face structure of the intermediate frequency spot welding machine affect the geometric size of the melt nucleus and the strength of the solder joint. For commonly used conical electrodes, the larger the electrode body, the cone angle of the electrode head α The larger the size, the better the heat dissipation.
but α When the angle is too large, the end face is constantly subjected to heat and wear, and the diameter of the electrode working surface increases rapidly; if α If it is too small, the heat dissipation conditions are poor, the surface temperature of the electrode is high, and it is more prone to deformation and wear. In order to improve the stability of spot welding quality, it is required to minimize the variation in the diameter of the electrode working surface during the welding process.
Therefore, α The angle is generally selected within the range of 90 ° -140 °; For spherical electrodes, due to the large volume of the head, the contact surface with the welded part expands, the current density decreases, and the heat dissipation ability strengthens. As a result, the welding penetration rate will decrease and the diameter of the melt nucleus will decrease.
However, the indentation on the surface of the welded part is shallow and smoothly transitions, which will not cause significant stress concentration; Moreover, the current density and electrode force distribution in the welding area are uniform, making it easy to maintain stable solder joint quality; In addition, the installation of the upper and lower electrodes requires low alignment and slight deviation, which has little impact on the quality of the solder joints.
Post time: Dec-09-2023
