Laser welding method for sealing nail

Abstract

The invention discloses a laser welding method for a sealing nail. The laser welding method for the sealing nail comprises the following steps that the sealing nail is welded through welding equipment with a laser device, a welding track is arranged on an area to be welded, closed-loop welding is conducted in the area to be welded according to the welding track, the laser device is modulated into a high-frequency pulse mode through a control box, the welding power of the laser device is 0.5-1 KW, and the welding time of the laser device is 1-2 h; and the welding frequency after modulation is 80-100 Hz. The laser is modulated into the high-frequency pulse laser, the laser is emitted in a small-pulse-width and high-frequency mode, heat input in the welding process is effectively reduced, and the welding defect that a large number of air holes are formed at the end-to-end combination joint of a circular welding seam due to the fact that residual electrolyte in a liquid injection hole is heated and decomposed into gas under the action of a high-energy laser beam is avoided. And meanwhile, higher welding speed can be adapted, and the production efficiency is high. And after welding, the appearance is good, the consistency of fusion depth and fusion width is high, and the welding seam size stability is high.

Description

technical field [0001] The invention belongs to the field of battery laser welding, and more specifically relates to a laser welding method for sealing nails. Background technique [0002] In recent years, the new energy vehicle industry has developed vigorously. As the core component of new energy vehicles, power batteries have a decisive impact on the performance of the vehicle. Laser welding of sealing nails is the last welding process in the manufacture of square aluminum shell batteries. Product quality and efficiency are very important. Once welding defects occur, the battery will be scrapped directly, resulting in a huge waste of manpower, material resources and cost invested in all previous processes. [0003] If the continuous fiber laser is used for butt welding directly, with the increase of heat input, the residual electrolyte in the liquid injection hole will be decomposed by heat under the action of the high-energy laser beam, resulting in the addition of rubbe...

AI Technical Summary

Problems solved by technology

Laser welding of sealing nails is the last welding process in the manufacture of square aluminum shell batteries. Product quality and efficiency are very important. Once welding defects occur, the battery will be scrapped directly, resulting in a huge waste of manpower, material resources and cost invested in all previous processes.

[0003] If the continuous fiber laser is used for butt welding directly, with the increase of heat input, the residual electrolyte in the liquid injection hole will be decomposed by heat under the action of the high-energy laser beam, resulting in the addition of rubber nails and sealing nails. After sealing, the air pressure in the cavity is too high, and it is easy to form a large number of air hole welding defects at the junction of the head and tail of the circular weld seam, which will affect the sealing of the battery and lead to scrapping

Therefore, the welding of the sealing nail and the liquid injection port of the top cover is generally carried out by YAG pulse laser for butt welding, and the welding speed is generally within 3mm / s~8mm / s, and the production efficiency is low

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