Battery Sealing Pin Welding Inspection
Ensure that sealing pins are placed, welded correctly, and free from defects
Once a battery cell is sealed, it is filled with liquid electrolyte through a small hole in the cap. When filling is complete, the hole is covered by a sealing pin, or cover cap, which is then welded in place to secure it.
The proper placement of the sealing pin has traditionally been confirmed by determining its height with a laser or other 3D displacement sensor. But defects in the weld itself, such as dents, burns, pinholes and breaks, are not easily detected through traditional machine vision due to the variety of possible defects and the reflective background of the battery cap.
After the weld is complete, Cognex Deep Learning’s defect detection tool can identify numerous potential defects on the sealing pin weld. The deep learning application is trained on a wide selection of properly sealed batteries to learn the full variation of normal parts, including the acceptable level of cosmetic defects, lighting highlights and shadows.
Once on the production line, Cognex Deep Learning analyzes and flags any sealing pin welds that are outside of the acceptable range, while minimizing false positives from purely cosmetic defects.
Users can pass the detected defects to Cognex’s classification tool. This tool is trained on a range of labelled weld and placement defects so that it can identify them properly. At runtime, the classification data is used to take the corrective action upstream for whatever type of defect is detected.
Depending on customer preferences, the Cognex DSMax, a 3D laser displacement sensor, can easily be integrated into the inspection process without the need for any third-party software. Together Cognex Deep Learning and the DSMax can provide full inspection of the sealing pin and its weld to ensure it is free from defects and welded and placed correctly.