[Application Case] Battery Module Busbar Pre weld&Post weld Inspection

Project background

In the process flow of the module pack section, Busbar welding connects different battery cells in series and parallel through connecting paddles. To ensure welding quality, the gap between the paddles and the pole column needs to be controlled before welding, and the appearance of the weld seam needs to be inspected after welding to prevent welding defects from flowing into the next process.

Pre welding inspection: It is necessary to check the gap between the connecting piece and the pole, with a tolerance control of 0~0.2mm;

Post weld inspection: burst points, weld penetration, etc; Weld size: length, width, area, etc.

Solution

Camera model: 3D line scanning laser sensor.

Scanning speed: 150mm/s.

Detection method: Use grayscale image for straight line fitting measurement of weld size, and use height image for defect detection.

To solve visual obstruction, a dual camera reverse installation method is adopted for detection.

Effect display

Project Summary

Pre weld gap detection: dynamic repeatability 0.02mm.

Post weld defect detection: It can stably detect defects such as weld burst points, dents, and weld penetration.

Post weld defect detection: The measurement accuracy of weld length and width is 0.1mm.

Misjudgment rate<0.3%; Misjudgment rate: 0%.

Risk detection:

1. The pressure of the copper nozzle has a significant impact on measurement stability, and it is necessary to first determine the pressure standard value before measurement;

2. The depth of spot welding is relatively deep and needs to be distinguished from the testing standards in other areas.