As the state supports the development of new energy vehicles, the trend of foreign brand new energy vehicle accessories in domestic OEM is on the rise, which has also promoted the rapid growth of the automotive power battery industry in recent years, and the requirements for technology are getting higher and higher.
In the production process of the electric core of the automobile power battery, multiple parts such as the cover plate and the shell need laser welding and friction welding. If the welding quality is not good, there are bubbles, and the welding strength is not enough, it will cause the liquid in the electric core to leak, etc. , is a major quality problem and poses a safety hazard.
In addition, where friction welding electrodes are used, the welding quality requirements are also very high, otherwise it will increase the risk of poor bonding and falling off after welding, and at the same time, the resistance caused by grease and cleaning agent residues will increase, thereby affecting electrical properties.
Therefore, the main engine factory has very high requirements on the welding quality of the battery cells, and no air bubbles are allowed. Aluminum parts will be polluted by various lubricating oils and coolants in the early production, stamping, and cutting processes. If they are not fully cleaned on the cleaning line, or if the drift is not clean and there is cleaning agent residue, it will increase the failure of the welding joint. risk.
At present, there is a new detection method that can detect whether there is any pollutant residue in the welding position within a few seconds, quantify the cleanliness of the welding position, and quickly judge whether the part can enter the next welding process. On the other hand, through detection and collection, production optimization Process, improve welding yield.
The German SITA cleanliness meter adopts the principle of fluorescence to quantitatively measure the pollution degree of the metal surface, and the reading unit is RFU (relative to the total amount of fluorescence, the larger the reading, the more serious the pollution). The measured data on site at a factory familiar with automotive power batteries are as follows:
Cleanliness Readout (RFU) | |
Friction Welded Failed Parts | 100-200 |
Qualified parts for friction welding | < 50 |
The value of cleanliness is measured before welding, which has a significant effect on improving the yield rate of welding and optimizing and improving the process of friction welding.
