In the automobile manufacturing process, laser technology is mainly used for tailor welding of body plates with different thickness, body welding and auto parts welding. laser pointer welding is used in automobiles, which can reduce the weight of the car body and achieve the purpose of fuel saving; improve the assembly accuracy of the car body, increase the rigidity of the car body, thereby improving the safety of the car body; reduce the stamping and assembly costs in the car body manufacturing process, and reduce the body The number of parts and increase the degree of body integration.
Application of laser welding technology in automobile manufacturing. Laser self-fusion welding, that is, the two or more parts of the welding are melted by themselves and finally cooled and condensed into a whole. This welding method does not need to add auxiliary flux or filler, and completely uses the material of the workpiece to be welded together.
Laser self-fusion welding is mainly divided into two parts in automobile body manufacturing: body assembly welding and tailor welding. The group welding mainly includes the connection of the top cover and the side wall, the side wall group welding and the door welding. However, with the development of technology, laser group welding is more and more widely used in this part of the welding. At present, only Volvo is still using it. Laser self-fusion welding; Ford SUV and car have a laser self-fusion welding on the side wall, and many models of Volkswagen are also using it.
Automotive laser tailor welding. Tailor-welded blanks (Tailor-welded blank, TWB) are welded by steels with different strengths, different thicknesses or different coatings. Due to the advantages of high efficiency of laser welding and good weld formation, the current automotive tailored blanks are all laser welded Become.
Compared with ordinary steel plates, tailor-welded blanks have the following three main advantages:
1. Reduce the weight of the car body-use the welding method to optimize the thickness of the sheet to reduce the weight;
2. Improve the service and collision performance of the body-mainly including safety, driving performance, fatigue and corrosion resistance and body rigidity;
3. Reduce costs-mainly from the reduction of materials, reducing processing procedures and reducing the number of molds.
The use of blue laser pointer tailor-welded blanks in car body manufacturing can reduce the number of parts, molds and welding tooling, reduce body weight and cost, and improve the market competitiveness of products. Figure 3 shows the main application of tailor-welded blanks in automotive body-in-white, which are mainly used in covering parts, and some are used in structural parts.
Application of laser welding technology in automobile manufacturing. Tailor-welded blanks for automobiles can be classified into three categories according to the types of welds:
1. Single straight weld;
2. Multiple straight welds;
3. Non-linear weld.
Among them, the single straight line weld type is most used, and the production process is relatively simple. Non-linear welds are the most complicated. Generally, welds are designed according to the shape of the stamped parts, so as to improve the strength and stamping performance of the product.
Since the tailor-welded blanks of automobiles must be stamped and formed laser engraver, the forming quality and defect control requirements of tailor-welded blanks are particularly strict. Mainly include appearance (scars, cracks, inclusions, holes and scratches, etc.), weld formation (weld width, weld protrusion, effective depth of weld, backside fault and weld misalignment, etc.) and mechanical properties, etc. (Testing the welding seam for tensile, cupping, hardness and bending) requirements. For example, it is required to break in the non-welded area in the tensile performance test, and the cracked area in the cupping test cannot be greater than the specified value in the weld or the cupping value.