Interview with Mr. Zhao Weihua, Welding Manager of Beijing Benz DaimlerChrysler Automotive Co., Ltd.

In the face of traditional spot welding, arc welding and other processes, laser welding has gradually become a new favorite of people's attention. However, for automobile manufacturers, not only factors such as the advanced nature of the technology and the welding effect must be considered, but also the problems such as cost investment and rate of return, because the survival and development of the enterprise ultimately depends on profits. In the increasingly competitive situation in the automotive industry, the high cost of laser welding technology has made many companies unmatched by this process. At the same time, the welding of dissimilar metals, energy saving, environmental protection and many other issues have also brought new requirements for welding technology. As a result, another welding process, pressure riveting technology, has quietly developed and provides enterprises with a new choice...

Reporter: Due to the characteristics of laser welding in terms of quality and other aspects, many people nowadays respect laser welding. How do you view laser welding? How should companies consider their application in actual production?

Zhao Weihua: Welding is a service technology. Which kind of welding process is used mainly depends on how the designer designs it. At the same time, it needs the analysis of the technician and then decides what kind of welding method to use. At the time of studying welding engineering at Beijing Aviation College, he learned about laser welding. Therefore, laser welding is not new, but it was widely used in aerospace. However, in terms of its application in the automotive field, it is relatively new technology. At present, some automobile manufacturing companies use laser welding, but the welding method always has its purpose no matter which method is adopted. The same applies to the laser welding technology. Otherwise, why should it be adopted? We know that the cost of laser welding is very high and its equipment is expensive. It is several hundred times or even thousands of times more expensive than gas shielded welding. Therefore, if the work that can be done by gas shielded welding, laser welding will not be used unless it can bring great benefits. Personally, I believe that regardless of the welding technology used, it must be based on the actual needs of the company's production, and not only on the advanced nature of equipment technology. Vacuum electron beam welding has a higher level than laser welding. Its deformation amount and welding quality are better than laser welding. It is the most advanced welding method. It has many applications in the aerospace field. Of course, its price is also high. For the actual situation of China's automobile manufacturing industry, the specific welding method must be based on the actual needs of the product. Considering the “full life cycle” of the product, “applicable” is the best.

Reporter: As far as the current situation is concerned, laser welding has not been universally applied. So, what is the current status of welding technology in automotive companies? How are the future technological developments?

Zhao Weihua: Due to the development history and current status of China's automobile manufacturing industry, at present, resistance spot welding and gas shielded welding are used in automotive manufacturing. Gas-shielded welding requires the use of filler material, welding wire, compared to spot welding, whereas spot welding does not require it. In addition, the pollution of gas shielded arc welding is relatively large. Under the current situation of constantly emphasizing “energy saving and environmental protection”, enterprises must pay full attention to the actual technological transformation, such as setting up smoke and dust removal systems. In addition, gas shielded welding is not as efficient as spot welding.

From this point of view, resistance spot welding still has many advantages. However, resistance spot welding imposes excessive demands on the power supply, and the power distribution capacity of the power supply is also required to be very high, resulting in high energy consumption. Moreover, under normal circumstances, companies will not use only one welding machine, so the one-time investment in the previous production line is also very large. In addition, spot welding often produces a lot of splashes at work. In actual work, there are many first-line operators who have been injured by splashes. Even wearing glasses is hard to prevent. Therefore, spot welding operations have certain risks and sometimes even cause fires.

Through long-term practice, I personally believe that pressure riveting technology will be greatly developed in the future. This is mainly because the riveting technology has many advantages that spot welding does not have: it basically does not use the power source, just compresses the air; Compared with the spot welding very energy-saving, the environmental protection - does not have the spatter production, moreover its one-time investment ratio Less welding. It can be predicted that with the increasing maturity of the riveting technology, a considerable part of the spot welding process in the BIW connection will be replaced by the riveting technology.

Reporter: Although riveting technology has made up for many defects in spot welding, does it have certain shortcomings? And is there a way to overcome this shortcoming?

Zhao Weihua: Yes, pressure riveting technology, of course, has its shortcomings, such as its accessibility is not very good. This technique requires a lot of force, almost a few tons of force to a point, so the size of the clamp body is very large. The inside of the car body always has a lot of gossips, and it is not easy to use the riveting technology. However, the accessibility of the press riveting technology can be compensated by the designer's design. If the designer does not design the connection parts of the vehicle body in the hard-to-access place, this problem is also avoided.

At present, the pressure riveting technology is already very mature technology, and the reason why it has not been widely promoted has a great relationship with the design of the car body by the designers. From the end of design to application in practice, this will take some time. At the same time, planners and craftsmen are also required to recommend to the designers, telling him that this technology can save costs, and has solid data in terms of strength, fatigue resistance, etc., in order to be considered by designers. At present, because we have not yet used the riveting process on a large scale, we have not yet reached a firm conclusion. However, considering a variety of factors, of course, including the data provided by suppliers, I believe that in the automotive industry, pressure riveting technology must have a huge development prospects.

Reporter: It takes a process to put any new technology into use. From the perspective of the status quo of China's automobile manufacturing industry, what factors are needed to promote the development of pressure riveting technology?

Zhao Weihua: I first knew the technology of riveting from Kelesler. Later, when I visited the BMW workshop, I saw that the cast aluminum parts were riveted and used even in locations where spot welding is difficult to complete. Press riveting technology to achieve.

Of course, many people didn't understand it when they first started contacting the riveting technology. Usually, two pieces of material are welded together. If spot welding is used, the surface after welding is very flat and the vision is very good. If the riveting technique is adopted, the welded material has concave and convex pits, which is not very beautiful. The feeling is not very comfortable. However, from the actual situation, 90% of the parts on the car body used for spot welding are in places we cannot directly see, neither the driver nor the occupants can see it, and will not cause any impact. The bumps are just the characteristics of the riveting process. Once people approve it, it doesn't matter. Of course, the adoption of any technology requires a process. During this process, there will be many factors to continuously promote its development. This is especially true for the application of pressure riveting technology in the automotive industry, and perhaps its development. The road to be longer and arduous.

As we all know, there are very few self-developed models in China, that is, lack of self-owned brands. Most of them are counterfeiting models of other countries, and they are intact, and thus they do not have their own intellectual property rights. In this way, if a certain part of the car you think should use the riveting technology better, but the patent owner does not agree, you also do not have the right to change the welding method. If it is a self-developed model, then you can decide which technology to use for processing. At the same time, many well-designed body technologies are currently not suitable for the use of riveting technology. In addition, in the domestic automobile manufacturing enterprises, many people are not yet familiar with pressure riveting technology and are still using spot welding technology because they are familiar, mature, and assured technologies. But in fact, pressure riveting technology is also mature and assured. The existence of a series of similar problems will restrict the development of the riveting technology. Of course, with the improvement of independent development capabilities and the improvement of other related issues, people will have a more in-depth understanding of the pressure riveting technology, and thus further promote the application and development of pressure riveting technology.