Laser scanning welding technology applied to Audi A4 doors
2018-05-07 00:01:13
In the manufacturing process of automobile body, the traditional solid-state laser welding has been a mature process, and the development of laser welding process has prompted the robot to control the birth of the laser scanning welding process. In the manufacturing process of this new process, the movement of the robot arm can be closely matched with the high dynamic positioning movement of the laser scanner, and Audi has taken the lead in introducing this efficient manufacturing technology on the door of its subsequent products.
In the development of robotic control laser scanning welding technology, the biggest challenge is to develop laser sources that can excite high-quality laser beams. In the traditional laser welding applications, the industrial applicability of a 25 mm mrad lamp pump system with a beam quality of 25 mm has been proven. However, for laser scanning welding, higher beam quality is required because the size of the working space of the optical scanning system and the possible working area depend on the beam quality. Simply improving the beam quality by changing the geometry of the laser bar is no longer sufficient. Only newer, revolutionary lasers can meet the need for improved beam quality. TRUMPF has developed disc lasers for industrial users and has been widely used worldwide (as shown in Fig. 1). It has become a high-power laser with a beam power of 8mm.mrad, and its maximum power is 8kw. Disc lasers can be used in all laser applications, from cutting, traditional welding to laser scanning welding.
In addition, TRUMPF has also developed dedicated scanning solder joints for industrial applications of high power lasers. At present, only the robot guidance solution developed by this company has passed the rigorous certification test of the German automotive industry and has been applied in its series production (see Figure 2). Recently, DaimlerChrysler’s new car body was manufactured using this process.
Compared with the traditional welding process, the biggest advantage of laser scanning welding is that the production efficiency is greatly improved. In the past, the time spent on positioning the robot was greatly reduced due to the rapid mirror image movement of the scanning head, which greatly shortened the entire processing time. Traditional spot welding has a welding speed of 0.5 welds per second, whereas laser scanning welding can typically complete 3 to 4 welds per second. This allows more efficient use of laser sources, which in turn can significantly increase economic efficiency. In addition, a highly efficient disc laser system ensures lower long-term use costs for laser sources. Compared with lamp-pumped laser systems, laser-scanning welding systems can save up to 25% of the cost of electricity and reduce the user's infrastructure requirements (floor area and cooling equipment).
After the Passat trial production in small batches, the laser scanning welding process and its system components are in progress. In 2005 it was applied to Volkswagen's series of products. The high availability of system components has been verified and improved profitability. Audi now implements this process in its range of products. From the beginning of 2007, the subsequent Audi A4 door already used the laser scanning welding process and a 4kw disc laser manufactured by TRUMPF. With this technology, four manufacturing units can produce 1800 doors per day. The laser scanning system is the TruDisk 4002 produced by TRUMPF. It uses the latest disc laser. The device only produces 4kw laser output from 2 discs. Audi's advantage of relying on a laser network (TLN) allows the lasers to be interconnected and shared with each other when necessary, making it easy to maximize the use of laser sources.
In the development of robotic control laser scanning welding technology, the biggest challenge is to develop laser sources that can excite high-quality laser beams. In the traditional laser welding applications, the industrial applicability of a 25 mm mrad lamp pump system with a beam quality of 25 mm has been proven. However, for laser scanning welding, higher beam quality is required because the size of the working space of the optical scanning system and the possible working area depend on the beam quality. Simply improving the beam quality by changing the geometry of the laser bar is no longer sufficient. Only newer, revolutionary lasers can meet the need for improved beam quality. TRUMPF has developed disc lasers for industrial users and has been widely used worldwide (as shown in Fig. 1). It has become a high-power laser with a beam power of 8mm.mrad, and its maximum power is 8kw. Disc lasers can be used in all laser applications, from cutting, traditional welding to laser scanning welding.
In addition, TRUMPF has also developed dedicated scanning solder joints for industrial applications of high power lasers. At present, only the robot guidance solution developed by this company has passed the rigorous certification test of the German automotive industry and has been applied in its series production (see Figure 2). Recently, DaimlerChrysler’s new car body was manufactured using this process.
Compared with the traditional welding process, the biggest advantage of laser scanning welding is that the production efficiency is greatly improved. In the past, the time spent on positioning the robot was greatly reduced due to the rapid mirror image movement of the scanning head, which greatly shortened the entire processing time. Traditional spot welding has a welding speed of 0.5 welds per second, whereas laser scanning welding can typically complete 3 to 4 welds per second. This allows more efficient use of laser sources, which in turn can significantly increase economic efficiency. In addition, a highly efficient disc laser system ensures lower long-term use costs for laser sources. Compared with lamp-pumped laser systems, laser-scanning welding systems can save up to 25% of the cost of electricity and reduce the user's infrastructure requirements (floor area and cooling equipment).
After the Passat trial production in small batches, the laser scanning welding process and its system components are in progress. In 2005 it was applied to Volkswagen's series of products. The high availability of system components has been verified and improved profitability. Audi now implements this process in its range of products. From the beginning of 2007, the subsequent Audi A4 door already used the laser scanning welding process and a 4kw disc laser manufactured by TRUMPF. With this technology, four manufacturing units can produce 1800 doors per day. The laser scanning system is the TruDisk 4002 produced by TRUMPF. It uses the latest disc laser. The device only produces 4kw laser output from 2 discs. Audi's advantage of relying on a laser network (TLN) allows the lasers to be interconnected and shared with each other when necessary, making it easy to maximize the use of laser sources.