AWL laser welding machines provide speed and flexibility.
AWL based in Harderwijk in the Netherlands has come up with a new concept for laser welding auto seats for a German car seat manufacturer. The concept includes a turntable with four working positions, which according to AWL director Piet Mosterd, can also be used for laser welding other products. “The welding speed of this system is of course very important”, says Piet Mosterd. “But even more important is the greater flexibility.”
The concept has been developed in cooperation with a large automotive supplier in Germany which has already for some time now been wanting to get into laser welding, and had already been involved in a number of developments with another partner. However they did not come up with a working production system. In February 2008 the first meeting with AWL took place when they took up the challenge to develop the concept further. This has resulted in the first system being installed this September 2008. The second system is currently under construction in Harderwijk, with the third and fourth already at the component manufacture stage, and the fifth system currently under negotiation.
Courage
It would appear that there is actually more to it than meets the eye. This is because the AWL customer, who has several operations in various European countries, has actually dared to stick its neck out by transferring everything to laser welding, and for which the market seems to have rewarded it. “It is pulling in orders from everywhere”, According to Piet Mosterd. “The competition can only whistle in the wind.” The AWL director is well aware of this, because many other companies in the same market segment are AWL customers too.
Previously, the welding of the back support was carried out by using a combination of two separate processes: arc and resistance welding. But this particular supplier was aware of its very competitive position, and therefore considered it vitally important to add something completely new to its production process in order to stay ahead of its competitors. They finally decided on high speed laser welding. “It wasn’t an easy decision”, Piet Mosterd emphasised. “A large measure of courage was needed as well, because apart from the considerable investment involved in the new production facilities, it also required a complete redesign of the product.”
In one run
The installation that has already been built by AWL consists of a turntable concept with four working positions: two insert positions, a welding position and an automatic removal position. At the insert position all the materials are clamped for a single run. At the welding position these are all welded together with sixteen separate welds into a back support. This is done using a remote laser welding system that is fed through a Rofin CO2 laser source. In the near future Piet Mosterd thinks that he will be able to offer a fiber laser welding source as well. This will help to make the system more compact and energy efficient. Utilization of the fiber laser also creates savings in the amount of investment required, because with fiber lasers the laser beam comes out of the fiber, so that the expensive bridge construction is no longer required.
The welding is completed within ten seconds, with the entire run only taking eighteen seconds. The customer in Germany takes twenty seconds to complete the run as the machine must wait for the inserts. In comparison with the older production methods with conventional arc and resistance welding, the time saved amounts to 30% thanks to laser welding.
But although every second counts with automotive suppliers, the speed of the welding process is not the biggest gain from this system. According to Piet Mosterd they see the real gains in the area of flexibility. “The level of flexibility that now exists at our customer’s factory has risen dramatically. They have actually purchased increased capacity. The machine is no longer the determining factor, but the trick is actually in being able to rapidly exchange jigs. This way a whole range of products can be welded at the same time. Every jig can work on any of the machine so that the various production series can be welded just as easily on one machine, as they can on another. Anything from a small series through to large production flows.”
The installation jig sets are not supplied by AWL, although the machine engineers in Harderwijk are fully involved. “We are busy with acquiring a position in jig production”, said Piet Mosterd, who stated that the jigs are a vitally important element in laser welding. “We can store a large number of jig programs – ten or even twenty - in these machines. It is simply a question of the capacity of the memory in the PC. Furthermore, the read-off programs can be altered quite simply.”
Robots
Well thought out jigs can ensure a quick conversion/adjustment to the production resources for other production flows, and according to Piet Mosterd that is one of the reasons why the installation already built would also prove to be an interesting proposition for products other than back supports for auto seats. The AWL director talked about the production of the slides onto which the auto seats are attached, for example. "You also use these slides in office cabinet drawers, oven guide rails and burners.”
Even Dutch companies, who do not tend to have such enormous production series as the automotive industry for example, ascribe to Piet Mosterd’s prospects for similar systems. “Certainly if you mounted a remote laser welder onto a robot. You see, the installation that we have just completed is a 2 ½ D system. And for us it is just one small step to fit this concept out with a robot. You can certainly do things in a correct and profitable way if you go one step further and start using fiber laser - even for the smaller series. The robot has a scanner, just fires a couple of times at the product, and everything is done.”
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