Rofin’s remotely controlled 6kW CO2 slab laser, available from Laser Resources , was shown at Schweissen & Schneiden performing high speed laser-spot welding of automotive seat backs.
The highlight among the exhibits on the Rofin Sinar stand at Schweissen & Schneiden (Welding and Cutting) exhibition in Essen, Germany, was the new Remote Welding System ('RWS'), which now has an even greater working space.
The system is equipped with the Rofin DC 060W, a CO2 Slab laser with an average output power of 6kW.
Passenger vehicle seat backs were welded live at the trade show using the system. The RWS is designed to implement highly flexible, multiple spot welds within a large work area at high speeds.
The version diversity in the welding geometry has no limits here: All requirements can be fulfilled in a short time based on simple programming, whether they are dots, circles, lines, waves or any other forms.
The laser beam of the RWS is expanded through a telescope and is focused within the work space by optics at a focal distance of up to 2m to allow processing in a large work area.
The positioning of the focal point occurs through this optics in the Z axis through the assembly on a linear motion slide, while the coordinates of the X and Y axis are controlled through a rotating mirror.
The work area is again expanded by an additional traverse movement of this mirror along the Y axis. The highly rapid traverse motion between individual processing points, described as rapid move, sets standards in regards to speed in multiple spot weld applications.
These rapid moves provide considerable potential reductions in cycle times as compared to conventional spot welding.
The rapid move concept also sets new standards related to machine availability and process optimisation: Approximately 20 million welding cycles at more than 300km of weld joint lengths in a three shift operation without replacing typical system wear parts make this welding system suitable over conventional processes using mechanical axle drives and many spot welding guns.
The production process is optimised in regards to time and cost with the option to carry out an x-amount of joint versions without requiring any adjusting and clamping operations and due to the high speed.
The RWS will be presented at the trade show in combination with a diffusion-cooled CO2 Slab laser from Rofin's patented DC series, the Rofin DC 060W, a laser with a good beam quality.
Only high power outputs at a high beam quality (<5mm x mrad) make the economically logical use of wide-range remote welding possible, since a high energy density must be specifically guaranteed for the very long focal distances. The term remote' is derived from the great distance between optical components and the work piece.
The lasers of the DC product family have a perfect fundamental mode structure over the entire performance range, which produce an energy density even at great focus distances, from which the high welding speeds result.
A working range of 2.9 x 1.8 x 1.0m therefore results at a focusing distance of 2000mm. The RWS will be seen in a compact version at the trade show, since the low dimensions of the laser head of the DC 060 W allow a placement above the processing cell.
This results in a complete system with little space requirements, which is ideally suited for processing of larger components or assemblies. Specifically in the field of automotive vehicle body manufacturing (body in white), designs are increasingly demanding more accessibility during processing.
Therefore, welding positions are made available by the flexible positioning capability of the laser beam, which cannot be achieved in resistance spot welding.