Valk Welding: 2005

ETAP is a leading manufacturer, established in Malle - Belgium, midway between Antwerp and Turnhout, and known all over Western Europe for utility lightning, safety lighting and light control systems.

Exact custom-made work is the basic condition
Fittings Tig-welding without finishing process
Lightning appliances are mostly made of thin-walled steelplate. Difficult to weld, not the least because of the high requirements regarding the weld appearance of these products, certainly when sold as ‘design’. Carrying out such works with a welding robot is a true challenge for the robot integrator. Valk Welding took up this challenge together with ETAP, a leading Belgian manufacturer of lightning appliances for the project market.

 
 
(The new type of fitting for which ETAP made use of the Valk Welding robot, here corner mounted).

Design and ergonomics
ETAP, established in Malle - Belgium, midway between Antwerp and Turnhout, and known all over Western Europe for utility lightning, safety lighting and light control systems. Design, ergonomics and energy efficiency form the central concern in the company philosophy; the showroom is a fine example of the courage and originality to meet the design freedom architects want today. At the same time, high demands are made as regards finishing and safety. The robot welding installation, the first recently taken into use by ETAP, was specifically designed for a new series of fittings; no existing process is being automated, rather a completely new production line for fittings was developed. These design products are being made in series of 50 to 250 pieces. consisting of long products in various designs that are being folded from 0.8 mm thick steelplate. The turned sides are assembled and then the robot is used to weld the outer corner joints. This must be done in such an exact and controlled manner, that no further treatment is required. Hence, wire feeding and manual welding were never considered a solution. High requirements are made on the one hand, for the folding technique, involving a tolerance of only ± 0.2 mm (the corners must be firmly closed), and on the other side on the robot technique used. Exact custom-made work of the starting material is a basic condition.

 
 
(The robot is positioned between two workstations, separated by a screen. The welding mould to position and press the sides is clearly visible in front).

Technical data robot (above)
Panasonic 6 axes
Type: VR008L
Working range: 1,895 mm
Load: 8 kg
Control:
- Global controller
- Digital + PPS
- calibration system
Welding power source: TIG AC/DC Pulse
- type TIG Star
- 300WX3-II

Feasibility tests
Product developer Jurgen Lambrechts: “Before embarking with a certain supplier, we first studied all the possibilities offered on the robot market. A number of potential suppliers were given test products and asked whether these were suitable for automatic welding, in such a way that the welds would look like bent ribs, and not like welds, and all this without extra finishing work. It was clear to us, that high demands would be made for the robot welding process.” From these tests, Valk Welding emerged as the best. ETAP particularly appreciated the fact that a number of feasibility tests could be carried out with the robot integrator. Process engineer Lucie De Bont: “We were extremely attracted by the fact that Valk did not avoid the challenge others clearly thought of as too risky, in particular concerning quality welding of a thin plate. Based on some tests, and thanks to their expert know-how, they were able to estimate feasibility. We are also extremely satisfied with the technical support during the offer phase. Even after the installation had been mounted, the Valk people continued to follow and support the project intensively. We are very positive about the relation price/performance for this investment project.”

(The robot in action; note the large hose pack that is always carried along).

Hanging arrangement
The installation consists of two workstations with fixed table, with the robot in the middle; the workstations are separated by a screen. This hanging installation is very efficient: while the robot is finishing welding a workpiece in one station, a finished piece can be removed from the other and a new one can be positioned for welding. The installation is further provided with a mechanic breaker unit and cold wire feeding. Safety is ensured with a fixed guard, light protections for the installation as a whole and zone protection for the separate workstations. Moreover, the robot installation is not always busy welding the new design fittings for which the investment had been made initially, it is also useful for welding other products.

 

By: Erik Steenkist

(Source: Metallerie October 2005)