Complicated welded assemblies for high-rack storage components - SSI Schäfer welds using modern CLOOS Robot Technology

HRANICE – At its Czech factory, SSI Schäfer has started using a high-performance CLOOS robot welding machine for its complex welded assemblies.  Fitted with single wire and tandem welding torches, laser sensors and a dynamic 7-axis robot, the machine operates a 4-shift system and provides continuous high quality.

From the component manufacturers right through to the machine constructors, in recent years the factory has never stopped developing. “Today we construct complete machines, add the electrics, fit components and assemblies into complete machines and, if the customer wishes, we carry out the servicing” explains Robert Selzer, managing director of the SSI Schäfer factory in Hranice.  SSI Schäfer is also always adding to its own machine park: punch-nibbling machines can be found in the large production halls as well as laser and plasma centres and modern powder coating facilities on which parts can be painted to meet the customer’s requirements. “We utilise third party products for about a quarter of our production “ says Selzer. “In that way we have the possibility of testing our competitiveness in the market for real”.  

7-axis robot with 15 m manipulator

In addition to the 200 qualified hand welders, five CLOOS robot systems are also used in the factory. The most recent investment is a seven-axis CLOOS QIROX robot, which moves along a 15 m long pavement between two 5-tonne turntables. Correspondingly large components can be clamped between them.  The largest part at present is the partial mast for the storage and retrieval device, measuring a good 10 m in length: later the lifting truck will travel along it up and between the shelves. Up to 4 masts can be fitted on top of one another to give a total height of 45 m for high-rack storage, which certainly earns its name.

Selzer:“Their components are designed in such a way that they only have to be welded externally.  That therefore takes away the time-consuming internal welding for the welded assemblies.  The individual steel parts are put together, fixed manually with few weld points and then welded on the robot machine“.

CLOOS Robot system

On this CLOOS robot equipment SSI Schäfer welds the up to 10 m long components of the new storage and retrieval device – the image shows a lifting truck weighing about 600 kg. (Photo: CLOOS)

Single wire and tandem welding torches with laser sensors for optimum welding results

The CLOOS machine has several special points: the robot changes automatically between single wire and tandem welding torches in order to achieve the best weld seams for each case and to use maximum welding speed. A torch nozzle cleaning station is also integrated and, when needed, is automatically brought in by the robot. The laser sensor is also unique, as it is fixed on the robot arm and, irrespective of the torch used and the particular clearance, it ensures optimum arc welding performance. We have integrated this system although our clearance with tolerances of only two to three tenths of a millimetre is there from the pre-production work stage” says Robert Selzer, proud of the accuracy and high quality of his production.

From a welding technology viewpoint the robot machine is fed by two Quinto GLC 603 welding power sources which are computer-controlled to deliver the parameters for the speed and tandem weld MAG process used, the sheet metal thickness of between 4 and 12 mm and the various seam shapes.