Valk Welding, Netherlands - IFR-Partner
Welding wire sensing method detects all weld deviations and shapes
If a work piece has tolerances, the actual dimension and shape does not correspond to the programmed welding process and the robot programme has to be modified. The tolerance results in the welding robot failing to put the weld in the right position, which calls for subsequent processing and manual correction of the welding programme. But the welding robot can make that correction itself. Touch sensing, where the robot will use the gas nozzle detects the weld position and shape beforehand and automatically enters deviations into the program, is one of the cheapest and most commonly used methods.
A more recent method, (further) developed by Valk Welding, is touch sensing by using the welding wire as a 'sensor'. The principle of the wire sensing system is that the wire is clamped in the torch and then cut off by an automatic wire cutting unit. That precisely defines the position of the welding wire and the position of the work piece can be detected with the accuracy of the robot (within 1/10 mm). The main advantage of this wire search method is that it is not only possible to detect all weld forms, access is improved to areas that are difficult to reach and the detection works with both thin and thickwork pieces.
Since re-orientation of the welding torch in the welding programme is no longer necessary, Valk Welding regards the simpler programming as the biggest gain.
Advantage over gas nozzle touch sensing:
- Virtually all weld forms can be detected
- For thick materials searching with the wire is faster than with gas nozzle searching. Since it is not necessary to turn/re-orientate the torch each time, this is much faster and extends the life cycle of the cable assy.
- For thin materials, overlap seams from 1 mm can be located
- Access to places that are difficult to reach is optimised
- The effect on the overall cycle time is minimal (approx. 5 sec. per search)
- The programming is less time-consuming