Robot welding: a real challenge to work withPrint this page
For the production of various temperature sensors and thermowells, Thermo-Electra B.V. has recently bought a Minicell, fitted with a Panasonic VR-006 TIG welding robot with cold wire feeding.
With the Minicell, lengthy, monotonous and intensive manual welding can be automated in an affordable and simple way.
Thermo-Electra from Pijnacker (NL) is market leader in the Benelux in the field of temperature sensors and so-called “thermowells” (high pressure protective tubes) which are frequently used in the chemical industry, but also in other sectors where temperature measuring and monitoring are of paramount importance. Until recently, all products were welded manually by skilled and qualified welders. But not long ago, Thermo-Electra bought a welding robot.
The human factor
“When automating production, the human factor has always been the starting point for us”, says Jan van den Ende, Technical Director at Thermo-Electra. “Some of our products have a long cycle time of about 1 hour and a half. This is heavy and monotonous work for a manual welder. By using the robot, we were able to automate this part of the production, and now our welders can concentrate on other (more challenging) work. We did not want to reduce the required manpower, on the contrary what we wanted was making the work remaining after the robot did his bit, more attractive. Moreover, the welding robot ensures a more constant end result. Own research has shown that with the use of a robot we are able to realise a more constant burning-in compared to manual welding, thus ensuring the continuity of our production by robot in the future. People might get sick or have a bad day. That is normal but that never troubles robots. That thing just goes on producing.”
High quality end result
Because of the large variety of welding wire types used, Thermo-Electra has chosen to use a TIG welding robot with cold wire feeding. This robot is accommodated in a Minicell, but now with on the usual place of the welding wire drum, a Robustus handling device to rotate the workpieces. In view of the fact that a large variety of (high-alloyed) welding wire is used, Thermo-Electra chooses to use reels with welding wire (also from Valk Welding).
The robot is mostly used to weld small series and is operated by one of the welders, who does other work in the meantime and keeps an eye on the robot with the help of a small camera. In order to guarantee high quality end results, Thermo-Electra makes use of gas flow meters and wire sensors. In case of abnormal parameters in gas or wire feeding, the production process is automatically stopped, thus ensuring a minimum of rejections. It is also possible to load the robot again at the end of the day, to proceed production for another couple of hours.
Although, the robot is not in continuous production yet, this is exactly what Van den Ende has in mind for the future. “Beside heavy and lengthy welding work, we also have various products with a short cycle time of about 45 seconds. Here too, the Minicell is extremely suitable, certainly when offering several of these products in one clamping frame. Soon we will be doing this kind of work by robot.”
(Source: MetaalNieuws - 1 June 2005)