Contec - Novel contacting technology
Two moveable half-shells keep the contact surfaces and the contact forces between the contacting system and the welding wire exactly in the defined target range. The contact tip abrades uniformly, thereby minimising the adverse, hard-to-calculate consequences of uneven wear upon the process. The result is constant and unfluctuating contacting, extremely high process stability and a lower probability of failure due to contactingfaults. With its versatile contact shells, Contec is suitable for all diameters and materials of wire.
The cast of the wire leads to disturbance variables in the contact tip such as abrasion, and the tendency for abraded particles to burn onto the tube. The contacting points change, resulting in faulty welds and higher outage costs. In contrast to this, the versatile half-shells in the Contec system keep the contacting points constant even when subject to increasing wear. The probability of failure is signifi cantly lower.
Controlled process conditions are a key requirement if high quality, reproducible weld joints are to be achieved. However, the friction of the moving wire in MIG/MAG welding causes wear in the contact tube. The results are Changes in the size and position of the contact surface. Consequently, influences arise which have a detrimental effect on the welding parameters. The innovative "Contec" contact tube combats the resulting wear and its adverse effects on the process to a significant extent. In automated processes in particular, the user benefits from improved process stability and plant availability.
The experts at Fronius have designed the contact tube in such a way that the surface that the wire comes into contact with is as large as possible, yet as small as necessary. This achieves on the one hand a stable current transfer, but on the other hand it prevents the wire melting too soon due to friction caused by heat.
The contact is made by two elements in the form of conical half shells. The welding current flows through them in two paths into the wire electrode. The adjustable force of a spring pushes the two shells together and onto the wire passing between them. During welding, the tube system material is only subjected to wear in the ring-shaped contact areas at the front of the half shells. This results in a number of benefits for the user, in particular greater process reliability and extended availability in comparison with conventional contact tubes. This means consistently lower reject rates and helps save resources. Contec contact tubes have a service life up to seven times as long as their conventional rivals, while using only a fifth of the material used by conventional nozzles.
As the contact force is not dependent on the wire conditions when using Contec, it can be controlled relatively accurately, which minimises friction. Particles rubbed off the surface are carried out of the tube by the wire-feed unit, thus preventing "stub-in" and the associated obligatory down-times. The system operator can monitor the condition of the contact tube at a glance and get ready to replace it during an ongoing welding task. Contec is designed for all conventional wire diameters in standard steel and aluminum materials.