Robotics Industry News
PMC Pulse Welding Package for TPS/i MIG/MAG Power Source Platform
Fronius Posted 09/26/2014
Increased Control for Pulsed-Arc Welding
Based on the high measuring and control speed of its most recent TPS/i MIG/MAG power source platform, Fronius has developed the PMC (Pulse Multi Control) pulse welding package. It provides the welder with access to a large range of Synergic characteristics that fully exploit the potential of the latest generation of Fronius devices. An improved pulse correction function, an updated SynchroPulse welding process and completely newly developed functions, such as the penetration stabilizer and the arc length stabilizer, make the tried-and-tested welding process easier and provide even better welding results.
The newly developed penetration stabilizer keeps fusion penetration at a constant level by adjusting the wire feed speed, even when there are stick out fluctuations, for example, in corners that are difficult to access or trajectory fluctuations in robotic welding. Thanks to its high computing power, large memory, extremely quick system bus, and not least because of the highly dynamic wire feed speed, the TPS/i is capable of performing this control process in a particularly quick and precise manner without overshoots. This enables the arc length, and thus the fusion penetration, to be maintained at the same level over a large area. This makes handling noticeably easier. The user can set and limit the value of the wire feed speed, which has been readjusted to the maximum extent, within a window of up to 10 m. This also guarantees that the welding procedure specifications comply with the corresponding requirements when the stabilizer is active.
The arc length stabilizer, also a brand-new function, is at least as helpful as the penetration stabilizer when it comes to manual and automated welding. This allows the user to influence the arc length directly via the welding voltage. The result is a short arc, meaning that short circuits occur, ensuring droplet transfer which is reliable and resistant to interference. In this case, quick control keeps the duration of the short circuit to a minimum and reduces the voltage at the right time with the result that bonding flaws and spatter are effectively prevented. The user does not need to perform any manual readjustment in the case of external interference (e.g., as a result of shifts in torch position, changes in sheet thickness, uneven heat extraction).
For users who would nevertheless prefer to work with the usual correction function for the arc length or are required to do so according to welding procedure specifications, Fronius has also integrated these functions into the PMC. Pulse dynamic correction has also been incorporated into the package. This means that it can also be used with the TPS/i to speed up (or slow down) the droplet detachment, whilst now also keeping the energy input per unit length at a constant level. PCS (Pulse Controlled Spray-Arc) is also included in the scope of supply of the PMC process. This characteristic enables users to switch seamlessly between pulsed arc and spray arc, with the problematic intermediate arc being hidden.
Furthermore, Fronius has achieved significant developments in terms of the start-up and shut-down phases. The ignition energy now adapts to the respective temperature of the wire end, meaning that less power has to be applied for ignition when the wire end is still hot. With an installed PMC process, the wire is retracted at the end of the welding process. This has the additional result that the current is reduced and burnback is prevented. Both measures improve the energy balance and protect the wearing parts.
Since all elements of the TPS/i relating to wire feed have been designed with more precision and for a higher dynamic, the proven SFI (Spatter Free Ignition) now also functions with the standard equipment. It is therefore no longer necessary to acquire a more complex push-pull unit in order to use the SFI. In combination with the newly developed SFI HotStart, the power can be increased for up to two seconds at the start of the welding process and bonding flaws as a result of 'cold' ignitions can be avoided.
Finally, Fronius has fine-tuned the SynchroPulse function and introduced a duty cycle welding parameter, by means of which the user can determine how long the high-current pulse phase should last proportionally per cycle for SynchroPulse welding. This means that the heat input can be controlled more accurately than was previously the case with the result that even less experienced welders are able to produce a perfect weld seam in all positions.