Latest welding developments, highlighting the focus on automated function and flexibility
In the automotive sector, welding is very much about automation. Long periods of unmanned operations demand special requirements, not least reliability. With this in mind, Fronius has just introduced its second generation Contec nozzle technology for arc welding. In automated arc welding, Contec is said to prolong the endurance time of the torch several times over compared with using a conventional nozzle.
Fronius says that its second generation Contec MD boasts endurance times up to 15 times longer, in the joining of both aluminium and steel. Among its other benefits are higher process stability and system availability, exact TCP (tool centre point) and a flaw-free weld pattern.
The enhanced contacting system from Fronius guides the wire in V-shaped grooves that are now 12mm long, under a defined contact pressure. Even after the half-shells start to wear, a mechanical spring ensures that the contact zone remains constant, providing defined current transfer. In conjunction with stable TCP, and without needing any readjustment, this results in high process stability, which also has a positive effect on seam quality. The system has been trialled up to 300A for welding low alloy steels and up to 200A for CrNi steels.
Fronius has recently paired with ABB Robotics to develop fully equipped robotic welding packages as part of a global collaborative agreement. The packages are designed to provide modular, cost-effective solutions that enable OEMs or supply chain manufacturers to more easily initiate or upgrade robotic welding systems.
ABB is featuring two new offerings using Fronius technology. The first, the ArcPack U2 featuring the new ABB IRB 1520ID arc-welding robot with Fronius equipment, is a modular welding cell with two fixed stations. The standard twin table configuration is aimed at small components and can be provided as either a complete welding function package or a fully integrated cell.
The conventional contact tip of an arc-welding torch is a wearing part, with all the classic drawbacks that this entails. When being fed through, hard welding wires gradually abrade the cylindrical internal diameter into a conical shape. This causes the electric contact zone between the tip and the electrode to migrate uncontrollably in what tends to be the opposite direction from the wire feed.
After only a relatively short time, the contact tip needs replacing which means interrupting the machine’s operation. With the soft electrodes used in aluminium welding, these abrade and then alloy to the inside of the contact tip – eventually blocking the wire travel. When the wire is stopped in this way, the arc may burn as far as the contact tip and damage the torch. Contec MD from Fronius claims to lessen these infl uences and risks considerably.
The second new product is an EthernetIP integrated communications interface for programming and operating Fronius power sources on the ABB FlexPendant HMI. This single point of programming will allow weld data to be controlled by the FlexPendant through the interface.
Moving to the latest spot welding innovations, again many of the latest developments are related to automation. For instance, Fanuc Robotics has recently launched its cableintegrated spot welding concept. First seen at the IMTS exhibition in Chicago at the end of last year, Fanuc’s new R-2000iB/210FS robot was demonstrated to event visitors using servo weld gun control to simulate spot welding inside a truck cab. The new robot has a hollow wrist with internally routed utilities and signal cables, thus providing users with high dress-out reliability and long cable life compared with robots that are dressed conventionally.
At the same exhibition Fanuc showcased its iRVision tip inspection software, a system that verifies welding tip condition and checks for proper alignment to help spot and arc welding customers reduce part manufacturing issues and scrap/rework costs. From a spot welding perspective it measures tip wear and alignment, and provides verification for alignment, tip dress and new cap/cap type. For arcwelding users, the system measures contact tip wear, maintains accurate TCP and calculates maintenance cycles.
Shifting emphasis to laser welding, among the latest market technologies is the Trumpf TruLaser Robot 5020 automated welding cell. According to Trumpf, any manufacturer making its first transition from conventional welding to laser welding will find the chucking and clamping function to be a challenge. In the past this had to be made up separately for each part, involving considerable effort for new parts.
Trumpf says its TruLaser Robot 5020 provides a modular and flexible chucking system for clamping components of differing sizes and shapes – from simple sheet metal parts to formed profiles – with a single jig in preparation for laser welding. The clamp is matched quickly to the workpiece and the laser welding process can start right away. Here it makes no difference whether the user is performing conduction welding or deep-penetration welding, long seams or corner connections.
Once the part has been selected and the clamping unit is set, a highly productive manufacturing process is required for automotive applications. Here, the TruLaser Robot 5020 is fitted with an automatic rotation changer with turning axes, permitting high speed, round-the-clock operation to turn out larger piece counts.
Finally, it would be remiss to exclude friction welding; a technology vital in the production of safety-critical parts such as axle components and steering links. Here, the latest AX direct-drive series of machines from Thompson Friction Welding, for example, is designed to friction weld commercial vehicle axles for both OEMs and tier one manufacturers. The benefits of the AX series include high accuracy hydraulic control, hidden tie bars and Thompson FlexiBase technology, enhanced heavy-duty shear flash removal and moveable clamps that ensure wide variation in overall lengths.
Automotive customers that use Thompson friction welders include Meritor, Dana, Ford and Schmitz Cargobull among others, and now SAF-Holland has specified two Thompson AX series machines. The company will use the fully automated equipment to join axle components at plants in Bessenbach, Germany, and Warrenton, USA.
“Our product range is expanding so it’s essential that our friction welding operations are highly flexible and efficient,” says Jürgen Kestler, SAF-Holland’s director of operations for Europe and Asia, who concludes on a point with which everyone should concur when it comes to welding equipment specification. “We want to use the best technology available to deliver top quality products to our customers.”
The motions for the turning axes on the Trumpf TruLaser Robot 5020 are matched exactly to the robot’s moves to maximise productivity during welding. While the joining process is taking place inside the cell, the operator can set the next part on the outward-facing side of the changer unit, thus reducing downtime.
The motions for the turning axes on the Trumpf TruLaser Robot 5020 are matched exactly to the robot’s moves to maximise productivity during welding. While the joining process is taking place inside the cell, the operator can set the next part on the outward-facing side of the changer unit, thus reducing downtime.