Automation

• Are you looking for new ways to make your production more efficient, effective and to reduce cost?
• Your product needs a high positioning accuracy of the welded stud and the quality of the weld should be repeatable and reproducible?
• Your order volume is increasing and you want to minimize the associated personnel costs?

Automation makes stud welding unbeatably economical

The costs for a product and the subsequent welding quality are already defined in the product development and in the design phase and only then generated in production. The production i.e. welding of the studs must then be carried out reliably, reproducibly, accurately positioned and this in large quantities with appropriate documentation and tests. In all these steps a good knowledge of the special features of stud welding is required in order to rule out subsequent cost factors or production and quality problems.

The user's desire to increase production output while at the same time reducing costs and increasing product quality and process reproducibility quickly leads to the topic of automation, which, for example, allows automatic feeding and positioning of the stud.

Apart from the considering required production volume or the total number of pieces, the technical criteria such as application, component, number of (different) studs, welding process, positioning accuracy, traverse speed are decisive for the required components when selecting a system and thus the investment.

High efficiency cost and time savings

• high degree of automation ensures high productivity, effectiveness and efficiency as well as increased quality
• reduction of unit costs: minimization of technically required personnel and associated costs
• high welding capacity (up to 50 studs/min)
• high traverse speed
• high positioning and repetition accuracy / minimization of reworking
• Number of different studs (dimensions, material) or number of (different) sheet metals (number, dimensions possible per welding system)
• standardized interfaces
  

welding element / Stud

• low costs due to the use of standardized studs
• besides a large number of standardized welding elements, customized studs adapted to the application are possible

investment volume

• budget and amortization

Technical criteria

• number of pieces, cycle and feed times
• tolerances and accuracies in position
• sheet metal / workpiece dimensions (l x w x h) -> work plate, working range and traverse speed, working stroke, workpiece fixtures, downholder, ground clamps, grounding
• number of different studs (dimensions, material) or number and dimensions of (different) workpieces -> number of welding heads and stud feeders, stud switches for special feeders,
• welding process -> welding equipment, spraying device (wetting of the component surface as spatter protection), shielding gas tripod
• material and thickness of the sheet metal, stud design -> welding process -> welding equipment, milling device (surface cleaning)
• process capability and stability of the welding system
• positioning and clamping devices, turning or tilting devices for the angular position of the welding head
• workplace requirements, safety -> terms and standards (machinery directive), machine housing, light barriers, noise and environmental protection
• comfort operation, control and handling, component feeding, training, service and support, CAD/CAM interfaces
• technical expansion stages or system extensions (system modules, convertibility, device technology, accessories)
• technical connections and interfaces
• spare and wear parts (costs)

On the market an extensive range of stud welding equipment for process automation is available, from manual equipment with hand-held automatic welding guns to comprehensive, customized CNC or robot stud welding systems integrated into fully automatic production lines, table 3.

In the basic version, these systems consist of a welding gun or welding head, where the studs are inserted or fed manually. The component or workpiece is fed manually.

In the expansion stage, the studs are fed automatically, e.g. via feed units (VBZ). So up to 20 studs/min can be welded. The positioning of several studs on the sheet metal or component can, for example, be carried out using templates.

CNC automatic systems, where the component or the workpieces are only inserted and removed after the welding process, are the highest expansion stage. Up to 30 studs/min can easily be welded with such systems. Automatic systems can also be integrated into production lines, designed as customer-specific shuttle table systems or designed as modular robot systems.

In this contest, however, it would go too far to describe all technical possibilities in detail.

In principle, an automatic hand gun is used wherever it is difficult to move the component or workpiece due to its shape, size or weight. The disadvantages are less positioning accuracy and the direct influence of the welder on the result.

Automatic welding heads are used on one hand for small to large workpieces that can be fixed on X-Y coordinate tables. The infeed movement of the head to the welding position can take place either via a pneumatic or a motor-driven Z-axis. Automatic welding heads can also be used in conjunction with a welding robot in "three-dimensional" positions on the component.

Modular systems consisting of an X-Y coordinate table (CNC system), power unit, welding head, feed unit (vibrator with sorter and separator) and feed hose are standard solutions. Different stud geometries must be taken into account, because different stud diameters already make it necessary to adapt the equipment (automatic chuck, feed tube, feed hose, vibrator) accordingly.

The user must therefore carefully check and evaluate his tasks and requirements based on the technical possibilities - e.g. the specifications in the technical data sheets (working range, cycle rate, travel speed, position accuracy, technical modularity).

Here it makes sense to involve the future supplier of the equipment technology already in the product development and to carry out referencing test welds with the planned technology and configuration with components which will be used in series production. In this way, the product parameters required later can be adapted and ensured.

The best possible basis for ensuring the process and the quality of the welded product is therefore provided a system solution "process responsibility = equipment and welding technology + welding element" can be offered by the manufacturer / supplier of the automatic welding system. In case of a problem, there is only one contact for the quality-influencing criteria technology / equipment and welding element.

An automation solution as an investment in the future should therefore not only consider the pure price of the system or components, but also the corresponding selection of the included welding technology and equipment, in particular the competence and experience of the producer of the automatic welding system (customized applications, project work) as well as the technical support (e.g. consulting, training, service, rental or leasing of welding equipment, costs for spare and wear parts).