© 2012 por Jose Carlos.

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Jose Carlos Moreno

International Welding Engineer - IWE

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Antorchas de soldadura - Welding torches

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WELDING 

AND ROBOTICS

WELDING and industrials ROBOTS.

welding blog

Welding torches for robots, important points for your choice.

Choose from an optimal or inadequate robotic torch, it could mean the difference between achieving your weekly goals of quality and productivity and strive to ensure timely delivery. To help you select the right torch for your application and maximize operating efficiency, quality and profitability equipment should consider these 8 key points:

 

1. Understanding the Tool Center Point (TCP)

Tool Center Point, or TCP, is a point in space with a mathematical reference to a robot flange. GMAW welding for robotics, this is mostly how the robot knows where the tip of the welding wire is. Robots are good to repeat the same path of movement and again, if the tip of the welding wire changes due to thermal or physical distortion, the placement of welding change. In extreme cases, the torch collided with the workpiece or welding.

A change of TCP over time means that the robot will deposit the weld bead somewhere other than the center of the board. When this happens, operators can compensate the deviation of TCP increasing the bead width, for example by reducing the moving speed or programming a slight oscillation in the movement of the torch to ensure that the weld covers both plates and provides sufficient fusion. Unfortunately as a result of an incorrect TCP, cords larger than necessary welding costs increase filler metal and gas, cycle time, heat input and weld total cost. In short, compensation kills profitability in automated welding and may compromise the mechanical properties as well. The selection of a robotic torch with a consistent TCP can be the first step in improving welding and reduced consumption of filler metal.

 

TCP is the most important to consider when evaluating robotic torches attribute. To ensure a consistent and repeatable TCP, look robust necks and systems accurate and stable mounting.

 

2. Evaluate configurations and necks.

While a mounting neck 23 degrees with 22 degrees basically provides the same amount of curvature of a mount with a collar 0 degrees 45 degrees, the latter combination works best for welding small circles, as about an axis. With a neck 45 degrees, the torch is rotatable about the sixth axis of the robot (where the torch to the robot arm is mounted) into smaller circles. By contrast, a montage of 0 degrees with a neck 22 degrees works well when you need to reach a small opening.

If you have a suitable application for a neck 45 degrees and other application where a neck 22 degrees works best, choose a package torch with a modular design. This allows you to change the package neck torch (toolless) and insert the right neck for the application. For workshops, this modular approach adds flexibility and reduces changeover time between pieces.

 

3. Rotation of the torches.

The answer depends on how many points require programming and the amount of time of each movement. External cables of a conventional torch limit rotation of +/- 240 degrees arm. After making a circular weld, the next item on the program brings the torch to a safe space and unroll the cable. A rotational coupling +/- 360, the arm can move to the next weld directly. Torches with more turning angle reduces programming time and reduce downtime in the air. For parts with many circular welds, a torch of +/- 360 reduce unit costs compared to a conventional torch. As an added bonus, by having more rotation on your system turning the useful life of the torch is multiplied.

 

4. Test configuration torch.

Before production begins and assembly installation, order a 3D model and test it on virtual reality. This will ensure the correct selection of the torch before buying.

 

5. Stability torera gas.

There are two systems for holding a gas nozzle of the torch neck. Threaded nozzle which has the advantage of being more reliable and less gas leak protection but if not well designed and can loosen tight thermal changes. Nozzle clamping equipped pressure of grooves that expand and push the nozzle against the neck welding, this may provide better cooling but also greater losses of gas through the slots, plus support is not as secure with the threaded system.

There are systems where both methods are combined and have the advantages of both, but it is difficult to maintain that advantage with the wear and tear of the gas nozzle and ends up losing or maintaining the pressure of the slots.

 

6. System shielding gas and blowing.

It is important to consider that the flare system for robots is provided with a gas blowing tube, this tube is independent of the protective gas and is used for the cleaning of the torch. It is important that both systems of this separated gas duct welding wire, thread dust causes wear and offers variations of gas flow resistance.

The best systems of welding torches are equipped with separate circuits for each type conduction abnormalities.

 

7. Use the most durable possible consumables.

When analyzing consumables, you should consider both the cost of downtime as the differences in the cost of consumables. In most cases, downtime costs are significantly higher than the cost of consumables. We recommend using the contact tip CuCrCz long lasting and consumables to ensure a useful life as long as possible, as it will help to avoid downtime unplanned and reduce the cost of welding.

 

8. Consider cable coatings.

The rotation of the arms of the robots with the combination of the heat generated by the welding causes the outer sheath of the torch is subjected to a large thermal-dynamic stress, so it is advisable a good choice of cover materials such as PA . If the environment was especially welding end it is possible to cover the sleeve with outside decks as Kevlar, aluminized fabric or leather with treatment.