Resistance spot welding
ELMA-Tech is a global supplier for innovative multifunction spot welding machines for industrial applications, in the automobile production (prototype, pre-production, post-processing) and for vehicle body production and repair purposes.
Increased and diverse demands of today’s car bodies
Through the use of high- and ultrahigh strength steels in car bodies the requirements for the repair- tools and concepts steadily increase in case of any damage. Especially the joining of different materials, hardened steels with varying thicknesses, prove to be a problematic case. In the future more and more composite materials will also come into play and expand this deep pool of materials even more.
For modern car body structures which are composed of a different mix of steels and metal combinations it is absolutely crucial to have access to detailed instructions for the body repairs especially for the welding work. This is made even more difficult by the corrective maintenance during the car body manufacturing process e.g. the use of structural adhesives and anticorrosion coated repair components.
The usual operating and control concepts of general parameter settings on the market today oftentimes proves to be difficult in practice because the adjustment of the Current-Time control is based on a previously made “OK test-weld”. While this method may have served well for the thin sheets used in cars before, the materials used today require a much more precise maintenance of welding parameters especially when several hardened and coated sheets with different thicknesses are going to be joined.
ELMA-Tech offers future-proof welding solutions
To ensure a good connection in such cases the conventional current-time controlled spot welding machines are no longer sufficient. The new requirements demand a control strategy which is rooted deeper in process and also a clear quality statement after each weld.
In recent years, with the introduction of the energy based control technology “Virtual Machine” and in combination with innovative and advanced welding machines and spot welding guns ELMA-Tech was able to develop many high quality welding solutions.
All welding points in the pictures were welded in automatic mode.
- The first three pictures show peel tests of a combination with three plates (high-strength, galvanized, black metal).
- The fourth figure shows a welding with a chewing gum between the sheets.
- In the fifth image, a foam stripe of 1 mm width was stuck between the sheets. A first welding test exactly in the area of the stripes resulted in a full insulation, which is also indicated by the system in the control panel display. Another welding point (in the picture the upper one) was set as a shunt next to the stripes. After this, a welding point could be set successfully in the stripes area.
- The last picture shows a welding point with a business card placed between the sheets.