The new drive enables early process diagnostics through process-integrated, 100% quality assurance and fault detection. © BalTec

No off-the-peg drive

Klaus Huber, Product Manager at BalTec, played a leading role in the development of the new electromechanical Electric machine generation. "During the evaluation phase, we already had a clear idea of what the new control and drive supplier should bring to the table," emphasizes Huber. "We found the required criteria with Sigmatek. First and foremost, this included flexibility in terms of drive technology. An off-the-shelf drive was out of the question for our riveting technology, as two AC servomotors are compactly integrated in one housing. The drive is now a patented custom-made product from BalTec." The special drive consists of a motor for the linear movement and another for the rotary movement of the process head. All stators are equipped with thermal sensors for temperature monitoring. A total of three position measuring systems are used for the linear axis, two of which are safety-relevant. The different process heads can be exchanged in a few simple steps. An adjustable feed speed of 1 to 140 mm/s and a force of 3 to 15 kN can be achieved with one spindle. The two servo controllers and power units for controlling the motors, including mains filter and mains choke, are installed in one housing, which reduces the footprint in the control cabinet. The bottom line is that the use of servo drives offers users advantages over conventional pneumatic and hydraulic solutions:

• higher production output (up to a factor of 2),
• short cycle times,
• lower maintenance costs,
• compact design allows closer positioning in systems,
• Energy savings compared to pneumatic/hydraulic systems,
• Investment protection through dynamic and flexible adaptation to new products and production requirements,
• early process diagnostics thanks to process-integrated, 100% quality assurance and fault detection.

Everything under control

The modular, highly compact S-DIAS automation system from Sigmatek fits into any control cabinet. © Sigmatek / BalTec

"Another advantage over previous solutions is that the Sigmatek S-DIAS control system can access the motor parameters in real time during the riveting process. This enables the customer to achieve much more precise forming results. Recording, visualization and storage of process data and force/displacement process curves for the riveting process are also easily possible," emphasizes Huber. The recorded process data is important for traceability in the automotive industry, for example. This results in the following advantages for the customer:

• Compliance with and verification of predefined quality features,
• Proof of quality through complete documentation of the process,
• Reduction of scrap and rework costs,
• Reduced process times thanks to dynamic workpiece recognition,
• Relevance for proof of process capability and product liability.

The Varan real-time Ethernet bus is used for fast data exchange between the controller and the SDD 210 servo drive, which scores points for speed and data security.

Together with another partner, BalTec developed a new Windows 10-compatible HPPi user interface for the "Electric" and electrical machines. The HMI portal supports the user in the safe, efficient and productive use of the machines. An open, bidirectional data interface facilitates communication with a higher-level control system and thus meets the standards for Industry 4.0. The HMI is not required for pure machine operation. Once the parameters have been defined, it works autonomously.

Security technology implemented

From small to large: Sigmatek offers the right drive technology for every drive task. © Sigmatek

"Everything from a single source, compact and modular: These were our ideas for the control concept. In other words, PLC, drive, safety and a convenient development environment were also important decision criteria," continues Huber. "The safety level of our riveting machines corresponds to that of a press, which is why we paid particular attention to this. A huge advantage of the Sigmatek solution is that the safety modules are not only fully integrated into the control hardware, but also into the software. Our riveting machines are often integrated into a fully automated production process. In these cases, communication works via digital inputs and outputs.

However, we are increasingly communicating with our machines via Ethernet interfaces with OPC UA protocol. This connection is also easily possible with the Sigmatek control system. In certain cases, the workpieces to be processed on our riveting machines are inserted by hand. It makes no difference to BalTec whether a light protection grid or a safety door with safety contacts is used for safety during the insertion process. The customer has the choice. The integrated safety functions STO (Safe Torque Off) and SOS (Safe Operation Stop) are used in the event of unauthorized intervention by the operating personnel."

Technology was not the only decisive factor

Soft skills also play a key role in the selection of a partner for control and drive technology when developing a new generation of machines such as the "Electric" from BalTec. "We at BalTec had the ideas and the knowledge of what our customers will need in the future, as well as the idea of what the new machine should look like. In addition to the hardware and tools, Sigmatek also had the necessary technological expertise," summarizes Huber. "Furthermore, factors such as flexibility in the drive solution, openness to the innovative safety requirements and a large portion of interest were decisive for the success of the project."

Ingrid Traintinger, Head of Communications at Sigmatek / ag