Process automation for industrial production and testing with Smart Single Stations

Turnkey solutions from Kistler for assembly and testing processes: integrated measurement technology know-how for industrial production, tailored to each user's individual requirements. These manufacturing or testing cells are designed exactly in line with customers' specifications. Depending on how complex the requirements are, they can be operated as simple single cells, semi-automated single cells or fully integrable automated cells.

Industrial production processes in sectors such as automotive, electronics or medtech often have to comply with the highest quality standards. Manufacturers must also conform to additional requirements for sustainability, traceability and efficiency that can only be met with advanced production technologies. Components and systems equipped with measurement technology are the key to improving production processes such as part joining and press-fitting, or end-of-line quality testing – and they also make these processes more transparent.

Kistler offers these solutions not only as single products or modules, but also as customized turnkey solutions – known as Smart Single Stations (SSTs). They are used in any situation where precise, quality-assured and traceable production processes play a critical part. Smart Single Stations can be used to perform a vast range of assignments – and in many cases, flexible and energy-efficient electromechanical joining systems from Kistler are integrated into the solution. Here are three examples of SST applications:

• Manual workstation in a test line for electric motor production
• Complex circuit board assembly for an electric pickup vehicle
• Complete line production of valve islands for an active brake system

Highly individualized manual workstation for prototype production

A major European manufacturer of utility vehicles commissioned Kistler to supply a high-caliber customized manual workstation for its electric motor production. Its function: press-fitting of various rotor stacks onto a shaft. This application uses a special angled version of the NCFN NC joining system from Kistler with a high nominal joining force of 400 kN. To ensure ergonomic loading and unloading of the cell, the solution integrates a motorized precision-movable table that can accommodate components weighing up to 75 kg. "We also had to come up with solutions for a whole series of challenges in response to the safety and design specifications requested by our customer," says Wadim Weber, Sales Engineer for Smart Single Stations at Kistler. "An additional force transducer was integrated to cope with small forces and also to act as a reference sensor. What's more, the system features a handheld electronic scanner – so the measurement programs for the different rotor stacks can be called up directly from the maXYmos NC process monitoring system."

Once the shaft has been assembled successfully, the measurement results and production data are transmitted from Kistler maXYmos to the customer's MES. The system includes a customer-specified industrial PC that not only visualizes the process data from maXYmos, but also handles direct analysis of measurement data and can be used for other applications as well. Weber adds: "Due to factors such as the level of detail and the demanding safety and quality requirements for this project, a period of around one year was needed from receipt of the order to commissioning in the manufacturer's prototype production department."

Complex semi-automated circuit board assembly

In this case, the customer was a U.S. company that is driving ahead the electrification of the pickup trucks that are so popular in America. Kistler supplied a complex semi-automatic system to assemble semiconductor elements (insulated-gate bipolar transistors, or IGBTs). A process known as cold welding is used to permanently join a total of seven components of different types to the circuit board. "Following manual insertion, the individual positions are approached automatically so the joining processes can be performed with high precision and reliability," according to Klaus Hoffmann, SST Product Manager at Kistler. He continues: "The joining module had to be movable in the X and Y directions, and the tool had to be rotatable through 90 degrees. We implemented both these requirements exactly according to the customer's specifications. The operator simply has to remove the automatically assembled board at the end of the process."

To maximize the system's operating efficiency, an open design was chosen for the work area and two light barriers were installed for protection. The work surface is equipped with appropriate fixtures, and it can be retracted and extended with a handle to make assembly easier. "Thanks to this combination of a manual workstation with sophisticated process automation, we did a very successful job of meeting the customer's requirements for repeatability, precision and efficiency," Hoffmann adds.

Fully automated in-line system production

Multiple SSTs can be combined to form a complex line whenever required: this approach means that several assembly steps can be executed consecutively and simultaneously, so short cycle times are achieved. On behalf of the plant engineer of a major Chinese car manufacturer, Kistler is currently working to design combined assembly and testing cells for a fully automated production line. Comprising a total of six Smart Single Stations, this line to produce components of a braking and assistance system in electric cars should be able to assemble 450,000 systems per year with a cycle time of 30 seconds.

Cao Yue, Engineering Manager at Kistler in China, explains: "All in all, 12 electromechanical joining systems are used to assemble a complete valve island. Five stations with identical structures are used to press-fit and rivet 36 balls into each of six different valve bodies. Finally, at the sixth station, three more balls are joined at a different angle, and these are also riveted." As additional features, each Smart Single Station includes robot handling, automatic tool changing and air-sprung work surfaces. At the start of the line is a laser marking cell from Kistler with fully automated (robotic) loading; this cell also assigns a data matrix code to the valves being manufactured so as to ensure traceability. Chaining of the test cells and integration of the robotics are handled by the plant engineer in close collaboration with Kistler.

Flexible production technology – exactly as customers want it

Kistler's Smart Single Station concept is not limited to joining processes such as press-fitting, clinching, riveting or similar operations. In particular, optical testing technology can also be integrated flexibly into these systems to perform quality assurance: in this case, parts are inspected with the help of high-resolution cameras and the KiVision software from Kistler to ensure compliance with the highest quality standards – up to and including zero-defect production. Other technologies can also be integrated on request to create turnkey systems that meet customers' individual requirements: examples include automated fastener testing, e-motor testing and industry-specific process monitoring solutions for semiconductor production or medtech applications – to name only a few.