Technical Papers

In many areas the requirements to machines or applications are so specific that precise adaptations of functions and design are needed. Application-oriented and performance-based modification of servomotoric techniques, for example, may be complex and cost-intensive. SIEB & MEYER AG provides customized system designs as solutions for these applications.

Normally, system adaptations in this field pose major challenges already during development and construction. The core competence lies in the realization of complete systems rather than subsystems. The technical purchasing, however, responsible to procure all required materials and services on time, is also affected by this. Although the major part of companies say that the enormous pricing pressure is the most important challenge for them, 47 percent of the purchasing departments of German mechanical engineering companies are hardly or even not at all integrated into production processes; 50 percent of the purchasers do not sit together at the same table with developers and have thus no chance to calculate materials and services at optimum costs already in the early phase of product development. These are the results of the studies "Strategic Challenges for Purchasing in the Mechanical Engineering Industry in Germany" (original title: "Strategische Herausforderungen für den Einkauf in der Maschinenbauindustrie in Deutschland") by the Kerkhoff Competence Center of Supply Chain Management at the University of St. Gallen, the Institute for Public Opinion Research Allensbach and the VDI News.

According to the studies, cost-saving potentials are often not used. Another possibility to save time and work in different company areas are customized system solutions. As structural changes in the cooperation between the involved departments are not required and capacity-binding trial and error processes for do-it-yourself products can be avoided, better cost efficiency can often be reached.

Key Factors for Best Performance

Alfing Montagetechnik GmbH (AMT), for example, based in Aalen in Baden-Wuerttemberg (Germany), has specialized in solutions for handheld and built-in tools, assembly machines as well as automation processes for customers in the automotive and automotive supplier industry. One product category are controlled fastening systems, mainly used in assembly lines in the automotive industry and their suppliers. Thanks to the networking capability of the control system, nut running systems can be integrated into the control and quality management systems of AMT customers. This allows recording and tracing critical fastening processes at any time, which is an essential requirement in automotive applications.
When developing solutions for fastening applications, focus is set not only on the individual fastening process, but error prevention by suitable workplace design as well as error diagnosis by means of innovative monitoring strategies. These fastening systems are for example able to monitor the correct fastening positions via ultrasonic triangulation or via the patented Railnet-System, allowing detection and prevention of missing fastenings or wrong fastening positions.

The motto is: Maximal performance with minimal hardware equipment. This allows realization of cost effective system solutions. This effect is also contributed by the drive amplifiers delivered as customized solution by SIEB & MEYER and integrated into AMT solutions. With corresponding know-how and in-house production, SIEB & MEYER develops and manufactures customized solutions on the basis of the available established and powerful products: just-in-time and cost-effective. Customers benefit from quickly available special solutions at an attractive price-performance ratio. The range of products is far reaching, including simple hardware adaptations as well as completely new devices and functions.

Two versions of the drive amplifier for AMT have been developed on the basis of the servo amplifier SD1. The first version in a housing is intended for switch cabinet mounting, while the second "open version" is mounted in one-channel nut runners. Both versions are designed as customized solutions for AMT with specific connectors for the special modules. The drive controllers are used for the complete range of handheld nut runners and built-in tools, equipped with certain control functionalities and allowing autarkic execution of fastening processes. Due to the motor and positioning control the controllers play a central role in the complete system. The torque sensor interface for torque monitoring is also integrated. "As a standard, angle encoder signals are also provided by the drive amplifier", says Thomas Zeller, R&D Manager at Alfing. "The control unit also receives information on turning angles from the device, so that there is no need for separate angle encoders or incremental encoders". Reducing hardware components saves costs and minimizes the required space. With the new device generation SIEB & MEYER convinced with technically sophisticated systems available at fair prices. The R&D manager points out main reasons for working with SIEB & MEYER: engineering competence, flexible realization of solutions, device quality and reliability of the support team. The standard device was already quite good. The standard two-board solution was modified for AMT as a single-board solution, allowing plugging on the control card and creating space for various interface connectors. "We can directly integrate our control card into the device via the dual port RAM interface, which is an enormous advantage compared to the products of other manufacturers, who only provide external interfaces", says Zeller. Furthermore, the software was modified for the fastening functions as stand-alone device. The demand-oriented and application-optimized modification with the corresponding space or the control card could certainly also have been realized by some other supplier, but this would have failed due to the required lots or system costs.