Technical Papers

The Knack That Makes the Difference

In many areas the requirements to machines or applications are so specific that precise adaptations of functions and design are needed. This applies for example for servomotor drives of electronic nut runners used in the automotive industry for assembling applications, where performance with high quality requirements is an important factor.

The internationally operating Alfing Montagetechnik GmbH (AMT), based in Aalen in Baden-Württemberg (Germany), was founded 30 years ago as a subsidiary of the Alfing Group. AMT 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, and is one of the leading manufacturers in the product category Electronically Controlled Fastening Systems. The powerful, reliable and ergonomic tools are mainly used in assembly lines in the automotive industry and their suppliers and ensure high productivity even at short cycle times. 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, thus allowing 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 position of fastening positions via ultrasonic triangulation or via the patented Railnet-System, thus allowing detection and prevention of missing or wrong connections.

Key Factors for Best Performance

The control systems optimally adapt to the needs of the customer. The motto is: Maximal performance with minimal hardware equipment. This allows realization of low-cost system solutions. This effect is also contributed by the drive amplifiers delivered by SIEB & MEYER and integrated into AMT solutions. AMT benefits from customized solutions from a partner with appropriate know-how and competence. Because customized solutions are the core competence of SIEB & MEYER as a manufacturer of control and drive electronics.

Well established basic developments are modified by the highly-qualified and experienced SIEB & MEYER engineering and manufacturing team: just-in-time and cost-effective. Customers like AMT benefit from quickly available special solutions at an attractive price-performance ratio. The range of products is far reaching, including simple hardware adaptations and completely new devices and functions.

Two versions of the drive amplifier for AMT, for example, have been developed on the basis on the servo amplifier SD1. The first version in a housing is intended for switch cabinet mounting, while the second "open version" is mounted in AMT one-channel nut runners. Both versions are customized solutions and are provided with specific connectors for AMT. 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.

Although an industrial PC controls the main processes, as for example the number of nuts to be set or which fastening programs are to be executed, the SIEB & MEYER drive amplifier has the central role in the complete system. It controls the motor and monitors the position of the rotor. The sensor interface for the torque sensor 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". The reduced hardware allows saving costs and 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. "SIEB & MEYER has a long-year experience and high competence in drive technology and has very quick reaction times. Any question or problem is solved in a rapid and unbureaucratic way", appreciates the R&D manager the know-how of SIEB & MEYER.

Demand-oriented in Any Case

Customized boards and housings or heat sinks, firmware, application software or motor connectors – the lists of references of SIEB & MEYER is long. Customers do not only benefit from the extensive application-specific and control engineering know-how of the SIEB & MEYER team in the field of servo amplifiers and high-speed frequency converters, but also from profound knowledge about digital and analog switching techniques, programming of microcontrollers, FPGA and user interfaces, component layout (from power electronics to high-speed components), fieldbus systems or feed-in technologies. The production site at Lueneburg comprises SMD and THT mounting lines with inline AOI systems as well as ICT/Flying Probe, sheet manufacturing and customized labeling and burn-in-tests. All specific solutions are realized with the highest quality demands by the company certified according to ISO 9001:2008.