Straightening reliably
MAE Götzen has entered a new era at its Erkrath location. “Ever greater flexibility is expected of us as machine manufacturers as well as the users of our straightening presses,” says Manfred Mitze, Director of Technology at MAE Götzen. “That’s why, together with Siemens, we have fundamentally redesigned the control and drive concept of our presses.” At the moment, MAE Götzen is gradually converting its engineering to the TIA Portal engineering framework and uses powerful standard components from Siemens throughout its configured machines.
The first machine with the new controller and drive technology is a manually controlled 1,000 kN servo straightening press in C design. Oliver Kaiser, Technical Manager at MAE in Erkrath, explains how it works: “Like all our straightening presses, this machine operates on a path-controlled basis. The user doesn’t specify the force with which the part – the shaft, axis, or whatever component – is straightened. Rather, they specify by how many hundredths or thousandths of a millimeter the part should be deformed in order to achieve the straightening effect. For this reason, the power transmission is path-controlled and servo-hydraulic. A swivel pump with variable displacement adapts the characteristics of the hydraulics to the various process phases. For infeed, straightening and retraction, very different speeds, forces and levels of positioning precision are required.”
On this basis, MAE servo straightening presses have been established in the market for several years. That said, the swivel technology and the variable displacement are a real challenge for the drive controllers of the pump motor. Not only does the load situation but all characteristics of the power transmission change depending on the process phase. The operating mechanism is regularly exposed to unpredictable disturbances.
Components for increased benefits
Since the swivel technology and the variable displacement are a major challenge for the drive controllers of the pump motor, Siemens extended the algorithms of the servo pump application in the Sinamics Drive Control Chart (DCC) to a customer-specific version for MAE. It can also handle hydraulic pumps with adjustable displacement.
The drive control of the servo straightening press is a combination of SINAMICS S120 drive and DCC algorithms, controlled by a fail-safe SIMATIC S7-1500F. The pump motor is a SIMOTICS S 1FK/1FT. Together with Siemens, MAE has designed drives and controllers in versions for three performance categories, which now serve as the basis for the future engineering of customized and newly developed servo straightening presses. The safety technology required for manual straightening presses is based on the Siemens press safety library, a fail-safe SIMATIC S7 controller, and the Profisafe protocol. Oliver Kaiser confirms: “The requirements of the trade association can be implemented much more easily with this solution than with conventional safety technology.”
The direct comparison is convincing
Having e-technology from a single source reduces system complexity and simplifies procurement. In emergencies, services and spare parts for Siemens components can be supplied quickly worldwide, which improves availability. This is a crucial selling point, since straightening presses are often bottlenecks – for hardened components, for example. After hardening, the workpieces are usually warped and can only be further processed or assembled after straightening. The revised control and drive concept of the presses improves precision and reduces maintenance costs.
Originally considered a prototype, the machine version with the new automation and drive technology quickly aroused interest in MAE’s showroom and laboratory. The clear, user-friendly HMI surface, the lean hydraulics and improved spare-parts situation in electrical engineering were very impressive. The open standard PLC, enabling easy connection to higher-level IT systems, is an added plus. Finally, workers also benefit from the advantage of servo technology from MAE Götzen. The press generates practically no background noise in standby mode or when the ram is stationary. As long as the surroundings are quiet, the straightening station is a peaceful place. This means it’s easy to communicate and work is less tiring, which also improves quality.
By coordinating its electrical engineering with TIA Portal, MAE has paved the way for the future, and the company knows it has a reliable partner at its side. “A vital part of our decision was that we’ve had constant and committed contacts at Siemens for many years, who’ve always been helpful,” says Manfred Mitze. Oliver Kaiser confirms: “The support provided by the Siemens Application Centers has played a decisive role in creating a solid overall package. The benchmark compared with the old technology is very good with regard to development time for the electrical design, commissioning as well as cost-effectiveness. Construction and development of customer-specific machine versions are now more flexible and efficient. The machines implemented in this way offer greater flexibility, ease of use and maintenance, and better IT connectivity.”
A vital part of our decision was that we’ve had constant and committed contacts at Siemens for many years, who’ve always been helpful.Manfred Mitze, Director of Technology at MAE Götzen
