The basis for virtual press shop planning is the analysis of the value stream from incoming goods to the finished parts warehouse. © Schuler

The process monitor integrated into the control system offers comprehensive monitoring options. In this way, overload protection is guaranteed over the entire press force curve and the entire movement curve; a minimum and maximum force can be defined to effectively protect the tool. The reaction times of the electronic overload protection are in the range of a few milliseconds, i.e. faster than with hydraulic overload protection. The press can be used again immediately after an overload is detected.

Low mass moments of inertia in the drive train enable short stopping distances and reaction times. While standard presses generally reduce the force in the event of an overload and continue to move the ram through the lower reversal point to the upper reversal point, according to the company, the MSP 400 has a "Smart Release" function: Here, the ram automatically moves back a defined distance after an overload is detected, thus relieving the tool and press.

Comprehensive condition monitoring

The integration of additional sensors - for acceleration, vibration or pressure, for example - enables comprehensive condition monitoring of the system, which can be displayed in the visualization of the control system. This is based on frequency spectra, which provide information about possible wear in the gearbox, bearing or motor. This prevents unplanned downtime and increases the productivity of the system. In addition, the process and status data allow for comprehensive quality control of the components produced.

At Euroblech in Hanover, Schuler presented the new MSP 400 servo press including the "Smart Assist" operator software. © Schuler

Unlike a conventional press, the pressure points on the MSP 400 are not located above the ram, but outside the actual table area. This allows the machine to absorb very high eccentric loads, and around 25 percent more press force is available on both the infeed and outfeed sides, according to the company. In this way, even high-strength materials can be formed in the first tool stage.

The geometric arrangement also results in a high mechanical tilting rigidity of the plunger. In addition, the spring deflection of the overall system is reduced because the drive is located far out in the head piece. This means that forming is gentle on the tool and higher component quality can be achieved. The electronic coupling enables force-independent parallel control: in the event of an off-center load, the drives are only readjusted on one side without any loss of force, and the ram is thus kept parallel.

Virtual press shop planning

Press shops also have to adapt to today's market requirements. It is now important to meet the required flexibility - short-term orders and decreasing batch sizes - and not at the expense of profitability. In order to sustainably increase efficiency in the press shop, there is no way around holistic optimization, including the entire material flow. Optimizing the presses is of course an important field of action. The "Overall Equipment Effectiveness" (OEE) can be determined by examining availability, efficiency and quality. By increasing the OEE using a wide range of measures, existing potential can be exploited and productivity increased.

One measure is software support. With the help of software tools, die and production parameters can be digitally optimized and the movement curves of the slide and transfer can be adapted to the respective die in order to fully exploit the possibilities of the presses. An increase in the number of strokes or a reduction in set-up time frees up a large number of production hours over the course of a year. With this additional time, more parts can be produced with the same equipment, batch sizes can be reduced or the time gained can be used for preventive maintenance. This reduces unplanned downtime and increases availability and delivery capacity.

Identifying optimization potential through a holistic approach

A holistic view of the press shop shows, for example, that frequent set-up reduces profitability. This is because the greater the number of variants and the larger the batches, the greater the storage volume and therefore the capital commitment. In order to reduce batch sizes, internal set-up must be shortened. Improved methodology and preparation, as well as appropriate employee qualifications, often offer enormous potential in set-up. It is just as important to store the tools in a well-maintained condition in order to be able to react flexibly to short-term changes in the production plan.

Together with the lean management consultancy Staufen, Schuler, as a system manufacturer and process consultant, offers an analysis of the press shop. The basis is the so-called Quick Check, which makes the individual performance visible. The analysis includes the complete value stream mapping of the material flow from incoming goods to outgoing goods and provides individual recommendations for action to increase efficiency. In addition, new ideal or real layouts of the pressing plant can be developed on the basis of the actual and target value stream, both for a new pressing plant (greenfield) and for existing production halls (brownfield). The order behaviour of internal and external customers is crucial for optimization. Ideally, the pressing plant should produce in line with customer cycles and be able to react flexibly to fluctuations in demand even without large inventories. If successive stations work in the same cycle as far as possible, no large stocks build up and the throughput time remains short.

A sustainable increase in efficiency always takes priority over short-term one-off effects. There is often great potential not only in production, but also in administrative areas such as production planning and control as well as container and store floor management. In the latter, managers are not only required to maintain regular communication, but also to manage with key figures and control the processes.

According to documents from Schuler / ag