PC-based Control for sheet metal working

For sheet metal processing systems, the real-time Ethernet fieldbus EtherCAT offers benefits for higher speed for punching, stamping or laser treatment.

The sheet metal working industry is booming. An increasingly wide variety of products, varying batch sizes and strong cost awareness require maximum flexibility in the face of global competition. This is where PC-based control technology from Beckhoff offers a significant competitive advantage through scalable and flexible solutions with high performance and high precision.

At the 20th EuroBlech fair in Hanover, Germany, between 21 and
25 October Beckhoff will present its PC-based control solutions for metal forming and sheet metal working in Hall 11, Booth G13.

Sheet metal components come in all shapes and sizes, requiring a wide range of machining processes including rolling, cutting, stamping, folding, drawing, joining, cleaning and finishing. Production is based on processing machines, presses, punch presses, machining centres or fully automatic production lines comprising sheet metal working equipment as well as handling devices, storage facilities, automatic material feeding and integration into the company network.

The production systems should be highly productive, precise, reproducible and, of course, cost-effective. This requires optimally adapted processes with minimum stoppage and setup times. In addition, large forces in combination with high velocities, as required for pressing, call for advanced control technology. Manufacturers of production machines demand expandability and flexibility in order to be able to meet customer requirements efficiently and cost-effectively.

The scalable and modular range of Beckhoff products enables customised solutions with regard to computing power, complexity and costs. Compared with conventional control systems, they significantly increase the productivity and flexibility of sheet metal working machines. The benefits of PC-based control technology, which integrates all processes including control, regulation, motion and HMI on a single PC, have been demonstrated in a wide range of applications in pressing, cutting, bending and welding systems worldwide. The high processor power offered by PC technology eliminates the need for special hardware: position and pressure controllers for hydraulic valves, for example, can be replaced with software. The PC effortlessly deals with even the most complex control algorithms and offers additional capacity for other functions such as measuring tasks. Complex and expensive special controllers and hardware PLCs with limited programming flexibility are no longer required.

High performance thanks to EtherCAT

Sheet metal working processes have to be fast and precise and offer high repeat accuracy. These are perfect conditions for EtherCAT Conventional fieldbus systems can easily be integrated into the EtherCAT I/O system via gateways. EtherCAT offers full Ethernet compatibility, maximum utilization of the Ethernet bandwidth, and outstanding real-time characteristics. The benefits of EtherCAT for sheet metal processing systems are, for example, higher speed for punching, stamping or laser treatment, since actuators with exactly defined rate time enable switching with an accuracy of < 100 ns and axis movements with maximum reproducibility.

Further benefits are Motion Control with many axes, synchronised through distributed clocks, with reproducible accuracy in the nanosecond range, e.g. for bending of sheet metal involving several synchronised axes. Distributed clocks precisely synchronise the EtherCAT devices such as axes, die cushion controllers or synchronism controllers for hydraulic cylinders.

TwinCAT – all functions integrated in one software

Precise sheet metal processing through bending, punching, stamping, cutting or joining requires synchronization of several axes with high repeat accuracy. TwinCAT NC and TwinCAT CNC replace the complete Motion Control hardware for all servo axes, including feed, ram or transfer components. Machine manufacturers can customise sheet metal working processes based on their system-specific control expertise. Even complex bending algorithms can easily be programmed in TwinCAT. With TwinCAT, subsequent modifications and revisions and the high degree of flexibility required for sheet metal cutting or nibbling are no longer a problem.

Comprehensive TwinCAT libraries with temperature, cam and hydraulic controllers, flying saw and cam plates simplify the programming. From the PLC drives can be programmed with the Motion Control library, cam plates, according to VDI Guideline 2143, with TwinCAT NC camming, or temperature compensation with the TwinCAT PLC Temperature Controller library in accordance with PLCopen.

Courtesy of Beckhoff