Even though automation technology has become highly sophisticated, there is always potential to make processes even better. A stacking system for blanks shows how even the smallest of innovations in pneumatic cylinders and valves can result in a major leap forward in safety and efficiency.
Today’s cars are shining examples of perfectly automated processes. From the smallest screw to the largest metal sheet, from the first second of production to the final engine performance test – behind every car is a seamless chain of thousands of individual steps. With advances in automation technology comes improved product quality. The safer and more reliable processes become, the more running costs for maintenance and machine downtime will fall.
Improved process reliability is therefore a decisive competitive advantage for companies like NSM Magnettechnik GmbH, a manufacturer of customised conveying systems that works with leading companies in the automotive industry. In a new system for stacking metal sheets, the experts have opted for a cylinder/valve combination consisting of individual valve VUVG and standard cylinder DSBC with self-adjusting end-position cushioning PPS. With five hundred of these cylinders, the ready-to-install solution ensures precise cushioning and synchronous motion.
Small changes, big impact
It is often the small things that make the biggest difference – take the changeover of pneumatic cylinders in a stacking system for sheet metal blanks, for example. If the blanks are to be made into perfect vehicle outer skin panels such as car roofs, doors, bonnets and boots, you need more than just a flawlessly cut blank.
The processes for setting down and stacking the blanks must also be error-free. If just one of the 500 pneumatic cylinders pushes the sheet transported by magnetic strip to the stack at the wrong time or in the wrong direction, this results in defects that impair product quality. In previous systems, the process for pushing the magnetically transported sheet metal parts was carried out using cylinders DNCB with manually adjustable cushioning PPV. Since the changeover to the new cylinders DSBC with self-adjusting cushioning PPS, process reliability has significantly improved.
Big is beautiful: 500 cylinders DSBC with self-adjusting cushioning PPS and individual valves VUVG push metal sheets synchronously.
The synchronous adjustment of the 500 pneumatic cylinders in the NSM stacking system used to be anything but easy. With the outdated cylinders DNCB, the cushioning PPV had to be adjusted individually. For safety and to facilitate visual inspection, the adjusting screws were covered with sealing wax. Adjusting the cushioning of the 500 cylinders to make sure that it was absolutely synchronous was not only extremely time- and labour-intensive, but also lacking in precision compared with the new cylinders DSBC.
Thanks to the new self-adjusting cushioning PPS, each individual cylinder is always cushioned identically and advances completely in sync. This not only protects the blanks, but also reduces maintenance costs by up to 70 per cent and permanently reduces downtimes for the new system. These are significant advantages for NSM Magnettechnik in the competitive automotive industry.
Gaps for even pressure: The pneumatic pusher heads operate between the magnetic conveyors.
Another key factor that contributed to increased process reliability and cost-effectiveness was the changeover from CPE to individual valves VUVG. With the valves CPE, the very small screws for clamping the cables frequently caused defects due to excessive tightening. The 8M plugs of the individual valves VUVG offer much greater reliability. For electricians, handling has also been made easier thanks to the 8M industry standard and standardised cable lengths.
With 900 plugs in the stacking system, this apparently small improvement makes a huge difference. In addition, the individual valve VUVG switches at a pressure of below 1 bar, while the CPE switched at 1.5 bar pilot pressure. Significantly higher parallel switching is thus achieved in the new stacking system from NSM Magnettechnik.
With a switching time of 100 to 150 milliseconds, the valves VUVG can achieve a high cycle rate of up to 90 pushing processes per minute. The output is 40 per cent higher than that of conventional systems.
Thanks to the ready-to-install solution supplied by Festo – consisting of cylinder DSBC, individual valve VUVG, fittings and tubing – NSM Magnettechnik has also reduced its assembly costs. In addition, the customised complete solution means that the company can respond extremely quickly to customer requests. The new high-performance components from Festo have not only increased the process reliability of the system, but also permanently improved service quality.
Area of business: Development, construction and sales of customised systems for press automation, packaging automation and conveying systems