Poppe+Potthoff: "The Power of One"
"The fact that we can source both the hydraulics and the electrical engineering from Eaton as a single supplier opens up new possibilities for us. By taking on our suppliers as partners, we can also increasingly give them greater responsibility."
Frank Baudler, head of engineering/R&D at Poppe + Potthoff Maschinenbau GmbH
Poppe + Potthoff is a company that specializes in the field of high pressure. From high pressure lines, pipe components and precision parts, right through to machines and services for testing technology, the group of companies develops and produces advanced technology solutions for the automotive and utility vehicle sector, shipbuilding and general industry.
At its Nordhausen site, Poppe + Potthoff concentrates on test systems for burst tests, autofrettage, pulse tests and rotating bending fatigue and for supporting series production and prototype development. The latest machines include a burst pressure test stand that is suitable for both testing tube fittings and also hydraulic hose lines. Test sequences can be programmed flexibly, not only allowing testing with linear pressure increases and decreases, as well as holding times at a constant pressure and volume. In a massive test chamber with a 10 mm stainless steel safety cage, test objects can be burst tested in a controlled manner at pressures of up to 4,000 bar.
The development of the test stand described placed particular requirements on the design of the system, particularly because of the different properties of the test objects, fittings and hoses.
Hydraulics from the drive to the control to the connection
In partnership with Eaton, an in-house hydraulic power unit was developed which is controlled by Eaton automation and switchgear technology.
“In order to create the pressure in our plant, the hydraulic power unit first of all generates a pressure of up to 350 bar," explains Johannes Montag, responsible for Design Construction at Poppe + Potthoff Maschinenbau GmbH. "For the first time we have used two pressure amplifiers to create the high pressure. These have different piston diameters so that we can pre-fill quickly with the large pressure amplifier and then, particularly for position-controlled burst pressure testing, very finely regulate the pressure at high resolution using the small pressure amplifier." The key components for the precise control of the pressure amplifiers and thus the pressures in the test chamber are the proportional valves.
Besides the proportional valves for the two pressure amplifiers, other important hydraulic components for the drive, control and connection are supplied by Eaton and integrate together seamlessly.
Fast and uncomplicated programming and commissioning of the test stand
The proportional valves of this burst pressure stand are connected to the controller via CANopen. Poppe + Potthoff chose Eaton‘s modular XC200 for the PLC. "For us, the XC200 offers two major benefits for this test stand," explains René Karwoth, who is responsible for software development at Poppe + Potthoff in Nordhausen. "Firstly, the integrated Ethernet interface allows us to connect the PLC directly to National Instruments LabVIEW and the network, without having to use MPI or PPI converters as was necessary before. Secondly, the CoDeSys-based software (SW-XSoft-CoDeSys-2) and the extensive range of functions of the closed-loop control toolbox enable us to complete programming and commissioning faster and more conveniently than before" Eaton‘s closed-loop control toolbox contains around 120 ready-to-use function blocks that make life easier for the developer by providing already implemented closed-loop control know-how, so that individual application solutions can be made simply and quickly by combining and cascading standard function blocks.
A commissioning screen created with the XSoft-CoDeSys Target visualization shows all important parameters at a glance, and thus not only noticeably simplifies commissioning, but also supports the end user with later optimizations.
"Thanks to this project and the close cooperation with Eaton, we are now able to also offer our customers Eaton hydraulic power units in future for different test stands," Frank Baudler, head of engineering/R&D at Poppe + Potthoff Maschinenbau GmbH, is delighted. "The fact that we can source both the hydraulics and the electrical engineering from Eaton as a single supplier opens up new possibilities for us. By taking on our suppliers as partners, we can also increasingly give them greater responsibility." In future the specialist for high pressure test stands will also use Eaton hydraulic power units in different performance classes. Thanks to the broad and comprehensive range of Eaton products a scaling of the unit is easy to implement.