Twenty-ton molds for lightweight carbon fiber components can easily be conveyed to huge ovens where their contents are hardened at temperatures of up to 400°C. This is made possible by an innovative heavy-duty AGV from Stäubli, which impresses with high maneuverability and other outstanding technical features.
Massive molds are used in the production of lightweight components destined for the aerospace industry. To move them around the shop floor of its facility in Augsburg, the DLR Center for Lightweight Production Technology (ZLP) has procured a heavy-duty AGV with a load capacity of 20 tons.
Augsburg has established a reputation as a hub for lightweight construction technologies and the processing of carbon fiber-reinforced plastics (CFRP), making it the perfect setting for ZLP, a research institute of DLR, the German Aerospace Center.
One of the main areas of interest and activity for ZLP is the cost-effective, high-quality manufacture of large carbon fiber components with a view to subsequent series production. The institute has control over the entire process chain and operates large-scale multifunctional facilities that are quite unique. They include gigantic industrial ovens in which, for example, structural components of aircraft, including complete fuselage segments, are hardened at temperatures of up to 400°C. The curing takes place in molds weighing up to 20 tons, which give the components their shape. The challenge here was how to get them into the oven. And the obvious answer was, with an automated guided vehicle (AGV).
A platform AGV from Stäubli WFT now performs this task in the production hall. The massive molds are moved around on a platform measuring 5 x 2 meters.
Considering its 20-ton load capacity, the AGV is a relatively low-slung vehicle, coming in at a height of only 460 mm. It wheels itself under the base frame of the mold and raises both by 200 mm. Six synchronized lifting cylinders ensure a smooth upward movement.
The AGV bearing the mold can then be moved towards the oven at a speed of between 0.1 and 5.0 km/h. And because the AGV is such a flexible vehicle, it is also charged with conveying new molds from the unloading bay to their designated point of use. In both scenarios, it is operated manually by radio remote control with twin joysticks.
There are sound technical reasons why the institute opted for a heavy-duty AGV from Stäubli WFT. As Toni Vogel, technician at ZLP explains, “There are vertical displacements in the floor of our production halls, and there are steel rails for the transport of molds and other items. These protrude by as much as 10 mm. Our AGV has to be able to drive over these small obstacles. For the Stäubli WFT vehicles with their Vulkollan® rollers that can rotate through 360 degrees, even a 20-mm height difference presents no problem. Another decisive criterion was the low tare weight of the AGV.”
The patented drive and control concept of the AGV with four separately steerable units, which facilitates maneuverability without putting too much strain on the casters, is truly impressive. The wheels have very high abrasion resistance and surmount the rails without undue wear.
The AGV is called to action when a mold needs to be conveyed to an oven. Since this typically requires it to travel only 30 to 50 meters, long-distance running is not of prime importance for this application. Instead, precise positioning and maneuvering as well as high availability are required, and in this respect the AGV designed and built by Stäubli WFT has never disappointed its users at ZLP in the seven years it has been in operation.