Scheppach, the renowned German based manufacturer of woodworking machines already had been using welding robots over the past 20 years. When the company was looking to invest in additional robotic welding, key to their needs was a system that could deliver high quality welding on various plate thicknesses and was flexible enough to accommodate their vast range of sub-assembly and final welding.
Solution
The layout of the innovate cell draws on many years of experience of YASKAWA Europe and features a MOTOMAN MA1900 welding robot that is suspended from a gantry system with a 3 m linear servo axis. This allows the robot to move to any conceivable welding position achieving optimal orientation. The superior wire feed system and integrated routing of the welding hose bundle guarantees the highest weld quality, maximum flexibility and reduced interference with fixtures.
The accurate twin station MOTOMAN RWV2 series positioner has a distance of 3 m between face plates and a handling capacity of 1,000 kg at each station and provides additional flexibility. This design separates the system into a welding area and an operator load area. The servo positioner has a horizontal rotational axis for station interchange and an infinite rotating axis at each station in order to bring the assemblies to the optimal welding position. The entire system is controlled from the high performance DX100 robot controller. This controller can coordinate up to 72 fully synchronised axes and makes light work of the ten axes in this system.
Results
The creative use of the new system at Scheppach is illustrated by the welding sequence for a completely new product, the jigging device for the Wox 700 Duo double log saw. “We break the large assemblies down into various sub-assemblies and weld two pre-welded items and one main welded item in a single operation. This enables us to reduce the complexity of these components and simplifies fixturing considerably” explains Sheet Metal Processing Team Manager, Jürgen Niederwieser, and adds: “We sometimes even have different assemblies for different end products on the system at the same time.”
It is not only the weld quality that is met with approval, but also the overall performance of the system. Since it was commissioned in July 2011, it has been running in 2-shift operation without any failure. This provided confidence to the decision makers at Scheppach for whom the decision in YASKAWA’s favour was not an easy one: “We had a short-list of several suppliers and observed reference installations from each of these at other companies. In the end we were convinced by the expertise of YASKAWA and their partnership approach towards the project. We now realise that we made the right decision. The system fully meets our ambitious requirements in terms of quality, flexibility and reliability,” affirms Jürgen Niederwieser.