Dipl. Ing. IWE Marcus Witt, Hartmannsdorf, Germany
Nowadays, when mobility and flexibility are becoming more and more important, it is of great importance to break new ground in production. Especially in the repair and spare parts production, it is often necessary to act quickly and efficiently on site. Conventional machine tools quickly reach their limits. But with the introduction of the mobile 5-axis machine tool, this problem has changed fundamentally.
Due to the continuously rising transport costs, a tense situation with supplier parts and the need to reduce CO2, a rethinking of the manner of manufacture and the further use of existing components is necessary.
The 5-strut parallel kinematics from metrom represent an innovative solution to meet the requirements of repair and spare parts production on site. Compared to conventional machine tools, the parallel kinematics enable high mobility and precision. By using 5 struts, the axes can be controlled simultaneously and independently. This means that complex processing can be carried out in one operation, which significantly increases efficiency and time savings. Furthermore, the outer machine shape of the icosahedron offers the greatest possible inherent rigidity, on the one hand to dissipate the machining forces and on the other hand to achieve resistance to influences such as machine transport. As a result, the set accuracy of the machines is retained even under adverse and changing conditions in mobile use. Due to the small moving masses, the machining is energy-saving with typical consumption values below 4kWh with a combination of roughing and finishing machining.
A major advantage of the mobile 5-axis machine tool is that it can be accommodated and operated in a container. Since the container protects the machine from environmental influences, it is possible to work in almost any environment. In combination with an interpolating rotary table under the 5-strut kinematics, it is possible to carry out repairs and spare parts production quickly without having to create complex logistics and transport plans. An example of production in containers is the mobile smart factory, which Rheinmetall uses to manufacture spare parts for critical components and offers to its customers. This consists of a 20″ logistics container and a 20″ production container.
The mobile smart factory works with the IRIS management system to enable the provision of data for the spare parts to be generated. The data is processed using HY5CAM as a CADCAM environment and a corresponding virtual model of the machine for a preliminary check of all accessibility to the component and collision avoidance with clamping devices. For all components that are not yet digitally available, the logistics container contains the option of reverse engineering.
The ideal metal build-up welding technology can thus be used according to the requirements for build-up rate, dilution of the base material, geometric accuracy, constrained position and material combination. The machine and the additional technologies are housed in a setup with 2 containers and can therefore be transported with a truck.
La technologie idéale de rechargement de métal peut ainsi être utilisée en fonction des exigences en matière de taux de rechargement, de mélange du matériau de base, de précision de la géométrie, de position forcée et de combinaison de matériaux. La machine et les technologies complémentaires sont installées dans un ensemble de deux conteneurs et peuvent donc être transportées par camion :
Another functionality of the mobile 5-axis machine tool is its use on large components. Due to the high mobility and flexibility of the parallel kinematics, the machine can be placed directly on the large component. This enables efficient on-site processing without having to transport the component. Variable mounting options as well as quick calibration of the machine to the workpiece due to the available 5-axes and the corresponding zero point and plane shift are the key to efficient machining.
This solution has proven to be extremely advantageous, especially in the field of power generation using gas and steam turbines, as well as in reactors and chemical plants, as well as in the shipbuilding industry, since the large components are often heavy and unwieldy.
But the mobile machine is also used in aircraft and automotive construction, for example to repair press tools by means of build-up welding and subsequent final contour milling through to the so-called try-out, i.e. the incorporation of the press mold into the respective press geometry at the installation site. It should be emphasized in particular that the manual work processes of welding and grinding, for which there are hardly any specialists anymore, can be replaced by a digitized and documentable solution.
The mobile 5-axis machine tool with 5-strut parallel kinematics from metrom offers innovative solutions for on-site repair and spare parts production. Due to the high mobility, precision and flexibility of the machine, complex processing of medium to very large components can be carried out quickly and efficiently. Use in containers and as a mobile machine on large components makes it possible to choose the place of use flexibly and avoid complex logistics. This contributes significantly to time savings and cost efficiency as well as the reduction of CO2 emissions. The mobile machines have been in use worldwide since 2008 and have been continuously supplemented with new additive technologies and additional processes for several years now in order to revolutionize on-site repair and spare parts production and open up new possibilities.