When a completely new foundry for producing axle and engine components for cars and trucks came on stream for Georg Fischer AG at its long-established Mettmann plant, a safe and efficient technical solution for pouring the molten iron into the moulding boxes was required.
Task definition
The brief was to achieve the greatest possible flexibility with the ability to pour the metal at any given point thus exploiting the moulding boxes to the full. As a rule, this task is carried out by systems that can only fill a sand mould at a single point. Since pouring is stationary at a fixed pouring position, flexible casting is not conventionally possible in these systems.
Solution
By using two KUKA KR 1000 titan heavy-duty robots for casting the molten iron, Georg Fischer has achieved flexibility and is able to exploit the mould area to optimum effect. Now, the pouring system no longer dictates where the castings are allowed to be, and where not. This solution from ROBOTEC Engineering GmbH was to use two KR 1000 titan robots working in parallel. A heat-resistant suit additionally protects the robots against the extremely hot conditions in the foundry. Mounted on the robot flange is a casting ladle that is filled with molten iron at 1400°C. A load cell is additionally installed between the casting ladle and the robot flange, as a means of weighing the quantity of molten iron. This means it is possible to add the precise amount of iron that is required to make up the correct quantity in the next casting cycle. The casting ladle only ever contains the optimum quantity of molten iron. The flexibility of the six-axis robots means the iron can be poured into the moulding box at any point. The sand moulds cool down to below 700°C before the castings can be taken out. Following further cooling to room temperature, the parts are blasted and subjected to a visual inspection before they are released for shipment. In the event of lengthy downtimes, the metal would cool down in the casting ladle and could no longer be used for the casting process. ROBOTEC has developed an innovative solution for this situation - the two robots are able to return process iron to the casting furnace in which the iron is heated back to the casting temperature. Another innovation is the fully automatic casting ladle change - the robot can put down the used casting ladle and pick up a new one, just like a robot gripper change. Using the KUKA robots also enables various set-up work.
System components
The KUKA KR 1000 titan F offers a highly compact design and comparatively low weight of 4,700kg. In addition, it can be integrated into complete systems without requiring expensive special foundations, and it can withstand very high payloads of around 950kg. It is not only able to lift exceptionally heavy loads, but is also able to position them with utmost precision and can bridge distances of up to 6.5m with ease. Its strength lies in its compact design, which optimally utilises the workspace and allows space-saving and cost-efficient integration into the system.
Results
Since the two robots are able to return process iron to the casting furnace in which the iron is heated back to the casting temperature, Georg Fischer has not only reduced its energy and logistics costs, but has also sustainably cut its CO2 emissions.
Georg Fischer AG was established in 1802 and its Mettmann plant has a history stretching back more than 100 years. Georg Fischer Mettmann forms part of the GF Automotive division of Georg Fischer AG with its headquarters in Schaffhausen/Switzerland. The Mettmann location employs about 1,000 people, and produces 190,000 metric tons of castings for the automotive industry every year.
Contact: KUKA Roboter GmbH, Hery-Park 3000, 86368 Gersthofen, Germany, Tel: +49 821 4533 0, www.kuka-robotics.com