New applications continue to emerge for robotic systems in metalcasting operations, for reasons that are obvious: Demanding jobs in harsh surroundings wear on foundry workers. Heat and dust takes a physical and mental toll, and training and keeping talented workers is a common concern for the management.
Just as significant, developers of robotic systems are expanding and improving the applications for their devices in foundry settings. Here are some examples:
ABB offers robots for coremaking, which it calls “a natural progression in automation in the foundry.” The robots remove the cores from the core machine and deburr, test, and assemble them into core packages.
Pneumatic grippers with automatic changeover systems reduce set-up times and increase machine availability. Designed specifically for cores, these grippers are part of the core shooter and can be used in various situations.
For dipping cold-box cores, robots offer a way to coat the cores in an even, reproducible surface application. Robots make it possible to minimize scrap and rework in the cleaning process, and the cores’ weight presents no significant problem. Pneumatic grippers can be equipped with adjustable fingers; tracking ensures safe and continuous movement along a conveyor; and personnel safety is ensured.
ABB also offers industrial robots for the labor-intensive effort of cleaning castings. Automation makes it possible to direct the blast cleaning nozzle in the cabin; a part-recognition system can identify the supplied workpieces and start the appropriate program; the blast cabinet can be part of the scope of the supply or an existing cabinet can be refitted with an industrial robot. A belt conveyor, sliding table, or turntable can do the loading.
By using robots in this situation, a consistent blast results. The workload is reduced, as is maintenance. The programming of the robot can be changed quickly too.
After blasting concludes, the unloading (or the loading prior to blasting) can be done with robots, too. Parts are taken from a roller table and placed in the loading position of the blasting machine. Once removed, the workpieces are shaken out through a collecting funnel, minimizing the residual amount of blast-cleaning abrasive.
Also, consumption of the blast-cleaning abrasive is reduced, along with the standard benefits — reduction in personnel workload, rapidly changed programming, low maintenance, and high availability— enjoyed elsewhere in the foundry.
KUKA Robotics offers robots, controllers, software, energy supply, linear units, and remote control to be used with their foundry robotics, and the developer cites four features it says sets its devices apart.
A pressure regulator was designed especially for robots used in spraying applications. Overpressure in the arm housing for optimal protection against the penetration of aggressive fluids from the outside. Additional seals are placed at the interface of the arm, the arm housing, the counterbalancing system, and the axis motor.
The KUKA in-line wrist withstands temperatures of up to 100°C for up to 10 seconds every minute. It is manufactured with corrosion-resistant materials and additional seals. Finally, the paintwork is a triple-coat, composed of two components for each coat of paint. The paint offers good final hardness, impact-resistance and against acids and alkalis, and is able to withstand temperatures up to 220°C.
KUKA robots offer a number of uses in a foundry. They are useful in general applications (machine tending, polishing, deburring, grinding, coating and bonding, handling, measuring and testing, assembly, palletizing and order picking, cutting, and welding) and in more specific applications (the KR 150-2 K F series is ideal for taking molten-metal samples.)
Classified by payload size, the KUKA robots serve a number of purposes. The low payloads (3-16 kg) are used in small-scale activities (component testing, assembly of small parts, grinding, polishing, or bonding). Medium payloads (30-60 kg) offer applications from simple handling tasks to complex operations, like measuring air currents in wind tunnels, or sewing leather seat covers. High payloads (100-240 kg) are great for spot welding and handling, loading, and unloading. Customers find the long reach and flexibility particularly helpful features. Finally, the robots can handle heavy-duty payloads (360-570 kg.)
In addition to the robotics, KUKA offers a series of support devices. Energy-supply systems can run the supply tube closer to the robot, allowing more freedom of movement and reducing cable wear. Linear units are installed as an external axis, cutting down on the amount of controllers needed. The remote-control feature is one of its kinds worldwide. KUKA is the first manufacturer to offer remote control via the World Wide Web for its robotics. Their experts can help service the robots from anywhere in the world. Software ranges from application and planning to simulation and communication.
Motoman robotics supplies dual- and multi-process robots for a variety of needs.
In the automotive industry, Motoman applied its SK120 and SK16 robots in a material handling-sealant dispensing project, so that the manufacturer was able to process eight different part combinations (in six different sizes) with right- and left-hand configurations. In addition, left-left and right-right only configurations were done for one part size.
The application also provided flexible tooling/fixtures to handle various part sizes and shapes without manual change over or interrupting the cycle. In fact, a cycle time of 30 seconds/set was achieved, as was a repeatability of +/- 0.5 mm.
The need for operators was cut down, keeping workers from the fume-filled environment. Additionally, productivity and flexibility was improved over existing gantry systems processing just one part size and configuration at a time, requiring manual changeover.
Another solution, this time a multi-process solution, was achieved using Motoman robotics in the automotive industry. By using an SK120 robot and a host of custom features, uniform resin dispensing was achieved. The operator eliminated the need to flatten manually the resin surface around the preformed edges; achieve accurate placement of large perform into the press dies; and meet required cycle times less than three minutes, including the press cycle.
In addition to the SK120 robot, Motoman applied a custom sealant-dispensing head, a custom mechanical gripper with three jaws to pull the veil from the automatic sheet dispenser; a custom fork gripper; EOA shock sensors; automatic tool changers; a 180° indexing turntable positioner; interface with a customer-supplied PLC that ran the press; and integrated work cell protection package for the human operators involved.
Motoman was able to predict and meet all results from its earlier computer simulation, and met the goal of a cycle time less than three minutes. Because of their many applications in various environments, foundry robotics will continue to move forward.
Rimrock is a North American distributor of several robotic systems, including the ABB robots and the decoring option, the Fill swingmaster sm3.
The swingmaster is based on a dynamically excited oscillation system. The main difference between the swingmaster and the conventional designs: the exciter drive motors aren’t mounted on the vibration system, but stationary in relation to the moving system.