in Vol. 7 - November Issue - Year 2006
Automation Solutions for Cast Part Processing
A system conquers the market
The cost saving alternative for deburring of components in continuous process
Innovations for a forward-looking industry sector <br><br> Technologically demanding cast products from Germany are among the best in the world. As a result, the cast iron and steel casting industry, as well as the non-ferrous metal casting industry, have grown by 6 and 3.5 percent, respectively. A substantial share of this growth can be attributed to increasingly automated expansion within the process chain: surface treatment, including deburring.
Gentle automated vibratory finishing solution
Processing delicate, thin-walled aluminum die castings in vibratory finishing systems requires a combination of technical expertise and the right equipment, especially parts loading systems. For years, Pressmetall Gunzenhausen (PMG) has been relying on Rösler finishing systems, and has added our linear continuous-flow systems to deburr die castings.
In the field of vibratory finishing technology, linear continuous flow systems are considered cost-effective alternatives to batch-processing vibrators, as the processing time and the related effects of deburring or finishing processes can be varied by adjusting the angle of the processing channel, the imbalance of the motor and the rotational speed. The PMG components posed a particular challenge due to their thin walls and the requirement of loading the parts gently.
In order to discharge raw parts from a palletized wire mesh parts bin, a lift and tip unit fills a Vario loading buffer system. Driven by a linear-operating magnetic oscillator with speed and bearing control, the loading quantity can be adjusted individually. The downstream parts transport conveyor transfers the components directly into the processing channel of the vibratory finishing system. The finishing process time is eight minutes. The system incorporates automatic media classification, which removes undersize media, and automatic parts cleaning during the separation process. Before being dried with hot air, the components pass through a pre-drying station equipped with a high-performance cold-air blower.
In order to deburr and radius components with dimensions of 120 mm (5 in) by 120 mm (5 in) by 40 mm (2 in), and create a uniform finishing pattern on the surfaces, a continuous-flow system with a channel width of 425 mm (17 in) and a length of 4,600 mm (181 in) was selected. Rösler produces systems with channel widths up to 850 mm (33 in) and lengths up to 6,600 mm (260 in).
Efficient, flexible-usable anywhere
Long radius vibratory systems are relatively new in the market. This Rösler innovation uses minimal floor space for this part of component production. At the same time, investment costs are low, and processing times are variable. The 400/9 LR, developed for a well-known Austrian manufacturer of die cast parts, was designed to meet their stringent specifications for parts cleaning.
A variety of magnesium die castings for passenger cars were to be finished, deburred, and radiussed. Due to the material properties of magnesium die castings, determining the right media and compound was crucial to achieving their requirements. In this case, ceramic cones and a special compound suitable for cycle operation was the ideal solution. The system configuration is based on the flexible, standard R 400/9 LR system. The components pass through the 400 mm (16 in) wide and 9,000 mm (354 in) long processing channel, in just 6.5 minutes, enough time to achieve the required surface quality and complete the vibratory finishing process. After finishing, the parts are cleaned by a vibratory spraying station. An intermediate pre-drying station blows off the retained water in angles, pocket holes and undercuts. The R 2000.2 BT hot-air conveyor dryer, operates in a circulating-air mode with two thermostat-controlled hot air blowers.
In addition to a high level of parts cleanliness, automation played a key role. The deflashing was required to ensure worker safety during the assembly process. The wide variety of different components can be processed with the Rösler system, without retooling. The efficiency of this compact continuous-flow long radius system is due to a combination of successful system design and the special integrated Rösler direct-drive imbalance motor.
The double-flange construction of the motor ensures a powerful, loss-free transfer of the vibratory energy into the process channel. Another important advantage of the total system concept is its space-saving installation with an integrated centrifugal process water recycling system for the water and compound supply, as part of the processing cell.
Long radius systems are not limited to processing magnesium components, punched parts such as clutch disks and bearings, as well as aluminum die cast housings are only some examples of its universal application range.
It is also possible to operate long radius systems in batch mode, by equipping them with an automatic separation flap, in order to process large quantities of components.
Rösler Oberflächentechnik GmbH