Gentle deburring of complex die-castings
Rösler has developed a continuous feed vibratory finishing system 780/2E-LR-So for a new diecasting line and has been completely integrated into the manufacturing flow. The component / work pieces are automatically fed into the system on a 20-second time cycle.
The Julius Schüle Druckguss GmbH, founded in 1951, specialises in the manufacturing of precision aluminum die-castings for automotive, pneumatic and gas heating assemblies. New additions to the companys product range required the installation of a new casting line at its headquarters in Schwäbisch Gmünd. The new line produces engine cradles with an integrated steel axle. This posed considerable technical challenges to the casting process itself as well as to the subsequent manufacturing steps. For this reason, the Rösler vibratory finishing system was custom engineered for this particular application. Herbert Nowak, production manager at Schuele Druckguss, explains: “On the one hand, we require a very gentle single component processing with the requirement for breaking of sharp edges and smoothing of uneven component surfaces. On the other hand, short processing times allowing a high throughput in a fully automatic 3-shift operation is a must”.
Surface finishing system and processing media perfectly adapted to each other
Rösler met this challenge with the innovative machine concept of the Long Radius
R 780/2E-LR-So, that could be perfectly integrated into the new casting line at Schuele.
Herbert Nowak explains the companys decision for choosing the Rösler finishing system:
“Because of the comprehensive technical knowledge of the Rösler sales staff and our excellent experience with other equipment, Rösler is one of our preferred suppliers”.
With a processing channel of 350 mm (14”) wide and 6,000 mm (236”) long this Long Radius system offers an intensive finishing process in a highly compact machine design concept and with a surprisingly small footprint. The consumables (grinding media and compound) required for the finishing process at Schuele were determined through processing trials in the Rὅsler test lab.
Work piece loading in 20-second cycles
The raw components produced by the casting cell are transported by conveyor belt to the trim press. A robot equipped with an image recognition system picks up the castings and places them into the press in the correct position. After trimming, the robot picks up the components and transfers them into the vibratory finishing machine in precise 20-second cycles. The rounded shape of the work channel / profile ensures the quick embedding of the components into the grinding media and optimises the media/work piece movement. This explains the excellent finishing results achieved in a surprisingly low total process time up to a maximum 10 minutes.
The separation of the finished components from the media is as gentle as the loading and processing: A specially designed separation screen guides the finished work, allowing a very gentle discharge from the LR machine. Subsequently, the cup shaped aluminum die-castings are transferred to a camera-controlled “flipping” station placing them to an optimum position for the following inline washing/cleaning process.
Effluent treatment included
Schüle Druckguss is recycling the process water from the vibratory finishing system. The water is cleaned in a compact semi-automatic centrifuge model Z 800 HA. With a centrifugal force of up to 2,000 g this system effectively separates the solid particles from the liquid. Even very tiny and light solids and particulate are deposited on the inner wall of the sludge basket inserted into the rotary drum. The sludge can be easily removed from the sludge basket.
Pleased with the results so far, Herbert Nowak summarises: ”The new vibratory finishing system not only enables the optimum processing result in the given cycle time, but provides by design, a very gentle handling of the components”.