New comprehensive shot blast solutions for components in electric vehicles

Aluminum, with its relatively low bulk density, allows significant weight savings in the production of components for electric vehicles, resulting in an expanded operating range of the battery. Therefore, the number of components produced from this light metal, made by die-casting and other production methods, is rapidly growing. Another goal for components for electrical vehicles is to create complex but, at the same, thin-walled designs, which allow additional weight savings. This also applies to the housings for different control devices manufactured by Alupress GmbH in Hildburghausen, Germany. At the Italian subsidiary of the Alupress AG in Brixen the growing demand from the automotive industry necessitated the investment into a new shot blast machine that was specially adapted to the strict customer requirements.

Automated all-around solution minimizes the risk of work piece warping
The shape and wall thickness of the aluminum and magnesium die-castings demanded a shot blast process that treats the components gently without warping them. At the same time, the shot blast operation had to be quick and run fully automatically. After the shot blast process the components pass through a cleaning device and, before they are packed and shipped, they undergo a quality control check. Therefore, besides the shot blast machine, the project scope also included a transport system that conveys the components automatically through the de-flashing and cleaning stations. Alupress chose Rösler as partner for this important project because of the convincing quality and productivity of the equipment as well as the excellent after-sales service. Another reason for working with this supplier was that Rösler had proven its technical competence in processing delicate work pieces in another, similar project. Moreover, for many years Alupress has utilized shot blast machinery from Rösler and, therefore, knows the quality, productivity and reliability of this equipment.

Equal application of force prevents warping of the work pieces
To ensure gentle but also fast and effective de-flashing in continuous flow, the continuous feed spinner hanger shot blast machine, model RHBD 13/18-So, is equipped with eight special turbines, each with an installed power of 11 kW. The turbines contain extra wide throwing blades generating a particularly broad blast pattern. Furthermore, contrary to the standard placement of the turbines on one side of the blast chamber, the turbines were placed on both sides. This duplex turbine placement, together with the broad blast pattern, generates a gentle blast operation, which significantly minimizes the risk of warping. But the comparatively high blast media throughput, needed for efficient de-flashing and cleaning the light metal components, ensures a fast and effective shot blasting operation.

Another feature for preventing work piece warping is that the work piece carrier, holding 60 to 80 components, not only rotates during the entire shot blast process but also oscillates back and forth in three positions. This guarantees that flashes and burs are safely removed, even in difficult-to-reach areas like undercuts. To prevent the blast media – very small aluminum cut wire – from being sucked out of the shot blast machine by the exhaust air flow and to maintain the required optimum operating mix, the dust collector and the cascade air wash separator were technically modified. Of course, the wet dust collector is in full compliance with ATEX requirement.
Necessary maintenance work is facilitated by multiple connections for cleaning equipment at different sections of the shot blast machine.

Ergonomic features for improved employee health
A power & free handling system ensures easy and trouble-free transport of the work pieces. At the load/unload station the height of the work piece carrier can be adjusted to the height of the respective operator, thus allowing ergonomic and comfortable working conditions. Moreover, generously laid-out buffer sections in the transport system permit continuous operation, even during breaks and rest periods. To ensure absolute safety of the personnel, all hazardous areas around the shot blast machine are equipped with safety mats instead of the usual sensors and enclosures.