AIA: Workstations, Track System Smooth Assembly
Faced with increased demand for its switch-cabinet cooling units, heat exchangers, heaters and filter fans, Pfannenberg GMbH (Hamburg, Germany) had no choice but to take stock of its assembly processes in an effort to weed out inefficiencies. In doing so, it discovered a number of problems, including poorly structured processes, inadequate workstation ergonomics and insufficient facilities for deploying extra personnel to meet peak demand.
"We had to produce more, yet had no extra reserves to do so," says Pfannenberg process engineer Frank Sauer. "The system...was too complicated in structure, not accurate enough and, in terms of ergonomics, was no longer up-to-date with present-day requirements."
Part of the solution involved constructing a series of linked manual workstations using standard components from Bosch Rexroth Corp. (Buchanan, MI), including the EcoFlow pallet transfer system, part of Bosch Rexroth's Manual Production System (MPS) range. Built to handle cooling units weighing more than 150 pounds and measuring 6 feet high, work tables now accommodate workpiece pallets that can be easily turned with the help of recessed ball rollers, making it possible to mount parts on either side. According to Sauer, this change alone made a big difference. Previously operators had to lift each workpiece to turn it.
The line also includes a pair of vertically adjustable tables that help operators secure each cooling unit in place. Whereas previously each unit had to be set up with the help of a crane, employees can now lower an adjustable table and let the cooling unit slide down onto the pallet, saving both effort and time.
Problems of quite a different type were created by the height of the cooling units. Components that had to be mounted down low literally forced employees to their knees; attaching components to the top of the larger units would often require a ladder.
Now, working in such awkward positions is a thing of the past-the new workstations include an adjustable platform off to one side, so assembly operations can be carried out either standing or sitting down.
In addition to these ergonomic features, the line includes improved lighting, shelves and containers for parts, and display boards with information on the work being performed at each station. All these components are secured using standardized aluminum framing, which serves as the foundation of the line.
As part of the material-transfer system, rollers, transverse supports, leg sets and other components are all inserted into the grooves of the EcoFlow framing profile. The rollers are clipped into a 300-millimeter-long roller carrier at 50-millimeter intervals. Plastic guide clips keep the rollers in position, and plastic corners on the pallets act as spacers to prevent employees from catching their fingers.
"There are a great many advantages compared with our former assembly line," Sauer says. "The workplaces are better illuminated. We have created more working room for the employees, and today we have brought the work sequences under far better control."
In addition, because it is constructed using standardized parts, the line is easy to modify or enlarge. During the latter part of the project planning phase, increasing production figures required that the line include a second testing station. According to Sauer, making that kind of last-minute modification would have been impossible with his company's previous system. But using Borsch Rexroth's standardized components, it was a snap.
"Extending this line...involved no difficulties at all," Sauer says. "The uniform concept with coordinated and optimally matched components made it possible to install an outfeed section and integrate another test station into the line in a matter of no time."
For more on workstations and workstation components, visit www.boschrexroth-us.com, call 800-REXROTH or eInquiry 4.