Page 32 - MetalForming August 2015

Servo-Press Technology
This tool, outside of the press, shows a number of air cylinders and electronic components. The simple tool in use at E.J. Ajax has been trans-
formed into a machine with logic, all made possible due to a
new servo press’ programmable motion and its controls-
programmable outputs and inputs.
century,” says Djubek. “We
need to move quickly into the best technologies and have our team take advantage of all that they can bring to us to ensure that we remain the best choice for our customers.”
In the past two years, these invest- ments have included a fiber-laser cutting machine, a new CNC turret press and stamping-press equipment with the lat- est direct-drive servo technology.
“We had investigated servo-press technology for some time and the pos- sibilities seemed exciting,” says Erick Ajax. “When we had to increase press- room capacity it became clear that our investment strategy had to include servo technology to keep us ahead. There were specific applications iden- tified where the servo would bring sig- nificant advantages.”
Tom Ajax identified those applica- tions.
“These were difficult parts we already made,” he says, “including drawn parts and those formed from stainless steels and other difficult-to- form material.”
In the fall of 2014 Ajax took delivery of its first 200-ton servo press, an Aida gap-frame model, followed by a second Aida 200-ton gap-frame.
Training started immediately, first with a nearly companywide meeting of operators, setup people, tool design- ers, and outside sales and sales man- agement personnel.
“Everyone needed to know what this new equipment could do in order for us to fully realize the benefits of the press’s abilities,” says Djubek.
Multiple rounds of onsite training were provided by the local Aida dealer, TCR, Inc., Wisconsin Rapids, WI, and by Aida’s engineering staff. The training time was surprisingly short, according
to the Ajax management team, as
the already-skilled operators became quick learners.
“It was exciting to see that just with- in the first week the operators had found ways to improve the perform- ance of our existing tooling,” says Don Wellman, E.J. Ajax vice president of purchasing. “They were buzzing with ideas on how the servo press could make each job run better and were clearly finding immediate applica- tions that showed how much they understood the technology and its impact.”
Adds Djubek: “The press is incredi- bly flexible, improving blanking, form- ing and drawing operations. We use it for hand-fed and progressive work and, because of its flexibility, the machine serves as a backup to many of our other presses.”
The most unusual discovery? The Ajax team found that it could take a tool from its hydraulic press, used for draw- ing, and run it on the new servo presses.
“That tool was actually too tall for the servo press’ standard shut height,” says Djubek. “But, we are actually able to run it in the servo press by pro- gramming its stroke so that it never reaches all the way to bottom dead center.
“We looked at the torque specifica- tions of the press,” Djubek continues, “and found that its direct drive pro- vided a lot of torque very high in the stroke. This allows us to draw a part at just a little less than half of the press’ stroke length. The servo’s ability to achieve full energy at even 1 stroke/min. meant that we can program the best contact and draw speeds for optimum
part quality without fear of stalling.” Not long after the two new-press installations, the Ajax sales team approached the tool-design group with a new part to quote, from 10-gauge Type 316 stainless steel. Slightly more than 6 in. long, the part is very nar- row, less than 1⁄2 in. in places. It also had holes and cutouts paired with a chal- lenging flatness specification. Since Ajax had run similar parts in the past, the team knew where the challenges
would lay.
“Besides the reverse-load issues
associated with blanking stainless, this part also had a shape that lent itself to twisting,” says Djubek. “When form- ing these types of parts in the past, we‘d start with a progressive die and add a secondary operation to flatten the parts. While an effective strategy, it adds labor and also creates work-in- process, with the associated added lead time and carrying costs.”
This time, the team looked to the new servo capabilities to develop a more efficient forming process and reduce costs. It wasn’t disappointed.
“We used the cushion in the servo press to help hold the part flat,” says Wellman, “but the real breakthrough was the press’ ability not only to pause but also to reverse direction.”
Immediately after forming but prior to lifting off the strip, the press’ pro- grammable control switches on an air valve so that the die-mounted air cylin- ders actuate and allow grippers to grab the strip. As the ram lifts the strip the cushion also lifts the part. With the
30 MetalForming/August 2015
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