Page 37 - MetalForming Magazine August 2022

This large front-of-line blank feeder features a gantry pick-and-place loader to perform blank destacking, along with an integrated blank cleaner/lubricator, a vision system to capture blank orientation, and robots to properly position each blank onto the load table
This can cause the stamper to reduce run rate, in some cases to less than 10 strokes/min., to ensure precise part positioning. Replacing the pneumatic and mechanical elements with servo actuators allows stampers to return their press lines to speeds closer to 20 to 25 strokes/min.”
Speed and productivity gains also come from feeding a press line from two blank stacks rather than one, using two destacking heads. While lines fed with one head typically top out at stroke rates in the mid 20s, Stirrett says, two heads and two blank stacks can push production to as high as 30-plus strokes/min.
“With two stacks and two heads,” he explains, “the heads deplete one stack in a precisely programmed motion profile to maximize feed rate without causing interference or, poten- tially, a collision. When they empty one stack, the heads then can begin feeding from the second blank stack while the empty stack is refilled, so that the press never stops. With only one blank stack, the press must stop and wait for a new blank stack to replace the empty one.”
Double Blanks Need a Home
A key component of every blank-
commodities, especially for larger OEM and Tier One stampers,” Stirrett says, “and come in at a lower cost than a custom-engineered gantry setup. And, the cost of vision systems has dropped as well, becoming very cost competi- tive. There even are cases where we propose the use of vision systems with gantry systems.
“When we know an application will include a destacker,” Stirrett continues, “we look at the geometry around the press—do we have enough room for robotics, because these setups can take up considerably more floor space than a gantry system. We also look at what the customer is most familiar with—if a company has a lot of experience with robotics, such as the OEMs, we tend to stick with that approach. But we also look at speed, and again this is where a custom-engineered gantry setup shines; we can dial these up, based, of course, on press capacity. If the press can only run a job at 16 strokes/min., robotics will suffice, and a gantry will be overkill.”
Blank Feeding 2.0
Asked to comment on what’s new regarding destacking and blank-feed technology, Stirrett turns to the 2.0 ver- sion of destackers: the use of servo drives. With an eye to the retrofit market, Stirrett sees huge opportunities for metal formers to implement servo tech-
nology and upgrade existing equipment, for a fraction of the cost of all-new destacking and blank-feeding systems.
“A stamper might have a 20-yr.-old blank-feed line where the actuators have become shaky over time, having developed mechanical slop,” he says. “There’s often no need to replace the entire system, just those components becoming problematic, which can cause the feed system to more or less throw the blanks into the die rather than gently and accurately place them.
34 MetalForming/August 2022
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This robotic destacking setup features a pair of robots that work together, alternating between blank stacks, and includes an integrated blank washer/lubricator and a vision system to ensure proper blank positioning.