Page 21 - MetalForming Magazine August 2022

Press-Line
Part Sensing—
Sooner is Better
The ability to detect blank and part presence, double sheets and more, prior to stamping, is a reliable money and time saver.
BY LOUIS A. KREN, SENIOR EDITOR
“Consider how much it costs to repair a die, replace the tooling or schedule a part sort, and then consider all of the related
downtime.”
That’s Brett Vance, business devel-
opment manager of general metal forming industries for Prime Controls, Kettering, OH. In the September 2020 issue of MetalForming, he explained how double-blank-detection systems can prevent such issues, and at only a small fraction of the cost that accrues from stamping a double blank. “In most cases, the cost of such systems easily would pay for themselves multiple times over when compared to the total cost of just one downtime issue.”
We reached out again to Vance, this time to discuss other methods of sens- ing for part presence and other con- ditions before part material even enters a press and tooling. His quotes above hold just as true here.
“The sooner the better,” Vance says, when commenting on the use of front- of-line and pre-die sensing. “If there’s any trouble or difficulties with mate- rial—whether thickness or orienta- tion—a stamper needs to know that sooner than later. Whether picking a blank off of a stack or feeding a blank or part into a press via robot or trans- fer, this information eliminates the chance for problems to occur down-
stream during stamping.”
Ideal for Transfer, Pick-and-Place
As for applications, while line and part/blank-feed speed can be a con- cern when metal formers assess use of such sensing, oftentimes other line and process components will produce the limiting factor. Consider that these sen- sor technologies are time-tested and battle-hardened in stamping environ- ments, even at dizzying speeds. For its part, Prime Controls has honed its part and blank-detection technology in demanding beverage-can applications, offers Vance, where 700 to more than a thousand can tops can pass through sensors each minute.
As with speed, such sensing works with a variety of line layouts and feed- ing processes, including transfer sys- tems and pick-and-place robots where detection components can be placed as part of end-of-arm tooling (EOAT).
“Direct-placement applications where robots use suction cups to pick blanks directly off of a stack for place- ment in dies are ideal for this technol- ogy,” says Vance. “There’s not much time to catch problems before the material enters the die, so it’s impera- tive to have double-blank detection or part sensing.”
Increased use of cobots, or collab-
orative robots, prove highly compati- ble with this sensing as, Vance reports, weight of the detection mechanisms rarely prevents their use in cobot applications.
“Especially in automotive and appli- ance applications, we see elimination of human interaction in picking and placing parts into a die or onto a con- veyer, which easily can be automated,” he explains. “Just the mundaneness of manual picking and placing can lead to double-picking or incorrect orien- tation of a part when placed manually into a die. Instead, metal formers can install a robot or cobot with EOAT, and sensor probes mounted inline with the suction cups or grippers.”
Integrates with EOAT
Integrators can help install these setups for robots and cobots, or the sensor provider can work with system and tool designers—as does Prime Controls—to design the sensors into the application.
“We can send 3D CAD files and other needed data to an integrator or the metal former that then designs and manufactures the EOAT with the need- ed sensing probes and brackets,” says Vance. “Using our spring-loaded com- pensation brackets, for example, when the suction cups contact the material, the sensing probe will be flush with
18 MetalForming/August 2022
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