Page 36 - MetalForming April 2017

Micro Transfer
The Jacar Micro Transfer system operates within a 30 by 45-in. die that runs on a 300- ton Minster mechanical press at 25 strokes/min. An attachment in the upper tool syn- chronizes transfer motion to ram movement. The die contains 12 sensors including part-presence sensors at each die station, and sensors to verify transfer motion, coil feed and part-out.
rails retract. Most of the Jacar systems, says Gunst, run at 15 to 30 strokes/ min.; the Clips & Clamps die runs at 25 strokes/min.
“The solution has worked perfectly,” says Williams. “We were able to avoid a costly carrier strip and secondary operations, and we were able to solidify our relationship with FCA by keeping the job inhouse. And, during the devel- opment of the die we actually improved on the part design, fit and function by specifying additional taper of the inside diameter of the part. This improved the assembly process and improved their function in service on the vehi- cles.”
Sensing, Tolerances and Testing
Always a critical factor when moving parts that reside within a stamping die is proper, reliable sensing, and this die has sensors aplenty. “The die contains 12 sensors,” says Szarek. “It’s the first tool here where we had to use both sides of the control’s channel setup. There are two umbilicals leading out of the die, and part-presence sensors at each die station. We also sense to verify transfer motion, as well as coil feed and part-out.”
Part quality has been exceptional from day one, Williams says. “We don’t even have to deburr the parts coming off of the die,” he says. They are sent directly to the plater.”
Tolerances are tight to accommo- date press-fit assembly—±0.2 mm on OD and 0.5 mm on draw height. The press operator periodically visually inspects parts exiting the tool for burrs, and employs a test gauge to measure part OD and runout. And, with every coil he performs a push-out test in the company’s quality lab, press-fitting the part onto a block and recording the amount of ft.-lb. needed to remove it.
“It’s a tricky die with a lot going on inside,” Williams adds. “While we typically would not make this type of part, the project was an over- whelming success—for us and for our customer.” MF
Six Small Transfer Operations
The plan: implement one of Gunst’s Micro Transfer systems, which he brought to market in 2007 under the company name Jacar Systems LLC, into a coil-fed die developed for Clips & Clamps. The resulting die, at peak producing some 30,000 parts/yr., features a transfer system with a 6- in. pitch, along with 2 in. of in-out travel and 1 in. of lift.
The part is stamped from 0.040-in.- thick mild steel delivered to a 300-ton Minster mechanical press as 3.85-in.- wide strip. The six die
stations create a
3.5-in.-dia.
round blank,
form a 1.5-in.
draw, trim the hat-
shaped part, coin the
edge and add the offset
bead feature.
Gunst’s all-mechanical transfer sys- tem runs directly off of press-ram motion—no electronics or servos. An attachment in the upper tool synchro- nizes transfer motion to ram move- ment—the downsized transfer rails move in as the press opens, then index the part forward as the ram reaches the top of the stroke. As the press clos- es, the transfer systems brings the parts down into their die stations and the
Tolerances are tight to accommodate
press-fit assembly—±0.2 mm on OD and
0.5 mm on draw height. The press operator periodically visually inspects parts exiting the tool for burrs, and employs a test gauge (shown here) to measure part OD and runout.
34 MetalForming/April 2017
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