Page 17 - MetalForming July 2011

150-ton press rating was sufficient, but when the firm brought the work in, early in 2010, it immediately discovered that it needed a new feed line. The feed line fea- tures a roll feed with an adjustable- height mounting bracket, and motor- ized pass-line height adjustment; a threading table designed for 23-in. effec- tive loop length; and a power straight- ener with a 15-HP AC variable-speed drive. The peeler station enables hands- free threading of the heavy-gauge high- strength coil. To minimize downtime for changeovers, the line includes a dou- ble-ended coil reel with powered hold- downs and coil guides. The customer specified the line for strip 6 in. wide by 1⁄4 in. thick; width capacity is 20 in.
Press Availability Soars
As part of the pressline rebuild proj- ect, a primary focus became removing as much setup responsibility from the press operator as possible. Instead, the project team looked to automate press and feed-line changeover tasks, so that the operator need only worry about setting the die and threading the coil. As a result, pressroom’s lean team tapped the brains of the OmniLink con- troller to automate setup functions, and the results are just as impressive as any home make-over you’ve watched on television.
Setup time has dropped, on average, from 2 hr. to as little as 20 min., say cus- tomer representatives, resulting in a 30-percent gain in press availability.
Here’s how they got there:
• Addition of magnetic die clamping (a Quad Stamp system from Techno- magnete), controlled by the OmniLink;
• Use of the press control to manage setup features such as automatic coun- terbalance adjustment, pass-line height adjustment of the servo feed and feed- line parameters such as feed speed, length and acceleration; and
• Tasking the press control with automatically turning on auxiliary devices typically turned on and off by the operator, such as scrap systems and part-out conveyors.
One of the pet peeves of the press- room manager is part conveyors and
To feed thick, high-strength steel coil, the OEM pressroom added this servo-feed line to its newly refurbished press. The line handles strip 6 in. wide by 1⁄4 in. thick; width capaci- ty is 20 in.
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scrap shakers, and how they seem to run all of the time. One of the areas the firm focused on, therefore, during the rebuild process was integrating con- veyors and shakers into the new press control, so that they automatically turn on and off with the press—one less thing for the operator to worry about. At startup as well as during produc- tion, should the control sense five strokes of the press without a shaker cycling, it triggers a press shutdown to avoid slug buildup.
All of this integration, as well as equipment-selection advice, came from TCR Integrated Stamping Sys- tems, Wisconsin Rapids, WI. Says TCR president Todd Wenzel:
“There is a master operator station that is pendant mounted. In it are all of the key controls to run not only the press control, but also the feed line, magnet and other auxiliary devices. All of that was installed on a pendant arm, allowing the operator to position it where best suited. The main control panels are removed from the opera- tor’s way and all electrical wiring cross- es over well above their heads to create a clean workspace.”
Adds the pressroom manager:
“We do not have the resources inter- nally to pull off this kind of project. We rely on outside technical expertise to bring the latest and greatest ideas to us, and my job is simply to decide on what makes the most sense. TCR truly hit a homerun by designing this total pack- age for us.”
Communication Cuts Down on Mistakes
About 40 percent of the rebuilt press’s run time is dedicated to the new low-volume project, running five dif- ferent progressive dies, each with three to five stations. The company is chang- ing the line over at least once per shift, sometimes two or three times per shift.
An additional feature of the control that contributes to speedy, accurate changeovers: The ability to input and display plain-language notes on the control. These notes alert the operator to any special setup requirements.
For example, a couple of parts stamped on the line require particularly long feed progressions—20 to 30 in. When this job runs, a note appears on the control panel to reference the unique feed-line program requires, just to warn the operator to check and make sure the proper feed program has been called up by the controller.
Another enabler of mistake-proof set- ups is the controller’s ability to automate pass-line height adjustment of the feed line. The previous feeder was difficult to adjust. As a result, operators tended to use the same pass-line height regardless of the job. That led to several instances of stock buckling and other issues.
Sixteen Channels of PLSs and Die Protection
Among the OmniLink 5000 control operations selected by the OEM press- room are 16 output channels for pro- grammable limit switches (PLSs). These