Page 24 - MetalForming April 2020

22 MetalForming/April 2020
www.metalformingmagazine.com
Contract Stamper Invests in Servo
the coil run.”
Engel runs the bracket in the pen-
dulum mode, resulting in more than double the stroke rate compared to running it on the conventional press.
“In addition to added speed, another key factor contributing to the ROI of the press and its ancillary equipment,” adds Rubin, “as illustrated with this particular part: minimum reverse ton- nage, since we can slow the ram just prior to breakthrough, which benefits tool life. We can run two to three times more parts than we used to before we have to perform maintenance on the tool, and we see this benefit on other tools run on the new press as well. Fur- ther, we used to suffer an inordinate amount of broken punches on this tool, a problem nearly eliminated now.”
All of this adds up to a remarkable improvement in overall run rate on the bracket—from 488 parts/hr. before to 1000 parts/hr. now. Of course, along with such an increase in run rate comes challenges in parts and scrap handling. Here, Engel, with Wenzel’s help, engi- neered a process to automatically stop and start the conveyors with a signal from the press. “Everything is managed from one central control pendant,” says Rubin, “including the coil line.”
Fast, Safe Coil Changes
Speaking of the coil line, the 10,000- lb coil capacity, as well as a new coil car, on the new line also pays measur- able dividends, compared to the 6000- lb.-capacity line it replaced on the aging 300-ton press.
“The higher-capacity coil line (a Coe model rated to 30-in. coil width, and 1⁄4- in. stock to 10 in. wide) obviously means that we’re changing coils less often, improving press uptime,” says Handzel. “Additionally, unique features of the new coil line better-equip it to flatten the higher-strength steel grades. Before, our coil-change team struggled to get the leading edge of each coil flat, often gen- erating a lot of scrap at the start of each new run. Now, the material runs flat from the leading edge of every coil.”
“Coe equips these feeds with soft- ware that allows users to input material
properties for each job,” explains Wen- zel, “and the feed-line control auto- matically calculates straightener-roll settings. This practice has been, until now, a black art for many stampers.”
Engel also is experiencing quicker coil changes with the new line com- pared to the old. One operator safely can change a coil, including thread- up, in 5 to 10 min., “thanks in large part to special features such as stronger holddowns and other safety equip- ment,” says Rubin. “On our other 300- ton press, it takes a team of three oper- ators as long as 30 min. to change and thread coils.”
The coil line even includes an auto- matic greasing system. “No one has excess maintenance capacity these days,” Wenzel says. “By adding the auto- matic lubrication system, we prevent unnecessary wear and tear, and even- tually maintenance, on the coil line. Here at TCR, we repair a lot of feed lines, with much of the damage caused by poor preventive maintenance.”
Infringing on Hydraulic Press Work
Another example of the versatility of the servo press: the ability to perform draw work previously performed only on hydraulic presses.
“We’re developing the process now to deep draw a can on the servo press, from 0.025-in.-thick stainless steel, which currently runs as an eight-step process on a hydraulic press,” says Handzel, noting that the process includes an outsourced annealing step between draws. “We think we can reduce the number of draws from four to three on the servo press, and elimi- nate the need for annealing between draws, which could open up a lot of potential for us, since we manufacture a lot of deep-drawn parts.”
At press time, Handzel expected to be deep drawing the cans on the servo press by the end of April.
...and Tackling Takeover Tools
In addition to moving several exist- ing tools to the servo press, the firm also has brought in several takeover