Page 32 - MetalForming August 2013

Servo Presses—Why Pay More?
the ability to stop, reverse direction and then stop-reverse again. So, we can restrike the same part two or more times all in one bending station. Also, because of the increased tool life, stam- pers may be able to use less expensive tool steels or coatings while maintain- ing an acceptable balance of speed and tool life.
At the same time that tooling cost can be reduced, part quality can improve. The servo press’s ability to reduce heat generation during forming will reduce workhardening of the part. This allows forming and drawing oper- ations to achieve greater dimensional accuracy and consistency. Hot parts not only workharden as they cool, they also can change dimensionally. There- fore less heating equals more accurate parts.
As noted above, by reversing the ram travel we can restrike a part in one die station. This immediate restrike does not allow the part to cool and workharden, so the restrike has greater
effect than if it were done in a later die station. This ability to restrike in one station also, again, minimizes the num- ber of required die stations.
The Benefits Keep on Coming
Elimination of secondary opera- tions: Because of the ability to slow and even pause momentarily without losing energy, operations such as hard- ware insertion and in-die tapping and welding can be added to the automat- ic production cycle. This can remove the need for what were traditionally manual secondary operations, often resulting in a tremendous reduction in piece-part price.
Reduced die development/debug time: Some servo presses can move in tiny increments during setup, or at least stroke at an extremely low rate. This step-feed capability reduces greatly the time required to check timing and debug new tools. As a result, lead time and associated costs from order to first production date can be minimized,
especially with very complex tools.
Stamping exotic difficult-to-form materials: The formability of very hard materials such as stainless and high- strength low-alloy steel is greatly increased using a servo press. These materials are very sensitive to impact velocity and forming speed, exhibit a great deal of springback, and often workharden more readily than softer materials. All of these complexities are easier to deal with in a servo press.
So Who Wins the Race?
The winning stamper (or race-car driver) that brakes late into the curves, accelerates early out of them, opti- mizes speed at every part of the race and leverages every edge allowed by the new rules will win the productivity race. No one would say the racecar drivers from the 1980s were not tal- ented or fearless. But if they were rac- ing with old technology and playing by old rules, they would not be very competitive today. MF
COE Code
Article #7: Boost Our Customer’s Productivity
At COE, we make it happen.
Our solutions are designed to improve throughput, allowing you to produce more parts while retaining world-class levels of quality. With COE, you get proven designs manufactured with attention to detail, all backed by the COE 24/7/365 service advantage.
The COE Code...putting the focus on you and your coil processing needs.
Complete lines, feeds, straighteners, reels, servo upgrades and more.
Serving automotive metalformers for 35+ years
Scan the QR Code to see our COE Code video.
COE Press Equipment
+1 (586) 979-4400 | info@cpec.com | www.cpec.com
30 MetalForming/August 2013
www.metalformingmagazine.com