Page 20 - MetalForming August 2015

Hydraulic Presses:
Control Technology Irons Out Pressing
Issues
Mismatched die halves were a disaster in waiting, and manual job setup lacked consistency from run to run. Control additions provided the necessary solutions.
BY THOMAS M. LAVOIE
Control upgrades, such as those performed on this 75-ton hydraulic press, can ensure proper die selection and proper job settings.
Application of control technology can help presses perform opti- mally, and provide solutions to vexing problems that often lead to catastrophes. Such was the case for this hydraulic-press user.
The metalformer, using a Greenerd C-frame hydraulic press with adjustable tonnage from 15 to 75 tons, needed to solve a couple of issues. The manufac- turer sought a way to prevent setup personnel from using the wrong upper- and lower-die combinations, as numer- ous tools for producing medical devices are similar in design and all use the same-sized die sets.
Another concern: The press required the exact same setup for each and every run of the same product. Manual setup made repeatability difficult, with exces-
Thomas M. Lavoie is applications engi- neering manager at Greenerd Press & Machine Co., Inc., Nashua, NH; www.greenerd.com.
sive time spent to ensure proper set- tings for each job.
It should be noted that the press’ speed is adjustable from 0.2 to 36 in./min., and features a 35-ton-capac- ity hydraulic knockout mounted in the end of the main ram along with a 20- ton-capacity cushion under the bed of the press. An Allen-Bradley Versa View industrial computer with data-logging capability provides touchscreen con- trol, and the press’ oil tank is equipped with a heater to ensure that oil tem- perature remain constant, allowing for repeatable pressure control.
Radio-Frequency
Tags Identify Die Halves
On several occasions, operators or setup personnel at this metalforming operation would grab the wrong upper- and lower-die combinations to produce a particular part. Not until the first part was made would personnel realize that the upper and lower tooling did not
A control upgrade allows a metalformer to adjust, store and recall settings, avoid- ing the hazards and time costs related to manual setup.
belong together. In some cases, this caused irreparable damage to the tooling, which then required rebuild or repair, and delayed part production. An addi- tional complication: The metalformer used heated dies to aid in forming parts from titanium, so any identifier for indi- vidual tools had to withstand tempera- tures of several hundred degrees.
Greenerd worked closely with the manufacturer to understand specific tooling issues, and ultimately, both par- ties agreed that the die halves would be identified with RFID (radio frequency identification) tags, which can withstand
18 MetalForming/August 2015
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