Page 23 - MetalForming November 2012

Even controls equipped with fewer die-protection inputs include valuable features. For example, the circular press- stroke chart shown here illustrates, in blue, where in the stroke the sensor needs to transition; the black shading shows in real time the actual points in the last stroke where the sensor switched on and off. This type of interface makes it easy for operators to see what is happening, and to prop- erly program the unit.
sought controls that could be easily under- stood on the shop floor, and that were scalable as needs change.
“We run a variety of work with secondary and progressive-tool- ing operations,” Mey- ers notes. “Some hand- fed dies require only a few sensors, while other progressive dies running complex parts require much greater capacity, 16 or more die- protection chan- nels. One size would not fit all.”
the five critical presses it had identified early in the process. Smaller presses received controls with less process- control capabilities, and the straight- sides received controls with more capacity for die protection and automation, such as automatic shut height. Being able to select the level of process control helped match capac- ity to need, and contain costs.
Also important to Meyers was the long-term support offered by Link. “Link sales manager Lance Curtis assured me that the company main- tains circuit-board production inhouse,” Meyers shares. “They can produce boards ‘one-off’ if necessary, even for models that ceased production long ago. I understand that Link still sup- ports products introduced into the field in the 1970s.”
“All of the new controls at D & H offer strong diagnostic features,” says Meyers, “with fault histories. And, the user interface maintains a similar struc- ture in the higher-capacity and the simpler versions, so operators can switch from simple to complex press lines without confusion,” he adds.
The results were immediate, and noticeable. “Not only did the new con- trols eliminate the risk of unplanned downtime due to old, unsupported controls failing, but we also gained technology that added to our capabil-
trols on a need basis. They immedi- ately deemed five presses as “extreme- ly critical to on-time delivery of prod- uct,” and these were slated for immediate upgrades. The team then developed an upgrade schedule for the remaining presses with unsupported controls.
“Engineering, production and main- tenance created a list of the control specifications we wanted, and then began investigating vendors to see what best met our needs,” says Meyers. Among the needs to be addressed: a new die-sensor program being imple- mented, which topped the wish list for the new controls. “The new controls needed to be ready to support our in- die sensing program, and provide tech- nology that would help us maintain low overhead, consistent part quality and on-time delivery,” stresses Mey- ers.
Support for Technology in the Tooling
D & H wanted every new control to have die-sensing inputs, programma- ble-limit-switch (PLS) outputs and ton- nage monitoring available. Many of its old press controls did not have any integrated process controls at all, which limited the firm’s ability to implement electronics to prevent crashes, reduce setup times and improve part quality. Additionally, Meyers and his team
Having sensors, PLS and tonnage settings stored as part of a job recipe was a must for the new controls. For its busiest straightside lines, D & H also wanted the ability to add setup-reduc- tion features, such as automatic shut height, as part of job recipes. Meyers estimated that the ability to store pro- grams and recall previously prepared setups would shave 10 min. per setup.
Meyers also knew that new controls meant the opportunity to take advan- tage of self-diagnostic capabilities. “Greatly improved diagnostics were considered a ‘must-have’ feature for any new control coming into the plant,” he says. With the
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MetalForming/November 2012 21
plant’s older controls, any press downtime events would require the attention of an expe- rienced electrician. And with the addition of 14 new presses, possible production delays caused by prolonged troubleshooting mis- sions were not accept- able.
Immediate, Noticeable Results
D&Hnowhaspur- chased and installed new controls (from Link Sys- tems, Nashville, TN) on
Control diagnostics provide detailed information describing every press stoppage. Shown here is a stoppage triggered by the tonnage monitor. Note that the operator also can see the press stroke rate when the press stopped, and exactly when the fault occurred.