March 11, 2008
Anchoring the March STAMPING Journal® --Press Issue--this multi-source press selection article offers readers advice on the criteria to consider when buying a press. The article examines application suitability, drives, and controls as well as the usual suspects--tonnage, frame construction, speed, and horsepower. This article is likely to be especially helpful to readers attending Metalform in April.
Editor's Note: This article is Part VII of a series covering questions and answers for those who are in the market for a press or press system.Part I, speed; Part IIcovers tonnage; Part III, materials; Part IV, part accuracy; Part V, best for operation; Part VI, best for part; Part VIII, matching automation to press; and Part IX, selecting the right press for your application.
The following questions–and their answers, provided by industry equipment manufacturers and experts–are intended as a general guide to help you simplify the daunting task of selecting a press or press system.
7. What Do I Need in a Press to Accommodate Automation?
Whatever press automation you choose–press-to-press transfer systems, robotic load/unload, destackers, or automated feed systems–certain rules of thumb apply and considerations should be made.
[Caveat]Automation—Pace. Blank feeding, transfer, and press load/unload equipment must be designed to operate at a pace that the press requires."During the part transfer segment of a stroke, the goal is to synchronize the slide movement with the motion of the transfer automation," Kinzyk said.
Automation—Clearance. Presses should have adequate clearances for installing transfer automation, Boerger said."These larger windows allow transfer rails and connections to extend beyond the side of the press."
[Rule of Thumb]"Tool changeover is a daily practice for most companies and efficiency is crucial in terms of production volumes," said Adam Allansson, president, AP&T North America."A press should have adequate clearances for mounting automation front to back or through the side windows, leaving the press bed area free and clear for tool change."
Automation—Interface."When selecting a press, it's important to have additional freely programmable inputs/outputs for external devices such as feed systems, in-die lubrication, or tool monitoring," Allansson said."This provides a common interface and simplifies connections between the equipment. You should also consider how the equipment will be mounted to the press.
"Signal interface between the press and automation system is also an important area to consider," Allansson continued."When adding external equipment such as automation, the press should have an interface that's 'automation ready.'
"The user interface should be intuitive and allow the operator to take advantage of today's technology, but not so difficult it requires a programmer to operate," Allansson pointed out."A graphical interface can reduce the learning curve and provide the operators with a higher level of comfort when programming or changing programs."
Automation—Frame Design."Frame design also plays an important role when considering mounting surfaces. This allows automation systems to be suspended or mounted directly onto the press frame, freeing up valuable floor space," Allansson said.
Automation—Electrical."Many stampers also appreciate an open platform with common electrical components that are locally available," Allansson said."This shortens the lead-time for spare parts and prevents unnecessary downtime due to long lead-times."
Automation—Clutch/Brake."A wet-type hydraulic-actuated, clutch/brake typically is used with press equipment performing single-stroke-type automation, such as in a tandem line," AIDA's Boerger said. An air-actuated clutch/brake is applicable for multistroke applications such as in a progressive-die or transfer press operation, he said.
[Tip]Automation—Servo, Hydraulic. In addition, a servo-mechanical press's and a hydraulic press's capability to dwell facilitates automated material handling, press manufacturers said. A mechanical part extractor can remove the part during the programmed dwell. And the ram can be programmed to dwell long enough to confirm, using sensor technology, that the part has been removed.
Automation—Pneumatic. Airam's pneumatic press construction is usually a rectangular assembly with a relatively low profile and a flat underside, Meyer said."This configuration is suitable for easy integration into automatic processing systems, as it can be mounted in unconventional attitudes, at any angled position—15, 30, 45, or 90 degrees, and so forth— or a totally inverted mounting 180 degrees."
STAMPING Journal® is the only industrial publication dedicated solely to serving the needs of the metal stamping market. In 1987 the American Metal Stamping Association broadened its horizons and renamed itself and its publication, known then as Metal Stamping. Print subscriptions are free to qualified stamping professionals in North America.