Page 14 - MetalForming June 2019

Tooling by Design
By Peter Ulintz
Modern Four-Slide Technology
This month’s article concludes a three-part series on four-slide forming processes. Following arti- cles on slide forming processes (April) and four-slide tooling (May), this month we look at modern four-slide controls and servo-drive technology.
Today hundreds, potentially thou- sands, of traditional mechanical four- slide machines dating back to the 1960s (or earlier) still operate, and tra- ditional slide forming remains an effective process for manufacturing small, intricate parts. Even so, there are limitations.
For example, complex mechanical motions and timing sequences require setup technicians and operators to have more training and higher skill lev- els than necessary for a conventional press. Moreover, the setup process can be very time-consuming as it calls for the following:
• Combination of standard and spe- cial cams to attain the slide stroke and timing necessary for forming the part around the center tool;
• Slide-tooling adjustments to attain part quality, requiring the setup person to advance or retard the timing on the cam;
• Feed-length setting, recognizing
Peter Ulintz has worked in the metal stamping and tool and die industry since 1978. His back- ground includes tool and die making, tool engi- neering, process design, engineering manage- ment and advanced product development. As an educator and technical
presenter, Peter speaks at PMA national seminars, regional roundtables, international conferences, and college and university programs. He also pro- vides onsite training and consultations to the met- alforming industry.
Peter Ulintz
Technical Director, PMA pulintz@pma.org
Modern four-siide forming equipment includes servo-driven systems.
that it may require further adjustment based on the amount of material stretching;
• Press-station adjustment for achieving proper die-shut height, the distance between the bottom of the ram and the top of the press bed or bolster at the full-closed position (e.g. 270-deg. die-shut height for a 180-deg. feed);
• Passing of the wire or strip through the feed mechanism and into the first station of the progressive die, if required;
• Cycling of the machine by hand and engaging the feed when the press is at the full-open position;
• Continued cycling of the machine by jogging or turning the machine by hand, through the die and to the cutoff station, where adjustments are made and lengths of cutoff blanks verified;
• Continued jogging or turning of the machine by hand, going through several cycles of forming to make a few parts; and
• Tooling adjustments (refitting or regrinding may be necessary) to bring parts within tolerance.
The lack of modern controls and servo technologies restrict setup time, part complexity and production effi- ciency when using mechanical slide forming machines.
Although A.H. Nilson Machine Co., U.S. Baird Corp. and Torin Corp., the Big 3 of traditional four-slides no longer exist (see April MetalForming, page 19), several domestic and international machine builders offer modern four- slide forming equipment, including servo-driven systems. When compared to traditional mechanical slide forming, the servo-driven systems provide greater versatility and flexibility to pro- gram slide motions, interchange com- ponents and store part-specific machine programs. Other benefits include reduced setup time, sometimes less than 1 hr. In addition, modern equipment eliminates the need for new cams requiring significant timing
12 MetalForming/June 2019
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