Page 24 - MetalForming Magazine May 2022

Barcodes in the Pressroom
Quality control further improves with the use of barcode readers. Metal for- mers use barcode readers to scan the tool and the work order to automatically upload new parameters for that part. Scans also can validate the press and die against the work order to ensure the use of the proper press for the job. Process data such as position, temper- ature and time can be logged for every part produced, and an employee’s badge can be scanned to check for permission to operate the press.
New PLCs enable process automa- tion by controlling multiple presses within a line, or by integrating a press with auxiliary equipment. This automa- tion provides consistent control over all press operations. Typical applica- tions include adding roll feeders for advancing sheet metal, rotary-index tables or robotic material handling built into a press line.
Motors and VFDs
Motors are much more efficient today, offering a reduced rotational mass and higher-quality copper with improved winding technology. Pumps also are more efficient, as improved seals and stronger hoses and couplings have virtually eliminated leaks and greatly minimized maintenance. Even hydraulic fluids exhibit increased effec- tiveness due to new additives, promot- ing improved pump performance. Also, state-of-the-art pumps and motors operate more quietly than do their aging counterparts, and they use off- the-shelf replacement parts.
Another development: the use of soft motor starters or variable-frequency drives (VFDs). These devices allow the motor to ramp up to full speed, decreas- ing the inrush current. A hydraulic press with a VFD will start the motor when the press is ready to perform work, and then shut the motor off when platen movement is not required, including during press idle times. This technology can run the motor at slower speeds when the press sits idle, to allow for accumulators to be charged and the oil to be cooled or filtered.
Finally, new options for increased press safety might include adding light- curtain circuits, presence-sensing devices, gates and barriers. Solid-state relays for anti-tiedowns on press but- tons is another consideration.
Pressing for Change
Metal formers ready for a hydraulic- press upgrade should evaluate their goals in relationship to their costs. Among the considerations to evaluate in determin- ing whether a retrofit or entire rebuild will prove most beneficial:
Retrofits/Upgrades
• Upgrade to the current ANSI B11.2- 2013 standards for safety.
• Build in speed control for handling hard-to-form materials and to increase cycle rates.
• Add closed-loop pressure and dis- tance control.
• Improve accuracy and repeatability.
• Integrate automation components (robotics, feeders, etc).
• Add the ease-of-use and accuracy of touchscreen controls with recipe storage.
Rebuilds
Rebuild services replace hydraulic, mechanical and electrical components. If some of the following components are needed, it may be time for a rebuild.
• Replace old, complex piping/valve systems with a single manifold system. • Replace or rebuild pumps and
motors.
• Replace leaky hydraulic pipe-
thread technology with oil ring seals (ORS and SAE).
• Rewire electrical systems.
• Rebuild cylinders.
• Replace worn-out platen guides/
slides.
• Strip down and repaint surfaces. • Replace ram gland rings and seals.
MF
Article provided by Greenerd Press & Machine Co. Inc., Nashua, NH; www.greenerd.com
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