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Hydraulic Presses: Better Than Ever

By: Joe Jancsurak

Friday, August 23, 2019
 


Josh Dixon, director of sales and marketing at Beckwood Press Co., answers questions at FABTECH Chicago.
While hydraulic press technology dates back to 1795 when inventor Joseph Bramah was issued a patent on the first such press, today’s press manufacturers offer a range of options. Hydraulic press expert Josh Dixon, director of sales and marketing, Beckwood Press Co., St. Louis, MO, shares his thoughts on today’s offerings and what metal formers need to consider when making their buying decisions.

MetalForming: When it comes to hydraulic-press technology, where are we seeing the greatest advancements?

Dixon: On the hardware side, continuous advancement in high-performance valves and feedback devices provide increasingly higher levels of force, positional accuracy and repeatability than a decade ago. The biggest advancements, however, are in software, sensors and controls.

MetalForming: How are these advancements improving hydraulic-press capabilities?

Dixon: The built-in intelligence afforded by advanced sensing and software developments enables the monitoring of nearly any parameter including press speed, pump efficiency, oil temperature, platen temperature, force and positional accuracy, and overall press performance over time.


Data acquisition systems measure and record key data points to monitor press health and performance and notify operators of require maintenance.
MetalForming: How are these data being used?

Dixon: Most significantly, we see that when combining the data points with software algorithms, this information tells the user when specific components will require attention. We rely on our electronics suppliers, Allen Bradley and Siemens, and our hydraulic suppliers, Parker-Hannifin and Rexroth, to provide us with high-quality components that are compatible with monitoring and reporting systems. These built-in intelligence systems meet the predictive-maintenance needs of metal formers.

MetalForming: How have these improved predictive-maintenance capabilities impacted overall equipment effectiveness?

Dixon: Our job as press builders is to eliminate downtime for our customers. Ten years ago, manufacturers commonly kept an array of spare parts and a highly skilled maintenance crew on-hand in anticipation of unplanned downtime. Today, we emphasize early detection and notification in order to maintain uptime.

MetalForming: What options are available to a metal former wanting to add machine intelligence to an existing press?

Dixon: The options for retrofitting machine intelligence into an existing press largely depend on the press’ configuration. If the majority of the machine's components are up-to-date, it is feasible to add machine intelligence with very few hardware modifications, focusing primarily on software. Older machines may require replacement of the entire hydraulic and/or control system to accommodate current software requirements. Either way, in most cases it is possible to achieve machine intelligence identical to that found on a new press.

MetalForming: What other after-market features increase throughput?

Dixon: Aside from machine intelligence/monitoring used to eliminate unplanned downtime, hydraulic- and control-system retrofits can increase productivity. Hydraulic systems can be reconfigured or replaced to increase machine speed while, in many cases, still using the existing frame, cylinders and controls. By combining hydraulic and electrical rebuilds, older, inaccurate machines can achieve modern force and positional-accuracy tolerances with built-in go/no-go functionality, reducing scrap and ensuring that every finished part meets the required specifications.


A 75-ton hydraulic press used to hot form titanium aerospace parts.
MetalForming: What advantages do hydraulic presses offer over other equipment options?

Dixon: Versatility and, in some cases, cost. We have the ability to customize nearly every aspect of a hydraulic press—bed size, tonnage, speed, daylight, stroke and more. For applications such as titanium hot forming, this is especially important because the speed at which titanium is formed directly impacts the finished part. The upfront cost, typically less than that of a standard servo-mechanical press, also is enticing.

MetalForming: You mentioned hot stamping and hot forming…what is the difference?

Dixon: During hot stamping, the workpiece—typically steel or aluminum—heats up to in excess of 1000 F in a furnace, automatically transfer into a press, and then is formed/ quenched in the die to increase the part’s overall strength. This process, most commonly used in the automotive industry, requires the use of a higher-speed press in order to make contact with the preheated workpiece before it cools.

When hot forming, to make the material more malleable and reduce spring back after the part cools, the press, mated tooling and blank material heat to in excess of 1300 F inside of the press. Hot forming presses, most commonly used in the aerospace industry to form titanium and other high-strength alloys, travel much slower than hot stamping presses. Because no quenching occurs, the overall microstructure of the material does not change.

MetalForming: Are hydraulic presses for hot stamping or hot forming designed differently due to the heat generated by the process?

Dixon: To protect the press’ structure from heat generated during the titanium hot forming process, hot forming presses typically feature 6- to 8-in.-thick ceramic insulation between the platens and cylinders as well as a water-chilled platen to dissipate the heat before it reaches the cylinder rods. Automated, insulated doors create a tight seal to efficiently contain the heat within the forming area and increase energy efficiency. Additionally, fire-retardant fluid is used in lieu of regular hydraulic fluid, fire sleeves protect hoses in certain areas, heat shields direct heat away from electrical components and air conditioning units cool the electrical cabinets. Everything ratchets up with high-heat applications. Heat transfer into the press frame and components is less of a concern in automotive hot stamping because typically, the part heats outside of the press and quenching occurs inside of the die.


A 450-ton hydraulic deep draw press with dynamic bed cushion.
MetalForming: Besides hot forming, what other applications are well suited for hydraulic presses?

Dixon: Draw forming highlights the versatility of a hydraulic press. During a deep draw cycle, a stationary punch typically mounts on the press bed, with the blank material placed on a draw ring supported by the bed cushion. When the upper tool contacts the blank, the cushion, forced downward, forms the material over the punch. Press features such as Beckwood’s Dynamic Cushion Control allow for cushion tonnage adjustments throughout the entire draw process, giving the operator complete control over material flow to eliminate wrinkling and tearing. The ability to generate full force at any point throughout the stroke on both the main ram and the draw cushion gives hydraulic presses an advantage. Because mechanical presses only generate full tonnage at the bottom of the stroke, they are not ideal for this type of application.

MetalForming: What advice can you offer to metal formers seeking new production equipment?

Dixon: Application requirements often are the determining factor in machinery selection. For example, if a coil-fed application requires an output rate of 60 strokes/min. and the bed size and tonnage fit within the range for a standard mechanical or servo press, they may offer the best option. If not, a customized hydraulic press may be ideal. The end user must analyze application requirements for speed, force and positional accuracy before choosing a press.

With so much new technology, these are great but confusing times for companies considering press options. Discuss your application and production goals with several OEMs and choose the one that can tailor a solution to meet your exact needs. Try to consider not only what you need to satisfy current production requirements, but also what may be needed a few years down the road. Often, building ‘future-proofing’ features into a new machine up front, rather than trying to retrofit the same machine a few years later, saves money and time. MF

 

See also: Beckwood Press Company

Related Enterprise Zones: Presses


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