Brad KuvinDeep-Draw Sheet Hydroforming
March 29, 2024Comments
In less than a year’s time, the production team at Philadelphia-area Charles Schillinger Co., Bensalem, PA, has developed and run more than 75 jobs for its new deep-draw sheet-hydroforming machine. A full-service metal former, the firm added the new press to its 40,000-sq.-ft. production floor in late-summer 2023. It’s a 10,000-psi Triform model from Beckwood Press, bought to replace a past-its-prime 1968-vintage hydroformer. Per Beckwood literature, Triform deep-draw presses employ a pressurized rubber diaphragm that serves as a universal female die section. As pressure is applied, a punch extends into the diaphragm, which the firm says can form complex geometries to 12-in. dia. in a single cycle.
Charles Schillinger Co., a 95+-yr.-old metal-spinning and deep-draw metal former that also provides metal stamping, CNC machining and welding, hydroforms shapes to 12-in. dia., drawn to a maximum depth of 7 in.
“Hydroforming is 20 to 25% of the metal forming projects we take on,” says company president John F. McGeever, its third-generation owner. He’s in the process of transitioning leadership to his son, John Ryan McGeever, the firm’s manufacturing manager. “The benefits of the newer technology available with the Triform press allow us to reach new levels of productivity and quality, and satisfy customer requirements for ever-tightening lead times.”
The most notable difference between the old and new sheet-hydroforming machines lies in how the machines generate their pressure. Beckwood sales manager Caleb Dixon explains:
“Most older hydroforming machines for sheet forming have been replaced by modernized machines, which have become the cornerstone technology for progressive deep drawing companies, and at job shops such as Schillinger the advantages are numerous. Those older machines used a concept called displacement pressure to deliver forming pressure to the bladder. That technology made it difficult, if not impossible, to use smaller punches on larger machines, because the small punch could not displace enough hydraulic fluid in the chamber to generate adequate forming pressure. That limitation required metal forming companies to operate two or more machines to cover the range of part sizes.
Dixon finds that while hydroforming companies certainly can leverage the advantages provided by new state-of-the-art machines, metal forming job shops that perform deep drawing operations also find use for the technology. “This is particularly true for shops performing low-volume high-mix production … anything under 60,000 parts/yr.,” he says. “The tooling costs for sheet hydroforming—because one of the tools is a pressurized rubber diaphragm that serves as a universal female die—are low, typically 70 to 90% less expensive than a mated die set for use in a deep-draw stamping press.”
“Due to the use of displacement pressure in the older machines, the required pressure is more of a suggestion. On specific parts that require higher pressure early on in the draw, older machines using displacement pressure may not perform well. Having the ability to generate the exact pressure at the exact point needed in the draw allows these newer machines to form parts at lower pressures.”
