Transfer-Press Quartet Sings a Sweet Song of Success
Ontario is home to two of the three Fleetwood plants: a 220,000-sq.-ft. plant in Tillsonburg, with nine stand-alone presses (600-ton capacity) and three transfer presses; and a 96,500-sq.-ft. plant in Otterville, acquired by the company in 1985, with 24 presses (1000-ton capacity) including a five-press five-robot tandem line. The third plant, and the newest (opened in March 2005), is a 110,000-sq.-ft. facility in Sylacauga, AL, with eight stand-alone presses (800-ton capacity) and a 1500-ton transfer press added in mid-2008.
As a barometer of the company’s growth and evolution into bigger parts and bigger presses, consider that the Tillsonburg plant opened with 30,000 sq. ft. in March 2001. Just three years later the facility expanded by 30,000 sq. ft. to welcome its first two transfer presses, and another 60,000 sq. ft. to make room for an e-coat line.
For the Tillsonburg plant’s first foray into transfer stamping, Fleetwood acquired a pair of transfer presses, the first (commissioned in 2004) a 1500-ton four-point straightside—96-by-256-in. bed size—from Ontario neighbor Eagle Press & Equipment Co., outfitted with a Linear Transfer three-axis servo transfer system. Says vice president and general manager John Clarke, from the company’s corporate sales and engineering office in Windsor: “When we specified that press, we aggressively set out to achieve 20 strokes/min.,compared to the more typical 12 to 15 strokes/min. Our engineers worked with Linear Transfer’s very accommodating engineering team to make it happen.”
As explained by Clark and corporate sales manager Terry Soanes, to allow the transfer press to run 50 percent faster than other transfer systems would have been able to run, Linear modified the cooling system used to prevent drives from overheating. Heavier-duty chillers were added to the control cabinets, and “together, our engineering teams developed a counterbalance system to reduce the working load on the transfer system,” adds Clarke.
The counterbalance, now standard on certain Linear Transfer systems, is used on the lift axes to reduce motor RMS-torque requirements and extend ballscrew service life, which exponentially increases as load decrease. The pneumatic counterbalance-system pressure is monitored electronically and provides a warning for the operator should the system move outside its set points.
Adding flexibility to the new transfer press, Linear designed a high-speed blank-destacking system for one end of the press to allow blank feeding. The design allows for coil-feeding operations from the opposite end, thanks to the ability of the destacker to accommodate part movement through a passthrough tunnel.
Two Transfer Presses, Three Bolsters
The second transfer press installed at Tillsonburg, in mid-2005, is a 2000-ton Eagle, also 96 by 256 in., rated to 22 strokes/min. The added tonnage allows the press to tackle the plant’s toughest task—a rear suspension frame of dual-phase 780 advanced high-strength steel (AHSS). Parts are 3 mm thick, 60 in. long and 20 in. wide, “and it takes every bit of 1600 tons to run that die,” says Clarke.
The two press
“One of the keys to efficient change-overs,” notes Clarke, “is the system we developed to quickly change the transfer tooling from job to job.” The firm purchases transfer tooling from the Pressroom Gripper Series (PGS) manufactured by Norgren (formerly Syron). The tools for each job mount permanently to a subplate. A series of holes drilled into the subplate allow the operator to quickly locate it onto the transfer rails by sliding the holes over permanent dowels attached to the rails.
PGS grippers are available with regular, chisel, flange, shovel and needle-nose jaw configurations, and feature (according to Norgren literature) one-bolt assembly to enable 1-min. reconfiguration. Fleetwood uses Norgren’s flange-jaw grippers when parts require a firm grip; otherwise, it uses its own inhouse-designed and fabricated shovel-style tools.
Transfer Press Number Three
In mid-2006 the plant’s transfer-press lineup grew from duo to trio with the addition of a 1000-ton 84-by-210 in. Eagle press with a 48-in. adjustable pitch. This press is designed to tackle smaller dies that run at up to 30 strokes/min., stamping a variety of parts including sills, rear parcel shelves and flat floor parts.
“We designed this press similarly to the other two (with T-shaped floor rail to accommodate rolling bolsters), to be part of a two-press three-bolster cell,” says Soanes. “So, as our business continues to grow we can readily accommodate another press.”
In all, the plant runs about 70 transfer dies, each of which stays in the press long enough to run one week’s worth of parts. Run time averages three to four shifts to stamp parts for more popular vehicle models, and only half of a shift for lower-volume models.
On to Alabama
Last but not least, in mid-2008 Fleetwood installed its fourth Eagle Press-Linear Transfer system at its facility in Sylacauga, AL. It’s a 1500-ton 96-by-256-in. setup with a transfer system rated to a whopping 60-in. pitch. The press boasts Linear Transfer’s newer transfer-system design.
“The earlier models have a large nose-cone structure on one end,” says Clarke. “The new design drives the feed rails with belts attached right to the rail.”
In addition to the obvious benefit of a smaller footprint (and improved access for feeders, conveyors and fork trucks), the new transfer-system design brings a host of other benefits to the Alabama operation. Say Linear Transfer officials, describing the new design:
“The system is moving less of its own mass, allowing payloads to move at higher speeds.”
The system can drive the rails independently, improving flexibility in die design. For example, the transfer can change grip motion on one rail but not the other. It can run one part up one side of the press, and then back down the other side. Also, this added flexibility can allow a stamper to more easily accept takeover projects. MF
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