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VOL. 2, NO. 2, JANUARY 1982 87
furnaces for aluminum, titanium, and steel, and various other items of equipment for pickling, anodizing, dye pene- trant testing, etc .
The press itself was designed and built along the lines of two 75,000-ton hydraulic presses which have been in ser- vice in the U.S.S.R. for some 50 years. It features a dead— weight of 12,000 tons (excluding hydraulics) and was built on a granite bed 50 feet below plant level over which con- crete was poured to form the press bed. The support struc- ture alone weighs 4,000 tons. The ram motion is generated by five hydraulic cylinders. Press tonnage can be varied from a minimum of 25,000 tons, obtained by using only the four corner cylinders at approximately 5,000 psi hydraulic pressure, up to a maximum of 65,000 tons, obtained by using all five hydraulic cylinders at a pressure of 10,000 psi. When using only four cylinders, the fifth (central) cylinder can either be disconnected or used separately for punching or back-extrusion. Five 700 hp reciprocating pumps each feed 200 gpm at 5,000 psi into four hydraulic accumulators. Each accumulator has a 200 cubic foot capacity. The 10,000 psi hydraulic pressure necessary for the upper limit on forg- ing load is obtained via two intensifiers. Mr. Barbazanges added that the press is used between 25,000 and 40,000 tons two-thirds of the time, with the remaining one—third being in the 40,000 to 65,000 ton range. Current applications quoted included 15 different aluminum parts and eight different steel parts (including one weighing over 200 tons) for the European Airbus, armor plating and other ordnance components, and various parts for industries ranging from petrochemical to nuclear. The total cost of the 65,000—ton hydraulic press: over $25 million.
The other equipment-related talk was by T. Altan of
Battelle-Columbus Laboratories, on the use of innovative designs in multiple-action equipment (presses and tooling) to save raw material and increase precision in forging. Sev— eral such designs were reviewed by Dr. Altan, including:
• The use of a hydraulic cushion for flashless forging to close tolerances, featuring combined forward ex- trusion, backward extrusion, and lateral flow, with pos- sible applications in aluminum, copper, and steel (warm) forging.
A die set in which the upper die is first guided over the OD of the lower die and is subsequently moved in conjunction with the lower die, against the action of a hydraulic or pneumatic cushion, for combined forward and backward extrusion.
Method of forging zero-draft and undercut parts, simi- lar to the method employed by United States aluminum precision forgers (west coast), wherein segmented die pieces are ejected out of the die with the forged part and are reinstated upon retraction of the ejection pin.
Split tooling with knuckle-type arrangement for making undercut parts, such as chain rollers in off-highway
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equipment, in which an ejector knocks out the forged part when the die segments open.
Leaf spring-actuated side punch arrangement, in which the upper die contacts the lower die and pushes the latter against a set of springs. Further movement of the die actuates horizontal side punch movement toward the center of the die to forge indentations in the sides of the workpiece. Retraction of the upper die causes the side punches to retract as well, enabling part removal from the die.