Page 14 - MetalForming October 2010

TechUpdate A New Standard in Flow-Forming Technology
Germany’s Leifeld Metal Spinning GmbH has reportedly developed the world’s largest flow-forming machine for Anji Precision Pipe Manufacture Co., Sichuan, China. Leifeld machines, dis- tributed in the United States by Inter- national Technologies, Inc., Schaum- burg, IL, allow tube forming in forward flow forming to 9 m, and in reverse flow forming to 13 m. Its machine for Anji can process pipe from 60- to 650-mm dia., and a maximum tube weight of 4 tons. Production capacity exceeds 2 tubes/hr.; feed rate peaks at 15 m/min.
The new ST 650 H 9100-4RS model can handle wall thicknesses in excess of 30 mm, and can achieve the reduction limit of 90 percent in only one run- over. Leifeld engineers were challenged to develop a new concept for a large-scale flow-forming machine that could be built in only eight months, while main- taining an attractive price/performance
ratio and low entrepreneurial risk. The machine was designed to employ rein- forced modular assemblies so that all of the main components could be used in the construction of smaller machines, with a reduced manufacturing time. Despite a length of nearly 30 m and a weight of almost 200 tons, the machine can be constructed in parts, reducing the procurement time for the large machine bed and frame components, and making it significantly easier to transport.
Due to the high forces and driving powers involved, Leifeld employed an extremely robust frame structure that already had been proven in smaller
machines. The machine bed and cross beam were optimized with regard to stiffness and deflection. The stiffness of the overall machine frame was further increased by prestressing the two ballscrew drives, arranged diagonally with respect to each other and attached to the frame. To date, these have been installed in smaller machines with a length of approximately 6 m, and are employed here for the first time with a length of more than 11 m for the advance feed of the slide and tailstock.
In order to optimize forming capacity, Leifeld relied on a four-roller flow-forming slide. The forces of the roll-feed axes
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12 METALFORMING / OCTOBER 2010
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