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Bending of Thin-Walled Tubes by Combined External Mechanical Forces and Internal Fluid Pressure

  • C. Boyd
  • F. W. Travist
Chapter

Summary

Results of tests are described on the ‘Z’ bending of thin-walled tubes in brass and stainless steel using a special purpose machine which employs combined mechanical forces and internal fluid pressure. The two right-angled bends produced by the ‘Z’ bending operation are of fairly small radius of curvature (1.5 times tube o.d.) and of closely held circular cross-section. It is demonstrated how the provision of a controlled internal fluid pressure can eliminate wrinkles and buckles in the tube walls and suppress a tendency to the development of an oval cross-section. Photographs and a line diagram of the forming machine are presented, along with photographs of typical formed tubes.

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References

  1. 1.
    Von Karman, T., V.D.I., Forschungsheft 118, Berlin (1912).Google Scholar
  2. 2.
    Maier, A., ‘Einfluss des Spannungszustandes auf das Form änderungsvermögen der rtietallischen Werkstoffe’, Berlin (1935).Google Scholar
  3. 3.
    Bridgeman, P. W., ‘Studies in large plastic flow and fracture’, McGraw-Hill, New York (1952).Google Scholar
  4. 4.
    Bridgeman, P. W., ‘The Physics of high pressure’, G. Bell and Sons, London (1949).Google Scholar
  5. 5.
    Pugh, H. L. D., ‘Recent developments in cold-forming’, Bulleid Memorial Lectures, IIIB (1965).Google Scholar
  6. 6.
    British Patent no. 701, 112.Google Scholar
  7. 7.
    Anon, ‘Hydraulic forming techniques applied to the manufacture of musical instruments’, Machinery, 82 1089 (1953).Google Scholar
  8. 8.
    British Patent no. 808, 809.Google Scholar
  9. 9.
    Anon. ‘Hydraulic forming excels for tubing’, Product Engineering, p. 75, August 15 (1966).Google Scholar
  10. 10.
    Remmerswaal, J. L., and Verkaik, A., ‘Use of compensating forces and stresses in difficult metalforming operations’, Proc. Int. Conf. on Manufacturing Technology, Ann Arbor, Michigan, September (1967).Google Scholar
  11. 11.
    British patent no. 1,029,892.Google Scholar
  12. 12.
    Ogura, T., and Ueda, T., ‘Liquid bulge forming’, Metalworking Production, p. 73, April 24 (1968).Google Scholar
  13. 13.
    Ogura, T., ‘Liquid bulge forming’, Proc. 1st. Int. P.D.M.T. Conf., Glasgow, September (1969).Google Scholar
  14. 14.
    Boyd, C., ‘The design and development of a tube bending machine employing fluid pressure and mechanical forces’, M.Sc. Dissertation, University of Strathclyde, 1970.Google Scholar

Copyright information

© Macmillan Publishers Limited 1972

Authors and Affiliations

  • C. Boyd
    • 1
  • F. W. Travist
    • 2
  1. 1.Now with Munroe and Miller LtdEdinburghUK
  2. 2.Production Engineering DepartmentUniversity of StrathclydeGlasgowUK

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