IJAT Vol.9 No.2 pp. 184-192
doi: 10.20965/ijat.2015.p0184


Back-Pressure Forging Using a Servo Die Cushion

Kiichiro Kawamoto*, Takeshi Yoneyama**, and Masato Okada**

*Advanced Processing Group, Komatsu Industries Corp.
1-1 Ono-machi-shinmachi, Kanazawa, Ishikawa 920-0225, Japan

**Institute of Science and Engineering, Kanazawa University
Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan

October 22, 2014
January 14, 2015
March 5, 2015
forging, back pressure, servo press, servo die cushion
The application of a servo die cushion to the back-pressure forging process improves the shape accuracy of forged parts. Servo die cushions have excellent performance in precise motion control and high responsiveness to set loads. To use a servo die cushion to obtain these features, back pressure is applied to the bottom outer punch during forward extrusion-type forging. Without back pressure, material flow delay around the central counter punch corner results in an unfilled corner at the bottom outer punch. Applying back pressure to the outer punch reduces the area of the unfilled corner. However, extensive back pressure at the beginning of the forming process causes burrs at the bottom because of the clearance between the counter punch and the outer punch; variable back-pressure settings along the punch stroke effectively remove burrs while also providing a smaller unfilled area by allowing for low back pressure at the beginning of the forming process and high back pressure during the forming process. Furthermore, using the flexible slide motion of the servo press to vary the punch motion leads to even further reduction in the unfilled area.
Cite this article as:
K. Kawamoto, T. Yoneyama, and M. Okada, “Back-Pressure Forging Using a Servo Die Cushion,” Int. J. Automation Technol., Vol.9 No.2, pp. 184-192, 2015.
Data files:
  1. [1] T. Altan and A. Groseclose, “Servo-drive presses-recent developments,” Umformtechnisches Kolloqium Darmstadt 10, 2009.
  2. [2] K. Osakada, K. Mori, T. Altan, and P. Groche, “Mechanical servo press technology for metal forming,” CIRP Annals-Manufacturing Technology, Vol.60, pp. 651-672, 2011.
  3. [3] K. Mori, K. Akita, and Y. Abe, “Springback behaviour in bending of ultra-high-strength steel sheets using CNC servo press,” Int. J. Mach. Tool Manu., Vol.47, pp. 321-325, 2007.
  4. [4] P. Kaewtatip, N. Prasitkhan, A. Khantachawana, V. Premanond, R. Paisarn, B. Sresomrerng, and N. Koga, “Bendability and forming behavior of high strength steel in U bending operation,” Proc. 9th Int. Conf. Tech. Plasticity, pp. 171-172, 2008.
  5. [5] T. Suganuma, “Application of servo press to sheet metal forming,” J. Jpn Soc. Tech. Plasticity, Vol.49 pp. 118-122, 2008.
  6. [6] H. Ando and H. Kinoshita, “Trends of servo, Driven Press and Application to Forging,” Press Working, Vol.40, pp. 22-25, 2002.
  7. [7] Y. Hata, J. Matsumoto, H. Sakurai, and S. Tamura, “Introducing AC servo press H1F series machines (High-speed version of dedicated servo press controller SIT),” Komatsu Technical Report, Vol.53, pp. 44-51, 2007.
  8. [8] H. Taoka, H. Nobuta, H. Meguri, and Y. Kageyama, “Optimization of Motion Control in High-Speed Servo Press Line,” Int. J. Automation Technology, Vol.4, No.5, pp. 439-445, 2010.
  9. [9] S. Yossifon, D. Messerly, E. Kropp, R. Shivpuri, and T. Altan, “A servo-motor driven multi-action press for sheet metal forming,” Int. J. Mach. Tool Manu., Vol.31, pp. 345-359, 1991.
  10. [10] K. Manabe, H. Hamano, and H. Nishimura, “A new variable blank holding force method in deep-drawing of sheet materials,” J. Jpn Soc. Tech. Plasticity, Vol.29, pp. 740-747, 1988.
  11. [11] K. Osakada, C.C. Wang, and K. Mori, “Controlled FEM simulation for determining history of blank holding force in deep drawing,” CIRP Annals-Manufacturing Technology, Vol.44, pp. 243-246, 1995.
  12. [12] K. Lange, Handbook of Metal Forming, first ed., McGraw-Hill, New York, 1985.
  13. [13] M. Milutinovi’c, D. Viloti’c, and D. Movrin, “Precision forging: Tool concepts and process design,” J. Tech. Plasticity, Vol.33, pp. 72-89, 2008.
  14. [14] K. Osakada, X. Wang, and S. Hanami, “Precision forging process with axially driven container,” J. Mater. Process. Tech., Vol.71, pp. 105-112, 1997.
  15. [15] K. Osakada, R. Matsumoto, M. Otsu, and S. Hanami, “Precision extrusion methods with double axis servo-press using counter pressure,” CIRP Annals-Manufacturing Technology, Vol.54, pp. 245-248, 2005.
  16. [16] N. Asakawa and H. Tanaka, “Development of Forging-Type Rapid Prototyping System (Tool Path Generation Considering Deformation Process),” Int. J. Automation Technology, Vol.4, No.6, pp. 530-535, 2010.
  17. [17] K. Takasugi, H. Tanaka, M. Jono, and N. Asakawa, “Development of a Forging Type Rapid Prototyping System (Relationship Between Hammaring Direction and Product Shape),” Int. J. Automation Technology, Vol.6, No.1, pp. 38-45, 2012.
  18. [18] H. Tanaka, S. Naka, and N. Asakawa, “Development of CAM Systme Using Linear Servo Motor to Automate Metal Hammaring – A Study on Forging-Type Rapid Prototyping System –,” Int. J. Automation Technology, Vol.6, No.5, pp. 604-610, 2012.
  19. [19] H. Yoshimura and K. Tanaka, “Precision forging of aluminum and steel,” J. Mater. Process. Tech., Vol.98, pp. 196-204, 2000.
  20. [20] S. Hanami, R. Matsumoto, M. Otsu, K. Osakada, and D. Hayashida, “Combined forward-backward extrusion with controlled reversal ram motion-Effect of reversal ram motion,” Proc. 8th Asian Symp. on Precision Forging, pp. 162-166, 2003.
  21. [21] K. Osakada, S. Hanami, and N. Arai, “Deformation mode in extrusion against counter pressure-Extrusion against floating tool supported by pressure I,” J. Jpn Soc. Tech. Plasticity, Vol.41, pp. 1026-1030, 2000.
  22. [22] R. Matsumoto, T. Kubo, and K. Osakada, “Improvement of forgeability of a commercial AZ31B magnesium alloy in cold backward extrusion with counter pressure,” Mater. T., Vol.49, pp. 1000-1005, 2008.
  23. [23] H. Ando, “Forging using servo press,” Press Working, Vol.47, pp. 27-31, 2009.
  24. [24] M. Otsu, D. Hayashida, K. Osakada, and S. Hanami, “Combined forward-backward extrusion with reverse ram motion – Application of gear,” Proc. 8th Asian Symposium on Precision Forging, pp. 158-161, 2003.
  25. [25] [accessed on September 26, 2014]
  26. [26] S. Kitayama, S. Hamano, K. Yamazaki, T. Kubo, H. Nishikawa, and H. Kinoshita, “The Square Cup Deep Drawing by Variable Blank Holder Force,” Trans. of JSME (C), Vol.76, Issue 766, pp. 1617-1626, Jun. 2010.

*This site is desgined based on HTML5 and CSS3 for modern browsers, e.g. Chrome, Firefox, Safari, Edge, Opera.

Last updated on Jun. 19, 2024