【正文】 Research Center for Net Shape and Die Manufacturing (ERC/NSDM), which is financed jointly by the Korean Science and Engineering Foundation (KOSEF)References Chen X. and Sowerby R., 1996, Blank Development and the Prediction of Earing in Cup Drawing, International Journal of Mechanical Science, Vol. 8, , pp. 509516. Date . and Padmanabhan ., 1992, On the Prediction of the Forming Limit Diagram of Sheet Metals, International Journal of Mechanical Science, Vol. 34, , pp. 363374. Hrivnak A. and Sobotova L.,1992, The Influence of the Deformation Aging and the Conditions of Stress on the Properties of the Deep Drawing Steel Sheet, Journal of Materials Processing Technology, Vol. 34, pp. 425430.Johnson W. and Mellor .,1983 Engineering Plasticity, 2nd Ed., Ellis Horwood, Camelot Press, UK. Kawai N. et al., 1992,Friction Behavior in the Cup Ironing Process of Aluminum Sheets., Journal of Engineering for Industry, Vol. 114, ., 1997, Prediction of the Limiting Drawing Ratio and the Maximum Drawing Load in CupDrawing, International Journal of Machine Tools and Manufacture, Vol. 37, , pp. 201213. Lange K., 1985, Handbook of Metal Forming, McGrawHill, New York, pp. 2022. Roger P., 1991, Sheet Metal Forming, Adam Hilger, New York, pp. 181242. Thiruvarudehelvan S. and Loh ., 1993, Drawing of Cylindrical and Hemispherical Cups using an Improved Tooling for FrictionActuated Blank Holding, Journal of Materials Processing Technology, Vol. 37, pp. 267280. Thomas . and Dadras Jr. P., 1981, Modeling of Sheet Forming ProcessesAn Overview, Wright State Univ., Dayton, Ohio, pp. 122. Yossifon S. and Tisosh J., 1991, On the Dimensional Accuracy of Deep Drawing Products by Hydroforming Processes,” International Journal of Mechanical Science, Vol. 33, , pp. 279295.12在拉深件內使用空氣壓提高鋁板的拉深極限比Young Hoon Moon*t, Yong Kee Kang, Jin Wook Park, Sung Rak Gong凈成形與模具制造工程研究中心釜山國立大學該研究主要是通過研究使用空氣壓對拉深的影響來提高鋁板的拉深能力，傳統的拉深過程是局限在某一個極限拉深比（LDR的）過后，將出現拉裂。 to the radius does not significantly affect the limiting drawing ratio(LOR). Therefore, according to the thickness of the blank, the most suitable shoulder radii for the dies and punches were selected to be 6mm with a constant punch diameter of . Test procedureA proper drawing speed is important for the deep drawing process: excessive speeds can cause wrinkling or fracture in the formed part and damage of the tooling: while insufficient speeds reduce the rate of production. In this investigation a drawing speed of 4 mm/sec is found to be the most suitable speed. The blank holder force is chosen to be the minimum force required to prevent wrinkling of the largest blank and is found to be 350kgf. An operation sequence is arranged for the tests and the punch forces are measured simultaneously as function of test variables. The airpressure is applied until the load reaches the maximum load because the airpressing after reaching the maximum load no longer affect better deep drawability. Each test is repeated two or three times, average values being obtained. All experiments were carried out by the cupdrawing operation shown in Fig. 3 and experimental variables applied in this study are described in Table 2. Press oil, mercial grade high pressure hydraulic oil, is brushed on to the blank before forming to diminish the friction at the contact interface. The effectiveness of the airpressing was judged by LOR that is determined by the maximum size of blank that could be formed into a cup, since the blank size determines the maximum cup depth, and can be measured more accurately.3. Results and Discussion To investigate the effect of air pressing on the deep drawability, the LOR is obtained at each process condition. For the calculation of LOR, the maximum blank diameter, this diameter being that below which the blanks will