【正文】 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. 1 在拉深件內(nèi)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(xué) 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(tǒng)的拉深過程是局限在某一個(gè)極限拉深比（ LDR 的）過后，將出現(xiàn) 拉裂。 Johnson and Mellor, 1983). To establish the geometry of a part that can be successfully and economically fabricated from a given material, it is essential to know the limit to which the part material can be formed without reaching failure. 3 This forming limit depends, in addition to the shape change and process conditions, on the ability of a material to deform without failure. The 39。 1 Deep Drawing With Internal AirPressing to Increase The Limit Drawing Ratio of Aluminum Sheet Young Hoon Moon*t, Yong Kee Kang, Jin Wook Park, Sung Rak Gong Engineering Research Center for Net Shape and Die Manufacturing, Pusan National University The effects of internal airpressing on deep draw ability are investigated in this study to increase the deep drawability of aluminum sheet. The conventional deep drawing process is limited to a certain limit drawing ratio(LDR) beyond which failure will occur. The intention of this work is to examine the possibilities of relaxing the above limitation through the deep drawing with internal airpressing, aiming towards a process with an increased drawing ratio. The idea which may lead to this goal is the use of special punch that can exert high pressure on the internal surface of deforming sheet during the deep drawing process. Over the ranges of conditions investigated for AI1050, the local strain concentration at punch nose radius area was decreased by internal airpressing of punch, and the deep drawing with internal airpressing was proved to be very effective process for obtaining higher LDR. Keywords: Deep Drawing, Internal AirPressing, Limit Drawing Ratio(LDR), AI1050 1. Introduction Aluminum alloy sheets are inferior in press formability pared to the mild steel sheets. Most of the aluminum alloys have an rvalue(plastic anisotropy value) between and , even though the rvalues for the aluminum alloys are only about half of steel(Roger, 1991), they show, under the right circumstances, quite satisfactory drawing 2 behavior. Among the aluminum alloys some noticeable differences in forming behavior on the stamping shop floor have been observed(Roger, 1991。 Kawai et al., 1992。39。然而，即使對于 r 值鋁合金大約只有鋼的一半（ Roger， 1991），在正常情況下，它們表現(xiàn)出令人滿意的拉深效果。 Yossifon and Tisosh, 1991。 第一 Awhor ?通訊作者， 電子郵箱： 電話： +82515102472 傳真： +82515121722 工程凈成形及模具制造，釜山國立大學(xué)，釜山 609735，韓國研究中心。 由于空氣壓可減少局部應(yīng)變集中，從而延緩了早期失效。在凸模通孔與高壓空氣管連接，通入高壓空氣，在這項(xiàng)中使用最大的空氣壓力為 110MPa。由空氣壓的 影響可以判斷板料最大尺寸可以成形拉深件，因?yàn)榘辶系某叽绱笮Q定了拉深的高度并更加準(zhǔn)確的加以衡量。換句話說， 8 內(nèi)部空氣壓本身并沒有改變變形，而是改變板料成形的變形抗力，有效的疏導(dǎo)了凸模圓角半徑對板料的效應(yīng)和提高了板料的拉深極