scholarly journals Study on micro extra deep drawing process with ultrahigh fluid pressure and press motion controls

2015 ◽  
Vol 21 ◽  
pp. 09016
Author(s):  
Hideki Sato ◽  
Daiki Kondo ◽  
Ken-ichi Manabe ◽  
Kuniyoshi Ito
Author(s):  
S Yossifon ◽  
J Tirosh

The feasibility of replacing the rigid blankholder in the conventional deep drawing process with a ‘soft’ hydrostatic fluid pressure is examined. The recommended fluid pressure range (the ‘working zone’) which guarantees a sound product in different circumstances is presented. The locus curve for possible failure by wrinkling of the flange and the locus curve for possible ductile rupture along the wall provide the lower and the upper limits respectively of the ‘working zone’. These loci are found by a systematic series of deep drawing tests with different constant fluid pressure blankholders for three kinds of materials (copper, aluminium and stainless steel) at various thicknesses and friction conditions. The influence of the friction coefficient, the drawing ratio and the workpiece wall thickness on the blankholder fluid pressure needed to suppress flange wrinkling becomes evident experimentally.


Author(s):  
Majid Fazlollahi ◽  
Mohammad Reza Morovvati ◽  
Bijan Mollaei Dariani

Fabricating flat sandwich sheets into components with a required shape and dimensions is a challenging job in the metal forming field. In this article, hydro-mechanical deep drawing was used for sandwich sheet forming. The aim of the work is to achieve higher drawing ratio of these sheets. Theoretical, numerical and experimental analysis of the hydro-mechanical deep drawing of sandwich sheets was carried out. Separated layers theory method is used for theoretical analysis of the process. Then, the numerical simulation of the process was developed by finite element method. The effect of core layer thickness on the forming force of the sandwich sheet and effective parameters of the process such as strain and forming force was investigated. Experimental works were conducted on the steel/polymer/steel sandwich sheets by a hydro-mechanical deep drawing die. A good agreement was observed between theoretical, numerical and experimental results. The safe zone of fluid pressure for achieving a part without rupture was obtained. It was shown that the limit drawing ratio is increased by increasing the pressure but after a particular point, the limit drawing ratio is decreased by increasing the chamber pressure. It was also observed that maximum drawing ratio for achieving a part without rupture in the hydro-mechanical deep drawing process is higher than conventional deep drawing process.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3993
Author(s):  
Thanh Trung Do ◽  
Pham Son Minh ◽  
Nhan Le

The formability of the drawn part in the deep drawing process depends not only on the material properties, but also on the equipment used, metal flow control and tool parameters. The most common defects can be the thickening, stretching and splitting. However, the optimization of tools including the die and punch parameters leads to a reduction of the defects and improves the quality of the products. In this paper, the formability of the camera cover by aluminum alloy A1050 in the deep drawing process was examined relating to the tool geometry parameters based on numerical and experimental analyses. The results showed that the thickness was the smallest and the stress was the highest at one of the bottom corners where the biaxial stretching was the predominant mode of deformation. The problems of the thickening at the flange area, the stretching at the side wall and the splitting at the bottom corners could be prevented when the tool parameters were optimized that related to the thickness and stress. It was clear that the optimal thickness distribution of the camera cover was obtained by the design of tools with the best values—with the die edge radius 10 times, the pocket radius on the bottom of the die 5 times, and the punch nose radius 2.5 times the sheet thickness. Additionally, the quality of the camera cover was improved with a maximum thinning of 25% experimentally, and it was within the suggested maximum allowable thickness reduction of 45% for various industrial applications after optimizing the tool geometry parameters in the deep drawing process.


Author(s):  
Hamidreza Gharehchahi ◽  
Mohammad Javad Kazemzadeh-Parsi ◽  
Ahmad Afsari ◽  
Mehrdad Mohammadi

1993 ◽  
Vol 115 (2) ◽  
pp. 224-229 ◽  
Author(s):  
K. Yamaguchi ◽  
K. Kanayama ◽  
M. H. Parsa ◽  
N. Takakura

A new deep drawing process of sheet metals is developed to facilitate small-lot production of deep cups with large drawing ratio. In this process, unlike the conventional deep drawing method, a few drawn cups are always stacked on the punch and used as a part of punch for the subsequent deep drawing of a given blank. Before drawing a new blank, a drawn cup which is in contact with the punch is stripped off. The repetition of such stripping and drawing operations makes it possible to carry out both the first-stage drawing and the subsequent slight redrawings in one drawing operation using only one pair of punch and die. In this paper, this new deep drawing process is applied to the production of tapered cups and the main feature of the process is shown.


2014 ◽  
Vol 53 ◽  
pp. 797-808 ◽  
Author(s):  
H. Zein ◽  
M. El Sherbiny ◽  
M. Abd-Rabou ◽  
M. El shazly

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