Pressure generated in the hydraulic-pressure augmented deep-drawing process

1998 ◽  
Vol 74 (1-3) ◽  
pp. 286-291 ◽  
Author(s):  
S Thiruvarudchelvan ◽  
H.B Wang
Author(s):  
R.UDAY KUMAR

This paper presents evaluation and effect of blank radius on radial stresses through mathematical formulations in hydroforming deep drawing process using castor oil medium. Hydraulic pressure can enhance the capabilities of the basic deep drawing process for making cups. In hydroforming deep drawing process, applying the hydraulic pressure on blank periphery in radial direction. It is obtained through the punch movement within the fluid chamber, which is provided in punch and die chambers. These two chambers are connected with the bypass path and it is provided in the die. During the process punch movement within the fluid chamber the pressure is generated in fluid and it is directed through the bypass path to blank periphery, the fluid film is created on the upper and lower surfaces of the blank and subsequently reduces frictional resistance and is to reduce tensile stresses acting on the wall of the semi drawn blank. The blank is taking at centre place in between blank holder and die surface with supporting of high pressurized viscous fluid. The radial stresses are produced in the blank in radial direction due to punch force applied on it, the shear stresses acted by viscous fluid on the both sides of blank, so apply viscosity phenomenon to this analysis. The radial stresses are determined in terms of viscosity of castor oil, blank geometry and process parameters for magnesium alloys.


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.


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