Investigation of a Modified Hydrodynamic Deep Drawing Assisted by Radial Pressure with Inward Flowing Liquid Process

Abstract

Hydrodynamic Deep Drawing (HDDRP), the combination of hydroforming and conventional deep drawing, accommodates the advantages of the two processes. A technique, called HDDRP with inward flowing liquid, has been introduced based on the idea of insertion of radial pressure around the blank rim. The radial pressure created on the blank edge, can increase the drawing ratio. Thus, increasing the radial pressure to an amount greater than the cavity pressure, and independent control of these pressures is the basic idea of this research for forming cylindrical parts. To perform the experiments, two independent pumps were used to provide the two pressures independently. The pressure supply system and the die set were designed in a way that provides simultaneous control of the pressures throughout the process. Then, the effects of radial pressure paths on thickness distribution of cylindrical St13 cups were investigated. In addition, a comparison between HDDRP and HDDRP with inward flowing liquid processes has been performed experimentally. Results indicated that using a higher radial pressure than the cavity pressure and controlling their values at any moment of the process enhances the thickness distribution of the formed part in all regions.

Investigation of consecutive two-stage hydrodynamic deep drawing of aluminum cylindrical cups

“…The PDR is approximately equal to the drawing ratio of the second stage. The limiting drawing ratio of stage one (b 0 ) and the limiting redrawing ratio (b n ) are obtained from equations (10) and (11), respectively:…”

“…Salahshoor et al 9 investigated the effects of several HDDRP parameters on punch force and thickness distribution of pure copper cylindrical cups with a drawing ratio of 1.9 numerically and experimentally. Khademi et al 10 modified the HDDRP with inward flowing liquid. Also, they studied the effect of controlling radial pressure and the cavity pressure on thickness distribution numerically and experimentally.…”