Deep drawing using a novel hydromechanical tooling

A new type of passive-pressurized hydromechanical deep-drawing (PHDD) tooling with two pistons is designed and manufactured: one piston installed inside is used to enhance the die pressure, the other is used to promote the radial-pushing pressure, which provides the radial-pushing and blank-holder forces. The advantage of the PHDD tooling is that it needs no external pressurizing source. Aimed at motions of the two pistons, a mathematical model is presented to calculate the hydraulic pressures of all chambers. Furthermore, relationships between those hydraulic-pressure zones are developed. Hydraulic deep-drawing experiment on 1.00-mm-thick 08Al steel was conducted, and a drawing ratio of 2.63 was obtained. Further analysis shows that the design of the new tooling is reasonable and the hydraulic pressure used in all experiments is in good agreement with the analytical results.