Patent attributes
A hydroforming device includes a top die and a bottom die, set between which is a metal element to be formed and which are pressed against one another during a hydroforming process. A relative movement of the two dies between the open condition and the closed condition is controlled by a hydraulic cylinder. The opening of the two dies during the hydroforming process, when the forming cavity is filled with liquid at a high pressure, is prevented by applying on the two dies a force generated by means of two wedge-shaped members, which are horizontally mobile, controlled by respective actuator means and having inclined surfaces in contact with corresponding inclined surfaces of a vertically mobile member. The mobile member and the hydraulic cylinder are set operatively in series between one and the same die of the two dies and the base of the hydroforming cell. On the opposite side, the two dies rest against a top cross member of the fixed structure of the hydroforming cell, which is rigidly connected to the base by means of two shoulders so that the vertical forces that are generated during the hydroforming process are discharged on the shoulders, which are subject to tensile stress.
