A method for electrohydraulically forming a blank of material includesa blank of material to be deformed is placed between a mould and a blank holder,a cavity containing electrodes is filled with liquid to a predetermined liquid level,the blank of material is placed in contact with the liquid in the cavity,a first electric discharge is generated between at least two electrodes so as to deform the blank of material against the mould,the mould is brought nearer to the electrodes by moving the mould so as to reduce the distance between the electrodes and the blank of material to be deformed after the first electric discharge has been generated,at least one other electric discharge is generated between at least two electrodes so as to deform the blank of material against the mould.

A method for electrohydraulic forming a material blank includes: a material blank to be shaped is placed between a mould and a blank holder; a tight cavity containing electrodes is filled with liquid up to a predetermined liquid level; the material blank is brought into contact with the liquid of the cavity; the material blank is hydraulically preformed; and the material blank is electrohydraulically formed. The liquid of the cavity is pressurised for the hydraulic preforming by moving all or part of one of the walls of the cavity.

A method for electrohydraulic forming a material blank includes: a material blank to be shaped is placed between a mould and a blank holder; a tight cavity containing electrodes is filled with liquid up to a predetermined liquid level; the material blank is brought into contact with the liquid of the cavity; the material blank is hydraulically preformed; and the material blank is electrohydraulically formed. The liquid of the cavity is pressurised for the hydraulic preforming by moving all or part of one of the walls of the cavity.

An electro-hydraulic forming machine (1) for the plastic deformation of a projectile part (P13) of the wall (P1) of a workpiece (P) to be formed, preferably a cylindrical tubular workpiece, via a forming fluid (F), includes a tool (4) for applying the forming fluid on the inner face (P11) of the projectile part (P13), the application tool (4) including:a chamber (44) intended to contain the forming fluid (F), cooperating with elements (3) for generating a shock wave in the forming fluid (F) intended to be contained in the chamber (44), andat least one downstream port (42), intended to open opposite the projectile part (P13) of the wall (P1) to be deformed and in fluid communication with the chamber (44), in order to allow the passage of the forming fluid and for propagating the generated shock wave towards the footprint (22) of a target support (2).

An electro-hydraulic forming machine (1) for the plastic deformation of a projectile part (P13) of the wall (P1) of a workpiece (P) to be formed, preferably a cylindrical tubular workpiece, via a forming fluid (F), includes a tool (4) for applying the forming fluid on the inner face (P11) of the projectile part (P13), the application tool (4) including:a chamber (44) intended to contain the forming fluid (F), cooperating with elements (3) for generating a shock wave in the forming fluid (F) intended to be contained in the chamber (44), andat least one downstream port (42), intended to open opposite the projectile part (P13) of the wall (P1) to be deformed and in fluid communication with the chamber (44), in order to allow the passage of the forming fluid and for propagating the generated shock wave towards the footprint (22) of a target support (2).

An indirect electrohydraulic draw-forming tool includes a body having a tubular cylindrical area, a chamber intended to be filled with a liquid, two electrodes, each of the electrodes having a portion arranged in the chamber, a punch. The tool also includes a piston mounted so as to slide in a sealed manner within the cylindrical area and sealingly defining the chamber. Moreover, the punch is carried by the piston on a face thereof that is opposite to the chamber.

An indirect electrohydraulic draw-forming tool includes a body having a tubular cylindrical area, a chamber intended to be filled with a liquid, two electrodes, each of the electrodes having a portion arranged in the chamber, a punch. The tool also includes a piston mounted so as to slide in a sealed manner within the cylindrical area and sealingly defining the chamber. Moreover, the punch is carried by the piston on a face thereof that is opposite to the chamber.

One or more electro-hydraulic forming tools are operated by a press and provide formed parts to a trimming operation. A locking mechanism holds the die against the chamber during the electro-hydraulic forming (EHF) discharge. The lock may be a pin or clamp. One method of manufacturing an article includes providing three EHF tools that feed a single trimming press on a line. An alternative embodiment discloses a single EHF tool that supplies parts on a production line to an electro-hydraulic (EH) trimming tool. An electro-hydraulic pulse generator may be used to provide a stored charge to the EHF tool and the EH trimming tool.

One or more electro-hydraulic forming tools are operated by a press and provide formed parts to a trimming operation. A locking mechanism holds the die against the chamber during the electro-hydraulic forming (EHF) discharge. The lock may be a pin or clamp. One method of manufacturing an article includes providing three EHF tools that feed a single trimming press on a line. An alternative embodiment discloses a single EHF tool that supplies parts on a production line to an electro-hydraulic (EH) trimming tool. An electro-hydraulic pulse generator may be used to provide a stored charge to the EHF tool and the EH trimming tool.

A method for forming a workpiece by stamping that allows spring back to be eliminated, wherein tooling (20) is used, at least one of the forming parts (21, 23) of which includes a cavity (26) filled with a liquid (27) and provided with electrodes (28) capable of generating at least one shock wave in the cavity and through the wall (25) of the forming part, a blank material (18) is deformed between the two forming parts under the action of a deformation pressure and, without releasing the deformation pressure, at least one shock wave is generated in the cavity so that the shock wave passes through the blank material orthogonal to its surface. The tooling (20) and a press (10) adapted to implement the method are also described.