Abstract: A method of joining parts with an electromagnetic joining process and an assembly made according to the process. Seals are assembled to a first part and a second part is assembled over the first part and the seals. A lubricant is applied to the first part between the seals to preoccupy or partially fill the area within the joint to prevent moisture from penetrating into the joint and causing corrosion. A portion of the second part is deformed into recesses formed in the first part to join the first and second parts.

Abstract: A hydromechanical forming tool is disclosed that may include electro-hydraulic forming chambers in which a stored charge circuit may be discharged through electrodes to improve the level of detail that may be formed in a blank. The hydromechanical forming tool may include a liquid chamber at the entrance to the draw chamber to reduce friction, as the blank is drawn into the draw chamber. The draw chamber may have a movable bottom wall that is moved in tandem with the punch to reduce the amount of liquid in the draw chamber and reduce the need to pump liquid into and out of the draw chamber during a hydromechanical forming tool cycle.

Abstract: An electro-hydraulic forming tool having one or more electrodes for forming parts with sharp corners. The electrodes may be moved and sequentially discharged several times to form various areas of the tube. Alternatively, a plurality of electrodes may be provided that are provided within an insulating tube that defines a charge area opening. The insulating tube is moved to locate the charge area opening adjacent one of the electrodes to form spaced locations on a preform. In other embodiments, a filament wire is provided in a cartridge or supported by an insulative support.

Abstract: A draw die set defines a die cavity. A die entry area is provided at the location where a blank is drawn into the die cavity. A plurality of rolling elements such as cylindrical rollers or spherical balls are retained in pockets formed at the die entry area. A punch may be provided with rolling elements that engage a blank on the opposite side from the rollers in the die entry area. The rollers in the die entry area and on the punch may be arranged in rows that form a tangent surface that engages the sheet metal blank as it is drawn into the die cavity.

Abstract: An electro-hydraulic forming tool having one or more electrodes for forming parts with sharp corners. The electrodes may be moved and sequentially discharged several times to form various areas of the tube. Alternatively, a plurality of electrodes may be provided that are provided within an insulating tube that defines a charge area opening. The insulating tube is moved to locate the charge area opening adjacent one of the electrodes to form spaced locations on a preform. In other embodiments, a filament wire is provided in a cartridge or supported by an insulative support.

Abstract: A metal member defining a hole in which the hole is reinforced by forming a flange and turning the flange back upon itself so that the rolled outer surface of the flange defines the perimeter of the hole. The sheared edge is spaced from the perimeter of the hole. The shaft of the fastener inserted in the hole contacts a non-sheared surface. A reinforcement ring may be assembled around the flange.

Abstract: A hydromechanical forming tool is disclosed that may include electro-hydraulic forming chambers in which a stored charge circuit may be discharged through electrodes to improve the level of detail that may be formed in a blank. The hydromechanical forming tool may include a liquid chamber at the entrance to the draw chamber to reduce friction, as the blank is drawn into the draw chamber. The draw chamber may have a movable bottom wall that is moved in tandem with the punch to reduce the amount of liquid in the draw chamber and reduce the need to pump liquid into and out of the draw chamber during a hydromechanical forming tool cycle.

Abstract: A hydro-forming tool is disclosed in which first and second electrohydraulic forming (EHF) electrodes are used to provide a pressure pulse in opposite ends of a tubular pre-form. Alternatively, an accumulator with a rupturable membrane may be provided in opposite ends of a tubular pre-form for hydro-forming the tubular pre-form. A multiple discharge hydro-forming tool is also disclosed in which several pairs of accumulators are provided with selectively rupturable membranes that are ruptured to provide a pressure pulse in opposite ends of a tubular pre-form. The accumulators or EHF electrodes may be sequenced to provide separate pressure pulses that may be coordinated with retraction of a filler plug or shifting of a split ring into their respective retracted positions. A plurality of pressure pulses may be used to form, pierce and trim the tubular pre-form.

Abstract: A method and apparatus are disclosed for making a hydro-formed part by first hydro-forming a tubular blank to form an initially formed part. The initially formed part is clamped in a calibration tool with clamps. The initially formed part is connected to a source of electric current and electric current is pulsed through the initially formed part to reduce internal stresses in the initially formed part and reduce spring-back to form the initially formed part to a target shape.

Abstract: A method of testing metal samples is provided to simulate stretch flanging of trimmed surfaces. A sample having planar sides and a sidewall extending between the planar sides is placed in a fixture so that the planar sides are confined. The sidewall of the sample is bent about a curved surface while restricting buckling out of a planar area. One testing machine is disclosed in which a test specimen is clamped in a die with a nesting slot while a punch bends a sample against a forming surface that has a radius. In another testing machine, a mandrel and clamping element engage the planar sides of the sample while first and second bending members engage first and second end portions to bend one of the sidewalls of the sample about the mandrel.

Abstract: A method of hydro-forming an elongated tubular member that has areas of predicted high strain and areas of predicted low strain. The tubular member is initially deformed into a preliminary preform shape by compression in a preform die. Metal in the areas of predicted low strain is stretched during the preforming process by radially deforming the tube between two halves of the preform die. The preliminary preform is then expanded with internal hydro-forming pressure to form a preformed tube. The preformed tube is then hydro-formed into a final die to form the final shape for the part. The extra metal in the areas of low strain is stretched into the areas of high strain in the final hydro-forming operation.

Abstract: A method of riveting two metal parts through a hole with an electro-hydraulic riveting tool. The electro-hydraulic riveting tool includes a tube that is inserted in the hole and an electrode that is inserted within the tube. A liquid is contained within the tube and the electrode is immersed in the liquid. A stored charge is discharged through the electrode to create a shockwave within the fluid that forms the tube into a rivet structure and creates solid state weld between the rivet flanges and the parts that are joined.

Abstract: A method of forming a tubular member with portions having finished corners formed in a hydroforming operation by initially forming a pre-form that includes sharp corners. The pre-form includes bulges of the tube material between the sharp corners that flow toward the intended corner locations as the tubular member is hydroformed. The bulges may be external ribs or internal recesses.

Abstract: A method of forming a tubular member with portions having finished corners formed in a hydroforming operation by initially forming a pre-form that includes sharp corners. The pre-form includes bulges of the tube material between the sharp corners that flow toward the intended corner locations as the tubular member is hydroformed. The bulges may be external ribs or internal recesses.

Abstract: A tool and method of hemming a panel wherein the tool engages a flange to apply a compressive force with a stop initially preventing a distal end of the flange from moving inwardly. The hemming tool bends the intermediate portion of the flange between the flange bend and the distal end toward the panel. The stop is withdrawn to allow the flange to be progressively formed toward the panel until the distal end is aligned with the intermediate portion.

Abstract: A tool for modifying a workpiece by either trimming or joining the workpiece. The tool is an electro-hydraulic tool that uses a pulse transmitted through a liquid to trim a workpiece or to join two thicknesses of metal together. A method of trimming the workpiece includes the steps of providing a high voltage discharge in a liquid that drives a workpiece into engagement with a cutting edge of a tool steel insert. A method of joining two or more thicknesses of metal together includes the step of creating a high voltage discharge through an electrode that accelerates one panel or thickness of metal into a second panel that is held stationary by a backing plate while the first thickness of metal is accelerated into the second thickness of metal.

Abstract: An apparatus and method for forming a style line with a sharp radius in a metal with lower formability than that of mild steel is disclosed. The apparatus and method use a die set with a means to back a portion of the metal having the style line formed with a material that moves with the surface of the style line as it is formed. In one embodiment an elastic member backs the metal panel, and in another embodiment a fluid medium backs the metal panel where the style line is formed. The apparatus and method achieve sharper radius style lines in metals like aluminum, advanced high strength steel, and ultra-high strength steel than a traditional hard surface die set can achieve.

Abstract: A metal member defining a hole in which the hole is reinforced by forming a flange and turning the flange back upon itself so that the rolled outer surface of the flange defines the perimeter of the hole. The sheared edge is spaced from the perimeter of the hole. The shaft of the fastener inserted in the hole contacts a non-sheared surface. A reinforcement ring may be assembled around the flange.

Abstract: A hydro-forming tool is disclosed in which first and second electrohydraulic forming (EHF) electrodes are used to provide a pressure pulse in opposite ends of a tubular pre-form. Alternatively, an accumulator with a rupturable membrane may be provided in opposite ends of a tubular pre-form for hydro-forming the tubular pre-form. A multiple discharge hydro-forming tool is also disclosed in which several pairs of accumulators are provided with selectively rupturable membranes that are ruptured to provide a pressure pulse in opposite ends of a tubular pre-form. The accumulators or EHF electrodes may be sequenced to provide separate pressure pulses that may be coordinated with retraction of a filler plug or shifting of a split ring into their respective retracted positions. A plurality of pressure pulses may be used to form, pierce and trim the tubular pre-form.

Abstract: A method of hydro-forming an elongated tubular member that has areas of predicted high strain and areas of predicted low strain. The tubular member is initially deformed into a preliminary preform shape by compression in a preform die. Metal in the areas of predicted low strain is stretched during the preforming process by radially deforming the tube between two halves of the preform die. The preliminary preform is then expanded with internal hydro-forming pressure to form a preformed tube. The preformed tube is then hydro-formed into a final die to form the final shape for the part. The extra metal in the areas of low strain is stretched into the areas of high strain in the final hydro-forming operation.