Electrode for an electrohydraulic forming chamber

Abstract

The invention relates to an electrode (100) for an electrohydraulic forming chamber (300), characterised in that it comprises: - a body (102) comprising a first end portion (150); and - a compression-locking attachment system (110) configured and designed to hold one end (240) of a fuse link (200) against the body (102) or in the body (102) of the electrode (100) in the first end portion (150) of the electrode; the attachment system (110) moving between a release position and a locked position: o the release position of the attachment system (110) being designed to allow the end (240) of the fuse link (200) to be positioned and withdrawn; and o the locked position of the attachment system (110) being designed to allow electrical contact between the end (240) of the fuse link (200) and the body of the electrode (100).

Description

[0001] Electrode for electro-hydroforming enclosure

[0002] Field of invention

[0003] The present invention relates to the field of electrohydraulic forming and more particularly concerns an electrode, provided with a fixing system, intended to be used in a discharge chamber of an enclosure for electrohydraulic forming. The present invention also relates to an electro-hydroforming enclosure comprising said electrode.

[0004] State of the art

[0005] The electro-hydroforming process, also called EHF (Electro Hydraulic Forming), is a very high deformation speed forming process. The EHF process allows the forming of complex shaped parts. This process is based on a high-energy electrical discharge stored in capacitors, either between two electrodes placed in a discharge chamber filled with fluid, or in a fusible wire, installed between two electrodes and placed in said chamber. When an electrical discharge is created in the fluid, a shock wave is generated in said fluid, it propagates and projects a sheet against a mold. The dynamic pressure thus generated on the sheet allows the high-speed deformation of the material constituting it which is projected against the mold, thus allowing its shaping.

[0006] The EHF process using a fusible wire between two electrodes has several advantages over the one without, including better repeatability of the phenomenon, lower voltage required to create contact between the electrodes, less energy lost in pre-breakdown, lower overall energy required which allows the use of a smaller generator, and lower manufacturing costs.

[0007] The fuse wire is a consumable part during the EHF process, so a new one must be installed for each discharge. In the state of the art, the fuse wire is fixed or clamped via a threaded screw, which ensures good electrical contact between the electrode and the fuse wire.

[0008] However, this installation system has disadvantages, including the time required to install the fusible wire on each electrode via a screw. First, it is necessary to shape the ends of the fusible wire, for example in an S shape, so that the fusible wire surrounds each screw, which requires specific tooling. Then, when tightening the screw, the rotation of the wire in the tightening direction hinders the tightening operation of said screw. In addition, a high tightening torque is required to ensure electrical contact, which requires significant effort from the operator. The setup time can thus reach approximately 10 minutes to install a fusible wire via a screw on an electrode, for each discharge of the EHF process to form a part.

[0009] On the other hand, the screw used for the installation of the fuse wire deteriorates quickly and must be replaced generally every 10 discharges. Regular tapping of the screw insertion hole in the electrode is necessary, which further prolongs the forming time and cost. In addition, the removal of the fuse wire residue is difficult because the residue welds onto the screw, especially in the threads of the threaded screw. This cleaning step is also very time-consuming. Indeed, the welded residue must be carefully removed to ensure good electrical contact the next time the screw is used. These cleaning problems can further cause considerable time loss during the process of installing the fuse wire via the screw, which increases manufacturing costs.

[0010] All these disadvantages can cause considerable costs and time losses for the electrohydraulic forming process with a fusible wire.

[0011] Statement of the invention

[0012] The present invention aims to solve the problems encountered when installing a fusible part on electrodes in an electro-hydroforming process. The objective is to provide an effective solution to reduce the time required for fixing the fusible part and removing residues while ensuring reliable electrical contact between the fusible part and the electrodes. This solution will simplify the fixing process and reduce the costs associated with the use of consumable fusible parts.

[0013] For this purpose, the present invention provides an electrode for an electrohydroforming enclosure, characterized in that it comprises: a body comprising a first end portion, and a fastening system, by compression locking, configured and intended to hold one end of a fusible plate against the body or in the body of the electrode, at the level of said first end portion of the electrode. Said fastening system evolves between a release position and a locking position: the release position of said fastening system being intended to allow the positioning and removal of the end of the fusible plate, and the locking position of said fastening system being intended to allow electrical contact between the end of the fusible plate and the body of the electrode.

[0014] The electrode according to the invention is thus provided with a fixing system which advantageously allows easy and rapid installation of the fusible plate against said electrode, easily moving from the release position to the compression locking position of said fixing system.

[0015] The fixing system comprises: a support piece, a head of which is intended to be in contact with the end of the fuse plate, and an elastic return member, linked to the support piece, configured so that in the locking position of said fixing system, said elastic return member exerts a return force on the support piece against the body of the electrode at the first end portion.

[0016] This fixing system allows an operator to more easily and quickly position the fuse plate by simply moving the support piece. In addition, the presence of the elastic return member facilitates the locking of the fuse plate against the body of the electrode by using its return force, thus ensuring the necessary and sufficient mechanical and electrical contact, without requiring external tools or special operations.

[0017] According to preferred embodiments, the invention further meets the following characteristics, implemented separately or in each of their technically effective combinations.

[0018] According to preferred embodiments, the elastic return member is chosen from: a compression spring, a tension spring, a torsion spring, an elastic. These elastic return members adapt easily to the fixing system, and do not require complex or special manufacturing.

[0019] According to first preferred embodiments of the first configuration of the electrode, the support piece comprises a rod connected to the head, and the body of the electrode comprises a transverse guide hole, at the first end portion, and intended to receive said rod. In addition, the elastic return member is a compression spring or a tension spring whose turns are wound around the rod. Such an arrangement advantageously allows guidance of the movement of the support piece and an improvement in the stability of the fixing system during the positioning of the fusible plate.

[0020] According to preferred embodiments of the first examples, a first end of the elastic return member is connected to the support piece, and a second end of the elastic return member is intended to be connected to a frame of the electrohydroforming enclosure.

[0021] According to preferred embodiments of the first examples, one end of the rod of the support piece is connected to the head, and another end of the rod comprises a nut. The body of the electrode is positioned between the head and the nut, and the return member is arranged, around the rod, between the body of the electrode and the nut.

[0022] According to preferred embodiments, the body comprises: a first flat, and a pair of helical ramps, on the first flat, arranged around the guide hole, said helical ramps being configured such that the head of the support piece moves between a top part and a bottom part of the helical ramps during a rotational movement of the support piece around a longitudinal axis of the rod.

[0023] And the electrode is configured so that: in the release position of said fixing system, the head of the support piece is located at the level of the upper part of the helical ramps, and in the locking position of said fixing system, the head is located at the level of the lower part of the helical ramps.

[0024] According to second preferred embodiments of the first configuration of the electrode, the elastic return member is a torsion spring, a first end of which is connected to the support piece, and a second end of which is connected to the body of the electrode. Said electrode is configured so that, in the locking position of said fixing system, said torsion spring is compressed.

[0025] According to third preferred embodiments of the first configuration of the electrode, the body of the electrode comprises: a longitudinal groove on the body, a slide comprising an arm intended to be inserted into the groove such that the slide slides along the groove, and two flats, called first and second flats, separated by a slope on the body of the electrode, the first flat being intended to receive the end of a fusible plate.

[0026] In addition, the support piece of the fixing system is connected to the slider in such a way that the head of said support piece moves between the first flat and the second flat, when the arm of the slider moves in the groove.

[0027] In addition, the elastic return member of the fixing system is a compression spring or a tension spring, a first end of which is connected to the support piece, and a second end of which is connected to the slider such that: in the release position of said fixing system, the head of the support piece is located at the level of the second flat, and in the locking position of said fixing system, the head is located at the level of the first flat.

[0028] According to fourth preferred embodiments of the first configuration of the electrode, the elastic return member of the electrode fixing system is an elastic band, and the fixing system is configured such that the elastic band transversely surrounds the support piece and the body of the electrode at the first end portion, in the locking position.

[0029] According to fifth preferred embodiments of the first configuration of the electrode, the elastic return member of the electrode fixing system is an elastic band, and the fixing system is configured such that the body of said electrode comprises two lugs so that the elastic band is held at said lugs, overlapping the support piece, in the locking position. The invention also relates to an electro-hydroforming enclosure comprising a discharge frame comprising an internal wall delimiting a discharge chamber. The electro-hydroforming enclosure comprises at least two electrodes according to the invention meeting one or more of the characteristics described above and / or below. Said at least two electrodes are intended to be opposite one another, arranged partly in the discharge chamber, and connected to each other via a fusible plate to carry out an EHF process.

[0030] In another electrode configuration for an electro-hydroforming enclosure, the electrode comprises: a body comprising a first end portion, and a fastening system, by compression locking, configured and intended to hold one end of a fusible plate against the body or in the body of the electrode, at the level of said first end portion of the electrode.

[0031] Said fixing system moves between a release position and a locking position: the release position of said fixing system being intended to allow the positioning and removal of the end of the fuse plate, and the locking position of said fixing system being intended to allow electrical contact between the end of the fuse plate and the body of the electrode.

[0032] The electrode is thus equipped with a fixing system which advantageously allows easy and rapid installation of the fusible plate against said electrode, easily moving from the release position to the compression locking position of said fixing system.

[0033] The fastening system has a truncated cone shape and comprises a first support piece and a second support piece. Said fastening system is intended to receive, between the first support piece and the second support piece, one end of the fusible plate. The body of said electrode comprises transversely an orifice, having a shape complementary to that of the fastening system and being configured to contain said fastening system, such that: in the release position of said fastening system, the fastening system is separated from the body of said electrode, in the locking position of said fastening system, the fastening system is inserted into the orifice of the body of said electrode.

[0034] Such an electrode can significantly reduce the time required for installing and removing a fuse board.

[0035] According to preferred embodiments, the fixing system has a truncated cone shape with a rectangular or circular section.

[0036] In connection with this other electrode configuration, the invention relates to an electro-hydroforming enclosure comprising a discharge frame comprising an internal wall delimiting a discharge chamber. The electro-hydroforming enclosure comprises at least two electrodes according to the invention meeting one or more of the characteristics described above and / or below. Said at least two electrodes are intended to be opposite each other, arranged partly in the discharge chamber, and connected together via a fusible plate to carry out an EHF process.

[0037] Presentation of figures

[0038] The invention will be better understood by reading the following description, given as a non-limiting example, and made with reference to the figures which represent:

[0039] Figure 1 schematically represents a sectional view of an electrohydroforming enclosure, in which a fusible part is positioned;

[0040] Figure 2 schematically represents a top view of different shapes of fusible part;

[0041] Figure 3 schematically represents a sectional view of a part of an electro-hydroforming enclosure comprising two electrodes according to a first variant of a first embodiment configuration of the invention;

[0042] Figure 4 schematically represents a cross-sectional view of an electrode according to a second variant of the first configuration, against which a fusible part is positioned;

[0043] Figure 5 represents an exploded view of a first end portion of an electrode according to a third variant of the first configuration, against which a fusible part is positioned; Figure 6 represents a perspective view of the first end portion of the electrode of Figure 5, in which a system for fixing the electrode is shown in the disengaged position;

[0044] Figure 7 shows a longitudinal sectional view of the first end portion of the electrode of Figure 6;

[0045] Figure 8 represents a perspective view of the first end portion of the electrode of Figure 5, in which the electrode fixing system is shown in the locking position;

[0046] Figure 9 represents a perspective view of a first end portion of an electrode according to a fourth variant of the first configuration, in which a system for fixing the electrode is shown in the locking position;

[0047] Figure 10 shows another perspective view of the first end portion of the electrode of Figure 9, in which the electrode attachment system is shown in the disengaged position;

[0048] Figure 11 shows a cross-sectional view of a first electrode portion according to a preferred form of a fifth variant of the first configuration;

[0049] Figure 12 shows a top view of the first end portion of the electrode of Figure 11;

[0050] Figure 13 shows a cross-sectional view of a first end portion of the electrode according to another preferred form of the fifth variant;

[0051] Figure 14 shows a top view of the first end portion of the electrode of Figure 13;

[0052] Figure 15 represents a side view of two first end portions of electrodes, according to a preferred form of a second embodiment configuration of the invention, said two first end portions facing each other;

[0053] Figure 16 represents a perspective view of the associated fixing system for each electrode of Figure 15, shown in the locking position;

[0054] Figure 17 represents a perspective view of the associated fixing system for each electrode of Figure 15, shown in the disengaged position; Figure 18 represents a side view of two first electrode end portions, according to another preferred form of the second configuration, said two end portions facing each other;

[0055] Figure 19 shows a perspective view of the attachment system for each electrode of Figure 18, shown in the released position.

[0056] Detailed description of the invention

[0057] Different figures and elements within a figure are not necessarily represented on the same scale. In all figures, identical elements bear the same numerical reference.

[0058] The terminology used in this description should not be interpreted in any way as limiting or restrictive, simply because it is used in conjunction with a detailed description of certain embodiments of the invention.

[0059] An electro-hydroforming enclosure 300 for forming a part to be formed 600 is illustrated, without limitation, in Figure 1. The electro-hydroforming enclosure 300 is made in two parts. Said enclosure 300 comprises a first part, called the discharge frame 320, and a second part, called the die 340.

[0060] The discharge frame 320 may represent an upper portion of the electrohydroforming enclosure (depending on the orientation of the figure) and the die 340 may represent a lower portion, as illustrated in Figure 1. The discharge frame 320 comprises an internal wall 322 delimiting a discharge chamber 310. The die 340 comprises a forming chamber 330 having an imprint intended to be complementary to the shape that the part 600 must take after deformation.

[0061] The discharge frame 320 and the die 340 are removable relative to each other so as to allow the insertion and removal of the part to be formed 600.

[0062] Said part to be formed 600 is arranged, at an interface between the die 340 and the discharge frame 320, and held in position in a hermetic manner. Once in position in the electro-hydroforming enclosure, the part to be formed 600 separates the forming chamber 330 from the discharge chamber 310. The discharge chamber 310 is intended to be filled with an incompressible fluid, preferably a liquid, for example water. A water supply conduit (not shown) is produced in the discharge frame 320 to allow the discharge chamber 310 to be connected to a tank (not shown) containing water and to supply said discharge chamber 310 with water. A water discharge conduit (not shown) is provided in the discharge frame 320 to allow the discharge chamber 310 to be connected to the same tank or to a different tank, and to drain the water out of said discharge chamber, into said tank.

[0063] The discharge frame 320 as well as the die 340 and other components essential for electrohydraulic forming are known to those skilled in the art in their operation and their form in general, and are therefore no longer described in detail in the present description.

[0064] In addition, the electro-hydroforming chamber 300 comprises an electrohydraulic discharge system. In the non-limiting example illustrated in Figure 1, the electrohydraulic discharge system comprises two separate electrodes 100, forming a pair of electrodes.

[0065] Each electrode 100 comprises a longitudinal body 102. The body 102 of the electrode comprises a first face 104 intended to come opposite the first face of the other electrode. The body 102 has a first end portion 150 extending from the first face. The body 102 of the electrode has a second face opposite the first face 104 and has a second end portion extending from the second face.

[0066] Each electrode 100 passes through the discharge frame 320. At least the first end portion 150 of the body of each electrode is positioned inside the discharge frame 320, in the discharge chamber 310. The second end portion of the body of each electrode, placed outside the discharge frame 320, is connected, via a power cable, to an electrical energy storage unit (not shown). The electrical energy storage unit comprises at least one capacitor. The various components of the electrical energy storage unit are known to those skilled in the art in their form and in their operation and are not described in more detail in the present description. The electrodes 100 are arranged in the electro-hydroforming enclosure 300 so as to create an inter-electrode distance, between their first faces 104 of the body 102.

[0067] As a variant, and without departing from the scope of the invention, the electrohydraulic discharge system may comprise several pairs of electrodes 100.

[0068] Alternatively, said system may comprise a central electrode and several electrodes arranged around the central electrode. A pair of electrodes is considered to be composed of the central electrode and one of the electrodes arranged around it.

[0069] The deformation of the part 600 is carried out in a forming cycle via the EHF process. The EHF process is based on an electrical discharge of high energy stored in capacitors between two electrodes. In a preferred variant, a fusible part 200 is arranged between the first two end portions of the electrodes.

[0070] The fusible part 200 is in the form of a plate, as illustrated in Figures 2(a) to (e). In the remainder of the description, the fusible part will be referred to as a “fuse plate”. The fusible plate 200 has a longitudinal body 220. The body 220 of the fusible plate has the shape of a straight block, of small thickness and width relative to the length. Said body preferably has a non-circular cross-section (perpendicular to the length), for example rectangular or square. The fusible plate 200 is preferably manufactured from a fusible material, such as aluminum. The body is delimited by two ends 240.

[0071] Preferably, the fuse plate 200 has at least one end 240 enlarged relative to the body, as illustrated in Figures 2(a) to (c) and (e).

[0072] Preferably, said end 240 of the fuse plate 200 comprises at least one orifice 241 as illustrated in Figure 2(a) or a notch 243 as illustrated in Figures 2(b), (c) and (e).

[0073] The enlarged end 240 of the fuse plate is designed to provide a larger contact surface with the body 102 of the electrode, at the first end portion 150, and to make it easier for the fuse plate to be held between the two electrodes. This design allows for better mechanical contact between the fuse plate and the electrodes, thereby advantageously reducing the risk of displacement or misalignment of the fuse plate. In addition, it also promotes optimal electrical contact between the fuse plate and the electrodes, thereby avoiding the formation of electrical micro-arcs.

[0074] Additionally, each type of fuse strip has its own advantages, which will be detailed below.

[0075] According to the invention, as illustrated in Figures 3-19, each electrode 100 is provided, at the first end portion 150, with a fixing system 110. The electrode fixing system is configured to reversibly hold one end 240 of the fuse plate 200 against or in the body 102 of said electrode 100, at the first end portion 150 of said electrode.

[0076] Preferably, the fixing system 110 is identical for each electrode 100 contained in the electro-hydroforming enclosure 300.

[0077] Each fastening system is a compression locking fastening system.

[0078] Said fixing system 110 moves between a locking position and a release position.

[0079] The locking position of said fixing system 110 is intended to hold the end 240 of the fuse plate 200 against or in the body 102 of the electrode 100, at the level of the first end portion 150 of the electrode, and to guarantee electrical contact between the fuse plate 200 and the body 102 of the electrode 100.

[0080] The release position of said fixing system is intended to allow the positioning and removal of the end 240 of the fuse plate.

[0081] Two electrode configurations with fixing system are envisaged according to the invention.

[0082] Depending on the attachment system, the shape of the ends of the fuse board can be adapted, to provide greater stability and strength when the fuse board is attached to the electrodes using the attachment systems described in the present invention.

[0083] First configuration

[0084] According to a first configuration, as illustrated in Figures 3 to 14, the fixing system

[0085] 110 of each electrode 100 is intended to hold the end 240 of the fuse plate

[0086] 200 against a surface of the body 102 of the electrode 100 at its first end portion 150. Said fixing system comprises a support piece 120, a head 124 of which is intended to be in contact with the end 240 of the fuse plate 200.

[0087] Said fixing system also comprises an elastic return member 140 connected to the support piece 120.

[0088] In the locking position of said fixing system, the elastic return member 140 exerts a return force on the head 124 of the support piece 120 to press it against the body 102 of the electrode, at the level of the first end portion 150 of the electrode. When the fusible plate is not positioned between the head 124 and the body 102 of the electrode, the elastic return member 140 exerts a force on the head 124 to keep said head in direct contact with the body 102 of the electrode, at its first end portion 150. When the plate is positioned between the head 124 and the first end portion 150 of the electrode, the elastic return member 140 exerts a force on the head 124 to reversibly hold the end 240 of the plate against the body 102 of the electrode, at its first end portion 150, and thus guarantee electrical contact between the fusible plate 200 and the electrode 100.

[0089] Preferably, the locking position is the rest position of the fixing system 110.

[0090] In this first configuration, five non-limiting variant embodiments of the invention will now be described.

[0091] First variant

[0092] According to a first variant of this first configuration, as illustrated in Figure 3, the fixing system 110 of each electrode 100 is a spring system.

[0093] In Figure 3, the fastening system 110 is shown in the released position.

[0094] The elastic return member 140 is preferably a compression spring 140, positioned between the head 124 of the support piece 120 and the inner wall 322 of the discharge chamber 310 of the enclosure. More precisely, a first end 141 of the compression spring 140 is in contact with the head 124 of the support piece 120, while a second end 142 of the compression spring 140 is in contact with the inner wall 322 of the discharge chamber 310. In this context, the term “in contact” can be understood as being synonymous with “connected to”, “fixed to” or “connected to”. The end 240 of the fusible plate 200 is intended to be positioned between the head 124 of the support piece and the first end portion 150 of the electrode 100. As an illustrative example, the fusible plate 200 shown in views (a) to (e) of Figure 2 can all be used with the fixing system of this first variant.

[0095] Preferably, the support piece 120 may comprise a rod 122 having a longitudinal axis. The head 124 is fixed to the rod 122. The compression spring 140 is arranged around the rod 122. The first end portion 150 of the electrode is provided with a guide hole 151, passing through, to receive the rod 122.

[0096] The rod 122 moves in an axial direction through the guide hole 151. Said rod has a length such that, during axial movement of the rod, the rod does not come into contact with the discharge frame 320. Alternatively, the discharge frame 320 comprises an orifice for receiving a portion of the rod 122, said rod has a length such that, during axial movement of the rod, the rod is partially inserted into the orifice for receiving the discharge frame 320.

[0097] When the rod 122 is present, the end 240 of the fuse plate preferably comprises a notch 243 sized to partially surround the rod 122. As an illustrative example, the plate shown in views (b), (c) or (d) of Figure 2 is adapted to the fixing system of this preferred form of this first variant. The fuse plate 200 shown in view (b), which has, at each enlarged end 240, a notch formed perpendicular to the length of the body 220, allows a lateral installation of the plate, each notch partially surrounding the rod 122. The fuse plate 200 shown in view (c), which has, at an enlarged end 240, a longitudinal notch also allows a lateral installation of the plate.Installation of the plate begins by positioning the enlarged end 240 with the longitudinal notch on an electrode 100, the longitudinal notch partially surrounding the rod 122 of said electrode. Then, the fusible plate can be pivoted in rotation in order to position its other end on the other electrode, until it comes into contact with the rod of the other electrode. Installation of the fusible plate is thus easier.

[0098] The locking position of the fixing system 110 is its rest position. In the disengaged position of the fixing system 110, the head 124 is separated from the body of the electrode. The compression spring 140 is more compressed in the disengaged position than in the locking position.

[0099] To insert or remove a fusible plate 200, deposited between the head 124 and the body of the electrode at the first end portion 150, the fixing system 110 is moved into the release position. For this, for example, an operator pushes the head 124 of the support piece, so as to move the head 124 away from the first end portion 150 of the electrode, in a direction according to the arrow A as shown in Figure 3. The compression spring 140 is thus compressed and the fusible plate 200 can be released or introduced as illustrated in Figure 3.

[0100] When the support piece 120 is provided with a rod 122, the operator can push either on the head 124 or on one end of the rod 122.

[0101] After removing or installing the fuse plate, the operator releases the support piece. Thanks to the return force exerted by the compression spring 140, the head (with the rod 122 if present) automatically moves towards the first end portion 150 of the electrode, in a direction according to the arrow B as shown in Figure 3. The fixing system 110 thus automatically returns to its rest position, i.e., its locking position.

[0102] In another embodiment of this first variant, not shown, the elastic return member 140 may be a tension spring instead of the compression spring, and the person skilled in the art will be able to adapt the fixing system accordingly.

[0103] Second variant

[0104] According to a second variant of the first configuration, as illustrated in Figure 4, the electrode fixing system 110 is a spring system.

[0105] The elastic return member 140 is a torsion spring.

[0106] One arm of the torsion spring 140 is connected, directly or indirectly, to the head 124 of the support piece 120, while another arm of the torsion spring 140 is fixed to the body 102 of the electrode 100. The support piece 120 is a lever. The head 124 of the lever 120 makes it possible to press and hold the end 240 of the fusible plate 200 on the body 102 of the electrode, at the first end portion 150 of the electrode thanks to a return force exerted by the torsion spring 140.

[0107] The locking position of the fastening system 110, as shown in Figure 4, is the rest position of the fastening system.

[0108] In the release position of the fixing system 110, the head 124 is separated from the body of the electrode to allow positioning or removal of the fusible link. The torsion spring 140 is more compressed in the release position than in the locking position.

[0109] To move the fastening system into the release position, for example, an operator lifts the lever 120. This causes a rotational movement of the torsion spring arm 140 linked to the lever 120 in a direction according to the arrow B as illustrated in Figure 4, deforming the torsion spring 140. The torsion spring 140 is thus compressed and the fuse plate 200 can be released or inserted.

[0110] After removing or installing the fuse board, the operator releases the lever 120. The arm of said torsion spring linked to the lever then moves in rotation in a direction A as illustrated in Figure 4. Thus, the head 124 of the lever 120 is returned towards the body 102 of the electrode at its first end portion 150, thanks to the restoring force exerted by the torsion spring 140. Said torsion spring then applies a certain contact pressure on the end 240 of the fuse board 200 via the lever 120, in order to ensure electrical contact between the fuse board and the electrode.

[0111] As an illustrative example, any type of fuse board shown in Figure 2 can be used with the fixing system of this second variant.

[0112] In a preferred embodiment, to hold the fuse plate more stably, the body 102 of the electrode comprises at its first end portion 150 a pin 158 arranged opposite the head 124, as illustrated in Figure 4. Thus, a fuse plate 200 comprising an end 240 with an orifice 241 or a notch 243 can preferably be used, and the pin 158 receives the orifice 241 or the notch 243 of the fuse plate. The pin is sized to the size of the orifice or the notch of the fuse plate. As an illustrative example, the plate shown in views (a), (b), (c) or (e) of Figure 2 is adapted to the fixing system of this preferred form of this second variant.

[0113] Third variant

[0114] According to a third variant of the first configuration, the fixing system 110 of the electrode 100 is a so-called “knob” system, as illustrated in Figures 5 to 8.

[0115] The support part 120 of the fixing system comprises the head 124 and a rod 122 having a longitudinal axis. One end of the rod 122 is connected to the head 124, while at another end of the rod 122, a nut 126 is fixed.

[0116] The elastic return member 140 is a compression spring arranged around the rod 122, between the body 102 of the electrode and the nut 126. A first end 141 of the compression spring 140 is fixed to the nut 126. A second end 142 of the compression spring is fixed to the body 102 of the electrode at its first end portion 150.

[0117] In a non-limiting manner, the body 102 of the electrode 100 is of circular section. Preferably, at the first end portion 150, the body 102 of the electrode is provided with a first flat 153. The first flat 153 extends from the first face 104 of the body of the electrode and is intended to receive the end 240 of the fuse plate.

[0118] The body 102 of the electrode comprises a guide hole 151 passing through at the level of the first end portion 150. The guide hole 151 opens at the level of the first flat 153. This guide hole 151 is intended to receive the rod 122 of the support piece 120, with a clearance, to allow the axial displacement of the rod 122 in said guide hole.

[0119] The body 102 of the electrode 100 further comprises, preferably, on the first flat 153, a pair of helical ramps 152 arranged around the guide hole 151, as illustrated in Figure 5. Each helical ramp 152 rises continuously from a lower part to a higher part, for example according to a semi-circular curvature.

[0120] The helical ramps 152 are diametrically symmetrical. The support piece 120 is arranged opposite the electrode body 102 so that the head 124 is arranged on the side of the first flat 153 and the nut 126 is arranged diametrically opposite.

[0121] In one embodiment, as illustrated in Figure 7, the body 102 of the electrode 100 comprises a recess 101, arranged diametrically opposite the first flat 153. The guide hole 151 opens into the recess 101. The recess 101 is dimensioned for the partial reception of the compression spring 140.

[0122] The head 124 of the support piece is intended to bear on the pair of helical ramps 152. Said head, and consequently the support piece, moves by performing a rotational movement along the helical ramps 152.

[0123] In the locking position of the fixing system 110, as illustrated in Figure 8, the head 124 is located at the lower part of the helical ramps 152, i.e., against the first flat 153 or against the plate arranged on the first flat, when said plate is present. The head 124 further comprises notches 127 for receiving the helical ramps 152, when the fixing system is in the locking position.

[0124] In the disengaged position of the fixing system 110, as illustrated in Figure 6, the head 124 is located at the upper part of the helical ramps 152. Thus, it is away from the surface of the body of the electrode. The compression spring 140 is more compressed in the disengaged position than in the locking position.

[0125] The transition from the locking position to the disengagement position, and vice versa, is achieved by a rotational movement of the support piece 120 around the axis of the rod 122.

[0126] To move the fastening system 110 into the release position, for example, an operator rotates the head 124 of the support piece about the axis of the rod 122, so that said head rises along the helical ramps 152, thereby compressing the compression spring 140. This causes the head 124 to move away from the first flat 153 in the axial direction of the rod 122, thereby allowing the fusible plate 200 to be removed, or to be inserted between the head 124 and the first flat 153, as illustrated in Figures 6 and 7.

[0127] To return the fixing system to the locking position, the operator releases the support piece, which allows the compression spring 140 to automatically return to its initial shape. Under the effect of the tension of the compression spring, the head 124 descends along the helical ramps to their lower parts, thus approaching the first flat 153 of the body of the electrode in the axial direction of the rod 122. Finally, the head 124 blocks the end 240 of the fusible plate against the first flat 153, as illustrated in Figure 8.

[0128] In a preferred embodiment, the upper portion of each helical ramp 152 has a flat surface. Thus, when the operator turns the head 124 of the support piece to place it on the flat surfaces of the upper portions of the helical ramps, said head can remain in place, which maintains the fixing system 110 in the disengaged position.

[0129] In this preferred embodiment, to lock the fuse plate 200, the operator must turn the head 124 so that said head leaves the flat surfaces of the upper parts of the helical ramps. Thus, under the effect of the compression spring tension 140, the fixing system 110 returns to its rest position, i.e., its locking position.

[0130] Preferably, the end 240 of the fuse plate is provided with a notch 243, which is designed to accommodate the helical ramps 152 of the electrode. As an illustrative example, the plate shown in views (b) to (e) in Figure 2 is adapted to the fixing system of this third variant.

[0131] Fourth variant

[0132] According to a fourth variant of the first configuration, the fixing system 110 of the electrode 100 is a so-called “slider” system, as illustrated in Figures 9 and 10.

[0133] Similar to the third variant, the electrode 100 has a body 102 of circular section. At the first end portion 150, the body 102 of the electrode is provided with a first flat 153, which extends from the first face 104 of the body 102 of the electrode. Said first flat is intended to receive the end 240 of the fuse plate 200.

[0134] The body of the electrode 100 further comprises a second flat 155. Said second flat is located in the extension of the first flat 153, in a longitudinal direction of the body. The second flat 155 preferably has a lesser depth than the first flat 153. The two flats are connected to each other by a slope 154. In addition, the body 102 of the electrode 100 longitudinally comprises at least one groove 131. The electrode 100 further comprises a slider 130 which is configured to move along the groove 131. In a non-limiting example, the slider 130 is provided with at least one arm 132 inserted into the at least one groove 131 to be guided by said at least one groove.

[0135] Preferably, the body of the electrode comprises two parallel grooves 131 arranged on two diametrically opposite sides of said body, as illustrated in Figures 9 and 10. The slide 130 then comprises two arms 132, each being intended to be inserted into one of the two grooves 131 and to slide along the corresponding groove.

[0136] The elastic return member 140 is preferably a compression spring, positioned between the slider 130 and the head 124 of the support piece. The compression spring 140 connects said slider and said head.

[0137] Preferably, the support piece 120 further comprises a rod 122, one end of which is fixed to the head 124. The slider 130 is provided with a passage hole 133 arranged to pass the rod 122, with clearance, and to allow the axial displacement of said rod. The compression spring 140 is arranged around the rod 122, between the slider and the head. The displacement of the head is thus more stable.

[0138] Thus, the fixing system 110 evolves between a locking position as illustrated in Figure 9 and a release position as illustrated in Figure 10:

[0139] In the locking position, the head 124 is positioned at the level of the first flat 153. The compression spring 140 is compressed to exert pressure on said head to hold it against the first flat 153.

[0140] In the release position, the head 124 is moved away from the first flat 153, and positioned at the level of the second flat 155. The compression spring 140 is preferably more compressed in the release position than in the locking position.

[0141] The transition from the locking position to the disengagement position, and vice versa, is carried out by a translation of the slide 130 along the groove(s) 131.

[0142] To insert or remove a wafer, deposited between the head 124 and the first flat 153 of the electrode body, the fixing system 110 is moved to the release position. For this, the operator translates the slide 130 towards the second flat 155 in a direction according to the arrow A as illustrated in Figures 9 and 10. The head 124 of the support 120 moves away from the first flat 153. The fusible wafer 200 is then released and can be removed, or a new fusible wafer can be placed.

[0143] Once a fusible link is placed, in order to lock the end of the fusible link against the electrode body, the fixing system is moved to the release position. For this, the operator translates the slider towards the first flat 153 in a direction according to the arrow B as illustrated in Figures 9 and 10. This causes the head 124 to move along the slope 154 until it is in contact with the end 240 of the fusible link, under the return effect of the compression spring 140.

[0144] As an illustrative example, any type of fuse board shown in Figure 2 can be used with the fixing system of this fourth variant.

[0145] In a preferred embodiment, as illustrated in Figure 10, the body of the electrode comprises, at the first flat 153, a pin 158 designed to fit into an orifice 241 or a notch 243 of the end 240 of the fuse plate 200, which allows a more stable fixing. Preferably, the fuse plate shown in views (a), (b), (c) or (e) of Figure 2 is adapted to the fixing system of this preferred form of this fourth variant.

[0146] In one embodiment, the pin 158 may have a thickness greater than a thickness of the end 240 of the fuse plate. In this case, in the locking position, an upper portion of the pin 158 is inserted into a housing 121 made in the head 124 of the support piece to improve stability.

[0147] However, in other embodiments of this variant, the elastic return member 140 may be a tension spring, and those skilled in the art will be able to adapt the fixing system accordingly to use such a tension spring.

[0148] Fifth variant

[0149] According to a fifth variant of the first configuration, the fixing system 110 of each electrode 100 is a so-called “elastic” system, as illustrated in Figures 11 to 14.

[0150] The support piece 120 of the fixing system is configured to be partially shaped to the surface of the body 102 of the electrode, at the first end portion 150. The elastic return member 140 of the fixing system 110 is a closed-loop elastic. The elastic is stretched in the locking position to compress the support piece well against the body of the electrode.

[0151] According to one embodiment, as illustrated in Figures 11 and 12, the elastic 140 transversely surrounds the entire support piece 120 and the body 102 of the electrode, at the level of the first end portion 150.

[0152] According to another embodiment, as illustrated in Figures 13 and 14, the body 102 of the electrode comprises two lugs 156, preferably arranged diametrically opposite, at the level of the first end portion 150. The elastic 140 is kept taut between the lugs 156, overlapping the support piece 120.

[0153] In the release position of the fixing system (110), the support piece 120 is separate from the body of the electrode.

[0154] In one embodiment, to move the fixing system 110 into the release position, for example, an operator pulls on the support piece 120, to move it away from the body 102 of the electrode, by tensioning the elastic. In this case, the elastic 140 can remain at the first end portion of the body of the electrode and it is more tensioned in the release position than in the locking position.

[0155] To return the fixing system 110 to the locking position, the operator releases the support piece 120, the return force of the elastic 140 bringing the support piece 120 closer to the body 102 of the electrode at the first end portion 150.

[0156] In another embodiment, to place the fixing system 110 in the release position, an operator removes or transversely shifts the elastic relative to the support piece, out of the first end portion of the body of the electrode, then removes the support piece 120. To put or put back the fixing system 110 in the locking position, the operator first repositions the support piece on the body of the electrode then puts the elastic back in position, surrounding or overlapping the support piece.

[0157] As an illustrative example, any type of fuse board shown in Figure 2 can be used with the fixing system of this fifth variant.

[0158] Preferably, the body 102 of the electrode is provided with a pin 158 designed to fit into an orifice 241 or a notch 243 of the end 240 of the fuse plate 200, which allows for a more stable fixing. Preferably, the fuse plate shown in views (a), (b), (c) or (e) of Figure 2 is adapted to the fixing system of this preferred form of this fifth variant.

[0159] In one embodiment, the pin 158 may have a thickness greater than a thickness of the end 240 of the fuse plate. In this case, in the locking position, an upper portion of the pin 158 is inserted into a housing 121 made in the support piece 120 to improve stability.

[0160] In all variants of the first configuration, the elastic return member 140 is chosen by a person skilled in the art so that the return force of the spring exerts sufficient pressure to guarantee electrical contact between the fuse plate and the electrode in the blocking position.

[0161] Second configuration

[0162] According to a second configuration of the invention, as illustrated in Figures 15 to 19, the fixing system 110 of each electrode 100 is intended to hold the end 240 of the fuse plate 200 in the body 102 of the electrode 100 at its first end portion 150.

[0163] As illustrated in Figure 16, the fastening system 110 is configured in a frustoconical shape, that is, the cross-section of the fastening system 110 decreases continuously from a large base 111 to a small base 112, along a longitudinal axis of said fastening system. The fastening system 110 comprises a first support piece 160 and a second support piece 170, which are distinct, assembled against each other at a longitudinal interface. A first base 161 of the first support piece 160 and a first base 171 of the second support piece 170 compose the large base 111 of the fastening system. Similarly, a second base 162 of the first support piece 160 and a second base 172 of the second support piece 170 compose the small base 112 of the fastening system.

[0164] The end 240 of the fuse plate 200 is intended to be placed at the longitudinal interface, between the first and second support pieces 160 and 170, as illustrated in Figures 15 and 18. According to a preferred embodiment of this second configuration, the shape of the fixing system 110 is a truncated pyramid, as illustrated in Figures 15 to 17. In a preferred non-limiting example, the first and second support pieces 160 and 170 have a truncated pyramid, of a shape similar to the fixing system. In addition, preferably, the first bases 161 and 171 of the first and second support pieces 160 and 170 are their large bases respectively.

[0165] According to another preferred form of this second configuration, the shape of the fixing system 110 is a truncated cone, as illustrated in Figures 18 and 19.

[0166] The body 102 of the electrode 100 transversely comprises an orifice 157, at its first end portion 150, which may or may not pass through. The orifice 157 is intended to receive the fixing system 110 with the fuse plate.

[0167] The orifice 157 has a shape complementary to that of the fixing system 110. The precise adjustment between the fixing system 110 and the orifice 157 makes it possible to ensure pressure contact between the fuse plate 200 and the fixing system 110. The fixing system 110 of the electrode 100 is made of an electrically conductive material in order to guarantee electrical contact between the fuse plate 200 and the body 102 of said electrode.

[0168] The body 102 of the electrode further comprises, on its first face 104, an opening 103 which is connected to the orifice 157, to allow the passage of the fuse plate 200 at the level of the first face and to place the fuse plate between the two electrodes.

[0169] As an illustrative example, any type of fuse board shown in Figure 2 can be used with the attachment system of this second configuration.

[0170] In the locking position, the fixing system 110 is inserted into the orifice 157 of the body of the electrode. Preferably, the body 102 of the electrode comprises a stop (not shown) to lock the fixing system 110 in its locking position.

[0171] In the release position, the fixing system 110 is separated from the body of the electrode, outside the orifice 157.

[0172] For each forming cycle via the EHF process, an operator prepares in advance an assembly, consisting of a fusible plate 200 and two fixing systems 110. To prepare the assembly, the operator separates the two support pieces 160 and 170 of each fixing system 100 and positions each end 240 of the fusible plate 200 in each fixing system, and reassembles the two support pieces.

[0173] To install the assembly in the two electrodes, the operator inserts each fixing system 110 into the orifice 157 of each electrode 100, by inserting each fixing system through the small base 112. The fixing systems 110 are thus in the locking position.

[0174] When an electric shock has been performed, he removes the assembly and installs a new assembly.

[0175] After removing the assembly, the operator separates the two support pieces of each fastener to remove the fuser plate residue. The fasteners can be reused to prepare a new assembly with a new fuser plate.

[0176] Preferably, the first support piece 160 comprises a pin 164 intended to cooperate with a complementary housing 173 of the second support piece 170 in the locking position, as illustrated in Figures 17 and 19. In this case, the end 240 of the fuse plate 200 preferably comprises an orifice 241 or a notch 243 to receive the pin 164 of the first support piece 160. As an illustrative example, the plate shown in views (a), (b), (c) or (e) of Figure 2 is adapted to the fixing system of this preferred form of the second configuration.

Claims

CLAIMS Claim 1. Electrode (100) for an electro-hydroforming enclosure (300) comprising: a body (102) comprising a first end portion (150), and a fixing system (110), by compression locking, configured and intended to hold one end (240) of a fusible plate (200) against the body (102) or in the body (102) of the electrode (100), at the level of said first end portion (150) of the electrode;said fixing system (110) evolving between a release position and a locking position: o the release position of said fixing system (110) being intended to allow the positioning and removal of the end (240) of the fuse plate (200), and o the locking position of said fixing system (110) being intended to allow electrical contact between the end (240) of the fuse plate (200) and the body of the electrode (100), characterized in that the fixing system (110) comprises: a support piece (120) of which a head (124) is intended to be in contact with the end (240) of the fuse plate (200), and an elastic return member (140), linked to the support piece (120), configured so that in the locking position of said fixing system (110), said elastic return member exerts a return force on the support piece (120) against the body (102) of the electrode (100) at the first end portion (150)..; Claim 2. Electrode (100) according to claim 1, in which the elastic return member (140) is chosen from: a compression spring, a tension spring, a torsion spring, an elastic. Claim 3. Electrode (100) according to claim 1 or 2, in which: the support piece (120) comprises a rod (122) connected to the head (124), The body (102) of the electrode comprises a transverse guide hole (151), at the level of the first end portion (150), and intended to receive said rod (122), and the elastic return member (140) is a compression spring or a tension spring whose turns are wound around the rod (122). Claim 4. Electrode (100) according to claim 3, in which: a first end (141) of the elastic return member (140) is connected to the support piece (120), and a second end (142) of the elastic return member (140) is intended to be connected to a frame (320) of the electro-hydroforming enclosure (300). Claim 5. Electrode (100) according to claim 3, wherein: one end of the rod (122) of the support piece (120) is connected to the head (124), another end of the rod (122) comprises a nut (126), the body (102) of the electrode is positioned between the head (124) and the nut (126), and the return member (140) is arranged, around the rod, between the body (102) of the electrode and the nut (126). Claim 6. Electrode (100) according to claim 5, in which the body (102) comprises: a first flat (153), and a pair of helical ramps (152), on the first flat, arranged around the guide hole (151), said helical ramps (152) being configured such that the head (124) of the support piece (120) moves between an upper part and a lower part of the helical ramps (152) during a rotational movement of the support piece (120) around a longitudinal axis of the rod (122), and in which the electrode is configured such that: in the disengaged position of said fixing system (110), the head (124) of the support piece (120) is at the level of the upper part of the helical ramps (152), and in the locking position of said fixing system (110), the head (124) is located at the level of the lower part of the helical ramps (152). Claim 7. Electrode (100) according to claim 1 or 2, in which the elastic return member (140) is a torsion spring, a first end (141) of which is connected to the support piece (120), and a second end (142) is connected to the body (102) of the electrode (100), said electrode being configured so that, in the locking position of said fixing system (110), said torsion spring is compressed. Claim 8. Electrode (100) according to claim 1 or 2, in which the body (102) comprises: a longitudinal groove (131) on the body (102), a slide (130) comprising an arm (132) intended to be inserted into the groove (131) such that the slide (130) slides along the groove (131), and two flats (153, 155), called first and second flats, separated by a slope (154) on the body of the electrode, the first flat (153) being intended to receive the end (240) of a fuse plate (200), in which the support piece (120) is connected to the slide (130) such that the head (124) of said support piece moves between the first flat (153) and the second flat (154), during the movement of the arm (132) of the slider (130) in the groove (131), and in which the elastic return member (140) is a compression spring or a tension spring, a first end (141) of which is connected to the support piece (120),and a second end (142) is connected to the slide (130) such that: in the release position of said fixing system (110), the head (124) of the support piece (120) is located at the level of the second flat (154), and in the locking position of said fixing system (110), the head (124) is located at the level of the first flat (153)., Claim 9. Electrode (100) according to claim 1 or 2, in which the elastic return member (140) is an elastic, and the fixing system (110) is configured such that the elastic transversely surrounds the support piece (120) and the body (102) of the electrode (100) at the first end portion (150), in the locking position. Claim 10. Electrode (100) according to claim 1 or 2, in which the elastic return member (140) is an elastic, and the fixing system (110) is configured such that the body (102) of said electrode comprises two lugs (156) so that the elastic (140) is held at the level of said lugs, overlapping the support piece (120), in the locking position. Claim 11. Electro-hydroforming enclosure (300), comprising a discharge frame (320) comprising an internal wall (322) delimiting a discharge chamber (310), characterized in that it comprises: at least two electrodes (100) according to one of claims 1 to 10, said at least two electrodes being intended to be opposite one another, arranged partly in the discharge chamber, and connected via a fuse plate (200).

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