Method and device for forming a wave-shaped conductor element of electrical windings

Abstract

The present invention relates to a method for forming a wave-shaped conductor element (2) of electrical windings, starting from a conductor wire (3). The method according to the invention entails a series of operating steps of dispensing the wire (3) onto a forming unit (4) according to respective rules of motion and operating sequences that ensure that the wave-shaped conductor element (2) is laid exclusively on an operating face (9) of the forming unit (4) by means of a respective dispenser (25) of wire (3).

Description

[0001] METHOD AND DEVICE FOR FORMING A WAVE-SHAPED CONDUCTOR ELEMENT OF ELECTRICAL WINDINGS

[0002] The present invention relates to a method and a device for forming conductor elements of the wave-shaped type. Such wave-shaped conductor elements are suitable for providing electrical windings, once they are inserted in ferromagnetic cores of electrical machines. The ferromagnetic cores of principal interest for the present discussion are of the type with open slots in order to allow an easy radial insertion of the conductor elements that make up the respective electrical winding. The slots can be open toward the outside or toward the inside of the ferromagnetic core. The wave-shaped conductor elements are then connected electrically to other wave-shaped conductor elements arranged on the ferromagnetic core, thus forming the electrical windings of rotating electrical machines, such as stators and rotors. Rotating electrical machines include motors (powered by alternating current and direct current), dynamos, alternators and electromagnetic brakes.

[0003] The wave-shaped conductor elements have, at the moment of insertion in the ferromagnetic core, a plurality of mutually adjacent linear portions, necessarily at least three, which extend parallel to each other, and a plurality of bridge-like portions interposed between them, to connect the adjacent linear portions to each other. The bridge-like portions are arranged alternately on one end side and on the other end side of the linear portions. The linear portions are inserted into the slots of a ferromagnetic core (for example the stator core), while the bridge-like portions protrude from respective end sides of the core of the ferromagnetic core (for example the stator core). The cross-section of the wire that forms the conductor element can be circular, square or rectangular. The dimension of the cross-section of the conductor element usually depends on the width of the cross-section of the slot in the core of the ferromagnetic core (for example the stator core).

[0004] Open-slot rotating machines are machines in which the slots of the ferromagnetic core which accommodate the winding (which can be provided in the stator or in the rotor) are open so as to allow the radial insertion of the linear portions of the conductor elements directly into the slot, differently from closed-slot machines in which it is necessary to introduce the conductor elements (for example of the type known as hairpins or of the type known as I-pins) longitudinally in each slot.

[0005] The ability to insert the conductor elements into the open slots means it is possible to subject them in advance to operations that enable the reproduction of parts of the winding to be provided (for example constituted by the specific shape structure of the conductor element that has straight portions connected by respective bridge-like portions), so as to make it possible to build the winding more rapidly, while minimizing the welds necessary to join the portions of conductor elements.

[0006] In order to speed up the operations to shape the conductor elements, the use is known of devices that make it possible to shape a shank of a conductor element in a wave-shaped structure.

[0007] Methods are known which involve winding the shank of the conductor element around a plate (of given dimensions) with a specific distribution, i.e., alternately laying the linear portions of a wave-shaped element on the two mutually opposite faces of the plate, so requiring its axial extraction upon completion of the distribution.

[0008] The above-mentioned process is very rapid, but it does not allow precision control of the orientation of the shank of the conductor element (if this has a polygonal cross-section it may be necessary to maintain a specific distribution of its lateral surfaces). Furthermore, the need to axially slide out the winding imposes specific and non-negligible dimensional constraints, in particular, a greater overall bulk.

[0009] Alternatively, the use is known of laying the shank of the conductor element on a fixed forming unit. Once the shank has been laid on such forming unit, adapted mobile grippers arranged on the forming unit are simultaneously actuated in order to deform the shank and obtain the desired wave-shaped contour of the conductor element: by adopting this solution, the grippers (or other dedicated devices) can also perform a transverse extraction (substantially along a direction perpendicular, or partially inclined, with respect to the laying surface) that makes it possible to reduce the overall bulk of the device adapted to provide the semi-finished product, constituted by the shank with the wave-shaped contour. With this technique, it is also possible to control the orientation of the wire with exceptional precision, and therefore maintain correct placements of the corresponding surfaces during the laying of the shank (particularly advantageous in cases where it is necessary to form a semi-finished product with a shank that is polygonal in cross-section). By contrast, in this solution the time required to produce the semi-finished product is rather long, and this therefore also has an impact on the final cost of the processing and of the semi-finished product itself.

[0010] The aim of the present invention is to solve the above-mentioned drawbacks, by providing a method for forming a wave-shaped conductor element of electrical windings that has a shape and orientation, within given tolerances, that correspond to the theoretical standards.

[0011] Within this aim, an object of the invention is to provide a method for forming a wave-shaped conductor element of electrical windings for rotating open-slot electrical machines, which ensures a productivity superior to that achievable with the method of laying the shank of the conductor element on a fixed forming unit.

[0012] Another object of the invention is to provide a device for forming a wave-shaped conductor element of electrical windings that offers reduced space occupation, in general lower than that of conventional devices which entail wrapping the shank of the conductor element around a forming unit.

[0013] Another object of the invention is to provide a device for forming a wave-shaped conductor element of electrical windings that operates with greater precision than that achievable with conventional devices which entail wrapping the shank of the conductor element around a forming unit.

[0014] Another object of the invention is to provide a device for forming a wave-shaped conductor element of electrical windings that ensures costs are lowered with respect to the prior art which entails laying the shank of the conductor element on a fixed forming unit using adapted grippers.

[0015] Another object of the invention is to provide a device for forming a wave-shaped conductor element of electrical windings that enables full automation of the shaping operations to produce a substantially wave-shape of the shank of the conductor element.

[0016] Another object of the present invention is to provide a method and a device for forming a wave-shaped conductor element of electrical windings which are of low cost, easily and practically implemented, and safe in use.

[0017] This aim and these objects are achieved by a method for forming a wave-shaped conductor element of electrical windings according to claim 1.

[0018] This aim and these objects are also achieved by way of a device for forming a wave- shaped conductor element of electrical windings according to claim 8.

[0019] Further characteristics and advantages of the invention will become better apparent from the detailed description that follows of a preferred, but not exclusive, embodiment of the method and of the device for forming a wave-shaped conductor element of electrical windings, which are illustrated by way of non-limiting example in the accompanying drawings wherein:

[0020] Figure 1 is a schematic perspective view of a device for forming a wave-shaped conductor element of electrical windings according to the invention in a first operative position during the application of the method according to the invention;

[0021] Figure 2 is a schematic perspective view of the device of Figure 1 in a second operative position during the application of the method according to the invention;

[0022] Figure 3 is a schematic perspective view of the device of Figure 1 in a third operative position during the application of the method according to the invention;

[0023] Figure 4 is a schematic perspective view of the device of Figure 1 in a fourth operative position during the application of the method according to the invention;

[0024] Figure 5 is a schematic perspective view of the device of Figure 1 in a fifth operative position during the application of the method according to the invention;

[0025] Figure 6 is a schematic perspective view of the device of Figure 1 in a sixth operative position during the application of the method according to the invention;

[0026] Figure 7 is a schematic perspective view of the device of Figure 1 in a seventh operative position during the application of the method according to the invention;

[0027] Figure 8 is a schematic perspective view of the device of Figure 1 in a first part of an operative rotation during the application of the method according to the invention;

[0028] Figure 9 is a schematic perspective view of the device of Figure 1 in a second part of an operative rotation during the application of the method according to the invention;

[0029] Figure 10 is a schematic perspective view of a first component of the device of Figure 1;

[0030] Figure 11 is a schematic view from above of the component of Figure 10;

[0031] Figure 12 is a schematic perspective view of a second component of the device of Figure 1;

[0032] Figure 13 is a schematic view from above of the component of Figure 12;

[0033] Figure 14 is a schematic perspective view of a forming element of the device of Figure 1; Figure 15 is a schematic view from above of the forming element of Figure 14, in the activated configuration in which it comprises a portion of shaped conductor wire;

[0034] Figure 16 is a schematic perspective view of a machine comprising the device for forming a wave-shaped conductor element of electrical windings according to the invention.

[0035] With reference to the figures, the reference numeral 1 generally designates a device for forming a wave-shaped conductor element 2 of electrical windings that is adapted to apply the method according to the invention.

[0036] It should be noted that the method according to the invention and the device 1 according to the invention are particularly indicated for providing wave-shaped conductor elements 2 that can be used as portions of electrical windings in rotating open-slot electrical machines, although it should be noted from this point onward that such conductor elements 2 can also be used in other, different applications.

[0037] With reference to one of the possible embodiments and use of the method and of the device 1 according to the invention, it should be noted that the electrical conductor elements 2 produced can be adapted to form part of electrical windings for rotating open-slot electrical machines (i.e. motors and / or generators and / or electromagnetic brakes wherein the slots are constituted by contiguous grooves provided on the surface of the electromagnetic core into which it is possible to insert the electrical windings following a substantially radial movement, or a movement with a radial component, with respect to the core).

[0038] As previously indicated, each wave-shaped electrical conductor element 2 can also be used for other applications, which in any case remain within the scope of protection defined by the present invention.

[0039] The method according to the invention is therefore adapted to produce a wave-shaped conductor element 2 of electrical windings, made starting from a conductor wire 3.

[0040] Such method comprises a sequence of steps executed in succession.

[0041] In a first step i) it is necessary to provide a forming unit 4, rotatable around a longitudinal rotation axis 5: such forming unit 4 must comprise an operating face 9 supporting a plurality of forming elements 11, 14, 15, 16, 17, 18, wherein each forming element 11, 14, 15, 16, 17, 18 comprises in turn a respective abutment base l id, 14d, 15d, 16d, 17d, 18d, a respective first abutment element l ie, 14e, 15e, 16e, 17e, 18e, and a respective second abutment element I lf, 14f, 15f, 16f, 17f, 18f.

[0042] In a subsequent second step ii) it is necessary to lock a terminal end of the conductor wire 3 to the forming unit 4 by means of a locking element 9a. The locking element 9a is integral with the operating face 9 of the forming unit 4 and comprises a seat 12 in which the terminal end of the conductor wire 3 can be locked.

[0043] In a subsequent third step iii) it is necessary to lay the conductor wire 3 along a first straight portion 10, starting from the end locked by the locking element 9a, along a direction transverse to the longitudinal axis 5.

[0044] Then it is possible to perform a fourth step iv) which entails activation of a first forming element 11 of the plurality of forming elements 11, 14, 15, 16, 17, 18 to constrain the conductor wire 3 at the end of the first straight portion 10.

[0045] The subsequent fifth step v) involves rotating the forming unit 4 by 180° with respect to the longitudinal axis 5 so as to obtain a first apical fold 23a of the conductor wire 3, at least partially arranged on the first forming element 11.

[0046] In the sixth step vi) it is necessary to lay the conductor wire 3 along a direction having a component parallel to the longitudinal axis 5 by dragging the first apical fold 23a onto the first forming element 11.

[0047] Dragging the apical fold 23 a defines the formation of an arc of conductor wire 3 corresponding to the bridge-like portion of the conductor element 2 that connects two contiguous linear portions (i.e. the portion 10 and the portion 13, in the present discussion): this arc starts from the first portion 10, which leads into an initial portion 22 of the arc which ends at the apical fold 23 (23a at the forming element 11); after this apical fold 23 there is an end portion 24 of the arc.

[0048] Basically the initial portion 22 is formed following the dragging of the apical fold 23 (in this case 23a); the end portion 24, on the other hand, assumes the respective arrangement following successive operations. Initially the conductor wire 3 is dragged onto the forming element 11, 14,

[0049] 15, 16, 17, 18, displacing the apical fold 23 (in the concerned case 23a) until it reaches the final position, thus forming the initial portion 22. Then, the conductor wire 3, which is already outside the forming element 11, 14, 15,

[0050] 16, 17, 18, is further dragged longitudinally for a distance substantially equal to the initial portion 22, before beginning a subsequent seventh step vii) of laying which will be described below. To this end, the second abutment shoulder element 29, 28 is activated so as to force the laying of the conductor wire 3 on parallel planes, once the wire has exited from the forming element 11, 14, 15, 16, 17, 18.

[0051] The formation of the initial portion 22 (displacement of the apical fold 23), is performed while the conductor wire 3 is locked between the respective forming element 11, 14, 15, 16, 17, 18 (in particular the first abutment element l ie, 14e, 15e, 16e, 17e, 18e) and the first abutment shoulder element 28, 29, and subsequently, in the absence of the forming element 11, 14, 15, 16, 17, 18, the conductor wire 3 is dragged, forcing it between the first and second abutment shoulder element 28, 29 of a wire dispenser 25, forming the end portion 24.

[0052] The subsequent seventh step vii) entails laying the conductor wire 3 along a second straight portion 13 starting from the first forming element 11 along a direction transverse to the longitudinal axis 5 in a direction parallel and opposite to the first straight portion 10. The second straight portion 13 starts from the front that is opposite to that connected to the apical fold 23 of the end portion 24.

[0053] The eighth step viii) consists in activating a second forming element 14, of the plurality of forming elements 11, 14, 15, 16, 17, 18, to constrain the conductor wire 3 at the end of the second straight portion 13.

[0054] In ninth step ix), it is necessary to rotate the forming unit 4 by -180° with respect to the longitudinal axis 5, i.e. in the opposite direction with respect to the previous step of rotation, so as to obtain a second apical fold 23b of the conductor wire 3, at least partially arranged on the second forming element 14.

[0055] The tenth step x) involves laying the conductor wire 3 along a direction having a component parallel to the longitudinal axis 5, by dragging the second apical fold 23b onto the second forming element 14.

[0056] In this case too, dragging the apical fold 23b defines the formation of an arc of conductor wire 3 corresponding to the bridge-like portion of the conductor element 2 that connects two contiguous linear portions (i.e. that of the second portion 13 to the subsequent one): this arc starts from the second portion 13, which leads into a respective initial portion 22 which ends at the apical fold 23b at the forming element 14; after this apical fold 23b there is an end portion 24 which leads to a subsequent straight section in which the conductor wire 3 is arranged.

[0057] The method according to the invention entails an eleventh step xi) of repeating the steps from the third iii) to the tenth x), for a given number of times, on other respective forming elements 15, 16, 17, 18 of the plurality of forming elements 11, 14, 15, 16, 17, 18, until obtaining a conductor element 2 constituted by portions of substantially wave-shaped conductor wire 3.

[0058] The twelfth, and last, step xii) involves removing the wave-shaped conductor element 2 and extracting it from the forming unit 4. The conductor wire 3 can be supplied pre-cut from an upstream station. Alternatively, the conductor wire 3 can be cut after the wave-shaped conductor element 2 has been completely modeled in the forming unit 4.

[0059] In the method according to the invention, advantageously, the wave- shaped conductor element 2 is laid exclusively on the operating face 9 of the forming unit 4 by means of a wire dispenser 25.

[0060] It should be noted that the possibility is not ruled out that the forming unit 4 could comprise two mutually opposite operating faces 9 and that a respective wire dispenser 25 would cooperate with each one of these faces, so as to allow the simultaneous production of two wave-shaped conductor elements 2.

[0061] It should be noted that the steps of activation of a forming element 11 , 14, 15, 16, 17, 18 can positively comprise a respective rotation of such forming element 11, 14, 15, 16, 17, 18 about a respective rotation axis I la, 14a, 15a, 16a, 17a, 18a which is perpendicular to the operating face 9: such rotation is performed by the forming element 11, 14, 15, 16, 17, 18 from a disengaged position to an engagement position.

[0062] The disengaged position and the engagement position of the forming element 11, 14, 15, 16, 17, 18 can be separated by an angle of given width, preferably 90°, which corresponds to the breadth of rotation about the respective axis I la, 14a, 15a, 16a, 17a, 18a.

[0063] The rotation of each forming element 11, 14, 15, 16, 17, 18 about the respective rotation axis I la, 14a, 15a, 16a, 17a, 18a can be achieved by way of an actuation system of the pneumatic type, although other embodiments are not ruled out.

[0064] At the engagement position, the conductor wire 3 is placed above a face of the abutment base l id, 14d, 15d, 16d, 17d, 18d of the respective forming element 11, 14, 15, 16, 17, 18 by way of a protruding portion 11g, 14g, 15g, 16g, 17g, 18g of the first abutment element l ie, 14e, 15e, 16e, 17e, 18e.

[0065] Basically, as can be seen in the accompanying Figure 15, the protruding portion 11g, 14g, 15g, 16g, 17g, 18g surmounts a part of the end portion 24 and of the first portion 10, locking them onto the face of the abutment base l id, 14d, 15d, 16d, 17d, 18d.

[0066] Such first abutment element l ie, 14e, 15e, 16e, 17e, 18e can profitably comprise a lateral wall 11b, 14b, 15b, 16b, 17b, 18b adapted to be placed along a flank of the conductor wire 3 in the engagement position of the respective forming element 11, 14, 15, 16, 17, 18.

[0067] Each one of the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can move between a retracted position and an extracted position, in which it oversteps with respect to the abutment base l id, 14d, 15d, 16d, 17d, 18d to constrain the conductor wire 3 in the engagement position.

[0068] According to a possible embodiment (illustrated by way of nonlimiting example in the accompanying figures) each one of the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can be movable between a retracted position, in which it is fully contained inside the respective abutment base l id, 14d, 15d, 16d, 17d, 18d, and an extracted position, in which it protrudes from such abutment base l id, 14d, 15d, 16d, 17d, 18d, protruding at least partially from it, abutting against a flank of the conductor wire 3, again in the engagement position assumed by the respective forming element 11, 14, 15, 16, 17, 18; each second abutment element I lf, 14f, 15f, 16f, 17f, 18f therefore constitutes an abutment shoulder against which the conductor wire 3 can rest in order to maintain the right geometric orientation.

[0069] According to this embodiment, the second abutment element I lf, 14f, 15f, 16f, 17f, 18f can be by contrast movable between a retracted position, in which it is fully contained inside the respective abutment base l id, 14d, 15d, 16d, 17d, 18d, and an extracted position, in which it protrudes from such abutment base l id, 14d, 15d, 16d, 17d, 18d: in such extracted and protruding position, it exits protruding from the respective abutment base l id, 14d, 15d, 16d, 17d, 18d to abut against a flank of the conductor wire 3 in the engagement position, so acting as an abutment surface for the conductor wire 3.

[0070] The second abutment element I lf, 14f, 15f, 16f, 17f, 18f can assume the respective extracted and protruding position only after the respective forming element 11, 14, 15, 16, 17, 18 has reached the mentioned engagement position.

[0071] The flank of the wire 3 on which the second abutment element I lf, 14f, 15f, 16f, 17f, 18f is arranged, acting as an abutment surface for the conductor wire 3, is opposite to the flank of the conductor wire 3 arranged resting against the lateral wall 11b, 14b, 15b, 16b, 17b, 18b: in this manner it is possible to lock the conductor wire 3 between the wall 1 lb, 14b, 15b, 16b, 17b, 18b, the second abutment element I lf, 14f, 15f, 16f, 17f, 18f, the abutment base l id, 14d, 15d, 16d, 17d, 18d and the protruding portion 11g, 14g, 15g, 16g, 17g, 18g (so ensuring that no unwanted plastic deformations can arise during the subsequent operations of laying and / or shaping).

[0072] The forming unit 4 is advantageously adapted to activate the egress of the second abutment element I lf, 14f, 15f, 16f, 17f, 18f, once the respective forming element 11, 14, 15, 16, 17, 18 has reached the engagement position, using preferably pneumatic actuation means. By way of example, it should be noted that each forming element 11, 14, 15, 16, 17, 18 can conveniently comprise a small hole under the second abutment element I lf, 14f, 15f, 16f, 17f, 18f in order to allow the passage of a compressed air flow originating from the forming unit 4 (in turn connected to a pneumatic actuation circuit) which lifts, and extracts by making it protrude, the second element I lf, 14f, 15f, 16f, 17f, 18f.

[0073] With reference to an alternative embodiment (for which no explanatory images are provided because its form and characteristics are intuitive), it should be noted that the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can also be constituted by adapted gripping means that exit from and retract into recesses in the forming unit 4 which are open on the operating face 9. These gripping means can be constituted by contoured grippers, which are therefore adapted to clamp the conductor wire 3 and hold it without damaging it, and which can be retracted completely into the recesses in the forming unit 4 (in such case, not posing any obstacle to the movements of the wire dispenser 25) and extracted only when necessary in order to clamp the conductor wire 3 and ensure the stability of its arrangement.

[0074] The possibility is not ruled out of having the recesses in substantial alignment with the perimeter of the forming elements 11, 14, 15, 16, 17, 18, so that the extraction of the gripping means can also ensure the locking of the forming elements 11, 14, 15, 16, 17, 18 in one (or potentially also in both) of the respective configurations (i.e. the active configuration and the passive configuration), increasing the overall rigidity of the device 1 and therefore ensuring a greater precision of forming the conductor element 2.

[0075] It should be noted that the apical folds 23 (for example the fold 23a made at the forming element 11, or the fold 23b made at the forming element 14) are obtained on the first abutment element l ie, 14e, 15e, 16e, 17e, 18e of a respective forming element 11, 14, 15, 16, 17, 18.

[0076] Basically, in the absence of the first abutment element l ie, 14e, 15e, 16e, 17e, 18e on a respective forming element 11, 14, 15, 16, 17, 18, it would not be possible to make the apical folds 23 with the conductor wire 3 and therefore it would not be possible to shape it like a wave -shaped conductor element 2, by operating only on the operating face 9 of the forming unit 4.

[0077] With reference to an embodiment of undoubted practical and applicative interest, the wire dispenser 25 and the forming unit 4 can move toward and away from each other.

[0078] In particular, at least one component selected from the wire dispenser 25 and the forming unit 4 can move in the direction of the longitudinal axis 5.

[0079] The wire dispenser 25 and the forming unit 4 interact with each other in the steps of laying and rotating, for the plastic deformation of the conductor wire 3 into the substantial wave shape of the electrical conductor element 2.

[0080] In particular the forming unit 4 can be capable of translating along the direction of the longitudinal axis 5, so as to align respective portions of the operating face 9 with the wire dispenser 25; in turn the wire dispenser 25 can advance and retreat, respectively toward and away from the longitudinal axis 5 along a direction transverse to that axis 5, for the purpose of passing from a configuration in which it is outside the contour of the forming unit 4 to a configuration in which it surmounts it, facing and proximate to the operating face 9.

[0081] The wire dispenser 25 can be profitably mounted on a movable arm 25a which can translate toward the forming unit 4 and away from it; the movable arm 25a is mounted so that it can slide on a guide bar 25b in order to be moved up and down.

[0082] The wire dispenser 25 can in turn advantageously comprise at least a first and a second abutment shoulder element 28, 29 arranged mutually opposite, with the conductor wire 3 (which exits through a respective channel 30) interposed.

[0083] Each abutment shoulder element 28, 29 is independently movable between a retracted position, in which it is contained inside the wire dispenser 25, and an extracted position, in which it protrudes at least partially from the wire dispenser 25 so as to delimit the conductor wire 3 during the corresponding step of longitudinal laying on the respective forming element 11, 14, 15, 16, 17, 18.

[0084] The protection offered by the present invention also extends to a device 1 for making wave-shaped conductor elements 2 for electrical windings starting from a conductor wire 3.

[0085] The device 1 according to the invention comprises a wire dispenser 25 for dispensing the conductor wire 3, for example originating from a supply apparatus, and a forming unit 4 which is mounted so that it can rotate about a longitudinal axis 5 and which comprises at least one operating face 9.

[0086] The device 1 according to the invention can further comprise an apparatus for supplying the conductor wire 3, which is not shown in the accompanying figures because it is conventional and which generally comprises a spool on which the conductor wire 3 is wound, conveyance means and, optionally, an accumulation buffer.

[0087] In an embodiment, the forming unit 4 can be mounted on a carriage that can be moved along the longitudinal axis 5. The relative movement of the forming unit 4 along the longitudinal axis 5 results in the dragging of the apical fold 23. In an embodiment, the wire dispenser 25 can be mounted on a carriage 4a that can be moved parallel to the longitudinal axis 5 of the forming unit 4.

[0088] On the operating face 9 of the forming unit 4, there is a locking element 9a adapted to lock an end of the conductor wire 3.

[0089] Furthermore, also on the operating face 9 of the forming unit 4, a plurality of forming elements 11, 14, 15, 16, 17, 18 is provided: each forming element 11, 14, 15, 16, 17, 18 of this plurality is adapted to interact with the conductor wire 3 dispensed by the wire dispenser 25 to produce the conductor element 2 in a preset wave shape.

[0090] According to the invention, each forming element 11, 14, 15, 16, 17, 18 comprises a respective abutment base l id, 14d, 15d, 16d, 17d, 18d against which portions of conductor wire 3 abut, a respective first abutment element l ie, 14e, 15e, 16e, 17e, 18e, and a respective second abutment element I lf, 14f, 15f, 16f, 17f, 18f.

[0091] The device 1 according to the invention further comprises at least one control and management unit 31 which is connected at least to the wire dispenser 25, to the forming unit 4, and to the plurality of forming elements 11, 14, 15, 16, 17, 18, and which can be programmed to execute the following instructions: - actuate the wire dispenser 25 so as to lay the conductor wire 3 along a first straight portion 10, starting from an end thereof locked by the locking element 9a, along a direction transverse to the longitudinal axis 5;

[0092] - activate a first forming element 11 (belonging to the plurality of forming elements 11, 14, 15, 16, 17, 18) to constrain the conductor wire 3 at the end of the first straight portion 10;

[0093] - rotate the forming unit 4 by 180° with respect to the longitudinal axis 5 so as to obtain a first apical fold 23 a of the conductor wire 3, at least partially accommodated on the first forming element 11 ;

[0094] - lay the conductor wire 3 along a direction having a component parallel to the longitudinal axis 5 by dragging the first apical fold 23a onto the first forming element 11 ;

[0095] - lay the conductor wire 3 along a second straight portion 13 starting from the first forming element 11 along a direction transverse to the longitudinal axis 5 in a direction parallel and opposite to the first straight portion 10;

[0096] - activate a second forming element 14 (belonging to the plurality of forming elements 11, 14, 15, 16, 17, 18) to constrain the conductor wire 3 at the end of the second straight portion 13;

[0097] - rotate the forming unit 4 by -180° with respect to the longitudinal axis 5, i.e. in the opposite direction with respect to the previous step of rotation, so as to obtain a second apical fold 23b of the conductor wire 3, at least partially accommodated on the second forming element 14;

[0098] - lay the conductor wire 3 along a direction having a component parallel to the longitudinal axis 5 by dragging the second apical fold 23b onto the second forming element 14;

[0099] - repeat the previous steps for a given number of times, on other respective forming elements 15, 16, 17, 18 (belonging to the plurality of forming elements 11, 14, 15, 16, 17, 18), until obtaining a conductor element 2 constituted by portions of substantially wave-shaped conductor wire 3; - remove the wave-shaped conductor element 2 and extract it from the forming unit 4. The conductor wire 3 can be supplied pre-cut from an upstream station. Alternatively, the conductor wire 3 can be cut after the wave-shaped conductor element 2 has been completely modeled in the forming unit 4.

[0100] In the device 1, the wave-shaped conductor element 2 is laid exclusively on the operating face 9 of the forming unit 4 by means of the wire dispenser 25.

[0101] The latter aspect is particularly important because it allows the waveshaped conductor element 2 to be removed from the operating face 9 using only gripping means that can execute a travel toward / away from the operating face 9 of the forming unit 4, i.e. with a structure that is far simpler than that in the prior art.

[0102] Each one of the forming elements 11, 14, 15, 16, 17, 18 is rotatably mounted on the operating face 9 about a respective rotation axis I la, 14a, 15a, 16a, 17a, 18a, between a disengaged position and an engagement position. The disengaged position and the engagement position of the forming element 11, 14, 15, 16, 17, 18 can be separated by an angle of given width, preferably 90°, which corresponds to the breadth of rotation about the respective axis I la, 14a, 15a, 16a, 17a, 18a.

[0103] The forming elements 11, 14, 15, 16, 17, 18 in the engagement position are arranged mutually alternately in two mutually opposite rows that are parallel to the longitudinal axis 5, as shown by way of non-limiting example in the accompanying figures.

[0104] In the engagement position, the conductor wire 3 is placed above a face of the abutment base l id, 14d, 15d, 16d, 17d, 18d by way of a protruding portion 11g, 14g, 15g, 16g, 17g, 18g of the first abutment element l ie, 14e, 15e, 16e, 17e, 18e. As already indicated previously, it can be seen in the accompanying Figure 15 that the protruding portion 11g, 14g, 15g, 16g, 17g, 18g surmounts a part of the end portion 24 and of the first portion 10, locking them onto the face of the abutment base l id, 14d, 15d, 16d, 17d, 18d.

[0105] It should also be highlighted that each first abutment element l ie, 14e, 15e, 16e, 17e, 18e comprises a lateral wall 11b, 14b, 15b, 16b, 17b, 18b which is positioned along a flank of the conductor wire 3, when the respective forming element 11, 14, 15, 16, 17, 18 is in the respective engagement position.

[0106] Each one of the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can move between a retracted position and an extracted position, in which it oversteps with respect to the abutment base l id, 14d, 15d, 16d, 17d, 18d, to constrain the conductor wire 3 in the engagement position.

[0107] According to a possible embodiment (illustrated by way of nonlimiting example in the accompanying figures) each one of the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can be movable between a retracted position, in which it is fully contained inside the respective abutment base l id, 14d, 15d, 16d, 17d, 18d, and an extracted position, in which it protrudes from the abutment base l id, 14d, 15d, 16d, 17d, 18d, protruding at least partially from it, abutting against a flank of the conductor wire 3, again in the engagement position assumed by the respective forming element 11, 14, 15, 16, 17, 18; each second abutment element I lf, 14f, 15f, 16f, 17f, 18f therefore constitutes an abutment shoulder against which the conductor wire 3 can rest in order to maintain the right geometric orientation.

[0108] With reference to an alternative embodiment (for which no explanatory images are provided because its form and characteristics are intuitive), it should be noted that the second abutment elements I lf, 14f, 15f, 16f, 17f, 18f can also be constituted by adapted gripping means that exit from and retract into recesses in the forming unit 4 which are open on the operating face 9.

[0109] These gripping means could be constituted by contoured grippers, which are therefore adapted to clamp the conductor wire 3 and hold it without damaging it, and which can be completely retracted into the recesses in the forming unit 4 (in such case, not posing any obstacle to the movements of the wire dispenser 25) and extracted only when necessary in order to clamp the conductor wire 3 and ensure the stability of its arrangement.

[0110] The possibility is not ruled out of having the recesses in substantial alignment with the perimeter of the forming elements 11, 14, 15, 16, 17, 18, so that the extraction of the gripping means can also ensure the locking of the forming elements 11, 14, 15, 16, 17, 18 in one (or potentially also in both) of the respective configurations (i.e. the active configuration and the passive configuration), increasing the overall rigidity of the device 1 and therefore ensuring a greater precision of forming the conductor element 2.

[0111] The first abutment element l ie, 14e, 15e, 16e, 17e, 18e of a respective forming element 11, 14, 15, 16, 17, 18 has a shape structure adapted to produce the apical folds 23.

[0112] The wire dispenser 25 and the forming unit 4 comprise respective actuators which are controlled by the control and management unit 31 and are adapted to move them toward and away from each other.

[0113] At least one of such actuators has a movement stroke of its movable element along a direction having at least one component in the direction of the longitudinal axis 5. The wire dispenser 25 and the forming unit 4 interact with each other in the steps of laying and rotating, for the plastic deformation of the conductor wire 3 into the substantial wave shape of the electrical conductor element 2.

[0114] According to a preferred embodiment, the actuators of the forming unit 4 make it possible to move it along a travel of advancement and retreat along the direction of the longitudinal axis 5, while the actuators of the wire dispenser 25 have a travel along a direction perpendicular to the longitudinal axis 5 that makes it possible to move the wire dispenser 5 toward and away from the operating face 9 (bringing it to partially overlap the face 9, or outside the contour of the forming unit 4 on which the face 9 is defined).

[0115] The wire dispenser 25 profitably comprises at least a first and a second abutment shoulder element 28, 29 which are arranged mutually opposite and delimit a channel 30 for dispensing the conductor wire 3.

[0116] Each abutment shoulder element 28, 29 is independently movable between a retracted position, in which it is contained inside the wire dispenser 25, and an extracted position, in which it at least partially protrudes from the wire dispenser 25 so as to delimit and convey the conductor wire 3 during the longitudinal laying thereof on the respective forming element 11, 14, 15, 16, 17, 18.

[0117] Each electrical conductor element 2 constituted by portions of a conductor wire 3 and formed by applying the method (for example using the device 1) can also be subjected to further forming operations (if these are indicated for their insertion into the open slots of the electrical machine for which it is intended).

[0118] According to a preferred embodiment, the forming unit 4 is substantially rectangular (although the possibility is not ruled out of adopting different shape structures that are generically elongated in one longitudinal direction, parallel to a reference axis 5).

[0119] Within such embodiment, it should be noted that the forming unit 4 is arranged with its long side 6 (more correctly its longer edge corresponding to one of the longer parallel sides of the rectangle that constitutes its shape) along a direction parallel to the longitudinal axis 5 and with the short side 7 (more correctly its longer edge) along a direction transverse to the longitudinal axis 5.

[0120] In addition, the forming unit 4 lies on a reference plane 8: the operating face 9 of the forming unit 4 is parallel to this reference plane 8.

[0121] It should further be noted that the forming elements 11, 14, 15, 16, 17, 18 protrude from the operating face 9 in a direction perpendicular to the reference plane 8.

[0122] With regard to the steps in which the forming unit 4 is rotated, it should be pointed out that, if we assume that the rotation imposed on the forming unit 4 during step v) corresponds to 180° (or -180°), then the next rotation that is imposed on the forming unit 4, during step ix), corresponds to -180° (or 180°).

[0123] It should be noted that the steps iv), vii) of longitudinal laying of the conductor wire 3 onto a forming element 11, 14 (but also on the forming elements 16, 17, 18 when these steps are being repeated) are executed along a given path which has at least one component in the longitudinal direction

[0124] 20 (shown in Figure 10) and at least one component in a transverse direction

[0125] 21 (shown in Figure 10). Such components 20 and 21 are contained on the reference plane 8 (or in any case they lie on that plane 8 or on a plane parallel to it). In the initial portion 22, the conductor wire 3 has a component 21 in the direction moving away from the axis 5 up until the apical fold 23; in the end portion 24, the conductor wire 3 has a component 21 in the direction moving toward the axis 5 up until the second portion 13.

[0126] Each forming element 11, 14, 15, 16, 17, 18, during the steps of laying iii) and vii) straight portions in which it is involved, can rotate between a standby position (for example shown in the accompanying Figures 1 to 6 for the forming elements 15, 16, 17, 18) moved away from the conductor wire 3 and an engaged position (for example shown in the accompanying Figures 1 to 6 for the forming elements 11 and 14 and in Figures 7 and 8 also for the forming element 15) in which at least one flap thereof abuts against a part of the surface of the conductor wire 3.

[0127] The rule of motion for laying the conductor wire 3 is defined by the interaction between the rule of motion of the wire dispenser 25 and the rule of motion of the forming unit 4, which are all determined by the respective actuators controlled and managed by the control and management unit 31.

[0128] Each forming element 11, 14, 15, 16, 17, 18 can optionally comprise retention elements 11c, 14c, 15c, 16c, 17c, 18c which are adapted to lock the end portion 24 after having formed the “curved” region constituted by the initial portion 22, the apical fold 23 and the end portion 24, so as to further ensure that region is locked, so preventing from unwanted plastic deformations.

[0129] With reference to an embodiment of undoubted practical and applicative interest, the forming elements 11, 14, 15, 16, 17, 18 which protrude from the operating face 9 of the forming unit 4 are a plurality, arranged side by side and contiguous along the longitudinal direction (parallel to the axis 5): these forming elements 11, 14, 15, 16, 17, 18 constitute an abutment gauge for correctly laying the conductor wire 3 in a shape structure defining a portion constituted by shaped portions of conductor element 2, substantially wave-shaped.

[0130] The retention elements 11c, 14c, 15c, 16c, 17c, 18c can conveniently be movable between a first, passive configuration wherein they are completely outside the corresponding forming elements 11, 14, 15, 16, 17, 18 without surmounting any part thereof (for example in Figure 1 the retention elements 14c, 15c, 16c, 17c, 18c are in this first, passive configuration) and a second, active configuration wherein at least one end thereof protrudes above a part of the respective forming element 11, 14, 15, 16, 17, 18, surmounting a portion of conductor wire 3 (in particular the end portion 24).

[0131] The retention elements 11c, 14c, 15c, 16c, 17c, 18c, optionally present on the forming unit 4, are configured to constrain the conductor wire 3 along the corresponding forming element 11, 14, 15, 16, 17, 18 thus preventing displacements and plastic deformations thereof.

[0132] The optional retention elements 11c, 14c, 15c, 16c, 17c, 18c are rotatable about a respective rotation axis on the operating face 9: in this case too, the rotation can be obtained by way of a respective actuator (for example pneumatic or electric or hydraulic). It is convenient to note that each abutment shoulder element 28, 29 is configured to impose a movement limitation (as a consequence force) on the conductor wire 3 during its laying in the portions 22 and 24 (before and after the apical fold 23). By virtue of the confinement of the conductor wire 3 between the abutment shoulder elements 28, 29 (or by virtue of the confinement defined by only one of them) the conductor wire 3 does not undergo unwanted plastic deformations induced by the mechanical stresses that are generated following the associated bending and twisting operations to which it is subjected.

[0133] The wire dispenser 25 has two mutually opposing abutment shoulder elements 28, 29 on two sides thereof (which delimit the end opening of the channel 30 inside the wire dispenser 25 inside which the conductor wire 3 slides): each abutment shoulder element 28, 29 can assume an extracted position (in which it protrudes from the end face of the wire dispenser 25) or a retracted position (in which it does not protrude from the end face of the wire dispenser 25).

[0134] When both abutment shoulder elements 28, 29 are retracted, the conductor wire 3 can pass freely, dispensed by the wire dispenser 25, so that the channel 30 acts as a guide (straight and transverse laying step) and as a fulcrum for the apical fold 23 of the wave-shaped conductor element 2 (during the step of rotation by 180°), performed on a corresponding forming element 11, 14, 15, 16, 17, 18.

[0135] When on the other hand an abutment shoulder element 28, 29 is in the extracted position (protruding), or when they both are, i.e. during the step of longitudinal laying of the conductor wire 3 (along the portions 22 and 24), the conductor wire 3 is subjected to a twisting force in the Z-shaped section (obtained by first extracting a first abutment shoulder element 28 and then a second abutment shoulder element 29) and in the subsequent S-shaped section (obtained by first extracting a second abutment shoulder element 29 and then a first abutment shoulder element 28). It is again emphasized that, according to the invention, it is possible to have an embodiment that has operating faces 9 on both of the mutually opposite surfaces of the forming unit 4.

[0136] In such case, the device 1 comprises two separate wire dispensers 25 which lay substantially simultaneously respective conductor wires 3 (for example originating from corresponding and separate supply apparatuses) on these mutually opposite operating faces 9.

[0137] This embodiment makes it possible to achieve a productivity that is substantially double that of the version described previously which has a single operating face 9.

[0138] The device 1 according to the invention can be provided so that, in order to form wave-shaped conductor elements 2, it can further comprise a removal tool 32 for removing the wave-shaped conductor element 2 once it has been completely modeled.

[0139] The removal tool 32 comprises at least one grip element 33 for gripping the wave-shaped conductor element 2 in order to remove it from the operating face 9 of the forming unit 4. In a preferred embodiment, such at least one grip element 33 is constituted by several grippers 34, which can move from a release position to a grip position. The grippers 34 can be arranged so that they can move with respect to each other within the removal tool 32 so that they can handle several shapes and sizes of wave-shaped conductor elements 2.

[0140] The removal tool 32 is mounted on a gantry robot 35, which can move in order to ensure at least one change in elevation of the removal tool 32 (by moving it up and down) and / or change in translation of the removal tool 32 (back and forth from the forming unit 4), so as to handle the wave-shaped conductor element 2 and hand it over to processes that take place downstream. The removal tool 32 can also be movable parallel to the rotation axis 5.

[0141] Advantageously the present invention solves the above-mentioned problems, by providing a method for forming portions of electrical windings for rotating open-slot electrical machines with high precision criteria. The portions of windings are constituted by conductor elements 2 which have a shape and orientation, within given tolerances, that correspond to the theoretical standards.

[0142] Conveniently, the method according to the invention ensures a productivity superior to that achievable with the method of laying the conductor wire 3 on a fixed forming unit 4.

[0143] Advantageously the device 1 for making portions of electrical windings for rotating open-slot electrical machines according to the invention offers reduced space occupation, in general lower than that of conventional devices which entail wrapping the conductor wire around a forming unit 4.

[0144] Profitably the device 1 according to the invention operates with greater precision than that achievable with conventional devices which entail wrapping the conductor wire 3 around a forming unit 4.

[0145] Positively the device 1 according to the invention ensures costs are lowered with respect to the prior art which entails laying the conductor wire 3 on a fixed forming unit 4 using adapted grippers.

[0146] Usefully the device 1 according to the invention enables full automation of the shaping operations to produce a substantially wave-shape of the conductor wire 3, in so doing providing a conductor element 2 that is extremely precise and repeatable.

[0147] Positively the method and the device 1 for forming portions of electrical windings for rotating open-slot electrical machines according to the invention are easily and practically implemented and at low cost; such characteristics make the method and the device 1 according to the invention innovations that are certain to be safe in use.

[0148] The invention, thus conceived, is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

[0149] In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be interchanged with other, different characteristics, existing in other embodiments.

[0150] In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

[0151] The disclosures in Italian Patent Application No. 102024000007696 from which this application claims priority are incorporated herein by reference.

[0152] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

C L A I M S1. A method for forming a wave-shaped conductor element (2) of electrical windings starting from a conductor wire (3), said method comprising the following steps: i) providing a forming unit (4), rotatable around a longitudinal rotation axis (5), said forming unit (4) comprising an operating face (9) supporting a plurality of forming elements (11, 14, 15, 16, 17, 18), wherein each forming element (11, 14, 15, 16, 17, 18) comprises a respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), and a respective first abutment element (l ie, 14e, 15e, 16e, 17e, 18e); ii) locking a first terminal end of said conductor wire (3) to said forming unit (4) by means of a locking element (9a); iii) laying a first straight portion (10) of said conductor wire (3), starting from the locked first terminal end, along a first straight direction transverse to the longitudinal axis (5); iv) moving a first forming element (11) of said plurality of forming elements (11, 14, 15, 16, 17, 18) in a respective engagement position to constrain said conductor wire (3) at an end of said first straight portion (10) distant from the locked first end; v) rotating said forming unit (4) by 180° about said longitudinal axis (5) to obtain a first apical fold (23a) of said conductor wire (3) on the respective first abutment element (1 le) of said first forming element (11); vi) laying said conductor wire (3) along a direction having a component parallel to the longitudinal axis (5) by dragging said first apical fold (23a) onto said first forming element (11); vii) laying a second straight portion (13) of the conductor wire (3) starting from said first forming element (11) along a second straight direction opposite to the first straight direction, transverse to the longitudinal axis (5), said second straight portion (13) being substantially parallel to the first straight portion (10);viii) moving a second forming element (14) of said plurality of forming elements (11, 14, 15, 16, 17, 18) in the respective engagement position to constrain said conductor wire (3) at an end of the second straight portion (13); ix) counterrotating said forming unit (4) by -180° about said longitudinal axis (5), namely in the opposite direction with respect to the previous rotation, to obtain a second apical fold (23b) of said conductor wire (3) on a respective first abutment element (14e) of said second forming element (14); x) laying said conductor wire (3) along a direction having a component parallel to the longitudinal axis (5) by dragging said second apical fold (23b) onto said second forming element (14); xi) repeating the steps of laying, moving and rotating with the remaining forming elements (15, 16, 17, 18) of said plurality of forming elements (11, 14, 15, 16, 17, 18), until obtaining a wave-shaped conductor element (2) consisting of plastically-deformed portions of conductor wire (3); and xii) removing the wave-shaped conductor element (2) from said forming unit (4); wherein said wave-shaped conductor element (2) lays exclusively on said operating face (9) of said forming unit (4).

2. The method according to claim 1, characterized in that said steps of moving the forming elements (11, 14, 15, 16, 17, 18) comprise a respective rotation of said forming element (11, 14, 15, 16, 17, 18) about a respective rotation axis (I la, 14a, 15a, 16a, 17a, 18a), preferably parallel to each other and perpendicular to the operating face (9), between a disengaged position and the respective engagement position.

3. The method according to one or more of the previous claims, characterized in that each first abutment element (l ie, 14e, 15e, 16e, 17e, 18e) is placed above the respective abutment base (l id, 14d, 15d, 16d, 17d,18d) of said forming elements (11, 14, 15, 16, 17, 18) and comprises a respective protruding portion (11g, 14g, 15g, 16g, 17g, 18g) protruding from the respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), said conductor wire (3) engaging said respective protruding portion (11g, 14g, 15g, 16g, 17g, 18g) in the respective engagement position to form said apical folds (23), when the forming element (11, 14, 15, 16, 17, 18) rotates.

4. The method according to one or more of the previous claims, characterized in that each first abutment element (l ie, 14e, 15e, 16e, 17e, 18e) comprises a lateral wall (11b, 14b, 15b, 16b, 17b, 18b) placed in contact with the conductor wire (3) in said engagement position.

5. The method according to one or more of the previous claims, characterized in that each forming element (11, 14, 15, 16, 17, 18) comprises a respective second abutment element (I lf, 14f, 15f, 16f, 17f, 18f) movable between a retracted position and an advanced position, wherein it protrudes from the respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), to constrain said conductor wire (3) in said engagement position.

6. The method according to one or more of the previous claims, characterized in that said conductor wire (3) is displaced with respect to the forming unit (4) along the longitudinal axis (5) to drag said first apical fold (23a) during the laying step of said conductor wire (3) along a direction having a component parallel to the longitudinal axis (5).

7. The method according to one or more of the previous claims, characterized in that said conductor wire (3) is supplied by a wire dispenser (25) which is movable back and forth and up and down with respect to the forming unit (4).

8. A device (1) for forming wave-shaped conductor elements (2) for electrical windings starting from a conductor wire (3), said device (1) comprising:- a wire dispenser (25) configured to supply a conductor wire (3),- a forming unit (4) comprising an operating face (9),- a locking element (9a) mounted on said operating face (9) and configured to lock a first end of the conductor wire (3) supplied by the wire dispenser (25),- a plurality of forming elements (11, 14, 15, 16, 17, 18) mounted on said operating face (9), each forming element (11, 14, 15, 16, 17, 18) of said plurality of forming elements being configured to interact with said conductor wire (3) supplied by said wire dispenser (25), wherein each forming element (11, 14, 15, 16, 17, 18) comprises a respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), and a respective first abutment element (l ie, 14e, 15e, 16e, 17e, 18e), and- a removal tool (32) configured to remove the wave-shaped conductor element (2) from said forming unit (4), characterized in that said forming unit (4) is rotatably mounted about a longitudinal axis (5), and in that it further comprises:- a controller (31) connected to said wire dispenser (25), to said forming unit (4) and to said plurality of forming elements (11, 14, 15, 16, 17, 18), and programmed to command:- displacing said wire dispenser (25) to lay a first straight portion (10) of said conductor wire (3), starting from the locked first end of said conductor wire (3), along a first straight direction transverse to the longitudinal axis (5);- moving a first forming element (11) of said plurality of forming elements (11, 14, 15, 16, 17, 18) in a respective engagement position to constrain said conductor wire (3) at an end of said first straight portion (10) distant from the locked first end;- rotating said forming unit (4) by 180° about said longitudinal axis (5) to obtain a first apical fold (23a) of said conductor wire (3) on a respective first abutment element (1 le) of said first forming element (11);- displacing said wire dispenser (25) and / or said forming unit (4) to lay said conductor wire (3) along a direction having a component parallel tothe longitudinal axis (5) by dragging said first apical fold (23 a) onto said first forming element (11);- displacing said wire dispenser (25) to lay a second straight portion (13) of the conductor wire (3) starting from said first forming element (11) along a second straight direction opposite to the first straight direction, transverse to the longitudinal axis (5), said second straight portion (13) being substantially parallel to the first straight portion (10);- moving a second forming element (14) of said plurality of forming elements (11, 14, 15, 16, 17, 18) in the respective engagement position to constrain said conductor wire (3) at an end of the second straight portion (13);- counterrotating said forming unit (4) by -180° about said longitudinal axis (5), namely in the opposite direction with respect to the previous rotation, to obtain a second apical fold (23b) of said conductor wire (3) on a respective first abutment element (14e) of said second forming element (14);- displacing said wire dispenser (25) and / or said forming unit (4) to lay the conductor wire (3) along a direction having a component parallel to the longitudinal axis (5), dragging said second apical fold (23b) onto said second forming element (14);- moving sequentially the remaining forming elements (15, 16, 17, 18) of said plurality of forming elements (11, 14, 15, 16, 17, 18) in the respective engagement positions, displacing said wire dispenser (25) and / or said forming unit (4), and rotating said forming unit (4) until obtaining a wave-shaped conductor element (2) consisting of plastically-deformed portions of the conductor wire (3); wherein said wave-shaped conductor element (2) lays exclusively on said operating face (9) of said forming unit (4).

9. The device (1) according to the previous claim, characterized in that each forming element (11, 14, 15, 16, 17, 18) of said plurality of formingelements is rotatably mounted around a respective rotation axis (I la, 14a, 15a, 16a, 17a, 18a), preferably parallel to each other and perpendicular to the operating face (9), between a disengaged position and the respective engagement position.

10. The device (1) according to claim 8 or 9, characterized in that said forming elements (11, 14, 15, 16, 17, 18), when in said respective engagement position, are disposed alternately on two opposite rows parallel to said longitudinal axis (5).

11. The device (1) according to one or more of claims 8, 9 and 10, characterized in that each first abutment element (l ie, 14e, 15e, 16e, 17e, 18e) is placed above the respective abutment base (l id, 14d, 15d, 16d, 17d, 18d) of said forming elements (11, 14, 15, 16, 17, 18) and comprises a respective protruding portion (11g, 14g, 15g, 16g, 17g, 18g) protruding from the respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), said respective protruding portion (11g, 14g, 15g, 16g, 17g, 18g) being configured, in the respective engagement position to be engaged by said conductor wire (3) to form said apical folds (23), when the forming element (11, 14, 15, 16, 17, 18) rotates.

12. The device (1) according to one or more of claims 8 to 11, characterized in that each first abutment element (l ie, 14e, 15e, 16e, 17e, 18e) comprises a lateral wall (11b, 14b, 15b, 16b, 17b, 18b) configured to be abutted by said conductor wire (3) in said engagement position.

13. The device (1) according to one or more of claims 8 to 12, characterized in that each forming element (11, 14, 15, 16, 17, 18) comprises a respective second abutment element (I lf, 14f, 15f, 16f, 17f, 18f) movable between a retracted position and an advanced position, in which it protrudes from the respective abutment base (l id, 14d, 15d, 16d, 17d, 18d), to constrain said conductor wire (3) in said engagement position.

14. The device (1) according to one or more of claims 8 to 13, characterized in that said wire dispenser (25) is mounted on a movable armwhich is movable towards and away from the forming unit (4), said arm being slidably mounted on a post to be moved up and down.

15. The device (1) according to one or more of claims 8 to 14, characterized in that said wire dispenser (25) is mounted on a carriage (4a) displaceable parallel to the longitudinal axis (5) of the forming unit (4).

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