Improved winding machine welding set

Abstract

The invention relates to an improved winding machine welding set, in particular to a winding machine used for producing middle-high voltage power transformer windings for power generation, power transmission and power distribution.

Description

Technical Field

[0001] The invention relates to a winding machine welding technology, in particular to a winding machine for producing windings of medium and high voltage power transformers for power generation, transmission and distribution. Background Art

[0002] The present invention relates to Figure 1 Winding machine of the type shown. This known winding machine essentially comprises: an unwinder unit (A) which allows the conductive material to be unwound from a suitable reel or coil (the unwinder unit can be detached from the frame of the machine); a central unit (B) for preparing / positioning the conductive and insulating material according to the winding steps (e.g. cutting the insulating material); and a winding unit (C) which allows the conductive and insulating material to be wound onto a winding core.

[0003] Specifically, the winding unit (C) includes two components, a tailstock (11) and a winding device (11'), which rotatably constrain the two ends (121, 121') of the winding drum (12) to be parallel to the ground (ie, along the X-axis).

[0004] The tailstock (11) has an opening / closing system, usually a hinged closure, which enables the winding core to be introduced and the winding coil to be withdrawn before and after the winding operation, respectively. The winding device (11') comprises a motor (15), usually for rotating the winding drum (12) at high speed.

[0005] In such a winding machine, the coil consists of multiple turns of copper wire (or other conductive material in the form of wire, foil or sheet) that are alternately wound around a winding core and between layers of insulating material (e.g. paper strips).

[0006] Although the invention is not limited thereto, it is particularly directed to winding machines of this type, which are primarily used to produce windings (or coils) of metal foil or metal sheet, which are typically used in medium and high voltage transformers for power generation, transmission and distribution.

[0007] For example, in such a transformer, the input electrode (termed "input rod") is connected to a high voltage (>50.000V) power source, while a medium voltage (eg 380V) is delivered through the output electrode (termed "output rod").

[0008] The input / output bars are made of copper or aluminum. Their shape, length and thickness depend on the characteristics of the transformer for which they are intended. They are usually 200 to 1500 mm long and about 20 mm thick. The foils that form the windings are made of copper or aluminum and are usually 200 to 1500 mm long and 2 mm thick. The windings need to be formed by wrapping the conductive foil around the insulating paper (or other dielectric material) around the core. The windings are limited by an inner end (where the coil begins) and an outer end (where the coil ends).

[0009] In manufacturing such transformers, it is necessary to weld the input and output bars at the inner and outer ends of the windings, respectively. Depending on the rated power of the transformer, and the size range of the bars and foils, the welding operation is carried out using two different techniques.

[0010] The first technique, known in the art as "head welding", places the coil plate (about 2 mm thick) and the head of the input / output rod (e.g. 20 mm thick) together and applies mechanical pressure in the axial direction. In this way, a side weld is formed along the entire length of the rod (e.g. 1500 mm). To facilitate the operation, the coil plate is pressed against the head of the rod by a set of presses, the number of which depends on the length of the machine. In this technique, the welding group is located in front of the winding unit (C).

[0011] In the power transformer industry, another welding technique is known as "butt welding". In this case, before welding, the winding plates are pressed against the input / output rods by two rows of side presses, the number of which depends on the length of the machine. Thus, the weld is formed on the top surface of the foil along the entire length of the rod. In this technique, the welding group is located behind the winding unit (C).

[0012] Normally, wire wrapping machines are configured to perform welding operations by only one of the techniques described. In fact, machines capable of performing both "head welding" and "butt welding" are too expensive compared to the benefits they achieve. Usually, "head welding" is best used when the rod or plate is thick and "butt welding" is not efficient.

[0013] In both technologies, it is essential that the welding operation not only provides a mechanically strong weld joint, but also and most importantly a highly uniform weld seam. In fact, an uneven weld seam will produce an uneven resistivity and stress on the weld joint part due to excessive current. This, in turn, can lead to performance deviations from specifications or even premature failure of the transformer due to the occurrence of a short circuit.

[0014] Currently, in order to obtain a good weld joint, the welding operation is carried out using a TIG welding torch in a helium or argon environment to prevent oxidation and allow the weld pool to melt properly. TIG welding has several disadvantages, mainly related to the low energy efficiency of the technology, which in turn leads to low productivity of the wire winder.

[0015] In fact, using a classic 500A TIG welding gun, it takes about 20 minutes to weld a 2mm copper (or aluminum) plate to a 20mm thick and 1500mm long copper (or aluminum) output rod.

[0016] In addition, the high temperatures generated by the welding operation can cause heat dissipation problems, which can slow down or stop subsequent processing operations. As a result, operators are often forced to use uncomfortable personal protective equipment or forced air cooling systems when handling windings, which further reduces energy efficiency. Finally, the high heat generated by the TIG welding gun can cause damage to the cylinders of the press-fit system.

[0017] Finally, the cost of helium has risen to unaffordable levels in recent years, forcing many welding equipment manufacturers to switch to argon. Unfortunately, this alternative is also expensive and does not address the root cause of the problem.

[0018] Although these limitations are well known, the inventors (with over 30 years of industry experience) have not found any significant improvements to date.

[0019] Recent research highlights alternative welding technologies. For example, several patent documents describe the use of laser welding systems in transformer winding manufacturing.

[0020] However, the application of this laser technology either involves welding robots for complex production lines (e.g., CN213702197U "eight-axis laser wire-wrap welding machine"), or machines with a structure completely different from that of the object of the present invention (e.g. Figure 1 As shown), they are intended for low voltage (<100V) small winding manufacturing. Examples of such machines are described in CN215955072U "Welding mechanism of surface mount inductor coil winding machine" or CN214505256U "Intelligent large toroidal core winding machine". It is worth noting that in such applications (e.g., the aforementioned utility model CN213702197U), the windings used are made of wire, not metal foil or plate.

[0021] In short, for those who want to use laser welding heads in Figure 1 The patent literature does not provide any useful teaching for a person skilled in the art to manufacture windings for medium and high voltages and therefore of larger dimensions. In particular, laser welding technology has not been applied to welding operations when manufacturing metal foil, metal sheet or metal strip windings for distribution transformers.

[0022] Therefore, the welding and assembly of winding machines for producing medium and high voltage power transformer windings for power generation, transmission and distribution still needs to be improved. Summary of the invention

[0023] 1. Purpose of the Invention

[0024] In view of the above situation, the present invention aims to provide Figure 1A winding machine of the type shown is provided to overcome the existing disadvantages and deficiencies of the prior art, the winding machine including an improved welding group which makes the weld between the input / output rod and the end of the coil more uniform, the coil being made of a metal foil, sheet or strip wound around a core.

[0025] A second important object of the present invention is to provide an improved welding group in the form of a welding kit that can be applied to a retrofitted winding machine equipped with a conventional TIG welding group or even not equipped with any welding group.

[0026] A third important object of the present invention is to provide a wire winding machine comprising an improved welding group or equipped with a modified welding kit capable of performing "head welding" and "butt welding" operations on metal foil, plate or ribbon conductors according to the specifications of the wire winding to be manufactured.

[0027] A fourth important object of the present invention is to provide a wire winding machine including an improved welding group ensuring greater safety for the operating personnel, in particular by reducing potential exposure to high temperature sources.

[0028] Finally, a fifth object of the present invention is to provide the wire winding machine and retrofit welding kit by known and cost-effective technology.

[0029] 2. Technical solution and invention concept

[0030] These objects, as well as other objects that will emerge more clearly from the detailed description that follows, are achieved by a welding group for a winding machine, a winding machine including a welding group, and a conversion kit including a welding group.

[0031] The general characteristics of the welding group, the winding machine and the conversion kit are set out in the appended claims 1, 6 and 10, respectively, while the advantageous characteristics are set out in the corresponding dependent claims. For the sake of brevity, the above-mentioned claims are specifically defined below and are made an integral part of this description.

[0032] In summary, the welding group of the invention is characterized in that it comprises a laser welding head integrated with a carriage slidably constrained to the structure of the winding machine by suitable means, such as linear guides combined with sliding blocks.

[0033] Thus, once the winding machine is equipped with a welding group (even by retrofitting a winding machine not equipped with any welding group or with a conventional TIG welding group), the carriage and the laser welding head can be shifted from a stationary position to a working position along the horizontal (X) axis by a suitable first actuator.

[0034] In turn, in order to provide the group with additional degrees of freedom, the laser welding head can also be slidingly constrained to the carriage by means of a suitable second actuator. The welding group can also be moved along other axes.

[0035] In an alternative embodiment, the carriage is not present and is replaced by a translation device.

[0036] In a further embodiment, the welding group is used as a retrofit kit to retrofit multiple wire winding machines not provided with any welding group, so that the welding group is shared by each machine and is only part of the wire winding machine when it is needed to perform welding operations.

[0037] In this way, the carriage or translation device, as well as the laser welding head, can be moved by suitable actuators along the horizontal axis (X) from a rest position to an operating position corresponding to the position of the plurality of winding machines required to perform the welding operation.

[0038] Obviously, this embodiment is particularly advantageous because the cost of the welding group is shared by different winding machines. Other advantages will become apparent from the detailed description of some embodiments below.

[0039] The welding group of the present invention is suitable for winding machines for producing windings of medium and high voltage transformers, the conductive material of which is preferably a metal foil, plate or strip. However, the present invention can also be used to produce windings whose conductive material is a winding wire.

[0040] In order to achieve optimal welding conditions, the welding group of the present invention preferably comprises a clamping device and a pressing device for fixing and pressing the transformer component to be welded (eg transformer input / output bar) to the metal plate or foil.

[0041] Finally, the welding group includes protective means, such as a housing or a panel integral to the carriage, arranged to prevent the radiation emitted by the laser welding head from becoming hazardous to operators near the winding machine.

[0042] This welding group is suitable for single winding machine or multiple winding machines for manufacturing windings of medium and high voltage power transformers used for power generation, transmission and distribution.

[0043] The winding machine can be of the type where the winding reel is parallel to the horizontal X-axis and is in a fixed position (such as Figure 1 as shown), or it can also be of the type in which the winding drum can be positioned to the optimal position by a processing unit, depending on the specifications of the winding to be carried out (in this type of machine, the winding drum always remains parallel to the horizontal X axis, but can be moved along the Z or Y axis).

[0044] In this regard, the Italian patent application (still under review and not yet published) 102022000006395 "Winding machine with positionable winding disc" filed by the applicant on March 31, 2022 provides useful teachings for the manufacture of a winding machine with a positionable winding disc, and the entire disclosure of the patent application is hereby incorporated by reference into this document for all purposes. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention will be more fully understood by reference to the following drawings, in which:

[0046] - Figure 1 A known type of winding machine not equipped with a welding group to which the present invention relates is shown;

[0047] - Figure 2 is a perspective view of a welding group according to a first preferred embodiment of the present invention;

[0048] - Figure 3 Is equipped with Figure 2 A perspective view of a winding machine of a laser welding group shown in;

[0049] - Figure 4 is a perspective view of a welding group according to a second preferred embodiment of the present invention;

[0050] - Figure 5 Is equipped with Figure 4 A perspective view of a winding machine for laser welding assemblies shown in FIG.

[0051] - Figure 6 is a perspective view of a welding group according to a third preferred embodiment of the present invention;

[0052] - Figure 7 Is equipped with Figure 6 A perspective view of a winding machine of a laser welding group shown in;

[0053] - Figure 8 A user interface for setting and adjusting parameters of a welding process with reference to a preferred embodiment of the present invention is shown;

[0054] - Fig. 9 is a perspective view of a conversion kit that allows multiple conventional-type winders to share a single welding group;

[0055] - Fig.10 Multiple winding machines sharing a single welding group are shown, where the machines at letter (a) are arranged in a "tandem layout" and the machines at letter (b) are arranged in a "matrix layout".

[0056] These drawings illustrate various features and embodiments of the present invention but are not intended to limit the present invention. DETAILED DESCRIPTION

[0057] In order to explain the present invention, but not to limit the present invention, four preferred but non-exclusive embodiments of the winding machine according to the present invention will be described in detail below.

[0058] For the sake of clarity, in the drawings and the description of some preferred embodiments, the welding group and the winding machine equipped with the group are always indicated by the reference numerals (2) and (1), respectively.

[0059] Example 1

[0060] The object of the present invention is to provide a winding machine welding group.

[0061] A first preferred embodiment, described herein by way of illustration and not limitation of the present invention, involves a laser welding assembly, which is attached Figure 2 The welding group (2) is configured to be mounted on Figure 3 On a winding machine of the type shown, which is suitable for making windings for medium and high voltage transformers used for power generation, transmission and distribution. In transformers of this type, the power range generally requires the use of conductive material in the form of metal foil or metal sheet, which is wound around the core by the winding machine.

[0062] In a first embodiment, this conductive material is a copper or aluminum foil with a thickness of about 2 mm (or two overlapping 2 mm foils) and a length of 1500 mm. The metal foil has a film of dielectric material sandwiched between it and is wound around a core. One end of the conductive material (the inner starting winding) must be welded to an electrode called the "input rod", while the other end of the winding (the outer ending winding) must be welded to an electrode called the "output rod". With an appropriate number of windings, such a transformer can transform voltages, for example, from 20,000 V to 380 V.

[0063] In this embodiment, the welding group (2) comprises: a carriage (20) slidably restrained on the winding machine structure by a first retaining device (21) and a single laser welding head (22) integral with the carriage (20).

[0064] In the first embodiment, the welding group (2) further comprises: a second holding device (23) for slidably restricting the laser welding head (22) on the slide (20) and allowing it to move along the axis (X); a clamping device (24) for restricting the input / output rod to be welded to the metal foil within a certain range.

[0065] Although the clamping device (24) is highly desirable, it is not necessary to practice the present invention. The second holding device (23) is also not necessary, as the laser welding head (22) can be fixed at a convenient location on the carriage (20).

[0066] In the first embodiment, the carriage (20) is a metal frame consisting of a lower portion (201), an upper portion (201'), a right side portion (202) and a left side portion (202').

[0067] Two pairs of sliding block devices (212, 212') are fixed on the upper part (201') of the right / left part (202, 202') of the slide (20). They are slidably fixed on corresponding linear guides (133), which slide along the axis (X), as described below, and the linear guides (133) are fixed on the structure (10) of the winding machine (1). Similar to the first retaining device (21), alternatives to the sliding block / guide rails can also be effectively used. For example, two pinions (212, 212') (one for each side column) can be rotatably attached to the upper part (201') of the two side parts (202, 202'). The pinions (212, 212') are then mechanically coupled to the rack (133) along the axis (X) direction and fixed to the structure (10) of the winding machine (1).

[0068] In any case, with the first holding device (21) and a suitable first actuator (211) fixed to the winding machine structure, it is possible to move the carriage (20) along the horizontal axis (X). In the first embodiment, the first actuator (211) is a translation screw socket, but other types of actuators, such as a rotation screw socket, a linear motor, a hydraulic cylinder, a pneumatic cylinder, a ball screw, can also be combined with each other for this purpose.

[0069] In a first embodiment of the present invention, the welding group (2) comprises a second holding device (23) which, compared with the first holding device (21), is used to slidably constrain the laser welding head (22) on the slide (20). In such an embodiment, the second holding device (23) is preferably a linear guide (222) slidably constrained to a pair of sliding block devices (223). The linear guide (222) is arranged along the horizontal axis (X) direction and fixed to the lower part (201) of the slide (20), while the pair of sliding blocks (223) are fixed to the support element of the laser welding head (22).

[0070] In turn, the support element is moved by a second actuator (231) fixed to the carriage (20) of the welding group (2). The second actuator (231) is preferably a linear motor, but other types of actuators can also be used. In this way, the laser welding head (22) can be moved along the horizontal axis (X) independently of the carriage (20).

[0071] As can be seen from the description of the carriage (20) provided, the positions of the first and second retaining means (21, 23) may differ from the positions described.

[0072] Additionally, equivalent alternatives to the slide / linear guide coupling, such as a pinion / rack coupling, can be used effectively.

[0073] By properly arranging the first and second holding devices (21, 23), it is apparent to those skilled in the art that the laser welding head (22) can be moved in more axes according to the characteristics of the parts to be welded.

[0074] In a first embodiment of the invention, the welding group (2) comprises a plurality of clamping devices (24) located in the lower part (201) of the carriage (20) to clamp the input / output rod to the metal foil or plate before and during the welding operation. The number of clamps and their distribution along the lower part (201) are selected according to the length of the rod (or other transformer component) to be welded. This ensures that the welding operation is carried out correctly. As described below, in the first embodiment, taking into account the geometry of the input / output rod, the welding operation is carried out along a straight path in the "head welding" and "butt welding" techniques.

[0075] In addition to mechanical clamping, other devices can also be used, such as vacuum clamping. However, using this technology, a system for generating vacuum must be established in the lower part (201) of the carriage (20).

[0076] In a first embodiment of the invention, the welding group (2) comprises a clamping device (25) which, like the clamping device (24), makes the welding operation easier, especially in the "butt welding" technique, as described below. In this embodiment, the clamping device (25) is a row of plate clamps, the number of which depends on the length of the machine.

[0077] Finally, in the first embodiment of the invention, which is presented herein by way of example and not limitation, the welding group (2) comprises a protective device (26) to prevent the laser radiation emitted by the laser welding head from causing harm to persons near the winding machine (1), in particular to the eyes.

[0078] For example, a suitable protective device (26) may be a shielding plate fixed to the carriage (20) or the laser welding head (22).

[0079] Such panels may be dimensioned and positioned according to known techniques and must ensure an adequate level of shielding while effectively dissipating the heat generated by the laser welding head.

[0080] As mentioned above, the laser welding group is arranged to be installed in Figure 3 A winding machine of the type shown is indicated by reference numeral (1).

[0081] The machine (1) comprises an unwinder unit (A) for conducting material, which in a first embodiment is in the form of a wound metal foil; a central unit (B) whose task is to prepare the material unwound by the preceding unit (A), for example, by cutting the insulating material into strips, or by coupling the insulating material to the conductor, or by properly positioning the material by means of suitable devices for subsequent winding operations; and a winding unit (C) for winding the conducting or insulating material prepared and positioned / oriented by the central unit (B) onto a suitable core integral with a winding drum (12).

[0082] In turn, the winding unit (C) comprises a frame (10), a tailstock (11) and a winding device (11'), as well as the aforementioned winding drum (12).

[0083] In a first preferred embodiment, the winding is for use in a medium or high voltage power transformer suitable for power generation, transmission and distribution.

[0084] Although not relevant to the practice of the invention, the winding core may be of any diameter and may be circular, square or more generally polygonal in cross-section.

[0085] In a preferred embodiment, the welding group (2) according to the invention comprises two independent actuators (211, 231) so as to first move the carriage (20) from the rest position to the working position and then move the laser welding head (22) along the welding line while keeping the carriage (20) in a fixed position during operation.

[0086] like Figure 3 As shown, in a first preferred embodiment, described without limitation to the invention, the welding group (2) is located in front of the winding unit (C). This configuration of the machine (1) is particularly suitable for welding the input / output rods to the winding foil using the "head welding" technique. Using this technique, the welding is carried out along a straight line parallel to the horizontal axis (X), depending on the geometry of the input / output rods. The following steps are provided as an example and not as a limitation of the invention.

[0087] First, the carriage (20) with the laser welding head (22) is moved from the rest position to the working position. The input rod is positioned manually by the operator at the bottom of the carriage (201) or by an automatic loading system. The rod is then fixed together with the metal foil by a clamping device (24) so ​​that the edge of the foil is in contact with the head of the rod and parallel to the head itself (i.e. oriented along the X axis).

[0088] At this stage, suitable actuators position the pressing device (25) along the axis (X) so that the edge of the foil presses against the head of the rod and avoids gaps between the rod and the foil that could slow down the welding operation or impair the quality of the weld.

[0089] The laser welding head (22) mounted on the support element is then turned on and moved along the linear guide rail (222) by a linear motor (231) to perform the welding operation according to the parameters set by the operator (more details will be provided below).

[0090] At the end of the operation, the laser welding head (22) is closed, the hold-down device (25) and the clamping device (24) are released, the carriage (20) returns to its rest position and the operation of winding the foil on the winding core is started. At the end of this operation, the output rod is welded to the foil in a similar manner to that described.

[0091] As previously mentioned, the welding operation performed by the machine (1) is managed by a control unit (14), such as an onboard computer.

[0092] In a first preferred embodiment, described by way of example and not limitation of the invention, the control unit (14) comprises a storage unit storing a computer program which, in addition to managing the conventional functions of the winding machine (1), can also control the winding machine (1) through a suitable user interface (e.g. Figure 8 The welding operation is managed by using a UI (schematically shown in FIG. 1 ).

[0093] Furthermore, in the storage unit, association data can advantageously be stored. The association data associates in a tabular form the parameters of the welding operation to be performed and the process parameters that influence the welding operation. As an example (not limiting the invention), these parameters include one or more of the following: the type of material of the transformer component to be welded; the geometry and size of the transformer component to be welded; the type of conductive material to be welded; the geometry and size of the conductive material to be welded; the type of welding, i.e. head welding or butt welding; the welding speed; the power of the laser radiation.

[0094] From the above description, it should be clear to those skilled in the art that the welding group (2) of the present application can also be effectively used to transform or improve a winding machine that is not equipped with any welding group or is equipped with a non-laser welding group (such as TIG type).

[0095] Example 2

[0096] In a second preferred embodiment of the present invention, the attached Figure 4 and 5 , the laser welding group (2) is located inside, that is, between the unwinder unit (A) and the winding unit (C). Compared with the first embodiment, in this configuration, the welding group (2) is no longer mounted on a carriage, but is slidably restrained on a translation device (30) by a second retaining device (23). For simplicity, in this embodiment, the second retaining device (23) is still represented by the same reference number as in the previous embodiment.

[0097] In the second embodiment, the translation device (30) is a metal part on which a linear guide rail (222) along the axis (X) is fixed. The guide rail is slidably fixed to a pair of sliding blocks (223) through supporting elements, and the sliding blocks are fixed to the laser welding head (22).

[0098] A second actuator (331) in the form of a linear motor moves the laser welding head (22), which is constrained on the linear guide (222).

[0099] Similar to the previous embodiment, the second retaining device (23) and the second actuator (331) may be different from that shown.

[0100] As regards the winding machine (1), the structure of the second preferred embodiment is particularly suitable for welding the input / output rod to the wound foil by means of the "butt welding" technique, in which the metal foil is welded to the upper surface of the input / output rod. Depending on the geometry of the input / output rod, the welding operation using this technique is also carried out along a straight line parallel to the horizontal axis (X), and its procedure is basically similar to the above procedure. However, in this case, a plurality of holding down devices (25) are arranged in two side rows. The number of holding down devices (25) is selected according to the length of the machine (1) and they work symmetrically with respect to the welding line to eliminate the "gap" between the aluminum foil and the input / output rod.

[0101] Other details for implementing the invention can be derived from the foregoing details, general knowledge known to a person skilled in the art, and practice of the invention.

[0102] Example 3

[0103] The third preferred embodiment of the present invention is described here by way of example and not limitation, with reference to the accompanying drawings. Figure 6 and 7 , relates to a welding group (2) and a winding machine (1), which are suitable for manufacturing windings with plate or strip-shaped conductive material.

[0104] In fact, the welding group (2) has the same structure as the second preferred embodiment, although on a smaller scale. In fact, the length of the plates used in medium and high voltage transformer construction is usually between 200 and 400 mm, so the length of the translation device (30) is significantly reduced.

[0105] As can be seen from the description provided, the inventive concept on which the present invention is based can be applied in other embodiments than the above-described ones. For example, the winding machine (1) according to the first embodiment is particularly suitable for utilizing the "head welding" technique. However, by appropriately modifying this embodiment, a "butt welding" operation can also be performed. This requires the insertion of an additional row of presses. Alternatively, a hydraulic cylinder is used instead of a coupled linear guide / slide block driven by an electric motor, requiring a manual or electric pump and valve to discharge fluid from the cylinder chamber to enable the piston to move in the opposite direction.

[0106] Furthermore, if the geometry of the transformer components requires the use of both welding techniques, the first and second embodiments can be combined to enable the welding group (2) to perform both "head welding" and "butt welding" operations.

[0107] Other details for implementing the embodiment will be obvious to a person skilled in the art based on the present disclosure or can be derived from general knowledge known to a person skilled in the art and through practice of the present invention.

[0108] Example 4

[0109] The object of the present invention is to provide a kit suitable for retrofitting a winding machine of conventional type, ie either not provided with a welding group at all or equipped with a welding group of known type, such as TIG technology.

[0110] In a fourth embodiment of the invention, described herein by way of example and not limitation, such a kit can be advantageously arranged so that a single welding group can be shared between multiple winding machines. In this way, the costs associated with laser welding groups can be advantageously reduced and the dissemination of the technology improved.

[0111] For the sake of simplicity, the plurality of common winding machines will be referred to hereinafter as (1j), where j is an integer, 1≤j≤N, and N is the total number of winding machines sharing a single welding group (42).

[0112] In a fourth embodiment, described herein by way of example and not limitation, the kit is attached. Fig. 9 Indicated by reference numeral (4), it comprises: a carriage (40) slidably constrained to a translation device (43) by a first retaining device (41) and a laser welding head (42) integral with the carriage (40).

[0113] In this embodiment, the translation means (43) comprises a linear guide rail directed along the axis (X), and the first retaining means (41) is a sliding block configured to be slidingly constrained to the linear guide rail (43).

[0114] The linear guide (43) is held at a suitable height by a support element having a base fixed to the floor, or it is fixed to the structure of at least one of the winding machines (1j) sharing a single welding group (42).

[0115] However, alternative solutions for the translation device are also possible, such as one or more rails fixed to the floor.

[0116] In any case, the configuration of the translation device (43) will obviously depend on the number and layout of the winding machines (40j).

[0117] In a fourth embodiment, the laser welding group (42) is shared by three winding machines arranged in a "serial layout", as shown in the attached Fig.10 As shown in (a).

[0118] In this case, the translation means (43) consist of a single linear guide (43) directed along an axis (X) and suitably positioned relative to the three winding machines (1j).

[0119] In the attached Fig.10 In the example shown in (b), the translation device (43) is more complex, in which four of the plurality of machines (1j) are arranged in a "matrix layout" and the welding group (42) moves along a more complex path.

[0120] In a fourth embodiment, the carriage (40) and the laser welding head (42) integrated therewith can be moved by a linear motor (44), but other actuators may also be used, such as a translational screw socket, a rotary screw socket, a hydraulic cylinder, a pneumatic cylinder, a ball screw, or even a combination thereof.

[0121] It should be clear to a person skilled in the art that the carriage (40) can have a similar structure to the first embodiment, or can have a different structure, depending first on the characteristics of the translation device (43), then on the characteristics of the actuator (44), and finally on the layout of multiple winding machines sharing the same laser welding group (42). For example, the actuator (44) can even be integrated into the carriage (40).

[0122] In any case, with the first retaining device (41) and the first actuator (44), the carriage (40) can be moved along a suitable path.

[0123] In the first example, as shown in the attached Fig.10 As shown in (a), three of the multiple winding machines (1j) are arranged in a "tandem layout" and the welding group (42) moves along a straight path.

[0124] In the second example, if Fig.10As shown in (b), the welding group (42) is shared by four machines (1j) which are arranged in a "matrix layout" so that the welding group (42) moves along a path that is more complex than a straight line path.

[0125] In a first embodiment, described herein by way of example and not limitation, the kit including the welding group (4) contains protective means to protect the operator from dangerous exposure to radiation emitted by the laser welding head.

[0126] The protective device is a shielding plate fixed to the carriage (40) or the laser welding head (42) and the machine (10j) sharing the laser welding group (42).

[0127] The shielding plates may be configured and positioned along the path of the laser welding group (42) in accordance with well known techniques to achieve an adequate level of shielding while effectively handling the heat generated by the laser welding head.

[0128] Finally, in a fourth embodiment, a suitable control unit manages the corresponding positioning of the laser welding group (42) and the winding machine (1j) that is required to perform the welding operation according to the expected working cycle.

[0129] The control unit has the same features as the first embodiment described above and may be identical to the control unit on a "master" winding machine (1j) belonging to a plurality. Alternatively, the control unit may be a separate unit physically separated from each machine (1j).

[0130] Finally, it should be noted that, in order to implement this solution, the conversion kit (4) comprises a second retaining device and Figure 2 The clamping device (24) highlighted in the drawing is not mandatory. In fact, fine movement of the laser welding head (22) can be obtained by choosing appropriate actuators without using the holding device (23), while the clamping device (24) and the clamping device (25) can be components of the machine (1j), for example integrated into the component feed section.

[0131] The welding operation basically follows the procedure of the first embodiment.

[0132] The carriage (40) on which the laser welding group (42) is mounted is first moved from a stationary position to a working position corresponding to a plurality of machines (1j) sharing the laser welding group (42).

[0133] The input rods are placed at the bottom of the carriage (40) manually by an operator or by an automatic loading system which may be dedicated to a single machine (1j) or a centralized input rod handling system serving all of the winding machines described.

[0134] The rod and the metal foil are then fixed together by means of the clamping means (24) of the machine (1j) so that the edge of the foil is in contact with the head of the rod and is parallel to the head itself (i.e. oriented along the X axis). At this stage, suitable actuators position the pressing means (25) of the machine (1j) so that the edge of the foil is pressed against the head of the rod and the gaps between the rod and the foil are eliminated, since they could slow down the welding operation or impair its quality.

[0135] The laser welding head (22) is then turned on and performs a welding operation according to parameters set by the operator while being limitedly moved along the linear guide rail (43) by the linear motor (411).

[0136] Taking into account the geometry of the input / output rods, the welding operation is carried out along a straight path in both the "head welding" and "butt welding" techniques.

[0137] At the end of the operation, the laser welding head (22) is closed, the hold-down device (25) and the clamping device (24) are released, and the machine (1j) starts to wind the foil onto the winding core. At the same time, the carriage (20) moves to another winding machine (1k), where k≠j is an integer with 1≤j≤N, or returns to its rest position after completing the working cycle.

[0138] The output rod is welded to the foil by a sequence of operations similar to that provided.

[0139] Other details for implementing the solution can be derived from the previous embodiments, from the general knowledge known to those skilled in the art and from practicing the invention.

[0140] advantage

[0141] From the above description, a person skilled in the art can understand that the improved welding group and the winding machine comprising the welding group according to the present invention have several advantages compared with the known solutions.

[0142] Firstly, due to the inherent properties of laser radiation, it is possible to ensure a higher quality and uniformity of the weld seam while reducing the heat generated. This in turn improves production efficiency and operator safety.

[0143] The use of laser technology does not require technical gases such as argon and helium, the costs of which have increased significantly in recent years.

[0144] Finally, this technology can also be applied as a retrofit kit to winding machines not equipped with any welding group, as well as to machines equipped with a conventional TIG welding group. In particular, the advantage of this retrofit kit is that a welding group can be shared between multiple winding machines. In this way, the costs associated with the introduction of this technology can be reduced and its penetration increased.

[0145] Summarize

[0146] It is obvious that the above invention fully achieves the intended objectives. In fact, the present application discloses an improved welding group winding machine, which has many advantages in manufacturing windings of medium and high voltage power transformers for power generation, transmission and distribution applications.

[0147] However, it should be understood that although the detailed description and specific examples show the preferred embodiments of the present application, they are given by way of illustration only, and those skilled in the art will readily appreciate various changes and modifications within the spirit and scope of the present application from the detailed description.

[0148] Therefore, any modifications of the present invention that fall within the scope of the appended claims are considered to be part of the present invention.

[0149] When features and techniques mentioned in any claims are followed by reference symbols, these reference symbols are used only to increase the intelligibility of the claims and thus these reference symbols have no limiting effect on the interpretation of each element identified by these reference symbol examples.

Claims

1. A welding group (2) for a winding machine (1), the winding machine being suitable for manufacturing windings of medium and high voltage transformers, the windings comprising conductive material in the form of wires, foils or metal sheets, the welding group (2) comprising: - at least one laser welding head (22); - A handling system (20) for at least one laser welding head (22), comprising: - a carriage (20), preferably in the form of a frame having a lower part (201), an upper part (201') and at least one right side (202) or left side (202'); - a first retaining device (21) for restraining the carriage (20) in a sliding manner on the structure of the winding machine (1), the device being preferably placed on the upper part (201') of the carriage (20); - a first actuator (211) which cooperates with the first holding device (21) to slide the carriage (20) on at least one axis (preferably the X axis), - optionally, a second retaining device (23) for slidably restraining at least one laser welding head (22) on one or more parts of the carriage (20) so as to be movable along at least one axis (preferably the X axis) by means of a second actuator (231), wherein the movement of the laser welding head (24) and the movement of the carriage (20) are independent, Alternatively, a manipulation system (20) for at least one laser welding head (22) comprising: - translation means (30); - Second retaining means (33) for slidably restraining at least one laser welding head (32) on the translation means (30) so as to be movable along at least one axis (preferably the X axis) by means of a second actuator (331).

2. The welding group (2) according to claim 1, further comprising one or more of the following components: - a clamping device (24), preferably in the form of one or more clamping devices (24), suitable for clamping the transformer component to be welded (for example, an input or output bar) to the conductive material, the clamping device (24) preferably being placed in the lower part (201) of the carriage (20); - a clamping device (25), preferably a plurality of clamping devices, arranged in one or two rows, for simplifying the operation of welding the conductive material to the transformer component when the conductive material is a metal foil or a metal plate; - a protective device (26), preferably a panel fixed to the carriage (20), configured in such a way as to prevent operators from being dangerously exposed to the radiation emitted by the at least one laser welding head (22) in the working area of ​​the winding machine (1).

3. The welding group (2) of claim 1 or 2, wherein the first holding device (21) is selected from one or more of the following: - a linear guide (133) arranged in the direction of the axis (X) and fixed to the structure (10) of the winding machine (1), the linear guide (133) being slidably constrained to a sliding block (212) fixed to the upper part (201') of the carriage (20) of the welding group (2); - a rack (133) arranged in the direction of the axis (X) and fixed to the structure (10) of the winding machine (1), the rack (133) being mechanically coupled to a first pinion (212) pivotally constrained to the upper part (201') of the carriage (20) of the welding group (2); 4. The welding group (2) according to one or more of the preceding claims, wherein the second holding device (23) is selected from one or more of the following: - at least one linear guide (222) arranged along the axis (X) and fixed to the carriage (20) or the translation element (221), the at least one linear guide (222) being slidably coupled to one or more sliding blocks (223) fixed to the laser welding head (22); A rack (222) arranged along the axis (X) and fixed to the carriage (20) or the translation element (221), the rack (222) being mechanically coupled to a pinion (223) pivotally constrained to the laser welding head (22).

5. The welding group (2) of one or more of the preceding claims, wherein the actuator (211, 231, 331) can be a translation screw socket, a rotation screw socket, a linear motor, a hydraulic cylinder, a pneumatic cylinder or a combination thereof.

6. A winding machine (1) for manufacturing windings of medium and high voltage power transformers for power generation, transmission and distribution, the winding machine (1) comprising: - an unwinder unit (A) for conductive and / or insulating material in the form of wire, foil or tape; - a winding unit (C) comprising a winding device (11') configured to wind the conductive and / or insulating material on a core (122) integral with a winding drum (12), the winding drum being arranged horizontally along an axis (X) and driven in rotation by a motor (15); - Optionally, a central unit (B) for preparing the conductive and / or insulating material coming from the unwinder unit (A) before said conductive and / or insulating material enters the winding unit (C); The winding machine (1) is characterized in that it comprises a welding group (2) according to one or more of the preceding claims 1 to 5.

7. The wire winding machine (1) as claimed in claim 6, further comprising suitable means for moving the winding drum (12) along the axis (Z) or the axis (Y).

8. The winding machine (1) according to claim 6 or 7, having one or more following layouts: - a welding group (2) located in front of the unwinder unit (A) for performing a head welding operation to weld the conductive material to the head of the transformer component; - a welding group (2) is located internally, i.e. between the unwinder unit (A) and the winding unit (C), and is configured to perform a butt welding operation, thereby welding the conductive material to the upper surface of the transformer component; The welding group (2) is movable between a first position in front of the unwinder unit (A) and a second position between the unwinder unit (A) and the winding unit (C), and the welding group (2) is configured to perform a head welding operation and a butt welding operation.

9. The winding machine (1) according to claims 6 to 8, characterized in that The welding group (2) is controlled by a control unit (29), which includes a storage unit in which a computer program executable by the control unit (29) is stored, wherein the program is configured so that a user can set a welding operation through an appropriate user interface, and wherein the storage unit stores association data between parameters of the welding operation to be performed and processing parameters affecting the welding operation, the processing parameters preferably being stored in a table form. The association data includes at least one of the following: the material of the transformer component to be welded; the geometry and size of the transformer component to be welded; the conductor material to be welded; the geometry and size of the conductor material to be welded; the type of welding, i.e., head welding or butt welding; the welding speed; and the intensity of the laser radiation.

10. Kit (4) suitable for retrofitting a winding machine (1) for manufacturing windings comprising a welding group (2) as claimed in one or more of the preceding claims 1 to 5.

11. The kit (4) of claim 10, comprising: - a carriage (40) slidably constrained to the translation means (43) by means of first retaining means (41); - a laser welding head (42) integral with the carriage (40); - at least one actuator (44) for moving the carriage (40) by means of translation means (43), The laser welding head (42) is shared by N winding machines (40j), where j is an integer of 1≤j≤N, and the slide (40) can be moved along a path including the winding machines (40j) by means of a translation device (43) and an actuator (44).

12. The kit of claim 10 or 11, wherein the translation means (43) comprises one or more linear guides, and the first retaining means (41) is one or more sliding blocks configured to be slidably constrained to the one or more linear guides (43).

13. The kit of one or more of claims 10 to 12, wherein: The actuator (44) may be a translating screw socket, a rotating screw socket, a linear motor, a hydraulic cylinder, a pneumatic cylinder, a ball screw, or a combination thereof.

14. The kit as claimed in one or more of claims 10 to 13, further comprising a protective device (45) to prevent the laser radiation emitted from the laser welding head (42) from causing danger to an operator in the working area of ​​the winding machine (1).

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