Welding station and method, in particular for high—thickness annular parts

Abstract

The present application relates to a welding station (260) for welding high-thickness annular parts (22;22',22") comprises support means, rotation driving means, and a welding device (270). The welding device comprises at least one high performance laser device capable of emitting a high power laser, configured to emit a single-mode laser beam dynamically modifiable in the focus shape and position.

Description

"WELDING STATION AND METHOD, IN PARTICULAR FOR HIGH-THICKNESS ANNULAR PARTS" DESCRIPTIONField of the invention

[0001] The present invention is in the field of industrial welding, in particular of parts having high thicknesses ; usually, such thicknesses are considered high if , in the case of , for example, welding steel parts , the thickness is greater than 25 millimeters . In particular, the object of the present invention is a device for the industrial welding of high-thickness , at least partially annular parts , such as for example the collars of a large floater for wind turbines , and the related welding method .Background of the invention

[0002] In general, industrial welding processes must be sufficiently precise with reference to the function of the parts to be welded, reliable, and fast , so as to ensure high productivity .

[0003] For this reason, whenever there are no contraindications , laser welding is used, which is generally precise, reliable, and fast , as it does not involve the melting of a filler material . In fact , in the laser welding process , the laser is focused on the facing edges in contact between the parts to be joined; the laser melts the material at the edges , forming a singlejoint .

[0004] This type of weld, known as a "pure laser" weld, does not envisage a particular shape of the edges in contact ( called "I-shaped" juxtaposition) and is generally applicable up to thicknesses of 10 millimeters (Fig . la) .

[0005] For greater thicknesses , such as up to 25 millimeters , it is necessary to shape the edges in contact with the parts so as to obtain a cavity ("Y- shaped" juxtaposition ) . A laser weld of the type described above is used to weld the contact regions , and at the same time a MAG (or MIG) weld is used for the remaining part , so that the cavity is filled with the molten filler material . In this case, it is called a "hybrid laser" weld (Fig . lb) .

[0006] Examples of laser welding devices are shown in US 2010 / 320174 Al , CN 208 800 897 U, KR 2022 0048565 A, and M . SCHMIDT ET AL "Advances in macro-scale laser processing" .

[0007] For even greater thicknesses , such as up to 60 or 70 millimeters , considerable difficulties still exist today for industrial welding . However, there is a need to weld parts having high thicknesses , such as in the production of large-sized floaters for off-shore wind turbines .Object of the invention

[0008] The object of the present invention is to provide a welding device for high thickness , in particular at least partially annular, approximately between 25 and 70 millimeters , such as for example the collar of a large floater for wind turbines . This object is achieved by a welding device according to claim 1 . The dependent claims describe additional advantageous embodiments of the invention .Brief description of the drawings

[0009] Fig . la and lb show the "pure laser" and "hybrid laser" welding types , according to the prior art .

[0010] The features and advantages of the present invention will become apparent from the following description, given by way of non-limiting example with reference to the further figures in the accompanying drawings , wherein :- Fig . 2a through 2 f show a large floater and parts thereof ;- Fig . 3 shows a station for forming a large floater;- Fig . 4a shows a welding device according to an embodiment of the present invention;- Fig . 4b shows a welding station comprising the welding device of Fig . 4a according to an embodiment of the present invention;Fig . 4c is a side view of the welding station inFig . 4b;- Fig . 4d is an enlarged view of the box IVd of Fig . 4c;- Fig . 5 shows a welding station comprising a welding device according to a further embodiment of the present invention;- Fig . 6 shows a welding station comprising a welding device according to a still further embodiment of the present invention .Description of embodiments of the invention

[0011] For clarity of description, reference will be made below to a welding station and a method for the welding of cylindrical collars for the manufacturing of a large floater, in particular for offshore wind turbines . It is however evident from the following description that the welding station and the method according to the present invention are generally applicable to the welding of two parts , in particular of high thickness , in particular at least partially or completely annular .

[0012] In this regard, the Applicant is the holder of the International Application PCT / IB2024 / 059636 for a "Plant for the manufacture of large floaters , in particular for wind turbines" and of the International Application PCT / IB2024 / 059897 relating to a "Strut application station for a plant for the manufacture of large floaters , in particular for wind turbines" , the teachingof which is explicitly incorporated herein as regards the construction of the collars .The floater

[0013] Typically, a floater structure comprises three cylindrical floaters , arranged at the vertices of an imaginary triangle, joined together, for example along the sides of the triangle, by trusses . Typically, the wind turbine, consisting of the column, the nacelle with the dynamo, and the blades , is supported by one of the floaters .

[0014] Referring to Fig . 2a through 2 f , a floater 10 consists of a cylindrical side wall 12 , extending along a central axis X between a lower end 14 and an upper end 16, a lower cap 18 , applied to the side wall 12 at the lower end 14 , and an upper cap 20 , applied to the side wall 12 at the upper end 16 . The side wall 12 has an outer side surface 12e and an inner side surface .

[0015] The side wall 12 of the floater 10 consists of a plurality of reinforced collars 22 which, arranged to be adjacent axially and welded together along the circumferential edges , form the side wall 12 . Each collar 22 has an outer side surface 22e and an inner side surface 22i .

[0016] The outer side surface 12e of the side wall 12 of the floater 10 is the union of the outer side surfaces22e of the collars 22 ; similarly, the inner side surface of the side wall 12 of the floater 10 is the union of the inner side surfaces 22i of the reinforced collars 22 .

[0017] Axially spaced circumferential reinforcing rings 24 are welded on the inner side surface 22i of each collar 22 ; each reinforcing ring 24 consists of a plurality of struts 25 made up of an arched T beam, the foot 25a of which is welded to the inner side surface 22i of the collar 22 .

[0018] The lower cap 18 and the upper cap 20 are prefabricated; the cap manufacturing process is not a subject matter of the present invention .The plant for manufacturing floaters

[0019] Referring to Fig . 3 , a floater forming station 250 of a plant for manufacturing large floaters comprises a welding station for the floater 260 comprising a pair of tracks 264 , arranged along a direction of travel A, a plurality of self-propelled carriages 230 and a welding device 270 .

[0020] A first carriage 230 ' , carrying the lower cap 18 (or the upper cap 20 ) , is arranged along the tracks 264 in a predefined position; a second carriage 230 ' ' carrying a first collar 22 ' , is placed next to the first carriage 230 ' , so that the first collar 22 ' is coaxial to the lower cap 18 (or the upper cap 20 ) and abuts with thelower cap 18 (or with the upper cap 20) . The welding station of the floater 260 is placed next to the carriages 230', 230' ' and welds the lower cap 18 (or the upper cap 20) to the first collar 22' along the respective circumferential edges.

[0021] Subsequently, a third carriage 230' ' ' carrying a second collar 22' ' is placed next to the second carriage 230' ' so that the second collar 22' ' abuts the first collar 22' . The first collar 22' and the second collar 22' ' are aligned. The welding station 270 is placed next to the carriages 230' ', 230' '' and welds the first collar 22' to the second collar 22' ' along the respective circumferential edges.

[0022] Lastly, preferably, the welding device 270 also welds the axial edges of the collar, which had only been spot-welded in the previous steps .

[0023] The process continues for subsequent collars.

[0024] At the end, a last carriage 230iv, carrying the upper cap 20 (or the lower cap 18) , is arranged along the tracks 264 and is placed next to the penultimate carriage positioned so that the last collar 22' ' ' abuts the upper cap 20 (or the lower cap 18) . The welding station 270 is placed next to the last carriage 230iv and welds the upper cap 20 (or the lower cap 18) to the last collar 22' ' ', along the respective circumferential edges.

[0025] This results in the floater 10 having a floating horizontal central axis J, parallel and coincident with the direction of travel A; in particular, the collars 22 ' , 22 ' ' , 22 ' ' ' are aligned along the horizontal central axis J . The floater 10 is supported by a set of carriages 230 which, collectively, constitute a transport unit 300 , movable along the tracks 264 to transport the floater 10 outside the factory .

[0026] Preferably, each carriage 230 is configured to rotate the relevant collar about the central axis J; consequently, preferably, the transport unit 300 is configured to rotate the structure being formed, consisting of the collars and the caps already welded, about the central axis J .

[0027] More generally, the transport unit is an example of the implementation of support means and rotation driving means , which are integrated with each other .The welding device

[0028] According to a first embodiment of the invention, the welding device 270 comprising a column carriage 272 which is translatable on command on the tracks 264 along a first horizontal translation axis X, a column 274 , which extends vertically and is supported by the carriage 272 , an arm carriage 275 applied to the column 274 and translatable on command along a second verticaltranslation axis Y, and an arm 276 supported by the arm carriage 275 and translatable on command along a third horizontal translation axis Z orthogonal to the first translation axis X and the second translation axis Y .

[0029] Furthermore, the welding device 270 comprises a laser device 278 suitable for emitting a laser beam towards a target region, supported by the arm 276 ; for example, the laser device is applied to the free end of the arm 276, distal from the column 274 .

[0030] The laser device 278 exhibits high performance . In particular, the laser device 278 is high power, i . e . has effective power between 7 and 28 Kw, circular polarization, wavelength 1064 ± 1 nm, preferably water- cooled . Furthermore, the laser device 278 is configured to emit a single-mode laser beam dynamically modifiable in the focus shape and position (dynamic beam laser) . For example, such a laser device is provided by Civan Advanced Technologies Ltd .Advantageously, a single-mode laser beam allows realizing welding on large volumes and high thicknesses , ensuring a good penetration depth . Furthermore, the possibility of dynamically modifying the shape and focus of the beam offers the advantage of adapting both the geometry of the weld and the depth of the focus as required during welding, without the need to replace the welding head .This combination of advantages allows obtaining greater speed (with consequent savings in time ) and welding depth, which are essential aspects for processing on large surfaces and high thicknesses .

[0031] A structure 15 , comprising a plurality of collars 22 , is supported by the transport unit 300 in a manner which is rotatable about the central axis J . In particular, the structure 15 comprises a first collar 22 ' , having a rear circumferential edge 23 ' and a front circumferential edge 25 ' . A second collar 22 ' must be welded to the first collar 22 ' . Said second collar 22" is placed on the transport unit 300 , coaxial to the central axis J of the structure 15 , adjacent to the first collar 22 ' . The second collar 22 ' ' thus has a rear circumferential edge 23 ' ' , facing the front circumferential edge 25 ' of the first collar 22 ' and intended to be welded thereto, and a front circumferential edge 25 ' ' .

[0032] The welding station 260 is moved on the tracks 264 , and the axle driving means are actuated in a controlled manner .

[0033] According to a first embodiment of the invention (Fig . 4a to 4d) , the third translation axis Z is arranged parallel to the central axis J, and the arm 276 at least partially penetrates the space delimited by the firstcollar 22' and the second collar 22 so that the laser device 278 is able to operate, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' on the inner side surface of the first collar 22' and the second collar 22' ' .

[0034] The structure 15, and in particular the first collar 22', and the second collar 22' ' are placed in rotation with a predefined angular rotation velocity about the central axis J, and the laser device 278 is actuated to emit the laser beam and to perform the welding, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ', on the inner side surface of the first collar 22' and of the second collar 22' ' .

[0035] According to a further embodiment of the invention (Fig. 5) , the third translation axis Z is arranged parallel to the central axis J, and the arm 276 externally overlaps the first collar 22' and the second collar 22' ' at least partially so that the laser device 278 is able to operate, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' on the outer side surface of the first collar 22' and the second collar 22

[0036] The structure 15, and in particular the first collar 22' and the second collar 22' ' are rotated at a predefined angular rotation velocity about the central axis J, and the laser device 278 is actuated to emit the laser beam and perform the welding, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' on the outer side surface of the first collar 22' and on the outer side surface of the second collar 22" .

[0037] According to yet another embodiment of the invention (Fig. 6) , the welding device 270 comprises the column carriage 272, the column 274, a first carriage arm 275', a first arm 276' carrying a first laser device 278', a second carriage arm 275", and a second arm 276" carrying a second laser device 278" at a different height along the second translation axis Y with respect to the height of the first laser device 278' .

[0038] The laser device 278' exhibits high performance. In particular, the laser device 278' is high power, i.e., it has an effective power between 7 and 28 Kw, circular polarization, wavelength 1064 ± 1 nm, preferably water- cooled. Furthermore, the laser device 278' is configured to emit a single-mode laser beam dynamically modifiable in the focus shape and position (dynamic beam laser) . Forexample, such a laser device is provided by Civan Advanced Technologies Ltd.

[0039] The third translation axis Z is arranged parallel to the central axis J, and the first arm 276' at least partially penetrates the space delimited by the first collar 22' and the second collar 22' ' so that the first laser device 278' is able to operate, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' on the inner side surface of the first collar 22' and the second collar 22' ' . At the same time, the second arm 276' ' externally overlaps the first collar 22' and the second collar 22' ' at least partially so that the second laser device 278' ' is able to operate, by gravity, between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' on the outer side surface of the first collar 22' and the second collar 22' ' .

[0040] The structure 15, and in particular the first collar 22', and the second collar 22' ' are placed in rotation with a predefined angular rotation speed about the central axis J. The first laser device 278' is actuated to emit the laser beam and perform the welding internally between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of thesecond collar 22 while the second laser device 278 is actuated to emit the laser beam and perform the external welding between the front circumferential edge 25' of the first collar 22' and the rear circumferential edge 23' ' of the second collar 22' ' .

[0041] A further object of the present invention is to provide a method for welding collars 22', 22'' .

[0042] The welding method for welding collars 22 ', 22' ' comprises the following steps in succession i) arranging a first collar 22' and a second collar 22' ' to be adjacent along a horizontal central axis J so that a front edge 25' of the first collar 22' is placed next to a rear edge 23' ' of the second collar 22' '; ii) rotating the first collar 22' and the second collar 22' ' about the central axis J; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it inside the collars 22', 22' ' between the front edge 25' of the first collar 22' and the rear edge 23' ' of the second collar 22' ' to perform the welding.

[0043] In a further embodiment, the welding method for welding collars 22', 22' ' comprises the following steps in succession : i) arranging a first collar 22' and a second collar 22' ' to be adjacent along a horizontal central axis J so thata front edge 25' of the first collar 22' is placed next to a rear edge 23' ' of the second collar 22' '; ii) rotating the first collar 22' and the second collar 22' ' about the central axis J; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it outside the collars 22', 22' between the front edge 25' of the first collar 22' and the rear edge 23' ' of the second collar 22' ' to perform the welding.

[0044] According to a further embodiment, the welding method for welding collars 22', 22' ' comprises the following steps in succession: i) arranging a first collar 22' and a second collar 22' ' to be adjacent along a horizontal central axis J so that a front edge 25' of the first collar 22' is placed next to a rear edge 23' ' of the second collar 22' '; ii) rotating the first collar 22' and the second collar 22' ' about the central axis J; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it inside the collars 22', 22' ' between the front edge 25' of the first collar 22' and the rear edge 23' ' of the second collar 22' ' to perform the welding, and iv) simultaneously with the rotation, emitting a second high power and single-mode laser beam, focusing itoutside the parts (22 ; 22 ' , 22 ' ' ) between the front edge (25' ) of the first collar 22' and the rear edge (23' ' ) of the second collar 22' ' to perform the welding.

[0045] Since the above description of the welding station and method are generally applicable to the welding of parts, in particular of high thickness, in particular at least partially or completely annular, that which has been discussed so far referring to collars 22, 22', 22' ', 22' ' ' may be generalized to parts 22, 22', 22' ' , 22' ' ' .

[0046] Innovatively, the welding device according to the present invention achieves the aforementioned object, in that it allows for sufficiently precise, reliable, and fast industrial welding to be carried out, so as to ensure high productivity, notwithstanding the high thicknesses of the parts to be welded.

[0047] It is clear that a person skilled in the art, in order to satisfy contingent needs, could make modifications to the welding station described above, said modifications all being contained within the scope of protection defined in the following claims.

Claims

CLAIMS1. A welding station (260) for welding parts (22; 22', 22' ' ) , comprising:- support means adapted to support a first part (22' ) and a second part (22' ' ) aligned along a horizontal central axis (J) so that a front edge (25' ) of the first part (22' ) is adjacent to a rear edge (23' ' ) of the second part (22 ' ' ) ;- rotation driving means adapted to rotate the first part (22' ) and the second part (22' ' ) about the central axis (J) ;- a welding device (270) comprising at least one first laser device (278' ) adapted to emit a welding laser beam and a first arm (276' ) , which supports the first laser device (278' ) and is translatable on command along a third translation axis (Z) to bring the first laser device (278' ) to weld the front edge (25' ) of the first part (22' ) to the rear edge (23' ' ) of the second part (22' ' ) ;- wherein the first laser device (278' ) is high power, configured to emit a single-mode laser beam dynamically modifiable in the focus shape and position.

2. A welding station according to claim 1, comprising tracks (264) , wherein the welding device (270) comprises a column carriage (272) translatable on command on saidtracks (264) along a first horizontal translation axis(X) , a column (274) extending vertically and supported by the column carriage (272) , a first arm carriage (275' ) applied to the column (274) and translatable on command along a second vertical translation axis (Y) , wherein the first arm (276' ) is supported by the first arm carriage (275' ) .

3. A welding station according to claim 2, wherein the welding device (270) comprises a second laser device (278' ' ) adapted to emit a welding laser beam and a second arm (276' ' ) , which supports the second laser device (278' ' ) and is translatable on command along a third translation axis (Z) to bring the second laser device (278' ' ) to weld the front edge (25' ) of the first part (22' ) to the rear edge (23' ' ) of the second part (22' ' ), a second arm carriage (275' ' ) applied to the column (274) and translatable on command along the second vertical translation axis (Y) , wherein the second arm (276' ' ) is supported by the second arm carriage (275' ' ) at a different height along the second translation axis (Y) with respect to the height of the first arm (276' ) , and wherein the second laser device (278' ' ) is high power, configured to emit a single-mode laser beam dynamically modifiable in the focus shape and position.

4. A welding station according to any one of thepreceding claims, wherein the support means comprise a movable transport unit (300) consisting of a plurality of self-propelled carriages (230) , each carriage being suitable for supporting a single part (22) , and said rotation driving means being integrated in said transport unit (300) .

5. A welding method for welding parts (22; 22', 22''), comprising the following steps: i) arranging a first part (22' ) and a second part (22' ' ) to be adjacent along a horizontal central axis (J) so that a front edge (25' ) of the first part (22' ) is placed next to a rear edge (23' ' ) of the second part (22' ' ) ; ii) rotating the first part (22' ) and the second part (22' ' ) about the central axis (J) ; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it inside the parts (22; 22', 22' ' ) between the front edge (25' ) of the first part (22' ) and the rear edge (23' ' ) of the second part (22' ' ) to perform the welding.

6. A welding method for welding parts (22; 22', 22' ' ) , comprising the following steps: i) arranging a first part (22' ) and a second part (22' ' ) to be adjacent along a horizontal central axis (J) so that a front edge (25' ) of the first part (22' ) is placed next to a rear edge (23' ' ) of the second part (22' ' ) ;ii) rotating the first part (22' ) and the second part (22' ' ) about the central axis (J) ; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it outside the annular parts (22; 22', 22' ' ) between the front edge (25' ) of the first part (22' ) and the rear edge (23' ' ) of the second part (22' ' ) to perform the welding .

7. A welding method for welding parts (22; 22', 22' ' ) , comprising the following steps: i) arranging a first part (22' ) and a second part (22' ' ) to be adjacent along a horizontal central axis (J) so that a front edge (25' ) of the first part (22' ) is placed next to a rear edge (23' ' ) of the second part (22' ' ) ; ii) rotating the first part (22' ) and the second part (22' ' ) about the central axis (J) ; iii) simultaneously to the rotation, emitting a first high power and single-mode laser beam, focusing it inside the parts (22; 22', 22' ' ) between the front edge (25' ) of the first part (22' ) and the rear edge (23' ' ) of the second part (22' ' ) to perform the welding, and iv) simultaneously to the rotation, emitting a second high power and single-mode laser beam, focusing it outside the parts (22; 22', 22' ' ) between the front edge (25' ) of the first part (22' ) and the rear edge (23' ' ) ofthe second part (22' ' ) to perform the welding.

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