FR3104044A1 - Welding wheel with removable ring. - Google Patents

Abstract

Title of the invention: Welding wheel with removable ring. The present invention relates to a welding wheel (1) for welding metal plates (50, 52), the wheel (1) comprising at least one disc (2) of a first material and a ring (4) d 'a second material distinct from the first material, an assembly means making it possible to mount the ring (4) on the disc (2). Abstract figure: Figure 1

Description

Welding wheel with removable ring.

The field of the present invention is that of welding wheels and more particularly welding wheels for the continuous welding of metal plates making up the walls of tanks, used for the storage and transport of liquefied natural gas.

Storage and transport tanks for liquefied natural gas (LNG) are made up of a tank wall which includes, among other things, thermally insulating portions and metal plates, ensuring the tightness of said tank wall. In order to secure and seal the metal plates together, it is known to weld them together. Indeed, the welding of the metal plates ensures optimal sealing of the tank as well as an effective joining of the metal plates between them. To this end, it is known to use a welding machine comprising at least one welding wheel capable of welding the metal plates, under the effect of an electric current flowing through the wheel. Such a welding wheel is then made up of an alloy of different metals, having electrical conductivity properties compatible with the voltage and the current involved. example of beryllium.

In order to reduce the manufacturing time of the tanks mentioned above, the speed of movement of the welding machine carrying the wheel is increased, which leads to an increase in the frequency of the electric current flowing in the wheel as well as the intensity of the current. electricity running through it. However, these increases have the disadvantage of significantly increasing the phenomena of overheating of the latter. Indeed, it was noted by the applicant that the current structure of the wheels was not optimal to resist this increase in the frequency and the intensity of the electric current and that this had the consequence of reducing their lifespan, in particular by wear of the knurl.

As a result of the reduction in the life of the wheel, it is necessary to replace it at a higher frequency than before the increase in the frequency and intensity of the electric current, which ultimately causes significant costs for the operator.

The object of the present invention is therefore to remedy the drawbacks mentioned above, by designing a welding wheel in two parts, one part of which comprising a higher concentration of noble metals, is separable and replaceable, independently of the other part. which can then be reused to carry a new portion dedicated to welding.

The invention thus relates to a welding wheel for welding metal plates, the wheel comprising at least one disk of a first material and a ring of a second material distinct from the first material, the ring peripherally surrounding the disk, the wheel being characterized in that it comprises at least one assembly means allowing removability of the ring relative to the disc.

The invention thus makes it possible to increase the speed of rotation of the wheel without having to increase its size, while maintaining the operating cost of the welding machine equipped with such wheels at an amount compatible with the constraints of construction sites. naval, in particular.

The welding wheel is used, for example, for welding metal plates making up the walls of tanks for storing and/or transporting liquefied natural gas (LNG). Such vessel walls are composed, among other things, of a thermally insulating portion, necessary for the low-temperature transport of LNG and also include a plurality of metal plates composed, for example, of Invar® or a high-manganese alloy. or stainless steel. The metal plates then have the function of sealing the tank. According to an embodiment of the vessel wall, the metal plates may have raised edges at the periphery. The welding wheel is then used to weld the raised edges of the adjacent metal plates. Such welding of the raised edges ensures optimal sealing of the LNG storage and/or transport tank.

The disc of the wheel corresponds to the central portion of the wheel intended to be fixed on a welding machine. The ring assembled around the disk of the wheel corresponds to the portion of the wheel intended to be in contact with the metal plate to be welded. To this end, the ring forms an electrode activated under the effect of an electric current flowing in the wheel and the activation of which causes a significant rise in the temperature of said wheel.

The significant rise in temperature can cause overheating phenomena which in the long term reduce the life of the wheel. The advantage of a ring separable from the disc by the assembly means is then understood, in that it makes it possible to replace a worn ring, without having to change the entire knurl. This reduces the cost for the operator of the welding machine.

According to the invention, the first material and the second material are distinct, and both have electrical conductivity properties compatible with a welding operation, that is to say for the passage of electric current to the ring of the wheel .

According to a characteristic of the invention, the ring delimits an internal space which houses the disc. In other words, the ring peripherally surrounds the disk, the latter bearing the ring.

According to one characteristic of the invention, the ring comprises an internal face facing the internal space and an external face opposite the internal face, the external face of the ring forming a contact surface of the wheel. The contact surface of the wheel constitutes the part of the wheel intended to be in contact with the metal plate to be welded. In other words, the contact surface of the wheel forms a welding surface.

According to one characteristic of the invention, the ring forms a ring and the contact surface is therefore circular.

It is then understood that the ring is of circular shape and that its internal face delimits an internal space which can be of any shape complementary to the external shape of the disc. By contact surface is meant the fact that the outer face corresponds to the face of the ring intended to be in contact with the metal plate to be welded. It is then understood that the plurality of electrodes of the wheel is located in the contact surface. The circular contact surface then makes it possible to carry out welding in continuous displacement along the metal plate.

According to one characteristic of the invention, the assembly means comprises the internal face of the ring facing the internal space and an external surface formed at the periphery of the disc.

It is understood that when inserting the disc into the internal space of the ring, the internal face of the latter forms with the external surface of the disc the assembly means of the wheel. In other words, the inner face of the ring and the outer surface of the disk are capable of cooperating so that the disk is secured to the ring. Such cooperation can be obtained by force fitting the disk in the ring.

According to one characteristic of the invention, the outer surface of the disc comprises a shoulder which extends radially, the ring comprising a bearing surface arranged against the shoulder. The bearing surface comes into contact with the shoulder and limits the axial displacement of the ring relative to the disc.

According to an example of the invention, the shoulder comprises at least one receiving edge which extends perpendicularly from the outer surface of the disc. The bearing surface of the ring is then arranged against the receiving edge of the shoulder. The shoulder has the particular function of increasing the retention of the ring around the disc by forming an abutment zone for the ring on the disc. Also, when the wheel is mounted on the welding machine and is rotated during the welding process, the shoulder allows the ring to be held on the disc in order to prevent the latter from separating from one another. the other.

According to one characteristic of the invention, the wheel extends mainly in a main plane, the shoulder having a first width measured between the outer surface of the disc and a peripheral free edge of the shoulder and along a parallel line to the main plane of the wheel and the ring has a radial dimension measured along the bearing surface, along the line parallel to the main plane of the wheel, strictly greater than the first width.

Advantage is taken of this characteristic in that it allows the outer face of the ring to be furthest from the center of the knurl. In other words, the ring forms a projection relative to the outer surface of the disc. Thus, when using the wheel for welding metal plates, only the contact surface formed by the outer face of the ring is in contact with said metal plate. This guarantees the precision of the welding and reduces the wear of the other portions of the wheel.

According to one characteristic of the invention, the disk comprises a first face and a second face opposite each other in a vertical direction of the wheel, the first face extending in a first main plane of the first parallel face to the main plane of the wheel and the second face extending in a second main plane of the second face parallel to the main plane of the wheel, the ring being contained in a space delimited axially by the first main plane of the first face and the second main plane of the second side.

Advantageously, the ring extends over an axial distance, less than the axial distance over which extends the space formed between the first main plane and the second main plane. Advantage is taken of this characteristic in that it reduces the vertical dimension of the ring and thereby reduces the cost of replacement of said ring by the operator.

According to an alternative of the invention, the internal face of the ring comprises a shoulder which extends radially, the shoulder being in contact with the disc.

The shoulder of the internal face of the ring can for example extend along the first face or the second face of the disc when said ring is mounted on the disc. This increases the mechanical connection of the ring to the disc after assembly.

According to a feature of the invention, the outer surface of the disk is in contact with the inner face of the ring.

According to an example of the invention, the contact between the outer surface of the disc and the inner face of the ring forms the assembly means of the wheel. The means of assembly can then be, for example, a force fitting or a screwing of the ring on the disc.

According to one characteristic of the invention, the wheel comprises a cooling system which comprises at least a first cooling circuit and a second cooling circuit independent of the first circuit.

The cooling system has the function of cooling the wheel during use. In particular, the cooling system with dual cooling circuits makes it possible to increase the cooling of the wheel and allows an increase in the frequency and intensity of the electric current passing through it.

According to one characteristic of the invention, the first material is an alloy comprising at least copper and the second material is an alloy in which at least one metal is chosen from beryllium, chromium, cobalt, zirconium, cadmium, tin and/or tungsten.

An advantage of the second material comprising the metal chosen from the list above is that it has electrical conductivity properties as well as a higher heat resistance than the first material. Similarly, this second material has a greater resistance to wear than the first material and thus makes it possible to give the ring an increased resistance to wear, thus authorizing the use of expensive metals for the manufacture of the ring.

The invention also relates to a method for assembling a welding wheel, comprising at least one ring and a disc according to any one of the preceding characteristics, method during which at least one step the ring is forcibly inserted on the disk.

Forced fitting results in the introduction of the disc into the internal space of the ring, then by the contact of the external surface of the disc with the internal face of the ring. The circumference of the internal space of the ring is then less than a diameter of the disc defined by the external surface of the latter. Such a force fitting guarantees both the possibility of removing the ring relative to the disk, the electrical conductivity of the disk with the ring as well as the thermal conductivity of the ring towards the disk.

According to an alternative of the invention, at least one step of the method consists in screwing the ring onto the disc. The wheel assembly means may thus consist of a thread which connects the ring to the disc. More precisely, the disk comprises a first thread on its outer surface and the ring comprises a second thread on its inner face. According to an exemplary embodiment, the direction of tightening of the assembly means by screwing is opposite to the direction of rotation of the welding wheel when the latter is used during the implementation of the welding process or of the welding machine .

The invention also relates to a welding machine for connecting a first metal plate and a second metal plate of a tank for storing and/or transporting a liquefied natural gas, comprising at least one wheel according to any one of previous features.

According to an example of the invention, the welding machine comprises a first welding wheel and a second welding wheel according to the invention. The first wheel and the second wheel are then arranged on either side of the raised edges of the metal plates of the tank being welded. The first welding wheel is then brought to a first electric potential, while the second welding wheel is brought to a second electric potential opposite the first electric potential. The welding wheels are then electrodes brought to the electrical potentials mentioned above in a discontinuous manner, at a given frequency and intensity which are higher than the frequency and intensity usually used.

According to one characteristic of the welding machine, the latter is configured to operate a continuous displacement welding at a speed greater than or equal to two and a half meters/min. The continuous welding is advantageously carried out at a speed of four m/min.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and several examples of embodiment given by way of indication and not limitation with reference to the appended schematic drawings on the other. part, on which:

is a general perspective view of a first face of a wheel according to the invention comprising a disc and a ring;

is a general perspective view of a second face of the wheel of FIG. 1;

is an axial sectional view of the wheel of FIG. 1, showing the disk comprising a cooling system and a shoulder;

is a general perspective view of a wheel ring;

is an axial sectional view of the wheel of FIG. 1 showing the arrangement of the ring on the disc;

is a close-up view of the ring in contact with the disc and secured together by screwing;

is a schematic view of a welding machine according to the invention, connected to a first welding wheel and a second welding wheel according to the invention.

The features, variants and different embodiments of the invention may be associated with each other, in various combinations, insofar as they are not incompatible or exclusive of each other. It is possible in particular to imagine variants of the invention comprising only a selection of characteristics described below in isolation from the other characteristics described, if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from to the state of the prior art.

In Figure 1 is shown a welding wheel 1 according to the invention. The welding wheel 1 makes it possible to weld metal plates together, by welding in continuous displacement and by points. To this end, the welding wheel 1 is fixed on a welding machine (visible in FIG. 7), the movement of which along the metal plates is continuous at a speed greater than or equal to two and a half meters/min. The movement of the welding machine then ensures the movement of the wheel 1 and the distribution of an electric current within it, allowing it to perform its welding function.

Such a wheel 1 can for example be used during the manufacture of transport and storage tanks for liquefied natural gas (LNG). Such tanks are composed, for example, of at least one thermally insulating barrier, ensuring the thermal insulation of the tank and in particular of its cargo and of a plurality of metal plates, ensuring its sealing and comprising for example one or more edges readings. The wheel 1 is then required to secure the raised edges of adjacent metal plates. The welding of the raised edges of the metal plates by the welding wheel 1, in particular ensures optimal and durable sealing of the LNG transport and storage tanks.

Welding wheel 1 visible in Figure 1 and Figure 2 is circular and extends in a main plane M of wheel 1. Welding wheel 1 then comprises a central axis X of rotation passing through a center D of said wheel 1. According to the invention, the wheel 1 comprises a disc 2 and a ring 4 removable relative to each other. By removable is meant the fact that in an initial state, the ring 4 and the disc 2 are separated from each other and that in a final state, these are assembled by an assembly means during of an assembly process. The assembly means and the assembly method will be detailed later in the following detailed description.

The disc 2 of the wheel 1 visible in Figures 1, 2 and 3, is circular in shape and comprises a peripheral outer surface 6, delimiting a first diameter D1 of the disc 2. The disc 2 also comprises a first face 8 particularly visible at the Figure 1 and a second face 10 particularly visible in Figure 2 and opposite the first face 8 in a vertical direction V of the wheel 1, perpendicular to its main plane M.

A central cavity 12 of circular shape, particularly visible in Figure 3 showing an axial sectional view of the wheel 1 along a first plane A-A, is provided on the first face 8 of the disc 2. The central cavity 12 is surrounded by an edge of circular cavity 14 and a second diameter D2 is defined corresponding to the diameter of the circumference of said central cavity 12. The second diameter D2 is then strictly less than the first diameter D1 of the disk 2.

It is understood by central cavity 12, the fact that the latter corresponds to a removal of material on the first face 8 of the disc 2, creating a recess in said disc 2. The central cavity 12 has the function of forming a keying means and centering of the welding wheel 1 for its assembly on a hub of the welding machine. The central cavity 12 thus makes it possible to center the knob 1 on said hub. It is therefore understood that the first face 8 of the disk 2 is the face facing said welding machine.

Once the welding wheel 1 has been positioned on the welding machine, at least one through bore 16, provided in the disc 2, makes it possible to secure said wheel 1 to the welding machine. By bore 16 crossing is meant the fact that it crosses from one side to the wheel 1, that is to say that the bore 16 is open at the level of the first face 8 and the second face 10 of the disc 2 as shown in Figure 3. The bore 16 is then adapted to cooperate with a fixing means, for example a screw, to secure the wheel 1 with the welding machine. According to an example of the invention particularly visible in Figure 3, the bore 16 has a countersink of a larger diameter on the second face 10 compared to the first face 8 of the disc 2. Such a characteristic makes it possible in particular to accommodate a head of a screw in a common plane with a second main plane P2 of the second face 10.

According to the illustrated embodiment, the knurl 1 comprises four through bores 16 provided on the disc 2. The four bores 16 are advantageously distributed in a peripheral manner in the central cavity 12 in order to provide a better hold of the knurl 1 on the machine. Welding.

As is particularly visible in Figure 3, in an initial state, the disc 2 of the wheel 1 is devoid of the ring. The assembly means then makes it possible, during the assembly process, to assemble the ring on the disc 2, this assembly means being able for example to be a fitting in force or a screwing of the ring around the disc 2. advantage of the removability of the ring relative to disc 2 in that it allows replacement of the worn ring of wheel 1, without replacing disc 2.

The wheel includes the cooling system 18 formed in its disc 2. The cooling system 18 advantageously includes a first cooling circuit 20 and a second cooling circuit 22 partly visible in Figure 3. The cooling system 18 includes holes inlet 24 and outlet orifices 26 in order to introduce a cooling fluid into the welding wheel 1, and these are formed in the central cavity 12 of the disc 2, as can be seen in FIG. 1.

The cooling system 18 has the function of cooling the wheel 1 during its use, that is to say during the flow of current therein. The cooling system 18 makes it possible in particular to limit the temperature of the knob 1 and thus reduces the phenomena of overheating which may eventually damage it. An advantage of the cooling system 18 comprising the double cooling circuit is that it increases the cooling effect of the wheel 1 and participates in increasing its lifespan.

A shoulder 28 extends radially from the outer surface 6 of the disk 2. According to the illustrated example of the invention, the shoulder 28 extends substantially perpendicularly with respect to the outer surface 6 and comprises a peripheral free edge 30 connected to the outer surface 6 of the disc 2 by a receiving edge 32 and an inclined edge 34. More specifically, the inclined edge 34 extends from the second face 10 of the disc 2 and at an angle of inclination between 10 ° and 80° with respect to the main plane M of the wheel 1 and in the direction of the first face 8 of the disc 1.

The receiving edge 32 extends perpendicularly from the outer surface 6 opposite the inclined edge 34 in the vertical direction V of the wheel 1. The peripheral free edge 30 then extends perpendicular to the main plane M of the wheel 1 , between the receiving edge 32 and the inclined edge 34 and so that it connects them.

The shoulder 28 comprises a first width E1 measured along a straight line parallel to the main plane M of the wheel 1, between the outer surface 6 of the disc 1 and the peripheral free edge 30 of the shoulder 28.

The ring 4 alone will now be described with Figure 4. The ring 4 is a ring of circular shape and it delimits an internal space 36 making it possible to accommodate the disc 2 of the wheel 1. More precisely, the ring 4 comprises a internal face 38 facing internal space 36 and an external face 40 radially opposite internal face 38, in the main plane M of wheel 1. Internal face 38 therefore delimits internal space 36 whose circumference has a third diameter D3. According to an example of the invention, the third diameter D3 can be substantially equal to or less than the first diameter D1 of the disc 2 of the wheel 1, which guarantees a force fitting of the ring 4 on the disc 2.

The outer face 40 of the ring 4 defines a contact surface 42 of the wheel 1 and it is then understood that this contact surface 42 is circular. By contact surface 42 is meant the fact that the outer face 40 of the ring 4 corresponds to the face of said ring 4 brought into contact with the metal plate to be welded. The contact surface 42 then forms a welding range of the wheel 1. To this end, the ring 4 forms an electrode which is activated under the effect of the electric current flowing in the wheel 1, to allow the welding of the metal plates .

The ring 4 of the wheel 1 is delimited axially by a bearing surface 44, visible in FIG. 5, and an upper face 46. In other words, the upper face 46 and the bearing surface 44 extend radially and parallel to the main plane M of wheel 1, so that they are opposite each other in the vertical direction V of said wheel 1.

The inner face 38 of the ring 4 extends perpendicularly between the upper face 46 and the bearing surface 44 of said ring 4, so that it connects them. The outer face 40 and an inclined face 48 extend opposite the inner face 38 in a radial direction of the wheel 1, and in such a way that they connect the upper face 46 and the bearing surface 44. More precisely, the external face 40 extends perpendicularly from the support surface 44 and the inclined face 48 extends from the upper face 46, and it is then understood that the inclined face 48 extends between the external face 40 and the top face 46.

A radial dimension R1 is defined as a width of the ring 4 measured along a straight line parallel to the radial direction of the wheel 1, between the inner face 38 and the outer face 40 of the ring 4. According to a characteristic of invention, the radial dimension R1 is strictly greater than the first width E1 of the shoulder 28. This feature allows the contact surface 42 of the wheel 1 defined by the outer face 40 of the ring 4, to be in projection from the rest of the wheel 1 in order to operate the welding of the metal plates.

As can be seen in FIG. 5, showing an axial sectional view along the first plane A-A visible in FIG. 1, when the ring 4 is assembled with the disc 2, the bearing surface 44 of the ring 4 is in contact against the receiving edge 32 of the shoulder 28. Similarly, the internal face 38 of the ring 4 is in contact with the external surface 6 of the disc 2. It is understood that the function of the shoulder 28 is to form a zone of axial stop of ring 4 during assembly of the latter on disc 2.

According to one characteristic of the invention, a second thickness E2 of disc 2 is defined, measured along a straight line parallel to the axial direction of wheel 1, measured between first face 8 and second face 10. Also, a third thickness E3 of the ring 4, measured along a straight line parallel to the vertical direction V of the wheel 1, between the upper face 46 and the bearing surface 44. The third thickness E3 of the ring 4 is then strictly less than the second thickness E2.

Still according to the invention, the third thickness E3 of the ring 4 is included in a space delimited axially by a first main plane P1 of the first face 8 of the disc 2 and the second main plane P2 of the second face 10 of the disc 2. Advantageously, the third thickness E3 of the ring 4 is less than the axial distance over which extends the space delimited by the first main plane P1 and the second main plane P2. Such a characteristic makes it possible to limit the axial dimension of the ring 4 and thus to reinforce its holding against the external surface 6 of the ring 4. The quantity of material constituting the ring 4 can also be contained.

According to one characteristic of the invention, the first material making up the disc 2 is for example a material such as copper. Conversely, the second material making up the ring 4 can be an alloy composed of noble materials such as beryllium, chromium, cobalt, zirconium, cadmium, tin and/or tungsten. We then understand the advantage of a wheel 1 comprising a ring 4 separable from the disc 2, in that it allows only the ring 4 of the wheel to be replaced when the latter wears out, the disc 2 then being able to be preserved and reused. This limits the costs of replacing the wheel 1 due to its particular composition which may include expensive materials for the operator of the welding machine.

According to a characteristic of the invention, the assembly of the ring 4 with the disc 2 can be a force fitting. This assembly in force can be achieved by the first diameter D1 of the disc 2 greater than the second diameter D2 of the internal space 36 delimited by the internal face 38 of the ring 4.

According to a second embodiment of the assembly means visible in Figure 6, the ring 4 can be screwed onto the disc 2 by means of a thread 39. More specifically, a first thread 39a is provided on the outer surface 6 of disk 2, and a second thread 39b is provided on the inner face 38 of ring 4 facing first thread 39a. It will be noted that the direction of tightening of the assembly means by screwing is opposite to the direction of rotation of the welding wheel 1 when the latter is used by the welding method which is the subject of the invention, or when this wheel is installed on the welding machine and that the latter produces a weld bead. In this way, the cooperation between the ring 4 and the disc 2 is guaranteed and it is ensured that the rotation of the wheel 1 during the welding process does not cause the ring 4 to separate from the disc 2.

According to an alternative of the invention not represented, a shoulder can extend radially from the inner face of the ring, such that the shoulder is in contact with the first face or the second face of the disc of the wheel. It is then understood that in this embodiment, the outer surface is flat.

The welding process will now be described with Figure 7, showing a first metal plate 50 and a second metal plate 52 respectively having a first raised edge 54 and a second raised edge 56. The first raised edge 54 and the second raised edge 56 are then arranged so that they face each other.

The welding machine 58 of Figure 7 is shown schematically and it is understood that its dimensions and its arrangement in relation to the welding wheels 1 are not to scale. Similarly, the electrical connections between the welding machine 58 and the welding wheels 1 are not shown, but it is understood that the welding machine 58 makes it possible to supply an electric current to the welding wheels 1 as has already been explained. previously in the detailed description.

A first welding wheel 1a and a second welding wheel 1b are arranged on either side of the raised edges 54, 56 of the metal plates 50, 52. More specifically, the first welding wheel 1a faces the first raised edge 54 and the second welding wheel 1b is facing the second raised edge 56. A first contact surface 42a of the first wheel 1a is then in contact with the first raised edge 54 and a second contact surface 42b of the second wheel 1b is in contact with the second raised edge 56.

During the implementation of the method of welding the metal plates 50, 52, an external device (not shown) makes it possible to move the welding machine 58 forward. When the welding machine 58 moves, the latter sends an electric current into the welding wheels 1a, 1b, causing the creation of a weld bead 62. The activation of the plurality of electrodes allows the raised edges 54, 56 of the metal plates 50, 52 to be welded but also causes a significant elevation the temperature at the contact surfaces 42a, 42b of the welding wheels 1a, 1b.

In order to avoid phenomena of overheating due to high temperatures, the first wheel 1a and the second wheel 1b respectively comprise a first cooling system and a second cooling system. Each of the first cooling system and of the second cooling system then comprises the first cooling circuit and the second cooling circuit described previously.

A first rotation shaft 61a extends between the first welding wheel 1a and the welding machine 58, and a second rotation shaft 61b extends between the second welding wheel 1b and the welding machine 58. In order to irrigate the first cooling circuit and the second cooling circuit of each of the wheels 1a, 1b with cooling fluid, a plurality of pipes 60 connects the latter to the welding machine 58.

The plurality of conduits 60 extend into each of the first rotation shaft 61a and the second rotation shaft 61b. In particular, a first pipe 60a connected to the first inlet orifice, a second pipe 60b connected to the first outlet orifice, a third pipe 60c connected to the second inlet orifice and a fourth pipe 60d connected to the second outlet orifice, extend into the first rotation shaft 61a. An identical configuration between pipes 60 formed in the second rotation shaft 61b and the inlet and outlet orifices is applied for the second cooling system of the second welding wheel 1b.

The plurality of pipes 60 therefore ensures the irrigation with cooling fluid of the cooling systems of the rollers 1a, 1b, in order to prevent these from overheating during the circulation of the electric current at high frequency and high intensity in their spans. welding 42a, 42b.

The invention thus achieves the object it had set itself by proposing a welding wheel whose structure allows the circulation of an electric current of higher frequency and higher intensity and whose replacement is optimized to reduce costs. . This allows faster welding of the raised edges of the metal plates and reduces the manufacturing time of the walls of the storage tank or LNG transport.

The invention cannot however be limited to the means and configurations exclusively described and illustrated, and also applies to all means or configurations, equivalents and to any combination of such means or configurations.

Claims (13)

Welding wheel (1) for welding metal plates (50, 52), the wheel (1) comprising at least one disc (2) of a first material and a ring (4) of a second material distinct from the first material, the ring (4) peripherally surrounding the disc (2), the wheel (1) being characterized in that it comprises at least one assembly means allowing removability of the ring (4) with respect to the disc (2 ). Welding wheel according to the preceding claim, in which the ring (4) delimits an internal space (36) which houses the disc (2). Welding wheel (1) according to the preceding claim, in which the ring (4) comprises an internal face (38) facing the internal space (36) and an external face (40) opposite the internal face (38), the outer face (40) of the ring (4) forming a contact surface (42) of the wheel (1). Welding wheel (1) according to the preceding claim, in which the assembly means comprises the internal face (38) of the ring (4) facing the internal space (36) and an external surface (6) formed by periphery of the disc (2). Welding wheel (1) according to the preceding claim, in which the outer surface (6) of the disc (2) comprises a shoulder (28) which extends radially, the ring (4) comprising a bearing surface (44) arranged against the shoulder (28). Welding wheel (1) according to the preceding claim, in which the wheel (1) extends mainly in a main plane (M), the shoulder (28) having a first width (E1) measured between the external surface (6 ) of the disc (2) and a peripheral free edge (30) of the shoulder (28) and along a straight line parallel to the main plane (M) of the wheel (1) and the ring (4) has a dimension radial (R1) measured along the bearing surface (44), along the straight line parallel to the main plane (M) of the wheel (1), strictly greater than the first width (E1). Welding wheel (1) according to the preceding claim, in which the disk (2) comprises a first face (8) and a second face (10) opposite each other in a vertical direction (V) of the wheel (1), the first face (8) extending in a first main plane (P1) of the first face (8) parallel to the main plane (M) of the wheel (1) and the second face (10) extending in a second main plane (P2) of second face (10) parallel to the main plane (M) of the wheel (1), the ring (4) being contained in a space delimited axially by the first main plane (P1) of first face (8) and the second main plane (P2) of second face (10). Welding wheel (1) according to any one of the preceding claims, in which the wheel (1) comprises a cooling system (18) which comprises at least a first cooling circuit (20) and a second cooling circuit (22 ). Welding wheel (1) according to any one of the preceding claims, in which the first material is an alloy comprising at least copper and the second material is an alloy in which at least one metal is chosen from beryllium, chromium, cobalt, zirconium, cadmium, tin or tungsten. Method of assembling a welding wheel (1), comprising at least one ring (4) and a disk (2) according to any one of the preceding claims, method during which at least one step is forcibly inserted the ring (4) on the disc (2). Method of assembling a welding wheel (1), comprising at least one ring (4) and a disk (2) according to any one of Claims 1 to 9, method during which at least one step is screwed the ring (4) on the disc (2). Welding machine (58) for connecting a first metal plate (50) and a second metal plate (52) of a tank for storing and/or transporting a liquefied natural gas, comprising at least one wheel (1) according any of claims 1 to 9. Welding machine (58) according to the preceding claim, configured to perform continuous welding at a speed greater than or equal to two and a half meters/min.