Welding device including an anti-contamination cover

Abstract

Title: Welding Device Comprising a Contamination Guard. Welding device (1) arranged to perform welding between at least two parts to be welded (2), the welding device comprising: a welding unit (3) arranged to perform welding along the junction (4) of two parts to be welded, generating a weld pool (5) at a weld zone (10); a contamination guard (6) arranged to be placed, in particular movable, in contact with the parts to be welded (2) such that the welding unit (3) and the contamination guard (6) encompass the entire weld pool (5) and that any half-line (7) extending from the weld pool intersects either the contamination guard or the welding unit, the welding device (1) being arranged in particular to move the weld zone (10) relative to the parts to be welded during welding. Figure for the abstract: Fig. 1

Description

Title of the invention: Welding device comprising an anti-contamination cover

[0001] The present invention relates to a welding device comprising an anti-contamination hood, particularly for operation in space.

[0002] Welding is a process for joining elements. In space, under vacuum conditions, structures are most often assembled by mechanical latching interfaces such as latches.

[0003] However, welding can be considered for the future construction of structures in space.

[0004] The use of welding requires the management of contamination created during the operation, such as weld ejecta or metallic vapors.

[0005] This is the case, for example, when using arc or laser welding, or electron beam welding.

[0006] For use in space, the problem of collecting welding ejecta is crucial, because uncollected ejecta could become space debris dangerous for the host system and all space vehicles.

[0007] Furthermore, the metallic vapors generated in the weld bath can interfere with the energy beam, altering the quality of the weld and generating defects in the assembly of the elements, or even come to be deposited on critical surfaces of the satellite, rendering it inoperative.

[0008] The invention aims to provide a solution to limit contamination of the external environment during the welding process.

[0009] The invention relates to a welding device arranged to perform welding between at least two parts to be welded, the welding device comprising: - a welding unit arranged to perform a weld along the junction of two parts to be welded, generating a weld pool at the level of a weld zone, - an anti-contamination hood arranged to be placed, in particular movable, in contact with the parts to be welded so that the welding unit and the anti-contamination hood encompass the entire weld pool and that any half-line extending from the weld pool intersects either the anti-contamination hood or the welding unit, the welding device being arranged in particular to move the welding area relative to the parts to be welded during welding.

[0010] According to one aspect of the invention, the welding device is arranged to perform a welding between at least two parts to be welded in a dynamic manner, that is to say in such a way that the weld zone moves along the junction between the parts to be welded during the welding.

[0011] According to one aspect of the invention, an ejecta expelled from the weld pool and following a straight trajectory is stopped by the anti-contamination hood, the welding unit, or the parts to be welded. Thus, the ejecta cannot exit in a straight line from the volume defined by the hood, the welding unit, and the parts to be welded.

[0012] A principal axis of the welding unit is defined.

[0013] According to one aspect of the invention, the main axis of the welding unit is, for example: - in the case of arc welding, the main axis of the welding electrode, - in the case of laser welding, the main axis of the laser beam, - in the case of electron beam welding, the main axis of the beam of electrons;

[0014] At each instant of the weld, the weld zone is defined as the intersection between the main axis of the weld unit and the surface of at least one part to be welded.

[0015] At each moment of the welding, the working distance is defined as the distance between the welding unit and the parts to be welded along the main axis of the welding unit, or the distance between the welding unit and the welding zone along the main axis of the welding unit.

[0016] At each instant of the welding, we note a the angle formed between the main axis of the welding unit and the parts to be welded.

[0017] In particular, angle a is defined as the angle between the principal axis of the welding unit and the plane tangent to the surface of the parts to be welded at the level of the welding zone.

[0018] According to one aspect of the invention, the welding unit is an electron beam gun, arranged to cause the melting of the parts to be welded by the emission of an electron beam striking the surface of the parts to be welded at the weld zone.

[0019] Alternatively, the welding unit may be a resistance welding device, or an arc welding device, or a laser welding device.

[0020] According to one aspect of the invention, the welding device is arranged to be used in space, under vacuum conditions.

[0021] According to one aspect of the invention, the welding device is in particular arranged for the assembly of structures in space.

[0022] According to one aspect of the invention, the welding unit is arranged to perform a weld generating a weld pool at the weld zone.

[0023] According to one aspect of the invention, the parts to be welded are flat.

[0024] Alternatively, the parts to be welded may be of any other shape, including curved or tubular shape.

[0025] According to one aspect of the invention, the anti-contamination hood is kept in contact with at least one part to be welded during at least part of the welding.

[0026] In particular, the anti-contamination hood is kept in contact with at least one part to be welded during the entire welding process.

[0027] According to one aspect of the invention, the welding unit and the anti-contamination hood encompass the entire weld pool without encompassing all the parts to be welded.

[0028] According to one aspect of the invention, the anti-contamination hood is formed from a single piece.

[0029] Alternatively, the anti-contamination hood is formed of several parts joined together, these different parts being able to be made of different materials.

[0030] According to one aspect of the invention, the anti-contamination hood comprises at least one part made of heat-resistant material, for example stainless steel.

[0031] According to one aspect of the invention, the anti-contamination hood comprises at least one part made of flexible material, for example a polymer.

[0032] Advantageously, the use of a flexible material makes it possible to keep the anti-contamination cover in contact with a non-smooth surface.

[0033] According to one aspect of the invention, the anti-contamination cover comprises: - an anti-contamination skirt, - an anti-contamination envelope.

[0034] According to one aspect of the invention, the anti-contamination envelope is tubular in shape.

[0035] Alternatively, the envelope may be of any other shape, in particular conical or domed.

[0036] According to one aspect of the invention, the anti-contamination skirt is formed of a flexible material with a low coefficient of friction, for example polymers.

[0037] According to one aspect of the invention, the anti-contamination envelope is fixed to the welding unit.

[0038] According to one aspect of the invention, the anti-contamination skirt is fixed on the anti-contamination envelope to form the anti-contamination hood.

[0039] According to one aspect of the invention, the anti-contamination envelope and the welding unit and the anti-contamination skirt are assembled irreversibly.

[0040] Alternatively, the welding unit, the anti-contamination envelope and / or the anti-contamination skirt are assembled reversibly, so as to allow replacement of the anti-contamination skirt and / or the anti-contamination envelope without damaging the parts.

[0041] According to one aspect of the invention, the anti-contamination hood is hermetic, that is to say, it forms a hermetically sealed space with the parts to be welded and the welding unit.

[0042] According to one aspect of the invention, the welding device comprises a vacuum pump connected to the hermetically sealed space formed by the anti-contamination hood and the parts to be welded, and arranged for the evacuation of metallic vapors.

[0043] Alternatively, the anti-contamination hood includes at least one opening arranged for the evacuation of welding fumes.

[0044] Advantageously, the use of an anti-contamination hood having at least one orifice makes it possible to avoid an accumulation of metallic vapors inside the anti-contamination hood.

[0045] According to one aspect of the invention, the anti-contamination hood comprises at least one part made of a porous material.

[0046] According to one aspect of the invention, the anti-contamination envelope is made of a porous material.

[0047] For example, the anti-contamination envelope includes a metallic foam or a lattice structure.

[0048] Alternatively, the anti-contamination envelope comprises a plurality of porous layers, for example by a plurality of perforated plates.

[0049] According to one aspect of the invention, the anti-contamination hood includes at least one drainage channel.

[0050] According to one aspect of the invention, the drainage channels comprise one end placed close to the weld pool generated by the welding unit, and one end connected to an orifice in the anti-contamination hood.

[0051] According to one aspect of the invention, the exhaust channels are arranged for the circulation of welding vapors from the welding bath to the outside of the anti-contamination hood.

[0052] Alternatively, the exhaust channels have one end placed near the weld pool generated by the welding unit, and one end connected to the vacuum pump, and are arranged for the circulation of welding vapors from the weld pool to the vacuum pump.

[0053] According to one aspect of the invention, the anti-contamination hood includes a protective shield.

[0054] According to one aspect of the invention, the protective shield is arranged inside the anti-contamination hood.

[0055] According to one aspect of the invention, the protective shield is placed around the main axis of the welding unit, and is arranged to limit the presence of welding ejecta and welding fumes along the main axis of the welding unit.

[0056] In particular, the protective shield is arranged to minimize, in a plane normal to the main axis of the welding unit, the passage surface that ejecta emitted by the weld bath and moving in a straight line could cross to reach the welding unit.

[0057] This passage surface minimized by the protective shield also influences the flow of metallic vapors that can propagate along the main axis of the welding unit and can disrupt the weld.

[0058] In the case of laser welding or electron beam welding, the protective shield thus advantageously limits the disturbance of the beam by vapors or ejecta which could alter the quality of the weld.

[0059] According to one aspect of the invention, the protective shield is tubular in shape.

[0060] Alternatively, the protective shield is flat in shape, and forms a perforated disc allowing the passage of an electron beam or a laser along the main axis of the welding unit.

[0061] Alternatively, the protective shield has a layered structure.

[0062] According to one aspect of the invention, the drainage channels are formed between the layers of the protective shield.

[0063] Alternatively, the drainage channels are tubular in shape.

[0064] According to one aspect of the invention, the protective shield can be formed as a single block with the anti-contamination envelope.

[0065] Alternatively, the protective shield and the anti-contamination envelope can be two separate parts.

[0066] According to one aspect of the invention, the drainage channels are formed as a single unit with the anti-contamination envelope or with the protective shield.

[0067] Alternatively, the drainage channels are separate parts.

[0068] According to one aspect of the invention, the anti-contamination hood includes a welding vapor capture zone.

[0069] According to one aspect of the invention, the welding vapor capture zone is domed in shape, in particular is a dome.

[0070] According to one aspect of the invention, the welding vapor capture zone can be formed by the anti-contamination skirt, by the anti-contamination envelope, by an exhaust channel or by the protective shield.

[0071] According to one aspect of the invention, the welding vapor capture zone is placed vertically above the welding zone, i.e. opposite the surface of the parts to be welded.

[0072] According to one aspect of the invention, the welding vapor capture zone is arranged to allow the condensation of welding vapors on the walls of the anti-contamination hood.

[0073] According to one aspect of the invention, the welding process creates a pressure differential, with a high pressure near the weld pool and a negative gradient moving away from the weld pool. This pressure differential causes the welding vapors to move from the weld pool to at least one vent arranged for the evacuation of welding vapors or to the vacuum pump.

[0074] According to one aspect of the invention, the welding vapor capture zone and the exhaust channels are arranged to increase the circulation time of the welding vapors inside the anti-contamination hood, so as to allow the cooling and condensation of the welding vapors on the surfaces of the anti-contamination hood, so as to limit the amount of metallic vapors ejected out of the anti-contamination hood.

[0075] According to one embodiment of the invention, the welding device is arranged to move in relation to the parts to be welded during welding.

[0076] In particular, the welding device is arranged to move laterally in relation to the parts to be welded during welding.

[0077] Thus, the movement of the welding zone along the junction between the parts to be welded is achieved by the movement of the welding device in relation to the parts to be welded.

[0078] According to one aspect of the invention, the main axis of the welding unit maintains a constant orientation relative to the welding device, in particular relative to the welding unit, during welding.

[0079] According to one aspect of the invention, the main axis of the welding unit maintains a constant orientation relative to the parts to be welded during welding.

[0080] At each instant of the displacement, a so-called "transverse" component of the displacement is defined as the component of the displacement which varies the position of the weld zone on the parts to be welded, while keeping fixed the working distance and the angle a formed between the main axis of the welding unit and the surface of the parts to be welded.

[0081] According to one aspect of the invention, the welding device is arranged to be set in motion during welding, this movement comprising a non-zero transverse component.

[0082] Thus, the anti-contamination cover moves laterally in contact with at least one part to be welded.

[0083] According to one aspect of the invention, the angle formed between the main axis of the welding unit and the parts to be welded remains substantially constant during the movement of the welding device.

[0084] According to one aspect of the invention, the angle a remains included during the entire movement of the welding device during welding in an interval [a0 - A, aO + A], with aO a reference angle between the main axis of the welding unit and the parts to be welded, and A representing a maximum deviation from this angle.

[0085] According to one aspect of the invention, A is less than 10°, in particular less than 3°.

[0086] Advantageously, limiting the maximum deviation from a reference angle aO makes it possible to guarantee a uniform weld during the welding process, in particular over the entire movement of the welding device.

[0087] According to one aspect of the invention, aO is equal to 90°.

[0088] Alternatively, the welding device is arranged to be placed inclined relative to the parts to be welded, and the reference angle aO is between 0° and 90°, in particular between 20° and 70°, in particular between 40° and 50°, in particular equal to 45°.

[0089] According to one aspect of the invention, the welding device is inclined so that the welding area is placed behind the welding unit in the direction of movement of the welding device.

[0090] According to another embodiment of the invention, the welding unit includes an orientation element arranged to modify the orientation of the main axis of the welding unit with respect to the welding device, in particular with respect to the welding unit, during welding.

[0091] According to one aspect of the invention, the orientation element is, for example: - in the case of arc welding, a controllable articulation of the welding electrode, - in the case of laser welding, a movable lens or mirror is placed in the path of the laser beam and arranged to direct the laser beam, - in the case of electron beam welding, a focusing coil is placed in the path of the electron beam and arranged to direct the electron beam,

[0092] According to one aspect of the invention, the welding device is arranged to remain stationary relative to the parts to be welded during welding.

[0093] Thus, the movement of the weld zone along the junction between the parts to be welded is achieved by changing the orientation of the main axis of the welding unit relative to the welding device by the orientation element.

[0094] The invention relates to a welding process carried out by a welding device as described, the welding process comprising the following steps in this order: - a step of placing the welding device in contact with the parts to be welded, - a step involving the activation of the welding unit, initiating the welding process and generating a weld pool, - a step involving moving the weld zone along the junction between the parts to be welded, - a step where the welding unit stops operating, thus completing the weld, - possibly, a cooling stage, - a step of removing the welding device, including a step of moving the welding device away from the parts to be welded.

[0095] Alternatively, the step of moving the welding device can begin before the welding unit is activated and / or end after the welding unit has stopped operating or after the cooling step.

[0096] According to one aspect of the invention, the cooling step is a waiting step allowing the solidification of the weld bath, and the condensation of the weld vapors.

[0097] According to one aspect of the invention, the step of moving the weld zone along the junction between the parts to be welded includes a step of lateral movement of the welding device in contact with the parts to be welded.

[0098] According to one aspect of the invention, the step of moving the weld zone along the junction between the parts to be welded includes a step of modifying the orientation of the main axis of the welding unit relative to the welding device.

[0099] Other features, details and advantages of the invention will become clearer upon reading the following description on the one hand, and several illustrative and non-limiting examples of embodiments given with reference to the accompanying schematic drawings on the other hand, in which:

[0100] [Fig-1] Fig. 1 is a schematic representation of a welding device according to a first embodiment of the invention.

[0101] [Fig.2] Fig.2 is a schematic representation of a welding device according to the invention placed in contact with parts to be welded of flat, curved and tubular shapes.

[0102] [Fig.3] Fig.3 is a schematic representation of a welding device according to an embodiment in which the anti-contamination cover is airtight, and the welding device includes a vacuum pump.

[0103] [Fig.4] [Fig.4] is a schematic representation of a welding device according to another embodiment in which the anti-contamination cover comprises at least one part made of a porous material.

[0104] [Fig. 5] [Fig. 5] is a schematic representation of a welding device according to an embodiment of the invention in which the anti-contamination hood includes drainage channels and a protective shield.

[0105] [Fig.6] Fig.6 is a schematic representation of a welding device according to an embodiment of the invention in which the welding device is inclined relative to the parts to be welded.

[0106] [Fig.7] Fig.7 is a front view and a top view of a welding device according to an embodiment of the invention in which the parts to be welded are tubular in shape, and the anti-contamination hood completely surrounds a tubular section of the parts to be welded.

[0107] [Fig.8] Fig.8 is a schematic representation of a welding device according to an embodiment of the invention in which the welding unit comprises an orientation element arranged to modify the orientation of the main axis of the welding unit relative to the welding device.

[0108] The features, variants, and different embodiments of the invention can be combined in various ways, provided they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features, described hereafter in isolation from the other described features, if this selection of features is sufficient to confer a technical advantage and / or to differentiate the invention from the prior art.

[0109] Figure [Fig.1] shows a welding device 1 according to an embodiment of the invention, placed opposite two parts to be welded 2.

[0110] The welding device 1 is arranged to perform a welding between the two parts to be welded 2.

[0111] The welding device 1 is arranged to be used in space, under vacuum conditions, in particular for the assembly of structures in space.

[0112] The welding device includes a welding unit 3, arranged to perform a weld along the junction 4 of the two parts to be welded 2, generating a weld pool 5 at the level of a weld zone 10.

[0113] The welding is carried out dynamically, so that the weld zone 10 moves along the junction 4 between the parts to be welded 2 during the welding.

[0114] The welding device also includes a movably placed anti-contamination cover 6 in contact with the parts to be welded 2 so that the welding unit and the anti-contamination cover encompass the entire weld pool 5.

[0115] Figure [Fig.1] shows half-lines 7 from the weld bath 5.

[0116] Any half-line starting from the weld bath 5 intersects either the anti-contamination hood 6, or the welding unit 3.

[0117] Thus, an ejecta 8 which is expelled from the weld bath 5 and which follows a straight line trajectory is stopped by the anti-contamination hood 6, the welding unit 3 or the parts to be welded 2. Thus the ejecta cannot exit in a straight line from the volume defined by the hood, the welding unit and the parts to be welded.

[0118] The welding unit 3 and the anti-contamination hood 6 encompass the entire weld pool 5 without encompassing all the parts to be welded 2.

[0119] The welding device 1 is arranged to move laterally in relation to the parts to be welded 2 during welding.

[0120] The movement of the welding device 1 in relation to the parts to be welded 2 thus allows the relative movement of the welding zone 10 on the parts to be welded.

[0121] The welding unit 3 is an electron beam gun. The welding unit causes the parts to be welded to melt by the emission of an electron beam 9 striking the surface at the level of an external body weld zone.

[0122] A principal axis of the welding unit 12 is defined as the principal axis of the electron beam 9, and the weld zone 10 as the intersection between the principal axis of the welding unit and the surface of the parts to be welded 2.

[0123] According to other embodiments of the invention not shown, the welding unit 3 may, for example, be a resistance welding device, an arc welding device, or a laser welding device. The main axis of the welding unit may thus be, for example, the main axis of a welding electrode or a laser beam.

[0124] The welding unit 3 is arranged to perform a weld generating a weld pool 5 at the weld zone 10.

[0125] The main axis 12 of the electron beam is then, for example, the main axis of the welding electrode, or the main axis of the laser beam.

[0126] In this embodiment, the main axis 12 of the welding unit 3 maintains a constant orientation relative to the welding device 1, in particular relative to the welding unit 3, during welding.

[0127] The main axis 12 of the welding unit 3 also maintains a constant orientation relative to the parts to be welded during welding.

[0128] At each instant of the movement, the working distance 11 is defined as the distance between the welding unit 3 and the parts to be welded 2 along the main axis 12 of the welding unit, i.e. the distance between the welding unit and the welding zone 10 along the main axis 12 of the welding unit.

[0129] The main axis of the welding unit 12 forms an angle a with the parts to be welded, and this angle a remains substantially constant during the movement of the welding device 1.

[0130] Angle a is defined as the angle between the principal axis of the welding unit 3 and the plane tangent to the surface of the parts to be welded 2 at the level of the welding zone.

[0131] At each instant of the movement of the welding device 1, a so-called "transverse" component 27 of the movement is defined as the component of the movement which varies the position of the weld zone 10 on the parts to be welded 2, while keeping fixed the working distance 11 and the angle between the main axis 12 of the welding unit 3 and the surface of the parts to be welded 2.

[0132] The angle a remains within the range [a0 - A, aO + A] during the entire movement of the welding device during welding, with aO a reference angle between the main axis 12 of the welding unit 3 and the parts to be welded 2, and A representing a maximum deviation from this angle.

[0133] In the embodiment shown, aO is equal to 90°, and A is less than 10°, in particular less than 3°.

[0134] Advantageously, limiting the maximum deviation from a reference angle aO makes it possible to guarantee a uniform weld during the welding process, in particular over the entire movement of the welding device 1.

[0135] The welding device 1 moves laterally in relation to the parts to be welded 2 during welding, i.e. is in motion during welding, this movement including a non-zero transverse component 27.

[0136] The anti-contamination hood 6 is kept in contact with the parts to be welded 2 during at least part of the welding, in particular during the entire welding.

[0137] Thus, the anti-contamination cover 6 moves laterally in contact with the parts to be welded 2.

[0138] The anti-contamination cover 6 is formed of several parts joined together, these different parts being made of different materials.

[0139] The anti-contamination hood 6 includes an anti-contamination skirt 16, and an anti-contamination envelope 17.

[0140] Alternatively, according to an embodiment not shown, the anti-contamination cover 6 is formed from a single piece.

[0141] The anti-contamination cover 6 comprises at least one part made of heat-resistant material 18, for example stainless steel, and at least one part made of flexible material 19, for example a polymer.

[0142] Advantageously, the use of a flexible material makes it possible to keep the anti-contamination cover 6 in contact with a non-smooth surface.

[0143] The anti-contamination envelope 17 is tubular in shape.

[0144] The anti-contamination skirt 16 is made of a flexible material with a low coefficient friction, for example in polymers.

[0145] According to an embodiment not shown, the anti-contamination envelope 17 can be of any other shape, in particular conical or domed.

[0146] The anti-contamination envelope 17 is fixed onto the welding unit, and the anti-contamination skirt 16 is fixed onto the anti-contamination envelope to form the anti-contamination hood 6.

[0147] The anti-contamination envelope 17, the welding unit 3 and the anti-contamination skirt 16 are assembled irreversibly.

[0148] Alternatively, the welding unit 3, the anti-contamination envelope 17 and / or the anti-contamination skirt 1 are assembled reversibly, so as to allow replacement of the anti-contamination skirt 16 and / or the anti-contamination envelope 17 without damaging the parts.

[0149] The anti-contamination hood 6 thus formed is hermetic, that is to say, forms with the parts to be welded 2 and the welding unit 3 a hermetically sealed space.

[0150] Figure 2 shows a welding device 1 according to the invention placed opposite parts to be welded 2 having a flat surface 13, a curved surface 14, and a tubular surface 15.

[0151] Figure 3 shows the welding device 1 according to an embodiment of the invention in which the welding device 1 comprises a vacuum pump 20 connected to the hermetically sealed space formed by the anti-contamination hood 6 and the parts to be welded 2, and arranged for the evacuation of metallic vapors.

[0152] Figure 4 shows the welding device according to an alternative embodiment in which the anti-contamination hood 6 has at least one part made of a porous material.

[0153] The anti-contamination hood 6 thus has a plurality of orifices 21 arranged for the evacuation of welding vapors.

[0154] Advantageously, the use of an anti-contamination hood 6 having at least one orifice 21 makes it possible to avoid an accumulation of metallic vapors inside the anti-contamination hood.

[0155] In this embodiment, the anti-contamination envelope 17 is made of a porous material, for example a metallic foam or a lattice structure.

[0156] In particular, the anti-contamination envelope comprises a plurality of porous layers 22, for example by a plurality of perforated plates.

[0157] Figure 5 shows a welding device 1 according to an embodiment of the invention in which the anti-contamination hood 6 has drainage channels 23.

[0158] The drainage channels 23 have one end placed near the weld pool 24 generated by the welding unit, and one end connected to an orifice in the anti-contamination hood 25.

[0159] The exhaust channels 23 are arranged for the circulation of welding vapors from the weld bath 5 to the outside of the anti-contamination hood 6.

[0160] According to an embodiment not shown, the evacuation channels 6 have one end placed near the weld pool generated by the welding unit, 3 and one end connected to the vacuum pump 20, and are arranged for the circulation of welding vapors from the weld pool to the vacuum pump.

[0161] A protective shield 26 of the anti-contamination hood 6 is also shown in this figure.

[0162] The protective shield 26 is placed inside the anti-contamination hood 6, around the main axis 12 of the welding unit 3, and is arranged to limit the presence of welding ejecta and welding fumes along the main axis of the welding device.

[0163] The protective shield 26 is arranged in particular to minimize, in a plane normal to the main axis of the welding unit, the passage surface 28 that ejecta emitted by the weld bath and moving in a straight line could cross to reach the welding unit 3.

[0164] This passage surface 28 minimized by the protective shield 3 also influences the flow of metallic vapors which can propagate along the main axis 12 of the welding unit 3 and which can disrupt the weld.

[0165] In the case of laser welding or electron beam welding, the protective shield 26 thus advantageously limits the disturbance of the beam by vapors or ejecta which could alter the quality of the weld.

[0166] The protective shield 26 has a layered structure, and the drainage channels 23 are formed between the layers of the protective shield.

[0167] According to an embodiment not shown, the protective shield 26 and / or the drainage channels 23 are tubular in shape.

[0168] The protective shield 26 and the evacuation channels 23 are formed as a single unit with the anti-contamination envelope 17.

[0169] According to an embodiment not shown, the protective shield 26, the drainage channels 23 and / or the anti-contamination envelope 17 may be separate parts.

[0170] Figure 6 shows a welding device 1 according to an embodiment in which the welding device is inclined, and the reference angle a0 is equal to 45°.

[0171] The welding device 1 is inclined so that the welding area 10 is positioned behind the welding unit 3 in the direction of movement of the welding device.

[0172] The anti-contamination hood 6 shown in this figure has a welding vapor capture zone 9, arranged to allow the condensation of welding vapors on the walls of the anti-contamination hood 6.

[0173] The welding process creates a pressure differential, with a high pressure near the weld pool 5 and a negative gradient away from the weld pool. This pressure differential causes the welding vapors to move from the weld pool 5 to at least one of the orifices 21 arranged for the evacuation of welding vapors.

[0174] The welding vapor capture zone 29 is arranged to increase the time of circulation of welding vapors inside the anti-contamination hood, so as to allow the cooling and condensation of welding vapors on the surfaces of the anti-contamination hood 6, so as to limit the amount of metallic vapors ejected out of the anti-contamination hood.

[0175] In an embodiment where the contamination hood 6 has exhaust channels 23, the exhaust channels are also arranged to increase the circulation time of welding vapors inside the contamination hood.

[0176] The welding vapor capture zone 29 is domed in shape, in particular is a dome 30, and is formed by the anti-contamination envelope.

[0177] In an embodiment not shown, the welding vapor capture zone 29 can be formed by the anti-contamination skirt 16, by the anti-contamination envelope 17, by an exhaust channel 23 or by the protective shield 26.

[0178] According to one aspect of the invention, the welding vapor capture zone 29 is placed vertically above the welding zone 10, i.e. opposite the surface of the parts to be welded 2.

[0179] In the embodiment illustrated in [Fig.6] the protective shield 26 is flat in shape, and forms a perforated disc allowing the passage of the electron beam along the main axis 12 of the welding unit 3.

[0180] Figure 7 shows a front view and a top view of a welding device 1 according to an embodiment in which the parts to be welded 2 are tubular in shape, and the anti-contamination hood 6 completely surrounds a tubular section 31 of the parts to be welded.

[0181] Figure 8 shows a welding device 1 according to an embodiment in which the welding unit 3 includes an orientation element 32 arranged to modify the orientation of the main axis 12 of the welding unit 3 with respect to the welding device 1, in particular with respect to the welding unit 3, during welding.

[0182] The orientation element 20 is a focusing coil placed on the path of the electron beam, in particular on the main axis 12 of the welding unit 3 and arranged to direct the electron beam.

[0183] In an embodiment not shown, the orientation element 32 may be a controllable joint of a welding electrode, or a movable lens or mirror placed on the path of a laser beam.

[0184] The welding device 1 is arranged to remain stationary relative to the parts to be welded 2 during welding. Thus, the movement of the weld zone 10 along the junction 4 between the parts to be welded 2 is achieved by changing the orientation of the main axis 12 of the welding unit 3 relative to the welding device by the orientation element 32.

Claims

Demands

1. Welding device (1) arranged to perform a weld between at least two parts to be welded (2), the welding device comprising: - a welding unit (3) arranged to perform a weld along the junction (4) of two parts to be welded, generating a weld pool (5) at the level of a weld zone (10), - an anti-contamination hood (6) arranged to be placed, in particular movable, in contact with the parts to be welded (2) so that the welding unit (3) and the anti-contamination hood (6) encompass the entire weld pool (5) and that any half-line (7) from the weld pool intersects either the anti-contamination hood or the welding unit, the welding device (1) being in particular arranged to move the weld zone (10) relative to the parts to be welded during the weld.

2. Welding device according to any one of the preceding claims, wherein the welding unit (3) is an electron beam gun arranged to cause the parts to be welded (2) to melt by the emission of an electron beam striking the surface of the parts to be welded at the weld zone (10).

3. Welding device (1) according to any one of the preceding claims, arranged for use in space, under vacuum conditions, in particular arranged for the assembly of structures in space.

4. Welding device (1) according to any one of the preceding claims, wherein the anti-contamination hood (6) comprises at least one part made of flexible material, for example a polymer.

5. Welding device (1) according to any one of the preceding claims, wherein the anti-contamination hood (6) comprises: - an anti-contamination skirt (16), - an anti-contamination envelope (17), the welding unit (3), the anti-contamination envelope (17) and / or the anti-contamination skirt (16) being assembled reversibly, so as to allow replacement of the anti- contamination (16) and / or the anti-contamination envelope (17) without damaging the parts.

6. Welding device (1) according to any one of the preceding claims, wherein the anti-contamination hood (6) is hermetically sealed, i.e. forms with the parts to be welded (2) and the welding unit (3) a hermetically sealed space.

7. Welding device (1) according to claim 6, comprising a vacuum pump (20) connected to the hermetically sealed space formed by the anti-contamination hood (6) and the parts to be welded (2), and arranged for the evacuation of metallic vapors

8. Welding device (1) according to any one of claims 1 to 5, wherein the anti-contamination hood (6) has at least one orifice (21) arranged for the evacuation of welding fumes.

9. Welding device (1) according to claim 8, wherein the anti-contamination envelope (17) is made of a porous material

10. Welding device (1) any one of claims 8 to 9, wherein the contamination hood (6) has at least one discharge channel (23) arranged for the circulation of welding vapors from the weld pool (5) to the outside of the contamination hood (6).

11. Welding device (1) according to claim 10, wherein the drainage channels (23) have one end (24) placed close to the weld pool (5) generated by the welding unit (3), and one end (25) connected to an orifice (21) of the anti-contamination hood (6).

12. Welding device (1) according to any one of the preceding claims, wherein the contamination hood comprises a protective shield (26) arranged inside the contamination hood (6), positioned around the main axis (12) of the welding unit (3), and arranged to limit the presence of welding ejecta and welding fumes along the main axis of the welding unit.

13. Welding device (1) according to any one of the preceding claims, wherein the contamination hood (6) includes a welding vapor capture zone (29) arranged to permit the condensation of welding vapors on the walls of the contamination hood (6).

14. Welding device (1) according to claim 13, wherein the angle formed between the main axis (12) of the welding unit (3) and the surface of the parts to be welded (2) remains within the range [aO - A, aO + A] during the entire movement of the welding device (1) during welding, with aO a reference angle between the main axis (12) of the welding unit (3) and the parts to be welded (2), and A representing a maximum deviation from this angle with A less than 10°, in particular less than 3°.

15. Welding device (1) according to claim 14, wherein the angle aO is equal to 90°.

16. Welding device (1) according to claim 14, arranged to be placed inclined relative to the parts to be welded (2) so that the weld area (10) is placed behind the welding unit (3) in the direction of movement of the welding device (1), and the reference angle aO is between 0° and 90°, in particular between 20° and 70°, in particular between 40° and 50°, in particular equal to 45°.

17. Welding device (1) according to any one of the preceding claims, wherein the welding unit (3) comprises an orientation element (32) arranged to change the orientation of the main axis (12) of the welding unit (3) relative to the welding device (1), in particular relative to the welding unit (3), during welding.

18. A welding process carried out by a welding device (1) according to any one of the preceding claims, the welding process comprising in this order the following steps: - a step of placing the welding device (1) in contact with parts to be welded (2), - a step of activating the welding unit (3), starting the weld and generating a weld pool (5), - a step of moving the weld zone (10) along the junction (4) between the parts to be welded (2), - a step of stopping the action of the welding unit (3), ending the weld, - optionally, a cooling step, - a step of withdrawing the welding device (1), comprising a step of moving the welding device away from the parts to be welded (2).

19. Welding method according to claim 18, wherein the step of moving the weld zone (10) along the junction (4) between the parts to be welded (2) includes a step of laterally moving the welding device (1) into contact with the parts to be welded.

20. Welding method according to any one of claims 18 to 19, wherein the step of moving the weld zone along the junction (4) between the parts to be welded (2) includes a step of changing the orientation of the main axis (12) of the welding unit (3) relative to the welding device.

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