WELDING MACHINE FOR WELDING TWO TUBULAR PARTS, AT LEAST ONE OF WHICH IS CYLINDRICAL

Abstract

TITLE OF THE INVENTION: WELDING MACHINE FOR WELDING TWO TUBULAR PARTS, AT LEAST ONE OF WHICH IS CYLINDRICAL. The welding machine (20) for welding two tubular parts (21, 22), at least one (21) of which is cylindrical, mechanically joined and having a common circular cross-section defining a weld line (15), comprises: - a welding head (28) positioned, during its operation, in a fixed position opposite the weld line; - a drive ring (37) mechanically attached to a cylindrical tubular part, which comprises two cylindrical half-rings and internal guide rollers that retain the ring opposite at least one roller, the axis of rotation of the drive ring being coincident with the axis of said tubular part; and - a drive system comprising a fixed motor (38) configured to rotate the drive ring during the operation of the welding head. Figure for the abstract: Figure 6

Description

Title of the invention: WELDING MACHINE FOR WELDING TWO TUBULAR PARTS, AT LEAST ONE OF WHICH IS CYLINDRICAL Technical field of the invention

[0001] The present invention relates to a welding machine for welding two tubular parts, at least one of which is cylindrical. More particularly, it relates to an automatic or semi-automatic welding machine for cylindrical tubes and bent tubes. State of the art

[0002] To date, the welding of tubular parts is carried out manually or using an orbital welding machine. In this machine, welding is carried out by rotating a welding head, or welding head, at least 360° around a fixed tubular part. The rotation of the welding head around the parts poses problems of geometry of the space to be left free around the parts to be welded. In addition, the quantity of molten metal is limited by the risks of flow under the effect of gravity, which limits the quantity of metal supplied with each pass of the welding head. In other words, the deposition rate is limited by the very design of the orbital welding machine and the total duration of a welding operation of two parts is high, which limits the productivity of the welding station.

[0003] When using an orbital welding machine, the operator must remain close to the machine to carry and guide the rotating cables. He must also perform difficult movements and adopt uncomfortable postures to monitor the quality of the welding with a welding mask in his hand. Beyond the physical efforts of the operator, there is a risk of illness linked to the exposure of the eyes to radiation, particularly ultraviolet radiation, emitted by the welding arcs and to the inhalation of welding fumes.

[0004] Furthermore, the different welding passes (up to 60 rotations of the machine per weld) automatically cause significant mechanical stresses which reduce the service life of the welding machine.

[0005] Furthermore, the orbital welding machine is not suitable for welding an assembly formed by two elbows, because of the size they represent in relation to the orbital welding head as well as the guide track. In any case, welding by orbital machine is punctuated by frequent stops to check the quality of the welding. Most of the time, the check is carried out by a service provider external. These control operations are expensive and reduce the productivity of a welding machine. Summary of the invention

[0006] The welding machine according to the present invention makes it possible to overcome all or part of the undesirable effects linked to the use of the orbital machine and manual welding. In the welding machine which is the subject of the invention, instead of requiring the rotation of the head, as in an orbital welding station, an assembly consisting of the tubular parts to be welded is rotated in a sealed manner around the tangent common to their axes, at the level of the weld line. This circular weld line is perpendicular to this common tangent. During the welding operation, the welding head is held in a fixed position, opposite this circular weld line which is rotated around its center where this tangent common to the two tubular parts to be welded passes.

[0007] Preferably, the two tubular parts to be welded in a sealed manner are preliminarily made integral by at least three welding points formed on the welding line to be produced. The correct positioning on the welding machine of the assembly formed from these tubular parts is thus facilitated as well as the rotation of the second tubular component which is thus made integral with the first.

[0008] By positioning the welding head vertically to the weld line (so-called "flat" welding position), the quantity of molten metal is increased, since the risks of flow are limited. The quantity of metal supplied with each pass of the welding head is thus increased. In other words, the weld deposition rate is increased compared to an orbital welding machine. The total duration of a two-piece welding operation is thus reduced, which increases the productivity of the welding station.

[0009] The welding head is preferably fixed on a jib and accompanied by a camera to allow an operator to remotely control the different stages of the welding process.

[0010] Preferably, at least one spring box supports the parts to be welded and absorbs mechanical vibrations.

[0011] Preferably, the assembly to be welded is balanced by the use of counterweights in order to bring the center of gravity of the assembly back onto the axis of rotation and thus avoid any variations in the rotation speed during welding.

[0012] By rotating the part to be welded, the rotation of the assembly of parts to be welded rotates the circular welding line around its axis. The welding machine can weld tubular parts with a nominal diameter greater than 100 mm, regardless of the lengths of these tubular parts. manufacturing process steps such as multiple intermediate quality checks are eliminated. In addition, productivity is multiplied by four compared to an orbital welding station and by ten compared to a manual welder.

[0013] This invention not only allows for an increase in production rates and welding quality, but also ensures good working conditions for the operator. The operator, away from dangerous and arduous operations, controls the quality of his work in real time, via an interactive screen. The welding machine that is the subject of the invention also improves the safety and health of operators, because they are at a distance from the welding in teleoperation and therefore away from sources of danger. Brief description of the figures

[0014] Other advantages, aims and particular characteristics of the invention will emerge from the following non-limiting description of at least one particular embodiment of the welding machine which is the subject of the present invention, with reference to the appended drawings, in which:

[0015] [Fig-1] is a schematic representation, in perspective, of a welding station comprising a first embodiment of the welding machine which is the subject of the invention,

[0016] [Fig.2] is an enlargement of a portion of [Fig.l], showing the machine of welding,

[0017] [Fig.3] is another schematic representation, in perspective, of the machine of welding illustrated in [Fig.2],

[0018] [Fig.4] is yet another schematic representation, in perspective view from below, of the welding machine illustrated in [Fig.2] and [Fig.3],

[0019] [Fig.5] represents, in side view, the welding machine illustrated in [Fig.2] at [Fig.4],

[0020] [Fig.6] represents, in front view, the welding machine illustrated in [Fig.2] at [Fig.5],

[0021] [Fig.7] represents, in top view, the welding machine illustrated in [Fig.2] at [Fig.6], and

[0022] [Fig.8] represents, in the form of a flowchart, the steps of implementation of the welding machine illustrated in figures 1 to 7. Description of the embodiments

[0023] The present description is given without limitation, each characteristic of an embodiment being able to be combined with any other characteristic of any other embodiment in an advantageous manner. It should be noted from now on that the figures are not to scale.

[0024] As understood from the present description, various inventive concepts may be implemented by one or more methods or devices described below, several examples of which are provided herein. The actions or steps performed in carrying out the method or device may be ordered in any suitable manner. Accordingly, it is possible to construct embodiments in which the actions or steps are performed in a different order than illustrated, which may include performing certain acts simultaneously, even if they are presented as sequential acts in the illustrated embodiments.

[0025] The expression "and / or", as used herein, is to be understood to mean "either or both" of the elements so conjoined, i.e., elements which are present conjunctively in some cases and disjunctively in other cases. Multiple elements listed with "and / or" are to be interpreted in the same way, i.e., "one or more" of the elements so conjoined. Other elements may optionally be present, other than the elements specifically identified by the "and / or" clause, whether or not they are related to these specifically identified elements.Thus, by way of non-limiting example, a reference to "A and / or B", when used in conjunction with open language such as "comprising" may refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[0026] As used herein, the term "at least one," with reference to a list of one or more elements, is to be understood to mean at least one element selected from one or more elements in the list of elements, but not necessarily including at least one of each element specifically listed in the list of elements and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than the specifically identified elements in the list of elements to which the term "at least one" refers, whether or not related to those specifically identified elements.Thus, by way of non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B", or, equivalently, "at least one of A and / or B") may refer, in one embodiment, to at least one, optionally including more than one, A, without B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, without A present (and optionally including elements other than A); in yet another embodiment, . to at least one, possibly including more than one, A, and at least one, possibly including more than one, B (and possibly including other elements); etc.

[0027] In the description below, all transitional expressions such as "comprising", "including", "carrying", "having", "containing", "involving", "holding", "composed of", and the like, are to be understood as open, i.e., as meaning including, but not limited to. Only the transitional expressions "consisting of" and "consisting essentially of" are to be understood as closed or semi-closed transitional expressions, respectively.

[0028] It should be noted, from now on, that the figures are not to scale.

[0029] In [Fig.l], we observe a welding station comprising a welding machine 20, a protective partition 11 and a screen 12 for monitoring the welding process. The operator 13 is positioned in front of the screen 12 during the welding operations. In this position, the operator 13 is protected from direct radiation emitted by the welding machine 20, thanks to the protective partition 11.

[0030] The welding machine 20 is shown, in different views, from [Fig.2] to [Fig.7]. This welding machine 20 is used to continuously and tightly weld two tubular parts 21 and 22 previously secured by welding points to form a rigid assembly.

[0031] The parts 21 and 22 are called “tubular” because they are made up of tube truncated sections, that is to say parts which have a circular section, perpendicular to a continuous line having at least one straight, curved or broken segment. This line is called the “axis” of the tubular part. For example, the parts 21 and 22 are made up of at least one truncated cylinder with a circular directrix and / or a truncated torus. In the example illustrated in Figures 1 to 7, the part 21 is cylindrical and the part 22 is toroidal. A weld line 15 is a circular section common to the parts 21 and 22. In other words, the axes of the parts 21 and 22 are tangent at this common circular section. Prior to the positioning of these parts 21 and 22, welding points are made on the welding line 15 so that the parts 21 and 22 form a rigid assembly.Once this assembly is positioned on the machine 20, the common tangent to the axes of the parts 21 and 22 at the level of the welding line 15 is collinear with an axis of rotation A of the welding machine 20. Thus, the welding line 15, circular, rotates in its plane around its center.

[0032] The machine 20 comprises a structure 23 which also supports a means for rotating the two tubular parts 21 and 22 around this predetermined axis A.

[0033] In the first embodiment, illustrated from [Fig.l] to [Fig.7] and particularly suitable for cases where at least one of the parts to be welded is cylindrical, this rotation means takes the form of a motor 38 mounted on a drive ring 37, integral with the tubular part 21, of two non-motorized turning devices provided with upper rollers 34 and lower rollers 31 and 30, these rollers 30, 31 and 34 being in contact with the tubular part 21. As shown, one of the turning devices, referenced 24, comprises jaws 51 and 52 movable in a plane perpendicular to the axis of rotation A of the welding machine 20. Two lower movable jaws 51 rotate around the same axes as the rollers 31, between a deployed configuration, in which the part 21 can be inserted between these lower jaws 51, and a folded configuration, in which one of the lower jaws 51 places the rollers 34 carried by an upper jaw 52, ​​in support on the part 21. A locking system 53 locks the other lower jaw 51 with the upper jaw 52, ​​ensuring sufficient support for the rollers 31 and 34.

[0034] The rotation of the tubular parts 21 and 22 is driven by the fixed drive ring 37 and by the motor 38 located above the tubular parts 21 and 22, so that this motor 38 is removed with the welding assembly.

[0035] The ring 37 comprises two cylindrical half-crowns (with a circular director centered on the axis A) resting on the tubular part 21 by means of flexible buffers 39 pinching the tubular part 21 without deforming it. The buffers 39 are adjustable in length (measured radially relative to the axis A) and interchangeable, which thus allows the mounting of the drive ring 37 on tubular parts in a wide range of diameters. Guide rollers 18 inside the drive ring 37 hold the ring 37 opposite rollers 17 driven by the motor 38. Guide rollers 19, on either side of the ring 37, make it possible to maintain the weld line 15 in line with the welding head 28 throughout the welding cycle and thus prevent the assembly of the rotating tubular parts 21 and 22 from "unscrewing" during rotation.

[0036] The rotation is thus ensured by friction by rollers driven by the motor 38, for example a stepping motor. This drive system is easily mounted and dismounted by a moderately skilled operator. The motor 38 is synchronized with the operation of a welding head 28. The speed of advance of the welding head 28 relative to the welding line 15 is proportional to the speed of rotation of the motor 38. This speed of advance is variable and is managed, like the direction of rotation, by a computer program.

[0037] Other lower rollers 30, not motorized, are carried by the structure 23 to support the tubular parts 21 and 22 at the level of a welding head 28. The welding head 28 is supported fixed relative to the structure 23, by a bracket 27. Means 32 for adjusting the height of the bracket 27 make it possible to adjust the height of the head of the welding head 28. The bracket 27 supports a horizontal beam 54 at an adjustable height.

[0038] The lower rollers 30 and 31 can be mounted on spring boxes whose springs absorb the vibrations linked to the rotation of the tubular parts 21 and 22.

[0039] Preferably, a counterweight 25 is secured to a tubular part (here the tubular part 21) by means of a peripheral connection 26 on the outer surface of the tubular part 21. This counterweight 25 is dimensioned so that the center of inertia of the assembly consisting of the two tubular parts 21 and 22, the connection 26 and the counterweight 25 is on the axis of rotation A. Thus, if none of the tubular parts 21 and 22 is bent, no counterweight 25 and no attachment 26 is put in place. If one of the tubular parts is bent, the counterweight 25 makes it possible to balance the load and thus avoids the phenomenon of unbalance during rotations.

[0040] Cables 29 supply the welding head 28. A filler metal feeder 33 supplies metal to the welding head 28.

[0041] Preferably, the structure 23, including the supports of the rollers 30 and 31, is adapted to the standard diameters of the tubes on the market, in a predetermined range of diameters, for example from 200 to 300 mm.

[0042] Preferably, a camera (not shown) is positioned next to the welding head 28 and its optical field covers at least the lower end of the welding head 28 and the welding zone. The image provided by this camera is transmitted to the supervision screen 12. This image allows the operator 13 to remotely control the various welding operations.

[0043] The structure 23 is fixed to the ground to stabilize the horizontal position of the welding machine 20. The assembly of welding elements, welding head 28, cables 29, reel 33, camera and the system for rotating the tubular parts 21 and 22 formed by the motor 38, is supported by a flexible cable 36, for example made of steel. This cable 36 allows this assembly to be placed and removed. The coupling system of the motor 38 on the drive ring 37 ensures the correct positioning of the assembly with respect to the tubular parts 21 and 22 to be welded.

[0044] By rotating the parts to be welded 21 and 22 on the structure 23, the automatic welding machine 20 makes it possible to weld tubular parts regardless of their lengths. The number of steps in the manufacturing process, such as the multiple intermediate quality controls, is greatly reduced. The output production rate is multiplied by four compared to orbital welding equipment and by ten compared to a manual welder.

[0045] [Fig-8] describes, in the form of a flowchart of a method 60, steps for implementing the device 20. This method 60 comprises, firstly, a step 61 for positioning the parts to be welded 21 and 22 in such a way that the lines tangent to their axes coincide at the level of the weld line 15, that is to say their contact line.

[0046] During a step 62, the parts to be welded 21 and 22 are mechanically secured. Preferably, this securing is carried out by spot welding on the weld line 15, for example four spot welds spaced a quarter turn apart. The parts 21 and 22 thus form a rigid assembly. Rotating the part 21 will therefore cause the part 22 to rotate.

[0047] During a step 63, this rigid assembly is placed on the welding machine 20 in such a way that the circular welding line 15 is perpendicular to the axis of rotation A and centered on this axis of rotation A and that it is located opposite the future position of the welding head 28. In the example of FIGS. 1 to 7, this involves positioning the welding line 15 slightly outside the roller 30, on the side opposite the rollers 31.

[0048] During a step 64, the jaws 51 and 52 of the turning gear 24 are closed and locked around the part 21. In addition, the drive ring 37 is mounted on the tubular part 21 by assembling its two crowns.

[0049] During a step 65, the welding assembly and the motorized system 38 are lowered to the upper crown of the motorized ring 37, by means of the bracket 27 and the flexible cable 36. Once the welding and motorization assembly is positioned in such a way that the welding head 28 is on the welding line 15, during a step 66, the system 38 is clamped on the ring 37. During a step 67, the welding assembly and the motorization system are fixed, by means of the spar 54.

[0050] During a step 68, the parts 21 and 22 are rotated and the operator 13 carries out the welding with the welding head 28, the welding generator (not shown) and the control panel 12. Of course, during step 68, the parts 21 and 22 can make several turns around the axis A without the operator having to manage the cables of the welding machine.

[0051] Once the welding of the parts 21 and 22 is completed, during a step 69, the reverse of steps 67, 66, 65 and 64 is carried out successively to move the welding assembly apart and reopen the turning gear 24. Finally, during a step 70, the parts 21 and 22 welded in a sealed manner are removed.

[0052] Variants

[0053] In variants of the first embodiment illustrated in figures 1 to 7: - the counterweight is positioned on the bent tubular part 22 to reduce, as close as possible to its source, the phenomenon of mechanical imbalance in the context of the assembly of two tubular parts, - to weld larger parts, a hydraulic or mechanical system is provided to replace the counterweight to neutralize the imbalance, - the gallows is independent of structure 23, - height adjustment means are added to the structure 23 to make it more ergonomic and adaptable to the size of the operator 13 and / or to the diameter of the parts to be welded, and / or - the means for rotating the drive ring 37 supporting the tubular parts 21 and 22 comprise a toothed wheel instead of a friction drive. In this case, the ring 37 is, for example, perforated or crenellated. Statement of the invention

[0054] The present invention aims to remedy all or part of the drawbacks of the prior art. To this end, the present invention aims at a welding machine 20

[0055] for welding two tubular parts, 21 and 22, at least one of which is cylindrical, mechanically integral and having a common circular section defining a weld line 15, which comprises: - a welding head 28 positioned during its operation, in a fixed manner opposite the welding line, - a drive ring 37, mechanically secured to a cylindrical tubular part, which comprises two cylindrical half-crowns and internal guide rollers which retain the ring opposite at least one roller, the axis of rotation of the drive ring being coincident with the axis of said tubular part, and - a motorization system comprising a fixed motor 38 configured to rotate the drive ring during operation of the welding head.

[0056] Thus, the drive ring 37 drives the tubular parts 21 and 22 around their axis, so that the weld line rotates in its plane around its center opposite the fixed welding head. The motorization system of this drive ring 37 ensures a rotation of the tubular parts 21 and 22 synchronized with the operation of the welding head 28. Thanks to its position remote from the surface of the tubular parts 21 and 22, the drive ring 37 has a larger rolling path of the motorization system than these tubular parts 21 and 22, which allows greater angular precision of the movements of these parts.

[0057] This drive ring 37 being made up of two half-crowns, it is easy to form it and close it around a tubular part: one of the half-crowns remains on the frame of the machine, while the other is removed during the positioning of the tubular parts on the fixed half-crown. Then this other half-crown is positioned and attached to the first to form the complete drive ring. The setting up of the machine is thus faster and its productivity is improved.

[0058] In embodiments, the cylindrical half-crowns of the drive ring 37 comprise flexible pads 39 bearing on the cylindrical tubular part 21.

[0059] These flexible buffers press sufficiently on the tubular part 21 so that, by static friction, the ring 37 drives it, but with a limited force to avoid a risk of deformation of the tubular part 21.

[0060] In embodiments, the welding machine 20 comprises guide rollers 18 inside the half-crowns of the drive ring 37, which retain these half-crowns opposite rollers 17 driven by the motor 38.

[0061] The driving and guiding of the drive ring 37 are thus precise.

[0062] In embodiments, the welding machine 20 comprises guide rollers 19, on either side of the half-crowns of the ring 37, configured to maintain the junction line of the tubular parts, 21 and 22, that is to say the weld line, in line with the welding head 28 during its operation.

[0063] This prevents the assembly of rotating tubular parts 21 and 22 from “unscrewing”, i.e. moving parallel to its axis, during rotation and operation of the welding head.

[0064] In embodiments, the welding machine 20 comprises a welding assembly comprising the welding head 28 and the motorization system 38 of the drive ring 37 and a means 27 for moving this welding assembly, on the one hand, away from the tubular parts 21, 22, on the other hand.

[0065] A single movement of this assembly allows both the welding head and the motorization system to be moved away from the tubular tubes. The installation and removal of the tubular parts 21 and 22 are thus facilitated and the productivity of the machine is increased.

[0066] In embodiments, the welding machine 20 comprises a jib 27 projecting above the tubular parts, 21 and 22, this jib 27 carrying the welding assembly (28, 38) below it.

[0067] The vertical movement of the welding assembly is thus facilitated.

[0068] In embodiments, the welding machine 20 comprises a means 32 of stem height adjustment 27.

[0069] In embodiments, the welding assembly (28, 38) is handled by a flexible cable 36 connected to the jib 27.

[0070] In embodiments, the welding machine 20 comprises a counterweight 25 secured to a tubular part 21, positioned and dimensioned so that the center of gravity of the assembly comprising the tubular parts, 21 and 22, the counterweight 25 and the mechanical connection between the counterweight and one of the tubular parts, is located on the axis of rotation A of the tubular parts.

[0071] This avoids unbalance phenomena during rotation of the tubular parts.

[0072] In embodiments, the welding machine 20 comprises at least one spring box comprising at least one roller, 30 and / or 31, supporting the tubular parts, 21 and 22, during operation of the welding head 28.

[0073] This dampens the vibrations linked to the rotation of the tubular parts.

Claims

Claims

1. Welding machine (20) for welding two tubular parts (21, 22) of which at least one (21) is cylindrical, mechanically integral and having a common circular section defining a weld line (15), characterized in that it comprises: - a welding head (28) positioned during its operation, fixedly opposite the weld line, - a drive ring (37) mechanically integral with a cylindrical tubular part, which comprises two cylindrical half-crowns and internal guide rollers which retain the ring opposite at least one roller, the axis of rotation of the drive ring being coincident with the axis of said tubular part, and - a motorization system comprising a fixed motor (38) configured to rotate the drive ring during operation of the welding head.

2. Welding machine (20) according to claim 1, in which the cylindrical half-crowns of the drive ring (37) comprise flexible pads (39) bearing on the cylindrical tubular part (21).

3. Welding machine (20) according to one of claims 1 or 2, which comprises guide rollers (18) inside the half-crowns of the drive ring (37), which retain these half-crowns opposite rollers (17) driven by the motor (38).

4. Welding machine (20) according to one of claims 1 to 3, which comprises guide rollers (19), on either side of the half-crowns of the ring (37), configured to maintain the junction line of the tubular parts (21, 22) in line with the welding head (28) during its operation.

5. Welding machine (20) according to one of claims 1 to 4, which comprises a welding assembly (28, 38) comprising the welding head (28) and the motorization system (38) of the drive ring (37) and a means (27) for moving this welding assembly, on the one hand, away from the tubular parts (21, 22), on the other hand.

6. Welding machine (20) according to claim 5, which comprises a bracket (27) projecting above the tubular parts (21, 22), this bracket carrying the welding assembly (28, 38) below it.

7. Welding machine (20) according to claim 6, which comprises means (32) for adjusting the height of the jib (27).

8. Welding machine (20) according to one of claims 6 or 7, in which the welding assembly (28, 38) is handled by a flexible cable (36) connected to the jib (27).

9. Welding machine (20) according to one of claims 1 to 8, which comprises a counterweight (25) secured to a tubular part (21), positioned and dimensioned so that the center of gravity of the assembly comprising the tubular parts (21, 22), the counterweight and the mechanical connection between the counterweight and one of the tubular parts, is located on the axis of rotation (A).

10. Welding machine (20) according to one of claims 1 to 9, which comprises at least one spring box comprising at least one roller (30, 31) supporting the tubular parts (21, 22) during operation of the welding head (28).