Arc welding system
The system addresses the challenge of complex weld geometry by using coordinated actuator movements and a control unit to achieve precise and defect-free welds through controlled torch orientation, enhancing weld penetration and adhesion.
Patent Information
- Application Number
- FR2023000505
- Authority / Receiving Office
- FR · FR
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-01-19
- Publication Date
- 2025-12-26
- Estimated Expiration
- 2043-01-19
AI Technical Summary
Existing arc welding systems face challenges in achieving precise and defect-free welds, particularly when welding parts with complex geometries, due to limitations in controlling the movement and orientation of the welding torch.
A system comprising a trolley with multiple actuators and a control unit that coordinates the movement of a welding torch, allowing for autonomous or semi-autonomous welding, with a laser profilometer for part geometry measurement, and a remote control for user input, ensuring precise control of the welding process.
The system enables the formation of welds with good geometry and minimal defects by maintaining the welding torch orientation close to the normal of the surface, resulting in improved weld penetration and adhesion.
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Abstract
Description
[0104] In the following description, identical elements or elements with identical functions bear the same reference numeral. For the sake of brevity, they are not described opposite each figure; only the differences between the embodiments are described.
[0105] In the figures, the actual proportions have not always been respected, for the sake of clarity.
[0106] An example of a system 1 for welding two parts P together has been illustrated in [Fig.1].
[0107] The system comprises a base, in this example a trolley 2, arranged to move across the surface of one of the parts P in a direction of advancement D.
[0108] In this example the trolley 2 has a platform 3 mounted on wheels 4, in this example four, only two being visible on the [Fig.1].
[0109] Each wheel 4 is driven.
[0110] The system 1 includes a support 6 for a wire-electrode arc welding torch T F.
[0111] The T welding torch is, for example, a standard torch used for welding MIG or MAG, a TIG welding machine, a submerged arc welding machine, a sub-slag welding machine, a plasma welding machine, or any other arc welding machine.
[0112] The torch T is, in this example, connected to a standard welding station, not shown for the sake of clarity in the drawings.
[0113] The system 1 also includes, mounted on the platform 3, a first linear actuator 10, connected via a deflection arm 15 to a second rotary actuator 11, itself connected to the torch support 6 T.
[0114] The first actuator 10 allows the arm 15, and therefore the second actuator 11, the support 6 and the torch T, to be moved in translation relative to the carriage 2 in the Y direction orthogonal to the normal of the surface of the base 3.
[0115] The Y axis is not parallel to the longitudinal axis L of the torch T.
[0116] The second actuator 11 has an X axis of rotation parallel to the direction of advancement D.
[0117] The two actuators 10 and 11 operate with motors and position sensors.
[0118] The system 1 also includes a control unit 20 configured to control in a coordinated manner the first actuator 10 and the second actuator 11 according to the trajectory to be given to the end 30 of the wire-electrode F.
[0119] The control unit 20 allows welding to be carried out autonomously or semi-autonomously.
[0120] The control unit 20 is, in this example, removably mounted on the platform 3 on a receiving area.
[0121] The control unit 20 also includes a rechargeable battery enabling its own power supply and that of the actuators 10 and 11.
[0122] The system 1 includes a wireless remote control 21 communicating with the control unit 20 via a transmitter-receiver system or by wired connection when the latter is placed on it.
[0123] The remote control 21 forms a user interface allowing an operator to remotely control and, possibly, correct the movement of the trolley 2.
[0124] The remote control 21 also allows data to be entered on the geometry of the weld to be made, such as the angle between the parts P, the thickness of the parts P or the angle of a chamfer between the parts P.
[0125] System 1 includes, in this example, a laser profilometer 22 measuring the profile of the parts P upstream of the welding torch T in the direction of advancement D of the latter.
[0126] Figures 2 and 3 illustrate a first example of a welding process using a system 1 as described above.
[0127] In this first example, the parts P are both flat. They each have a chamfer forming between them an angle opening Oc of 40°.
[0128] Initially, the system 1 is positioned on the outer surface of one of the parts P. Then, for example with the remote control 21, a user transmits information on the geometry of the parts P to the control unit 20.
[0129] The torch T is then moved to position itself for welding.
[0130] The carriage 2 is then set in motion in direction D and, at the same time, The electrode wire F produces an arc with one of the parts and is fed by the torch T, to form the weld bead J. In this example, the base 2 moves continuously or intermittently.
[0131] The first actuator 10 and the second actuator 11 move, by coordinated movements controlled by the control unit 20, the torch T to form the weld bead J.
[0132] As illustrated in [Fig.2], the two actuators 10 and 11 are moved so as to maintain the longitudinal axis L of the wire electrode F close to the normal N of the surface opposite the end 30 of the wire electrode F. In this example, the longitudinal axis L of the torch T forms with the normal N an angle Os of less than 15°.
[0133] To perform the weld bead J, the torch T is moved so as to perform a sweep orthogonal to the direction D. During this sweep, by coordinated movements of the two actuators 10 and 11, the orientation of the torch T is modified so as to maintain the longitudinal axis L of the wire electrode F as close as possible to the normal N of the surface on which the weld bead J is formed.
[0134] In this regard, the position of the welding torch T after a first sweep from left to right is illustrated in [Fig. 3]. In this position, and during the sweep, the angle Os remains less than 15°.
[0135] Maintaining this orientation is achieved by coordinated movements of the two actuators 10 and 11.
[0136] For example, when the torch T moves from the left position in [Fig.2] to the right position in [Fig.3], the first actuator 10 moves from left to right along the Y axis and the second actuator 11 rotates counterclockwise relative to the direction D around the X axis. Alternatively, the first actuator 10 may be fixed.
[0137] Such an orientation of the electrode wire F during scanning allows for a good The impact of the wire electrode (F) ensures good weld penetration and therefore good weld adhesion. This results in a weld bead (J) with good geometry and few or no defects.
[0138] During the movement of the carriage 2, the sweep is performed, for example, from right to left and then from left to right, until the weld is complete. In this example, the sweep movements, and therefore those of the two actuators 10 and 11, are coordinated with the movement of the carriage 2 so as to obtain a sweep with a relatively constant frequency. The wire-electrode feed speed F can be coordinated with the sweep speed and / or the speed of the carriage 2.
[0139] Figures 4 to 7 illustrate a variant of the system and method in which the two parts P form a right angle with each other and the system comprises three actuators 10, 11 and 12.
[0140] In this example, the first actuator 10 and the second actuator 11 are identical to those in the previous example. The first actuator 10 also allows the third actuator 12 to move in translation.
[0141] The third actuator 12 allows, in this example, the arm 15, and therefore the second actuator 11, the support 6 and the torch T, to be moved in translation relative to the carriage 2 in direction Z normal to the surface of the platform 3 and transverse to the direction of advancement D.
[0142] In this example, the weld bead J to be produced has, in a plane transverse to the direction of advancement D, a substantially triangular section.
[0143] As illustrated, the Y axis of displacement of the first actuator 10 and the Z axis of displacement of the third actuator 12 are orthogonal to each other, are included in a plane transverse to the direction of advancement D and not parallel to the longitudinal axis L of the wire F of the torch T.
[0144] The X axis of rotation of the second actuator 11 is, as before, parallel to the direction of advancement D.
[0145] In this example, base 2 is set in motion intermittently.
[0146] The scanning trajectory Tb that the end 30 of the electrode wire F makes during the welding operation is illustrated on the partial enlargement of [Fig.4] given to [Fig.5].
[0147] This trajectory Tb comprises a straight portion Tbl and two curved portions Tb2 and Tb3.
[0148] The sweep is performed periodically, for example by first sweeping the curved portion Tb2, then the straight portion Tbl, then the curved portion Tb3, then the straight portion Tbl again, and so on. This sweep is preferably performed while the carriage 2 is moving.
[0149] It is also possible to perform a plunge of the electrode wire F into the middle of the straight portion Tbl, forming a weld known as a fir tree weld.
[0150] To make the straight portion Tbl, as illustrated in [Fig.6], the linear actuators 10 and 12 are actuated while the rotary actuator 11 keeps the same orientation.
[0151] The displacement of the third actuator 12 along the Z axis produces a displacement ZI of the end 30 of the torch T. In this example, the displacement of the third actuator 12 along Z is equal to the product of the magnitude of Dt and the sine of the smallest angle a between Dt and the Z axis.
[0152] The angle a also corresponds to the smallest angle between the axis Z and an axis orthogonal to the longitudinal axis L of the wire-electrode F in a plane transverse to the direction of advancement D.
[0153] The displacement of the actuator 10 along the Y axis produces a displacement Y1 of the end 30 of the torch T. In this example, the displacement of the first actuator 10 along Y is equal to the product of the magnitude of Dt and the cosine of the angle a.
[0154] The sum of the displacements along the axes ZI and Y1 produces a displacement Dt of the end 30 of the torch T, in a plane transverse to the direction of advancement D.
[0155] The second actuator 11, during the formation of the straight portion, also moves in the direction Dt.
[0156] As illustrated, during the formation of the straight portion Tbl, the longitudinal axis L of the wire electrode F coincides with the normal to the surface N on which the weld is made, in this case on a part of the weld bead J already made.
[0157] The formation of the curved portion Tb2 which follows the formation of the straight portion Tbl of [Fig.6] is illustrated in [Fig.7].
[0158] To produce the curved portion Tb2, the weld is carried out by rotating the wire electrode F along an axis XI parallel to the direction of advancement D and passing through the end 30 of the wire electrode F, this axis XI being positioned at the center of curvature of the curved portion Tb2.
[0159] Thus, to form the curved portion Tb2, the end 30 can only be moved in rotation. There is, for example, no translation of the end 30. Alternatively, there may be a slight translation.
[0160] This rotation around the end 30 requires linear movements of the first actuator 10 and the third actuator 12 along the Z and Y axes in directions opposite to those during the formation of the straight portion Tbl.
[0161] The second actuator 11 is, during the formation of the curved portion Tb2, rotated around the X axis in the same direction of rotation as that of the end 30 around the XL axis
[0162] In [Fig. 7], the axis Fi is an axis orthogonal to the longitudinal axis L of the electrode wire F in a plane transverse to the direction of advancement D before rotation, and the axis F2 illustrates the longitudinal axis L of the electrode wire F before rotation.
[0163] As illustrated, to form the curved portion, the electrode wire F rotates by an angle [3 with respect to the axis F2.
[0164] To make this rotation, the third actuator 12 was moved along the Z axis by Lo (sin(a+ |3) - sin(a)), the first actuator 10 along the Y axis by L0(cos(a) - cos(a+ [3)) and the second actuator rotated around X by an angle [3, Lo being the length between the end 30 and the second actuator 11.
[0165] The different movements of the linear actuators 10 and 12 also produce a linear displacement of the second actuator 11 relative to the parts P in a direction Dtl.
[0166] This particular movement of the torch T around the end 30 makes it possible to keep the longitudinal axis L of the electrode wire F as close as possible to the normal N of the surface opposite the end 30.
[0167] For example, the Os angle is here less than 10°.
[0168] To produce the curved portion Tb3, the procedure is similar, with the different directions of movement or rotation being reversed compared to those during the formation of the curved portion Tb2.
[0169] These movements of the three actuators 10, 11 and 12, during the formation of the different portions are coordinated by the control unit 20.
[0170] In particular, the control unit 20 coordinates the movements so as to control the displacement of the end 30 of the electrode wire F with respect to a predetermined trajectory thereof.
[0171] In a variant illustrated in [Fig.8], the actuators 10, 11 and 12 can allow the movement of the torch T in a plane Pt whose normal Nt forms an angle Ot, called thrust angle, of 5° with respect to the direction of advancement D.
[0172] In an unillustrated variant, the angle Ot could be reversed, i.e. the torch T points slightly in the direction of advancement D.
[0173] The invention just described is not limited to the examples just described.
[0174] In particular, the angle between the parts P can be different open or closed, for example between 0° and 360°.
[0175] The weld bead section J may have a different number of curved portions, for example between 1 and 4.
[0176] The weld bead J may have a different number of straight portions, for example between 1 and 4.
[0177] The movements of the three actuators 10, 11 and 12 can be coordinated so as to form a curved portion by a rotation of the torch T around the end 30 and a translation of this end.
[0178] The movements of the actuators 10, 11 and 12 can be carried out in a plane whose normal forms an angle of less than 20° with the direction of advance of the base.
Claims
Demands
1. Arc welding system (1) for welding two parts (P) together, comprising at least: - a base (2) movable relative to the surface of one of the parts (P) to be welded in a direction of travel (D), - a torch support (6) (T) arranged to receive a wire-electrode arc welding torch (T) (F), - a first actuator (10) and a second actuator (11) for moving the support (6) relative to the base (2) in a plane (Pt) substantially transverse to the direction of travel (D) of the base (2) relative to the parts (P) and in two different directions and each not parallel to the longitudinal axis (L) of the torch, - a control unit (20) configured to control in a coordinated manner the first and second actuators (10, 11) according to the trajectory to be given to one end (30) of the wire-electrode (F).
2. System (1) according to claim 1, wherein the first actuator (10) is linear and the second actuator (11) is rotary and allows the torch (T) to be moved in rotation, preferably along an axis (X) substantially parallel to the direction of advancement (D).
3. System (1) according to claim 1, wherein the first and second actuators (10, 11) are linear, the directions (Y, Z) of movement of the linear actuators (10, 11) preferably being orthogonal to each other.
4. System (1) according to claim 1, wherein the first actuator (10) is linear, the second actuator (11) is rotary and allows the torch to be moved in rotation, preferably along an axis (X) substantially parallel to the direction of advancement (D), and wherein the system includes a third linear actuator (12) which allows the torch (T) to be moved in translation, the directions (Y, Z) of movement of the linear actuators (10, 12) preferably being orthogonal to each other.
5. System according to any one of the preceding claims, wherein the base (2) is a mobile trolley, a gantry or a rotating column.
6. System (1) according to any one of the preceding claims, wherein the base (2) comprises wheels (4), in particular each with an axis of rotation perpendicular to the direction of travel (D), and / or tracks, including motorized ones, allowing its movement along the parts (P) to be welded.
7. System (1) according to any one of the preceding claims, comprising at least one geometry sensor (22) of the parts (P) measuring the profile of the parts (P) to be welded upstream of the welding torch (T) in the direction of movement thereof, the control of the actuators (10, 11, 12) being able to be done automatically according to the profile thus measured.
8. System (1) according to any one of the preceding claims, comprising a welding torch (T) received by the torch support (6) (T).
9. A method of welding two parts (P) together using a system (1) according to any one of the preceding claims, wherein the base (2) is moved continuously or intermittently relative to the parts (P) to be welded, and, when the base (2) is in motion and / or between two movements thereof: - the welding torch (T) produces an arc, - the welding torch (T) is moved by coordinated movements of said first and second actuators (10, 11) so as to form a weld bead (J).
10. Method according to the preceding claim, wherein the movements of the first and second actuators (10, 11) are coordinated with the displacement of the base (2).
11. A method according to any one of claims 9 and 10, wherein the first actuator (10) is linear and the second actuator (11) is rotary, the welding torch (T) being moved by linear movements of the first actuator (10) coordinated with rotary movements of the second actuator (11) allowing the torch (T) to be moved in rotation relative to the parts (P), in particular along an axis (X) substantially parallel to the direction of travel (D).
12. A method according to any one of claims 9 to 11, wherein the welding torch (T) is moved by coordinated movements of the first and second actuators (10, 11) and a third actuator (12), preferably one of the three actuators (10, 11, 12) being rotary, the other two actuators (10, 11, 12) being linear.
13. A method according to any one of claims 9 to 12, wherein a welding torch (T) is swept in a direction or- thogonal to the direction of advancement (D).
14. A method according to any one of claims 9 to 13, wherein the weld bead (J) produced comprises a straight portion and / or a curved portion.
15. A method according to any one of claims 9 to 14, wherein a curved portion (Tb2, Tb3) of the weld bead (J) is formed after a straight portion (Tbl) of the weld bead (J), the directions of movement of the linear actuator(s) (10, 11) relative to the parts during the formation of the curved portion (Tb2, Tb3) being reversed with respect to those during the formation of the immediately preceding straight portion (Tbl).
16. A method according to any one of claims 9 to 15, wherein coordinated movements of the first actuator (10), the second actuator (11) and, where applicable, the third actuator (12) rotate the welding torch (T) relative to the parts (P) around an axis (XI) substantially parallel to the direction of travel (D) and passing through one end (30) of the electrode wire (F).
17. A method according to any one of claims 9 to 16, wherein, during the formation of the weld bead (J), the wire electrode (F) forms an angle (Os) less than 70°, preferably less than 45° with respect to the normal (N) of the surface to be welded opposite one end (30) of the wire electrode (F).
18. A method according to any one of claims 9 to 17, wherein a weld bead (J) of cross-section comprising a straight portion (Tbl) and a curved portion (Tb2, Tb3) is made between the parts (P), in particular two curved portions (Tb2, Tb3) at each end of the straight portion (Tbl).
19. A method according to any one of claims 9 to 18, wherein the control unit (20) coordinates the movements of the first actuator (10), the second actuator (11) and, where applicable, the third actuator (12) so as to control the movement of the end (30) of the electrode wire (F) to a predetermined trajectory of the electrode wire (F).