FR2998820A1 - Counter electrode, useful in spot welding device, includes first and second welding portions, and fixing body mounted on support in welding position, where first welding portion is configured to interact with electrode to weld piece - Google Patents

Abstract

The counter electrode comprises a first welding portion, and a fixing body mounted on a support (16) in a first welding position. The counter electrode is configured to cooperate with an electrode (12) of a spot welding device. The counter electrode and the electrode extend along an axis of welding. The first welding portion is arranged perpendicular to the welding axis, and is configured to interact with the electrode to weld a piece (20) interposed between the electrode and the counter-electrode. The counter electrode further comprises a second welding portion and a first welding face. The counter electrode comprises a first welding portion, and a fixing body mounted on a support (16) in a first welding position. The counter electrode is configured to cooperate with an electrode (12) of a spot welding device. The counter electrode and the electrode extend along an axis of welding. The first welding portion is arranged perpendicular to the welding axis, and is configured to interact with the electrode to weld a piece (20) interposed between the electrode and the counter-electrode. The counter electrode further comprises a second welding portion, a first welding face, a second welding face, a first welding head, which is connected to a first end of the body of the counter-electrode, a second welding head, which is connected an opposite second end of the body of the counter-electrode, and a fixing unit provided on the support. The counter electrode is fixed to the support in a second welding position in which the second welding portion is arranged perpendicular to the welding axis to interact with the electrode to weld the piece. The first welding face extends perpendicular to the welding axis, and defines the first welding portion. The second welding face is shifted angularly compared to the first welding face according to a second axis of orientation perpendicular to the welding axis, and delimits the second welding portion. The counter-electrode is angularly shifted from its first welding position to the second welding position according to the second axis of orientation. The first welding face defines a third welding portion, which is angularly shifted compared to the first welding portion about a third axis of orientation, which is parallel to the welding axis. The counter-electrode is further angularly shifted from the first welding position to the third welding position about the third axis of orientation. The third welding portion is arranged perpendicular to the welding axis to interact with the electrode. The first and second welding heads define the first and second welding faces, respectively. The body of the counter-electrode comprises a first fixing face and an opposite second fixing face. The first fixing face extends perpendicular to the first welding face and the second welding face, and is adapted to be supported on a fixing face (40) complementary to a support of the counter-electrode and to fix the counter-electrode on the support in the first or second welding position. The second fixing face extends perpendicular to the first and second welding faces, and is adapted to be supported on the fixing face complementary to the support of the counter-electrode and to fix the counter-electrode on the support in the third welding position or a fourth welding position. A first symmetry plane extends according to the second axis of orientation. A second symmetry plane extends according to the third axis of orientation.

Description

BACKGROUND OF THE INVENTION The invention relates to a counter-electrode adapted to cooperate with an electrode of a spot welding device.

Spot welding, also called resistance welding, makes it possible to locally assemble a part consisting of two superposed sheets, such as a lining and a door skin of a motor vehicle, for example. For this purpose, a type of welding device is known, such as the device described and shown in the document FR-A-2612104, which comprises an electrode and a counter-electrode which extend opposite to each other. -vis according to a welding axis. The counter electrode has a welding face which defines a welding portion designed to interact with the electrode. In addition, the counter-electrode comprises a fixing body which is fixed on a support of the welding device provided for this purpose, in a welding position in which the welding portion of the counter electrode is arranged perpendicular to the welding axis, vis-à-vis the electrode. The part to be welded is compressed between the electrode and the counter-electrode along the welding axis, and a high intensity electric current passes through the electrode and the counter-electrode through the welding portion of the counter-electrode. electrode. The heat generated by this current at the interface between the two sheets of the workpiece melts the metal locally, which creates a welding point. After one or more welds, depending on the welding conditions, the welding portion of the counter-electrode is said to be "polluted", that is to say that it is substantially deteriorated by the passage of the current, so that the Against the used electrode must be replaced by a new counter-electrode, to guarantee the quality of the following welds. The counter-electrode is generally made of copper or copper alloy. This type of material is expensive, and the frequent change of the counter-electrode represents a significant expense item. Indeed, the assembly of a door of a vehicle, for example, may require more than fifteen counter-electrodes.

The invention aims in particular to limit the consumption of the counter electrodes during a welding operation of a workpiece. For this purpose, the invention proposes a counter electrode designed to cooperate with an electrode of a spot welding device, the electrode and the counter-electrode extending along a welding axis, the counter-electrode comprising least a first welding portion, and a fastener body adapted to be fixed on a support in a first welding position in which the first welding portion of the counter-electrode is arranged perpendicularly to the welding axis, with respect to the electrode, so as to interact with the electrode for welding a part interposed between the electrode and the counter-electrode, characterized in that the counter-electrode comprises at least a second additional welding portion, and in that the counter-electrode is designed to be fixed on the support provided for this purpose, in at least a second welding position in which the second welding portion is arranged perpendicularly. to the welding axis so as to interact with the electrode, to weld the workpiece to be welded. The counter-electrode provides at least two solder portions, so that the counter-electrode is usable a greater number of times. According to another characteristic, the counter-electrode comprises at least: a first welding face which extends perpendicularly to the welding axis and which delimits at least the first welding portion, and a second welding face which is angularly offset relative to the first welding face along a second axis of orientation perpendicular to the welding axis, and which delimits at least the second welding portion, and the counter electrode is designed to be selectively driven from its first welding position to its second welding position, angularly offset about the second axis of orientation. According to this characteristic, the counter-electrode comprises at least two welding faces, each face comprising at least two welding portions. In addition, the first welding face delimits at least a third welding portion which is angularly offset relative to the first neighboring welding portion, around a third orientation axis which is parallel to the welding axis. and in that the counter-electrode is adapted to be selectively driven from its first welding position to a third welding position, angularly offset about the third axis of orientation, wherein the third welding portion is arranged perpendicularly to the welding axis so as to interact with the electrode. The counter electrode is able to change position by simple angular offset. Similarly, the second welding face defines at least a fourth welding portion which is angularly offset relative to the second adjacent welding portion, around the third orientation axis, and in that the counter-electrode is designed to be selectively driven from its second welding position to a fourth welding position, angularly offset about the third axis of orientation, wherein the fourth welding portion is arranged perpendicular to the welding axis so as to interact with the 'electrode. According to another characteristic, the counter-electrode comprises at least: a first welding head which is connected to a first end of the body of the counter-electrode and which delimits said first welding face, and a second welding head; which is connected to a second opposite end of the body of the counter-electrode, and which delimits said second welding face. In addition, the body of the counter-electrode comprises at least: a first fixing face which extends perpendicularly to the first welding face and to the second welding face, and which is adapted to bear on a complementary counter-electrode mounting face, for attaching the counter-electrode to the associated carrier selectively in its first or second welding position, and a second opposing attachment face which extends perpendicularly to the first welding face and the second welding face, and which is adapted to bear on said counter electrode fixing face, to fix the counter-electrode on the associated support 35 selectively in its third position welding or in its fourth welding position.

In another aspect, the counter-electrode has at least a first plane of symmetry extending along the second axis of orientation. Similarly, the counterelectrode has at least a second plane of symmetry extending along the third axis of orientation.

The first plane of symmetry and the second plane of symmetry favor the realization of the counter-electrode. Also, the counterelectrode comprises a fixing means on the associated support. The invention also relates to a spot welding device which comprises a counter-electrode according to any one of the preceding claims. Other characteristics and advantages of the invention will appear on reading the detailed description which follows for the understanding of which reference will be made to the appended drawings in which: FIG. 1 is a diagrammatic cross-sectional view, illustrating a counter electrode which is mounted on a welding device in a first welding position and which delimits a plurality of welding portions each designed to cooperate with an electrode; FIG. 2 is a diagrammatic perspective detail view, which illustrates the electrode of FIG. 1 comprising two welding heads, according to a first embodiment of the invention; FIG. 3 is a schematic view of detail similar to the view of FIG. 2, which illustrates an electrode comprising a welding head, according to an alternative embodiment of the first embodiment of the invention; Figure 4 is a diagrammatic cross-sectional view illustrating an electrode according to a second embodiment of the invention; FIG. 5 is a schematic perspective detail view, which illustrates the electrode of FIG. 4; Figure 6 is a diagrammatic cross-sectional view illustrating an electrode according to a third embodiment of the invention; FIG. 7 is a diagrammatic perspective detail view, which illustrates the electrode of FIG. 6. In the description and the claims, the terms "superior" and "lower" will be used in a nonlimiting manner with reference to the Upper and lower portions respectively of FIGS. 1 to 7.

Moreover, to clarify the description and the claims, the longitudinal, vertical and transverse terminology will be adopted in a nonlimiting manner with reference to the L, V, T trihedron indicated in the figures. FIG. 1 shows a spot welding device 5 which comprises an upper electrode 12 and a lower counter-electrode 14, the counter-electrode 14 being fixed on a support 16. The electrode 12 and the counter-electrode 14 extend along a vertical welding axis A so as to delimit a vertical space between them, in which a rabbet 18 of a workpiece 20 to be welded is arranged. The rebate 18 is here composed of an upper sheet forming skin 22, and a lower sheet forming a lining 24 of a door (partially shown in Figure 1) of a motor vehicle. In addition, the welding device 10 is equipped with an actuator (not shown) for driving the electrode 12 towards the counter-electrode 14 along the welding axis A, so as to compress the rabbet 18 of the piece 20 to be welded to pass an electric current. According to a first embodiment of the invention, shown in FIGS. 1 and 2, the counter-electrode 14 comprises a central body 26 which extends vertically and which is delimited transversely by a first fixing face 28a and a second face fasteners 28b arranged parallel to each other. The body 26 is traversed by a first hole 30 which extends transversely along a second axis B, for the passage of a screw 32 forming means for fixing the counter electrode 14 on the associated support 16. Complementarily, the support 16 has a protrusion 34 protruding transversely which is delimited by an upper face 36 horizontal, a lower face 38 and a vertical mounting face 40. The fixing face 40 of the support 16 is provided with a second threaded hole 42 which is designed to cooperate with the screw 32 for fixing the counter-electrode 14, so as to fix and lock the counter electrode 14. FIG. 2 shows the counter-electrode 14 having a first plane of symmetry of design which extends horizontally and transversely along the second transverse axis B.

Similarly, the counter-electrode 14 has a second plane II of design symmetry which extends vertically and longitudinally along a third vertical axis C passing through the center of the counter-electrode 14. The counter electrode 14 comprises a first head of welding 44a which is connected to a first vertical end of the body 26. The first welding head 44a is defined vertically by a first welding face 46a which comprises a first welding portion 48a, shown in dashed lines in FIG. by "welding portion" a zone of the associated welding face, which is able to interact with the electrode 12 to pass a high intensity electric current through the workpiece 20, so as to form a weld on the workpiece 20. By symmetry in the first plane I, the counter-electrode 14 has a second welding head 44b which is connected to a second opposite vertical end of the body. 26. The second welding head 44b is delimited vertically by a second welding face 46b which has a second welding portion 48b. In addition, by symmetry along the second plane II, the first welding face 46a comprises a third welding portion 48c which is angularly offset relative to the first neighboring welding portion 48a, in this case 180 ° around the third axis C. Similarly, the second welding face 46b has a fourth welding portion 48d which is angularly offset relative to the second welding portion 48b adjacent, here 180 ° around the third axis C. According to the invention, the counter The electrode 14 is designed to occupy a plurality of welding positions in each of which one of the welding portions is arranged opposite the electrode 12, so as to enable the part 20 to be welded. with reference to FIG. 1, the counter-electrode 14 occupies a first welding position in which the first welding face 46a is arranged upwards, opposite the electrode 12, and the first portion The welding 48a is arranged horizontally and perpendicular to the welding axis A, facing the electrode 12, so as to interact with the electrode 12 to weld the part 20 interposed between the electrode 12 and the electrode 12. the counter-electrode 14. In this first welding position, the first fixing face 28a bears on the complementary fixing surface 40 of the support 16 of the counter-electrode 14, along the second transverse axis B, for fixing counter-electrode 14 on the support 16. For this purpose, the transverse screw 32 fixes the body 26 of the counter-electrode 14 on the associated support 16. In addition, the counter-electrode 14 is designed to occupy a second welding position (not shown) in which the second welding face 46b is arranged upward facing the electrode 12, and the second welding portion 48b is arranged horizontally and perpendicularly to the welding axis A, facing the electrode 12, so as to interact with the electrode 12 to weld the part 20 interposed between the electrode 12 and the counter. -electrode 14. In this second welding position, the first fixing face 28a rests on the face 40 of complementary attachment of the support 16 of the counterelectrode 14, along the second transverse axis B, to fix the counter-electrode. Also, the counterelectrode 14 is adapted to be selectively driven from its first welding position to a third, angularly offset, or pivoting welding position around the third electrode. vertical axis, in which the first welding face 46a is arranged upwards, facing the electrode 12, and the third welding portion 48c is arranged horizontally and perpendicular to the welding axis A, with respect to the electrode 12, so as to interact with the electrode 12 to weld the part 20. In this third welding position, the second fixing face 28b bears on the face 40 of complementary fixing of the support 30 16 of the counter-electrode 14, according to the second transverse axis B, for fixing the counter electrode 14 on the support 16. In addition, the counter-electrode 14 is designed to be selectively driven from its second welding position to at a fourth welding position, angularly offset, or pivoting about the third vertical axis C, wherein the second welding face 46b is upwardly facing the electrode 12, and the fourth welding portion 48d is arranged horizontally and perpendicularly to the welding axis A, facing the electrode 12, so as to interact with the electrode 12 to weld the part 20. In this fourth welding position, the second face 28b of fixing, bears on the face 40 of complementary attachment of the support 16 of the counter-electrode 14, according to the second transverse axis B, for fixing the counter electrode 14 on the support 16. The driving of the against -electrode 14 from a position to another position described above, is for example performed by an operator who removes the screw 32, then angularly shifts the counter electrode 14 about the second axis B and / or the third axis C according to the chosen position, before repositioning the counter electrode 14 on its support 16 and fix the counter electrode 14 by means of the screw 32 provided for this purpose. Non-limitingly, the drive of the counter-electrode 14 from one position to another can be envisaged by an automatic device (not shown) for example. According to an alternative embodiment of the first embodiment of the invention described above, shown in FIG. 3, the counter-electrode 14 has a T-shape, the counter-electrode 14 having only one welding head 44a. . The welding head 44a is delimited vertically by a welding face 46a which comprises a first welding portion 48a and a second welding portion 48b. According to a second embodiment, represented in FIGS. 4 and 5, the counter-electrode 14 has the shape of a hexagonal nut traversed by a hole 50 which extends along a central transverse axis D, perpendicular to the axis A. welding. The counter-electrode 14 is delimited by six peripheral welding faces 52 which are distributed angularly in a regular manner about the central axis D, each welding face 52 comprising a welding portion 54. According to this second embodiment, the counter-electrode 14 The electrode 14 is designed to occupy a plurality of welding positions in each of which one of the welding portions 54 is arranged opposite the electrode 12, to allow welding of the part 20.

For this purpose, the counterelectrode 14 is pivotally driven about the axis D in increments, to selectively occupy one of its welding positions. The counter-electrode 14 is here fixed and locked on the support 16 5 in the chosen position by means of the screw 32. In addition, according to a third embodiment of the invention, represented in FIGS. 6 and 7, the counter-electrode 14 electrode 14 comprises a cylindrical body 56 which extends vertically along a pivot axis E parallel to the welding axis A.

In addition, the counter-electrode 14 has a welding head 58 which is arranged at an upper axial end of the body 56. The welding head 58 has the shape of an E-axis disk having a superior welding face 60 which extends perpendicularly to the welding axis A.

The welding face 60 delimits a plurality of welding portions 61, here four in number, which are distributed angularly in a regular manner about the axis E, in increments of 900. Complementarily, the support 16 of the counter-electrode 14 has an attachment face 62 which extends perpendicularly to the welding axis A, and which delimits a hole 64 of complementary shape to the body 56 of the counter-electrode 14. According to this third embodiment, the counter-electrode 14 is designed to occupy a plurality of welding positions in each of which one of the welding portions 60 is arranged opposite the electrode 12, to enable the welding of the workpiece 20. For this purpose, the counterelectrode 14 is pivotally driven about the axis E in 90 ° angular increments, to selectively occupy one of its welding positions. The counter-electrode 14 is fixed on the support 16 in the selected position 30 by means of a nut 66 which cooperates with a threaded portion of the body 56 of the counter-electrode 14 for example, as can be seen in FIG. Thus, the counter-electrode 14 has a plurality of welding portions so that the life of the electrode 14 according to the invention is increased, thereby reducing the frequency of change of the counter electrode 14.

Claims (10)

REVENDICATIONS1. A counter electrode (14) adapted to cooperate with an electrode (12) of a spot welding device (10), the electrode (12) and the counter electrode (14) extending along an axis (A) ), the counterelectrode (14) having at least a first welding portion (48a), and a fixing body (26) adapted to be fixed on a support (16) in a first welding position in which the first welding portion (48a) of the counter-electrode (14) is arranged perpendicularly to the welding axis (A), opposite the electrode (12), so as to interact with the electrode (12) for welding a workpiece (20) interposed between the electrode (12) and the counter-electrode (14), characterized in that the counter-electrode (14) comprises at least a second welding portion (48b) additional, and in that the counter-electrode (14) is adapted to be fixed to the support (16) provided for this purpose, in at least a second position of welding in which the second welding portion (48b) is arranged perpendicularly to the welding axis (A) so as to interact with the electrode (12), for welding the workpiece (20) to be welded. 20 2. counter-electrode (14) according to claim 1, characterized in that it comprises at least: - a first welding face (46a) extending perpendicular to the axis (A) of welding and which delimits at minus the first welding portion (48a), and 25 - a second welding face (46b) which is angularly offset with respect to the first welding face (46a) along a second axis (B) of orientation perpendicular to the welding axis (A), which delimits at least the second welding portion (48b), and that the counter-electrode (14) is adapted to be selectively driven from its first welding position to its second position welding position, angularly offset about the second axis (B) orientation. 3. Counter electrode (14) according to claim 2, characterized in that the first welding face (46a) delimits at least a third welding portion (48c) which is angularly offset relative to the first welding portion ( 48a) around a third axis (C) of orientation which is parallel to the welding axis (A), and in that the counter-electrode (14) is adapted to be selectively driven from its first position welding to a third welding position, angularly offset about the third orientation axis (C), wherein the third welding portion (48c) is arranged perpendicular to the welding axis (A) so as to interact with the electrode (12). 4. counter-electrode (14) according to claims 2 and 3, characterized in that the second welding face (46b) defines at least a fourth welding portion (48d) which is angularly offset relative to the second welding portion (48b), around the third axis (C) of orientation, and in that the counter-electrode (14) is adapted to be selectively driven from its second welding position to a fourth welding position, by shifting angularly about the third axis (C) orientation, wherein the fourth welding portion (48d) is arranged perpendicular to the axis (A) of welding so as to interact with the electrode (12). A counter electrode (14) according to any one of claims 2 to 4, characterized in that it comprises at least: - a first welding head (44a) which is connected to a first end of the body (26). ) of the counter electrode (14) and defining said first welding face (46a), and - a second welding head (44b) which is connected to a second opposite end of the counter electrode body (26) ( 14), and which delimits said second welding face (46b). 25 Counter-electrode (14) according to claims 3 and 4, characterized in that the body (26) of the counter-electrode (14) comprises at least: a first fixing face (28a) extending perpendicularly to the first welding face (46a) and the second welding face (46b), and which is adapted to bear on a complementary fixing face (40) of the support (16) of the counter electrode (14). ), for fixing the counter-electrode (14) on the support (16) selectively associated in its first welding position or in its second welding position, and - a second opposite fixing face (28b) extending perpendicularly to the first welding face (46a) and the second welding face (46b), and which is adapted to bear on said fixing face (40 complementary to the support (16) of the counter-electrode (14), for fixing the counter-electrode (14) on the support (16) selectively associated in its third position of welding or in its fourth welding position. 7. counter-electrode (14) according to any one of claims 2 to 4, and 6, characterized in that it has at least a first plane (I) of symmetry which extends along the second axis (B ) orientation. 8. counter-electrode (14) according to any one of claims 3 to 4, and 6, characterized in that it has at least a second plane (II) of symmetry which extends along the third axis (C) orientation. 10 9. counter-electrode (14) according to any one of the preceding claims, characterized in that it comprises a fixing means (32) on the support (16) associated. A spot welding device (10) which has a counter electrode (14) as claimed in any one of the preceding claims. 15