Mesh welding system having central clamping units

Abstract

The invention relates to a mesh welding system (1) for producing a mesh mat (10) composed of longitudinal wires (11) and transverse wires (12), the mesh welding system (1) comprising a plurality of welding units (2) having welding plungers (3) and counter-holders (4), wherein: the welding plungers (3) and the counter-holders (4) are arranged in pairs, the welding plunger (3) of a pair is located opposite the counter-holder (4), and the welding plungers (3) and the counter-holders (4) each comprise at least one electrical conductor (31, 41), so that a transverse wire (12) inserted between the welding plungers (3) and the counter-holders (4) can be welded, with the welding plungers (3) and the counter-holders (4) placed together, to longitudinal wires (11) located therebetween; at least one clamping unit (5) is provided for clamping the transverse wire (12) during the welding to the longitudinal wires (11). In order to avoid not only geometric distortion but also wire waste, according to the invention the at least one clamping unit (5), preferably all clamping units (5), are disposed between the welding units (2). The invention also relates to a method using a mesh welding system (1) of this type.

Description

[0001] Mesh welding system with central clamping units

[0002] The invention relates to a mesh welding system for producing a mesh mat from longitudinal wires and transverse wires, wherein the mesh welding system comprises a plurality of welding units with welding rams and counterholders, wherein the welding rams and the counterholders are arranged in pairs, wherein the welding ram of a pair is located opposite the counterholder, and wherein the welding rams and the counterholders each comprise at least one current conductor, so that a transverse wire inserted between the welding rams and the counterholders can be welded to the longitudinal wires located between them when the welding rams and the counterholders are placed against one another, wherein at least one tensioning unit is provided for tensioning the transverse wire during welding to the longitudinal wires.

[0003] Furthermore, the invention relates to a method for producing a grid mat from longitudinal wires and transverse wires, in particular with a grid welding system according to the above type, wherein a bundle of longitudinal wires and a transverse wire are introduced between welding rams and counterholders of a plurality of welding units and wherein the introduced transverse wire is tensioned, after which the welding rams and the counterholders are brought into contact with the longitudinal wires and the transverse wire lying therebetween and the transverse wire is welded to the longitudinal wires by applying current.

[0004] Mesh mats for various construction purposes, such as reinforcement mats, but also fences, security fences or gabions, are produced with a high degree of automation using industrial mesh welding systems. Mesh welding systems of the type mentioned above are used for this purpose. In such mesh welding systems, the longitudinal wires of the future mesh mat are fed to the welding units in a conveying direction. A bundle of longitudinal wires is arranged in the area of ​​the respective current conductors between the welding rams and the counterholders. The cross wires are also inserted individually between the welding rams and the counterholders perpendicular to the conveying direction of the longitudinal wires and held in this position. After this, the welding rams are placed against the counterholders and current is applied via the current conductors or electrodes, thus welding the cross wire to the numerous longitudinal wires at the welding points.The longitudinal wires, and thus also the welded cross wire, are then moved a predetermined distance in the conveying direction. The previously described process is then repeated with the next cross wire until the mesh mat is completed.

[0005] When welding the cross wires to the bundle of longitudinal wires, considerable heat is introduced into the cross wires. Without further measures, this can result in the cross wire no longer being welded at a right angle, resulting in significant geometric distortion. The mesh mat may, for example, have a bulged saddle surface. The mesh mat is then unusable and constitutes scrap. To avoid this, the state of the art provides for the cross wire to be pre-tensioned before the welding ram impacts and during welding to the bundle of longitudinal wires. For this purpose, two external tensioning units are arranged, with which the cross wire is held and pre-tensioned on the two outer sides of the mesh welding system. The tensioning units have suitable serrated grippers for this purpose.Once the cross wire has been inserted between the welding rams and pre-tensioned, it can be welded to the bundle of longitudinal wires. The protruding ends of the cross wires must then be trimmed. This creates waste and requires an additional work step.

[0006] Based on the prior art, the invention aims to provide a mesh welding system with which the cross wire waste is eliminated or at least reduced and with which the process can be carried out more easily.

[0007] A further aim of the invention is to further develop a method of the type mentioned at the outset in such a way that geometric distortion is avoided or at least reduced and which is characterized by a simple process control.

[0008] The object of the device is achieved in a mesh welding system of the type mentioned at the beginning when the at least one clamping unit, preferably all of the clamping units, is arranged between the welding units. The solution according to the invention makes it possible to minimize waste of cross wire. Since the clamping units are arranged between the welding units, the cross wire can be provided or used in its final length. Cutting to length after the welding process is no longer necessary. This also saves a work step. This results from the fact that the at least one clamping unit or all of the clamping units, if several are provided, are arranged within the final mesh geometry. The arrangement of the clamping units within the mesh geometry results in the further advantage that sectional welding can take place, whereby only some of the longitudinal wires are welded to a cross wire.

[0009] In principle, a single clamping unit is sufficient if a welding ram with a suitable insert serves to secure the cross wire. However, it is advantageous to use multiple clamping units, as the cross wire can then be clamped before the longitudinal wires are welded to the cross wire.

[0010] The clamping units can each be designed with a lower clamping part and an upper clamping part. The clamping units are relatively small overall so that they can be arranged between the welding units. The lower clamping parts can be stationary and the upper clamping parts can be adjusted to the lower clamping parts, particularly by vertical movement. A reverse configuration, in which the upper clamping parts are stationary and the lower clamping parts are moved vertically, is also possible. Finally, it is also possible, although this is more complex in terms of construction, for both the upper clamping parts and the lower clamping parts to be vertically movable. The vertical movement of the upper clamping parts and / or the lower clamping parts is generally linear. If the clamping parts are adjusted to one another, the longitudinal wires and a transverse wire are located between them.

[0011] Just as the counterholders are usually arranged in a stationary manner, this preferably also applies to the lower clamping parts. The upper clamping parts are then placed against the lower clamping parts to clamp and pre-tension a cross wire. The upper clamping parts have a suitable drive for this purpose, in particular a hydraulic drive. A pneumatic or electric drive is alternatively possible, as is a spring-loaded mechanism. The upper clamping parts are arranged in pairs with the lower clamping parts, as are the welding rams and the counterholders. The same applies if the lower clamping parts are movable, whereas the upper clamping parts are held fixed. The clamping parts can have an adjusting wedge that can be adjusted to the different wire diameters of the cross wire.

[0012] Basically and advantageously, two clamping units or a multiple of two clamping units are provided. In addition to a separate arrangement, it is also possible for the clamping units to be designed in combination with the welding units. With an integral design of at least one clamping unit with a welding unit, it is advantageous if pre-tensioning caused by the clamping unit is initiated before welding. Since a vertical movement of the clamping unit in this design variant occurs simultaneously with that of the welding ram, it can be expedient for the moving part of the clamping unit to move ahead of the welding ram for clamping and pre-tensioning the cross wire, but then to remain essentially stationary in a clamping and pre-tensioning position relative to the welding ram. This can be implemented structurally by suitably mounting the moving clamping part on the welding ram, for example via a spring mechanism.In this variant, only the welding ram moves once the cross wire is pre-tensioned. The welding ram's movement ends at the position in which welding occurs.

[0013] The clamping units are advantageously located adjacent to the externally terminating welding units. This allows the supplied cross wire to be pre-tensioned almost along its entire length. Only the cross wire sections remaining on the outside, in the area of ​​the external welding units, are not subject to pre-tension during welding. However, this can be tolerated, as these are short sections that protrude freely outward and cannot lead to any significant geometric distortion. In particular, the clamping units can be located directly in front of the last longitudinal wire on the outside.

[0014] The tensioning units are advantageously designed to clamp the cross wire in clamping areas and pre-tension it by applying tension to the clamping areas. The clamping action grips the cross wire in the tensioning units. By applying a tensile force, the required pre-tension is created for the subsequent welding of the cross wire to the bundle of longitudinal wires. The cross wire is thereby tensioned in the elastic range.

[0015] It is particularly advantageous if upper clamping inserts are arranged on the upper clamping parts and / or lower clamping inserts on the lower clamping parts to hold the cross wire. In contrast to the prior art, the clamping units engage the cross wire in an area that is not subsequently removed. In the prior art, the clamping units can engage the ends with a serrated gripper, since damage to the cross wire in these areas is not important because the protruding cross wire ends are cut off later. According to the invention, however, the cross wire is clamped with the clamping unit in areas that remain visible on the product. To ensure that the cross wire remains undamaged in the clamping areas, the use of clamping inserts on the upper clamping parts and / or on the lower clamping parts to hold the cross wire has proven expedient.The clamping inserts can each have an indentation in which the cross wire can be received in a flat manner. The upper and lower clamping inserts can be designed identically, but this is not mandatory. The indentations are advantageously shaped with an approximately semicircular cross-section transverse to the longitudinal axis of the fed cross wire, so that the cross wire is largely enclosed by the clamping inserts. With such a design, a tooth-free arrangement is achieved, in particular, so that the cross wire is not damaged by clamping and the application of a tensile force. The clamping inserts can be made of a metal or an alloy, in particular of steel or copper or a copper alloy, with the clamping inserts optionally being coated. The material is selected such that the corresponding forces can be applied, but the cross wire is not damaged as a result.Coatings of the clamping inserts can also be provided for this purpose. For example, these can be relatively hard coatings made of diamond or boron nitride, which are applied with a predetermined roughness. The coatings can be applied using chemical vapor deposition, physical vapor deposition, sputtering or other suitable methods. Polymers are also used to coat the clamping inserts. The lower clamping insert can be arranged so that it protrudes vertically from the lower clamping part. Analogously, the upper clamping insert can be arranged so that it protrudes vertically from the upper clamping part. The protruding arrangement of the clamping inserts, which interact during use, means that the cross wire is guided freely outside the clamping areas and does not rest against other parts of the device.

[0016] It can also be provided that the lower clamping insert and / or the upper clamping insert are each mounted in a holder, with the holder being detachably arranged in the clamping unit. This allows the holder with the clamping insert to be removed and, if necessary, replaced without the need for complex work on the clamping unit. It can also be provided that the clamping insert itself is detachably fixed in the holder, so that the clamping insert alone can be replaced if necessary, for example, due to wear or if different cross wire diameters are to be processed.

[0017] It is particularly preferred that the lower clamping insert and / or the upper clamping insert are mounted so that they can be moved, in particular linearly moved, between stops. This is advantageously provided for both the upper clamping insert and the lower clamping insert. The two clamping inserts can also be mounted identically, which results in the advantage of the most uniform force introduction possible on the cross wire. It can also be provided that one or more springs are arranged in the tensioning unit and the lower clamping insert and / or the upper clamping insert are mounted so that they can be moved against a spring force, so that the clamping inserts are automatically reset after pre-tensioning.In particular, it can also be provided that a first stop defines a first operating position and that the lower clamping insert and / or the upper clamping insert, when force is applied, can be displaced from the first operating position against one or more acting spring forces towards the outside of the mesh welding system in the direction of a second stop and at most up to this stop; the displacement takes place along a straight line which encloses a predetermined angle with the longitudinal axis of the cross wire, for example 10° to 40°, and is predetermined by the clamping inserts or two clamping units. The force is generally applied by the upper clamping part, although a reverse application of force with the lower clamping part is also possible.Automatic guidance of the clamping inserts, if necessary with holders or clamping slides, if the clamping inserts are fastened in such, can be easily achieved if an outwardly sloping guide is provided, on which the clamping insert, possibly including the holder, slides. By applying force with the upper clamping part, the cross wire already resting on the lower clamping insert is initially clamped. As the force is applied, the clamping insert and holder move laterally outwards due to the angled mounting of the holder. This pulls the cross wire outwards and thus pre-tensions it. The cross wire is pre-tensioned in the elastic range and, by the angled tensioning movement of the clamping slide, is placed on the longitudinal wire (or vice versa, on an electrode if the cross wire is below the longitudinal wires).When the predetermined force acting on the cross wire corresponds to the opposing stretching force of the cross wire, equilibrium is achieved. In this state, the cross wire is welded to the longitudinal wires at the weld points. The force acting through the upper clamping part can then be reduced and the cross wire finally released. The spring forces return the clamping insert and holder to the first stop and thus to the first operating position. The first operating position is fixed. For example, the holder can have a protruding nose that strikes another element of the clamping part in the first operating position. The first operating position is thus fixed. The second operating position, which corresponds to a deflection of the clamping insert, optionally with a holder, if one is provided, can be predetermined by the applied force.The force to be applied is also determined by the desired pre-tension that is to be achieved for the cross wire before welding.

[0018] The holder or clamping slide can also be easily reset if pneumatic connections are installed, allowing the holder to be pneumatically reset to its initial operating position. A mechanism with magnetic repulsion is also possible.

[0019] The lower clamping parts can be designed so that the height of the lower clamping inserts is adjustable, for example, via a manually or automatically operated adjustment mechanism. The mesh welding system typically includes at least one conveyor unit for feeding longitudinal wires and cross wires to the welding units. The at least one conveyor unit includes a servo motor, enabling high-precision feed of the longitudinal wires.

[0020] The procedural objective is achieved when, in a method of the type mentioned at the outset, the cross wire is tensioned between welding points. Tensioning between welding points, thus within individual external welding units of the mesh welding system, has the advantage that the cross wire can be fed to the longitudinal wires or welding units already in its final length. This eliminates the need for subsequent trimming of excess cross wires, which no longer exist. This also simplifies the method. A corresponding method can be carried out in particular with a mesh welding system according to the invention. The tensioning units are preferably arranged as far out as possible. The corresponding clamping areas for the cross wire can, in particular, be set directly at the connection of a first external welding unit.This means that the cross wire is only untaut in the area of ​​the external welding units, but in all other areas, and thus in the vast majority of the cross wire, it is untaut. However, the untaut areas cannot lead to any significant geometric distortion.

[0021] It is particularly preferred that the cross wire be tensioned against a restoring force within the elastic deformation range of the cross wire. After pre-tensioning and welding, and after the pre-tensioning force has been removed, the cross wire then returns at least approximately to its original length.

[0022] Further features, advantages, and effects of the invention will become apparent from the following exemplary embodiment. Reference is made to the drawings, which show:

[0023] Fig. 1 is a front view of a prior art mesh welding system; Fig. 2 is a perspective view of the mesh welding system shown in Fig. 1;

[0024] Fig. 3 is a front view of a mesh welding system according to the invention;

[0025] Fig. 4 is a side view of a mesh welding system according to the invention; Fig. 5 is a perspective view of the mesh welding system according to Fig. 3 and Fig. 4;

[0026] Fig. 6 a lower clamping part with a clamping insert;

[0027] Fig. 7 a clamping unit with clamping inserts;

[0028] Fig. 8 a clamping unit with clamping inserts in a cross section;

[0029] Fig. 9 is a front view of another variant of a mesh welding system; Fig. 10 is a perspective view of the mesh welding system according to Fig. 9.

[0030] Fig. 1 shows a mesh welding system 1 according to the prior art. The mesh welding system 1 comprises a plurality of welding units 2. Each welding unit 2 has a welding ram 3 and a counterholder 4. The welding ram 3 comprises current conductors 31 or electrodes. In the same way, the counterholder 4 comprises corresponding current conductors 41 or electrodes. The welding rams 3 are arranged in pairs with the counterholders 4. Viewed in the vertical direction, the current conductors 31, 41 lie one above the other. While the counterholders 4 are arranged in a stationary manner, the welding rams 3 are mounted so as to be vertically displaceable along a z-axis, so that the current conductors 31 of the welding rams 3 can be contacted with the current conductors 41 of the counterholder 4 via inserted longitudinal wires 11 and a transverse wire 12. With a view to Fig.2 a cross wire 12 is welded to longitudinal wires 11 by placing the welding rams 3 with the current conductors 31 against the counterholders 4 with the current conductors 41 and applying current. The cross wire 12 and the bundle of longitudinal wires 11 are then located between the welding rams 3 and the counterholders 4. By applying current via the current conductors 31, 41, the cross wire 12 is welded to the bundle of longitudinal wires 11. In this way, as can be seen in Fig. 2, a grid mat 10 can be produced. For this purpose, after a cross wire 12 has been welded on, the longitudinal wires 11 are moved a predetermined distance, after which the next cross wire 12 is positioned between the counterholders 4 and the welding rams 3 and the process is repeated. This is carried out until the grid mat 10 is created.

[0031] When welding a cross wire 12 to the bundle of longitudinal wires 11, a high heat input occurs, which can lead to deformation of the cross wire 12, which is usually made of steel, thus a material with good thermal conductivity. If no measures are taken, significant geometric distortion can occur, which can also render the produced grid mat 10 unusable. To avoid this, clamping units 5 are provided on the outside of the grid welding system 1 according to the prior art. The two clamping units 5 each comprise an upper clamping part 7 of the clamping unit 5 and a lower clamping part 6 of the clamping unit 5. Suitable grippers for the cross wire 12 are arranged on the upper clamping parts 7 and lower clamping parts 6 of the clamping units 5. The grippers are usually toothed.With the tensioning units 5, the supplied cross wire 12 can be gripped on the outside of the mesh welding system 1 and pre-tensioned to the desired level before the welding process begins. However, this requires that the cross wire 12 be provided in a greater length than is actually required for the production of the mesh mat 10.

[0032] 3 to 5 show a mesh welding system 1 according to the invention. With regard to the welding units 2, the mesh welding system 1 is designed in the same way as a mesh welding system 1 according to FIGS. 1 and 2. In contrast to the prior art, the clamping units 5 are arranged between the welding units 2. As can be seen in particular in FIG. 3, the welding units 2 are arranged as far outwards as possible and are each located between the last welding unit 2 on the outside. Unlike in the prior art, pre-tensioning takes place between welding points. Due to this arrangement of the clamping units 5, the cross wire 12 can be provided with the final length as desired for the mesh mat 10. There is no need for a cutting-to-length process for protruding parts of the cross wire 12. Furthermore, material is saved.

[0033] Fig. 6 to Fig. 8 show clamping units 5 and sections of clamping units 5 including clamping inserts 8, 9. The clamping inserts 8, 9 can be designed identically to the exemplary embodiment, although this is not mandatory. Advantageously, the clamping inserts 8, 9 can each have an indentation 13 on the head side, in which the cross wire 12 is received. On the head side, the clamping inserts 8, 9 are therefore advantageously designed such that they form an approximately semicircular groove in the direction of a longitudinal axis of the fed cross wire 12. If the two clamping inserts 8, 9 are placed against one another, they largely surround the cross wire 12 or, if appropriate, over its entire surface. As can be seen in Fig. 7, the clamping inserts 8, 9 can each be mounted in a holder 14 or clamping carriage. The clamping inserts 8, 9 can be detachably fastened in the respective holder 14. The holder 14 can in turn be detachably fastened in the lower clamping part 6 or the upper clamping part 7.Common fasteners such as screws can be used for this purpose. This makes it possible to replace flexible clamp inserts 8, 9 and, if necessary, the holder 14.

[0034] When the clamping inserts 8, 9 encompass a cross wire 12 in a clamping area, which is achieved by positioning the upper clamping part 7 against the lower clamping part 6, only a clamping force is present. In order to also be able to apply preload, the holders 14 with the clamping inserts 8, 9 fastened therein are slidably mounted between a first stop 15 and a second stop 16. The first stop 15 defines a first operating position. Since the holder 14 abuts against a part of the remaining clamping unit 5 with a nose 19 in this first operating position, the holder 14 cannot move further towards the center of the mesh welding system 1. The first operating position is thus restricted in the direction towards the center of the mesh welding system 1 by the first stop 15. The clamping inserts 8, 9 are in this first operating position when no force is acting through the upper clamping part 7.Furthermore, the holder 14 is mounted on an inclined guide 18. The guide 18 slopes outwards. Furthermore, a spring 17 is provided which presses the holder 14 into the first operating position when no force is applied. If the upper clamping part 7 is now lowered and the upper clamping insert 8 engages the cross wire 12, the cross wire 12 is initially clamped by the clamping inserts 8, 9 in a clamping area and is thus held. A further application of force by the upper clamping part 7 results in the force acting on the lower clamping insert 9 and the holder 14. The holder 14 begins to move outwards along the guide 18 due to the acting force. This movement continues until an equilibrium of forces is reached by the pre-tensioning of the cross wire 12 in the elastic deformation range.In this equilibrium of forces, the transverse wire 12 has optimal pretension for welding to the bundle of longitudinal wires 11. Thus, in a further step, the welding rams 3 can be positioned against the counterholders 4, so that the transverse wire 12 and the longitudinal wires 11 are held between the welding rams 3 and the counterholders 4, and welding can take place to create the mesh mat 10. Since the movement of the holder 14 or clamping carriage is laterally outward, but also downward, the clamping inserts 8, 9 are designed to protrude to compensate for this.

[0035] Next, the welding rams 3 are first moved vertically back to their starting position. The two upper clamping parts 7 can then also be moved vertically upwards to their starting position, releasing the cross wire 12. Since there is no longer any counterforce, the spring 17 automatically pushes the holder 14 and thus the clamping inserts 8, 9 back to the first operating position. The bundle of longitudinal wires 11 can then be advanced a predetermined distance using a high-precision device, and the next cross wire 12 can be welded on.

[0036] Fig. 9 and Fig. 10 show a further variant of a mesh welding system 1 according to the invention. In this variant, the mesh welding system 1 comprises welding units 2, each with a current conductor 31 or an electrode. This allows the clamping units 5 to be arranged directly in front of the two longitudinal wires 11 terminating on the outside.

[0037] Other design variants comprise more than two clamping units 5, for example four or six clamping units 5. This makes it possible to weld the longitudinal wires 11 to the supplied transverse wires 12 only in selected sections.

Claims

Patent claims 1. A mesh welding system (1) for producing a mesh mat (10) from longitudinal wires (11) and transverse wires (12), wherein the mesh welding system (1) comprises a plurality of welding units (2) with welding rams (3) and counterholders (4), wherein the welding rams (3) and the counterholders (4) are arranged in pairs, wherein the welding ram (3) of a pair is located opposite the counterholder (4), and wherein the welding rams (3) and the counterholders (4) each comprise at least one current conductor (31, 41), so that a transverse wire (12) inserted between the welding rams (3) and the counterholders (4) can be welded to the longitudinal wires (11) located between them when the welding rams (3) and the counterholders (4) are placed against one another, wherein at least one clamping unit (5) is provided for clamping the transverse wire (12) during welding to the longitudinal wires (11). is characterized in that the at least one clamping unit (5), preferably all clamping units (5),are arranged between the welding units (2)., 2. Grid welding system (1) according to claim 1, characterized in that the clamping units (5) are designed with a lower clamping part (6) and an upper clamping part (7).

3. Mesh welding system (1) according to claim 2, characterized in that the lower clamping parts (6) are arranged in a stationary manner and the upper clamping parts (7) can be adjusted to the lower clamping parts (6), in particular by vertical movement.

4. Mesh welding system (1) according to one of claims 1 to 3, characterized in that the clamping units (5) are arranged adjacent to externally closing welding units (2).

5. Mesh welding system (1) according to one of claims 1 to 4, characterized in that the clamping units (5) are designed to clamp the transverse wire (12) in clamping areas and to pre-tension it by tension applied in the clamping areas.

6. Mesh welding system (1) according to one of claims 1 to 5, characterized in that upper clamping inserts (8) are arranged on the upper clamping parts (7) and / or lower clamping inserts (9) are arranged on the lower clamping parts (6) for receiving the cross wire (12).

7. Mesh welding system (1) according to claim 6, characterized in that the clamping inserts (8, 9) have a recess (13) in which the cross wire (12) can be received in a flat manner.

8. Mesh welding system (1) according to claim 6 or 7, characterized in that the clamping inserts (8, 9) are formed from a metal or an alloy, in particular from a steel or copper or a copper alloy, wherein the clamping inserts (8, 9) are optionally coated.

9. Mesh welding system (1) according to one of claims 6 to 8, characterized in that the lower clamping insert (9) is arranged on the lower clamping part (6) projecting in the vertical direction.

10. Mesh welding system (1) according to one of claims 6 to 9, characterized in that the upper clamping insert (8) is arranged on the upper clamping part (7) projecting in the vertical direction.

11. Mesh welding system (1) according to one of claims 6 to 10, characterized in that the lower clamping insert (9) and / or the upper clamping insert (8) are each fastened in a holder (14), wherein the holder (14) is detachably arranged in the clamping unit (5).

12. Mesh welding system (1) according to one of claims 6 to 11, characterized in that the lower clamping insert (9) and / or the upper clamping insert (8) are mounted displaceably, in particular linearly displaceably, between stops (15, 16).

13. Grid welding system (1) according to one of claims 6 to 11, characterized in that one or more springs (17) are provided in the clamping unit (5). and the lower clamping insert (9) and / or the upper clamping insert (8) are mounted so as to be displaceable against a spring force.

14. Grid welding system (1) according to one of claims 6 to 13, characterized in that a first stop (15) defines a first operating position and the lower clamping insert (9) and / or the upper clamping insert (8) can be displaced from the first operating position against one or more acting forces, in particular spring forces, towards the outside of the grid welding system (1) when force is applied.

15. Mesh welding system (1) according to claim 14, characterized in that an outwardly sloping guide (18) is provided, on which the clamping insert (8, 9) or holder (14) slides.

16. Mesh welding system (1) according to one of claims 1 to 15, characterized in that the mesh welding system (1) comprises at least one conveyor unit for feeding longitudinal wires (11) and transverse wires (12) to the welding rams (3, 4).

17. A method for producing a grid mat (10) from longitudinal wires (11) and transverse wires (12), in particular with a grid welding system (1) according to one of claims 1 to 16, wherein a bundle of longitudinal wires (11) and a transverse wire (12) are introduced between welding rams (3) and counterholders (4) of a plurality of welding units (2) and wherein the introduced transverse wire (12) is tensioned, after which the welding rams (3) and the counterholders (4) are brought into contact with the longitudinal wires (11) and the transverse wire (12) lying therebetween and by applying current, the transverse wire (12) is welded to the longitudinal wires (11), characterized in that the transverse wire (12) is tensioned between welding points.

18. Method according to claim 17, characterized in that the transverse wire (12) is tensioned in the elastic deformation region of the transverse wire (12).

19. Method according to claim 17 or 18, characterized in that the transverse wire (12) is gripped by clamping inserts (8, 9) and tensioned laterally outwards.

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