SI24845A - A welding device and a welding procedure - Google Patents

Abstract

The invention relates to a welding device and welding process for welding tapes comprising a belt control system, a tensioning system, a drive system and a welding system, wherein the tensioning system is designed to exert mechanical stresses at least during the welding process in the welding region.

Description

Welding device and welding process

The invention relates to a welding device and a welding process for welding strips of metal or plastic, in particular endless strips.

When making strips of metal or plastic, it may be necessary for the two strips to be welded together along their longitudinal axis. So far, these strips have been laid next to each other, routed and welded together in a device in the floor area.

The disadvantage of the state of the art is that the routing process and the welding process are expensive and time-consuming, and thus stresses can later form in the welded strips, leading to material fatigue.

The object of the present invention is to eliminate the disadvantages of the prior art and to present a welding device and a welding process by means of which the user can optimally weld two strips to each other.

This task is solved by a welding device and a welding process according to claims.

The relative position data used below are interpreted each time in the intended direction of movement of the strip moving in the welding device. When e.g. cylinder 1 arranged in front of cylinder 2, i.e. the area of the strip passing through the welding device always passes first past cylinder 1 and then cylinder 2.

The welding device according to the invention for welding strips comprises a strip guide system, a tensioning system, a drive system and a welding system, the tensioning system being designed to expose the strips to stresses at least during the welding process in the welding area.

The welding process according to the invention for welding strips with a device according to the invention comprises the following steps:

- guiding at least two strips in the welding machine,

- tensioning of the strips in the welding area,

- longitudinal welding of at least two strips along their longitudinal axis, preferably at the edges facing each other, while the strips are taut,

- moving the strip stepwise or continuously with respect to the welding system, while the welding process of the taped strip continues stepwise or continuously.

The strips can be made of any material, but they must be weldable. The strips preferably contain plastics and / or metals. In particular, both strips are made of the same material (eg metal alloy). Even though the invention in the simplest case serves to connect two strips, it is advantageous in certain applications if three or more strips are connected at the same time. In particular, the invention relates to the connection of the strips along their longitudinal axis and preferably at their respective edges facing each other so as to form a wide strip as a final product.

Suitable welding systems are known to the person skilled in the art and contain at least one welding unit ('welding head'). Of course, they must be suitable for longitudinal welding of used strips. Preferred welding systems comprise welding units of the group of welding devices with heating surfaces, heating wires, heating rollers and laser, arc welding devices and welding devices in protective atmosphere (eg manual arc welding devices with coated electrode in protective atmosphere, welding with insoluble tungsten electrode in inert gas (TIG welding) or plasma welding).

According to a preferred embodiment, the welding system is arranged in the welding device so that the welding head runs parallel to the longitudinal axis of the strips (possibly overlapping longitudinal edges) and can be welded together and / or the strips are guided under the welding head. The welding head and the strips can thus be mounted stationary or movable in the welding device, the at least the welding head or strips being movable.

The guide system is designed to guide the strips through the welding device. The tensioning system and / or the drive system can be part of the control system, the reverse is also true that the tensioning system or. the propulsion system may be designed as a control system or contain it. Preferably, the guide system comprises a holding structure and guide elements arranged therein (eg rollers or rounded sliding elements).

The drive system is designed to move the strips and / or at least one welding unit of the welding system. Preferred drive systems comprise motors (eg electric motors or internal combustion engines) and movable drive rollers or axles by means of these motors (possibly via a gearbox). The drive system may also contain guide elements and is thus part of the control system or comprises part of the control system.

In a preferred embodiment, the rollers of the tensioning system move and serve as a drive. Thus, the tensioning system may be part of or comprise the drive system.

In a further preferred embodiment, which can be combined in particular with the previous one, at least one welding unit can be moved parallel to the longitudinal axis of the strips, in particular during the welding process.

The tensioning system is necessary in order to expose the strips to mechanical stress in the welding area at least during the welding process. Although this mechanical stress can be reduced when welding is not performed, it is nevertheless advantageous for the quality of the strip connection if the stress is maintained throughout the time period in which the strips are run side by side.

According to a preferred embodiment, the tensioning system comprises tensioning rollers through which the strips are guided, wherein at least one of the tensioning rollers is arranged in front of the welding area and at least one of the tensioning rollers is arranged behind the welding area. These tensioning rollers may form part of the guidance system and / or drive system.

In rotating rollers, in principle, there is torque between their jacket and their axis. For non-driven cylinders, this torque is always caused by braking based on the effect of friction and will be referred to below as the "braking torque". In driven cylinders, the driving torque prevails over the braking torque, so the resulting torque will be referred to as the “driving torque”.

In addition, there is always friction between the rollers and the conveyor belt above them, which during normal running, in which the roller jacket moves at the same speed as the belt, is pure bonding with an adhesive coefficient R.

The force applied to the tape by contacting the tension roller is a force determined by the torque of this tension roller. The direction of the force vector in question is in the direction of the belt movement (driving force) at the driving moment and exactly the opposite (braking force) at the braking torque.

According to a preferred embodiment, the coefficient of adhesion between the tensioning roller and the strip is greater than 0.3, in particular greater than 0.5. This is achieved in particular by the surface of the sheath of the tensioning rollers being made of a material or in a form which prevents the straps from slipping. Preferred materials are plastics (eg rubber), leather or rubber. Preferred forms are surface roughness or coatings of fine-grained granules which adhere to the tensioning roller with an adhesive.

According to a preferred embodiment, the welding device is designed so that the normal force caused by the strip on the tensioning roller at at least one point of the sheath of this tensioning roller is greater than the weight of the strip acting on this roller, preferably greater than 105%, especially greater than 110 %, in particular preferably greater than 130%.

This is preferably achieved by pressing the straps against the tensioning rollers via the compression rollers or by making the straps endless straps which are tensioned between the tensioning rollers. For example, tensioning between two tensioning rollers is performed so that the tensioning rollers are spaced apart by a distance of about half the entire length of the belt (of course by deducting each half the diameter of the tensioning rollers) and that the belt is tensioned between them.

The tensioning of the at least one strip is preferably achieved such that the resulting force vector from the force vector by which the tensioning roller acts on the strip behind the welding area, reduced by the force vector by which the tensioning strip acts on the strip in front of the welding area, points in the opposite direction. This means that the tension roller in front of the welding area must be braked harder or driven weaker than the tension roller behind the welding area. Thus, the strip in question is pulled towards the front roller in the welding area and thus tensioned.

According to a preferred embodiment, the welding device comprises a measuring system for measuring the voltage of at least two strips. Suitable measuring devices for this measuring system are known to the person skilled in the art, preferably this measuring system is designed to obtain its data from the tensioning rollers. The measuring system comprises, in particular, measuring devices for measuring the strength of electric current or energy and / or force acting on the axis of the tensioning rollers. In this way, the tension of the belts can be determined from the data on the magnitude of the force of the belts pressing on the rollers or the magnitudes of the torques of both rollers (measurement of driving force by the current of driving electric motors or current produced by a dynamo installed on rollers).

According to a preferred embodiment, the tension rollers in front of and / or behind the welding area are designed to touch only one of the strips and can rotate independently of the other rollers. In this way, the tension of the individual belts can be regulated by braking / driving or subsequently adjusting the position of the roller axes.

According to a preferred embodiment, the welding device is designed to weld endless strips along their length. For this purpose, at least one of the strips, in particular each strip, is made non-slip with a transverse weld, and the strips are then guided in a welding device and welded lengthwise to each other along their sides.

According to a preferred embodiment, the strips are guided in an endless state in the guide system next to each other and are tensioned in the welding area. For the purpose of welding, the welding head is guided along the longitudinal axis (especially the overlapping longitudinal edges) of the strips and these are welded to each other and / or the endless strips are guided under the (especially stationary) welding head.

The welding device is preferably designed so that its guide system is designed to guide endless strips and in particular has at least two rollers arranged so that the strips are guided with a predetermined voltage around the rollers so that they flow around.

In the simplest case, two tension rollers are oriented at a certain distance with parallel axes so that the strips run around the tension rollers like a caterpillar.

According to a preferred embodiment, the welding device comprises at least one support roller arranged in the welding area, in particular directly below the welding point, the welding strips being guided above the support roller. In this way, the strips are supported by a support roller during the welding process at the welding site. This prevents the strips from hanging at the welding site and ensures extremely precise guidance of the strips at the welding site.

The support roller is preferably arranged to cause the strips to rise, its jacket being closer to the welding unit when the rest of the strip guide feeds these strips (forming a lift opposite adjacent sections of the strip).

According to a preferred embodiment, the welding device comprises cylinders designed to drive both longitudinal edges of the strips for mutual welding to each other. This allows a welding process in which the two longitudinal edges of the strips to be welded together approach each other and then welded, the strips preferably approaching to such an extent that they touch in the area of the welding site. These rollers are in particular drive rollers and / or tension rollers.

According to a preferred embodiment, the welding device comprises rollers, in particular at least one drive roller and / or at least one tension roller, which are formed conically. This allows a welding process in which the longitudinal edges of the strips (especially the endless strips) are driven towards each other by means of these conically formed rollers.

Preferably, the rollers are formed in such a way that they have a smaller cross-sectional radius in the area of the roller in which the strips are welded than outside this area.

In the case where the strips are guided through a single cylinder, it has a larger radius, especially on its front sides, and a smaller radius in its middle.

If the strips are guided by separate rollers, at least one of these rollers shall have a minimum radius on its front side facing away from the welding edge of the strip in question and a minimum radius on its front side facing the welding edge of the strip in question. .

The radius of the cross section of the cylinder is preferably changed constantly so that the cylinder has partial areas in the form of truncated cones. The inclination of the tires with respect to the longitudinal axis of the roller is preferably less than 10 °, in particular less than 2 °, so that the rollers of the formations are only slightly conical.

In a preferred embodiment, the device also comprises (possibly additionally) conical cylinders, the shape or whose orientation is exactly the opposite of those described above. Thus, the belts may eventually be pulled apart, or one compression roller may have this “negative shape” to concentrate the stresses caused by the conical shape of the rollers in the belts in the center of the belts.

Examples of preferred embodiments of the device according to the invention are shown in the figures.

Figure 1 schematically shows a simple preferred embodiment in perspective,

Figure 2 schematically shows a preferred embodiment in a side view,

Figure 3 schematically shows a further preferred embodiment in a side view,

Figure 4 schematically shows a further preferred embodiment in perspective,

Figure 5 schematically shows a further preferred embodiment in a side view,

Figure 6 schematically shows a preferred embodiment with conical rollers.

Figure 1 schematically shows a simple preferred embodiment in perspective. The two strips 1, which are designed here as endless strips, are welded to each other along adjacent outer edges by means of a welding system 2. Meanwhile, the straps are guided, tensioned and moved forward by means of the active rotation of the rollers by means of tensioning rollers 3. The tension rollers 3 thus in this case serve as guide elements, tension elements and drive elements.

Figures 2 and 3 schematically show a preferred embodiment according to Figure 1 in a side view. While the strips 1 are welded to each other by means of the welding system 2, they are tensioned by means of tensioning rollers 3 at least in the welding area. The arrow above the strip 1 determines the possible direction of movement of the strips 1. In the continuous welding process, the strips can move continuously when in a sequential welding process it is advisable to move with pauses. During the welding process, it is also possible to move the welding system itself along the strip.

The tension in Figure 2 is achieved by a force pulling apart the tension rollers 3 (arrow on the rollers). The arrows in question do not show movement, but the relative force with which the two tensioning rollers 3 are pulled apart and thereby tension the strips 1. In such an embodiment, the strips 1 are tensioned both above in the welding area and below.

In Figure 3, the tension is achieved by the different torque of the tension rollers 3. The rounded arrows here illustrate that the torques of both tension rollers and thus also the forces with which the sheaths of the tension rollers 3 act on the strips 1 are different. For example, the force difference can be achieved by driving one tensioning cylinder 3 harder than the other tensioning cylinder 3 or even by braking the front of the tensioning rollers 3 (left). Here, the strips would be tensioned in the welding area (above) and there would be no tension in the lower area.

Figure 4 schematically shows a further preferred embodiment in perspective. As in Fig. 1, here the two strips 1, which are also designed here as endless strips, are welded to each other along the adjacent outer edges by means of a welding system 2. The strips are guided by means of tension rollers 3. A special example of tensioning is the guide via the support roller 5 in the welding area. This can achieve more precise guidance of the strips 1 in the welding area.

Figure 5 schematically shows a further preferred embodiment in a side view. In this embodiment, the strips 1 are not necessarily infinite. The tension rollers, which can also be used for guidance and drive, move with different torques, as in Figure 3. Additional compression rollers 4 prevent the strips 1 from slipping by increasing the adhesion between the strips 1 and the tension rollers 3 by increasing the normal force on straps and tensioning rollers. Here, too, the strips are welded together by means of a welding system 2.

Figure 6 schematically shows a preferred embodiment with conical rollers. The figure is a cross section showing the strips 1 on the conical rollers 3 from the front. The rotary axis of the tension rollers 3 lies parallel to the plane of the paper. Both arrows illustrate the inclination of the strips 1 to approach each other in the middle. This is due to the shape of the tension rollers 3.

If these conical rollers 3 were to be used in the embodiment according to Figure 1 or 4, they could take the place of the tensioning rollers 3 shown above without further ado.

Embodiments illustrate possible embodiments of the invention, it being noted that the invention is not limited to the specific embodiments of the invention, but various combinations of individual embodiments are possible, and this possibility of variations is due to technical knowledge in the field of the present invention. has an expert in the field.

Furthermore, the individual features or combinations of features of the various embodiments shown and described may also constitute stand-alone and inventive solutions according to the invention.

The problem solved by stand-alone inventive solutions is contained in the description.

All indications of value ranges in the present description should be understood as including all their optional and partial ranges.

Above all, the individual designs shown in the figures can be the subject of independent inventive solutions. The respective tasks and solutions according to the invention are contained in the detailed descriptions of these figures.

Finally, it should be noted that due to a better understanding of the structure, certain components of the images may not be partially scaled and / or enlarged and / or scaled down.

List of reference marks

Track

Welding system

Tensioning roller

Compression roller

Claims (12)

Patent claims A strip welding apparatus comprising a strip guide system, a tensioning system, a drive system and a welding system, the tensioning system being designed to expose the strips to mechanical stresses at least during the welding process in the welding area. Welding device according to Claim 1, characterized in that the welding system comprises at least one welding unit, in particular a TIG welding unit, which is arranged in the welding device so that at least one welding unit runs parallel to the longitudinal axis of the strips. and these can be welded together and / or the strips can be guided under at least one welding unit. Welding device according to one of the preceding claims, characterized in that the tensioning system comprises tensioning rollers through which the strips pass, at least one of the tensioning rollers being arranged in front of the welding area and at least one of the tensioning rollers being arranged behind the welding area , these tensioning rollers being in particular part of the guidance system and / or propulsion system. Welding device according to claim 3, characterized in that the coefficient of adhesion between at least one tensioning roller and at least one strip is greater than 0.3, wherein the surface of the tensioning roller shell is made of a material or in a form that prevents the strips from slipping. in particular of plastic, leather or rubber or in the form of a surface roughness or coatings of fine-grained granules adhering to the tensioning roller with an adhesive. Welding device according to one of the preceding claims, characterized in that the welding device is designed in such a way that the normal force on the tension roller caused by the belt is greater at least at one point of the shell of this tension roller than the weight of the belt acting on this roller , the straps being pressed against the tensioning rollers in particular via the compression rollers and / or the straps being endless straps tensioning between the tensioning rollers. Welding device according to one of the preceding claims, characterized in that the welding device comprises a measuring system for measuring the voltage of at least two strips, said measuring system being preferably designed to obtain its data from tensioning rollers. Welding device according to one of Claims 3 to 6, characterized in that the tensioning rollers in front of and / or behind the welding area are designed to touch only one of the strips and can rotate independently of the other rollers. Welding device according to one of the preceding claims, characterized in that the welding device is designed such that its guide system is designed to guide endless strips and in particular has at least two rollers arranged so as to guide the strips with a predetermined voltage around the cylinders so that they flow around. Welding device according to one of the preceding claims, characterized in that it comprises at least one support roller arranged in the welding area, in particular directly below the welding point, the welding strips being guided above the support roller. Welding device according to one of the preceding claims, characterized in that the welding device comprises rollers designed to drive both longitudinal edges of the strips for mutual welding to each other, the rollers of the formations being particularly conical, of which in particular at least one drive roller and / or at least one conical tension roller. Welding method for welding strips with a welding device according to one of the preceding claims, comprising the steps of: - guiding at least two strips in the welding machine, - tensioning of the strips in the welding area, - longitudinal welding of at least two strips along their longitudinal axis, preferably at the edges facing each other, while the strips are taut, - moving the strip stepwise or continuously with respect to the welding system, while the welding process of the taped strip continues stepwise or continuously. Welding method according to Claim 11, characterized in that the welding device is designed to weld endless strips along their length and at least one of the strips, in particular each strip, is made endless with a transverse weld and the strips are then guided in the welding devices and are welded lengthwise to each other along their sides.