ES2360355T3 - FLEXIBLE GUIDE FOR A WELDING WIRE WITH INDIVIDUAL ELEMENTS ARTICULATED IN ANY ADDRESS ONE WITH REGARD TO OTHERS. - Google Patents

Abstract

Flexible guide, in particular for a welding wire, formed by a plurality of individual elements (10) connected together in an articulated manner, the individual elements (10) being able to pivot with respect to each other in any direction, characterized in that each individual element (10) it is provided with a first and a second pair of guide rollers (96, 98), the axes of rotation of the first pair being oriented approximately perpendicular to the axes of rotation of the second pair, the support axes being fitted by at least two guide rollers (96, 98) in the body of the individual element (10) and the guide rollers (96, 98) being inserted in the body of the individual element (10) from the outside.

Description

The present invention relates to a flexible guide, in particular for a welding wire, according to the preamble of claim 1 (see, eg, FR 2 888 825). 5

This guide can be used to guide the welding wire used by a welding robot between a container for the welding wire and the welding head. The guide must be flexible so as not to prevent the movements of the welding head. In addition, the guide must ensure that the welding wire cannot bend, since the folds in the welding wire would interrupt the automated welding process. Finally, the guide must protect the welding wire against dirt and, in case of electric welding, if necessary, it must protect against contact with other objects to avoid a short circuit.

A large part of the problems that occur during automated welding is due to the friction of the welding wire that occurs within the guides, in which the welding wire is guided from the weld wire container to the drive rollers from the wire feeding device and from there to the welding head. Friction causes abrasion marks and deformations to occur on the surface of the welding wire. In electric welding, this results in a reduction in conductivity, problems with the arc and a reduction in welding quality. If the chips generated by friction or the lubricating agent used to reduce friction adhere to the surface of the welding wire, this results in irregular feeding of the welding wire, obstruction of the guides and problems with the voltaic arc on the welding head. If the welding wire, in its path from the weld wire container to the welded head-20 ra, bends excessively hard, the bending point that then leads to the welding head causes the voltaic arc to run next to the point where the welding wire should really be, which requires subsequent and expensive rectifications.

To avoid abrasion marks on the surface of the welding wire, attempts have already been made to use guides for welding wires made of plastic. However, the welding wire is cut due to the plastic wrap after a comparatively short time, so that considerable problems occur during feeding. In aluminum welding wires and / or an aluminum alloy or in welding wires with a passivated surface, abrasion marks on the surface of the welding wire can cause considerable problems with the welding power. All these problems underline the importance of a low friction feed of the welding wire to the welding head. 30

WO 2007/010171 A2 presents an example of a flexible guide for welding wires. This guide consists of different individual elements, each individual element being connected to the adjacent individual element by means of a rotating bearing, which allows movement only around a certain axis. Support rollers or similar structures of the guide for the welding wire are installed inside the base bodies of the individual elements. This solution, as a whole, has a very high construction effort and therefore very high costs.

Thanks to US-A-2,483,760 a guide is known for an electric cable that can be placed, for example, in a crazy motor. A base body is provided in which four support blocks can be installed, which are fixed with a screw respectively. Each support block has two holes for support shafts, in which a guide shaft is arranged respectively. 40

The objective of the invention is to create an economic guide for a welding wire that allows guiding the welding wire with low resistance and reduced costs.

For this purpose, according to the invention, a flexible guide is provided, in particular for a welding wire, formed by a plurality of individual elements connected together in an articulated manner, the individual elements being able to pivot with respect to each other in any direction, each individual element being provided with a first and 45 second pair of guide rollers, the rotation axes of the first pair being oriented approximately perpendicular to the rotation axes of the second pair, the support axes of at least two guide rollers in the body of the individual element and the guide rollers being inserted in the body of the individual element from the outside. This allows the use of universal individual elements that do not have to be placed next to each other in a determined order during assembly. fifty

Preferably, the individual elements are connected to each other by way of a spherical joint. This allows, in particular, the individual elements to fit together simply by inserting a spherical head of an individual element into a spherical bearing of the adjacent individual element.

Preferably, each individual element is provided with a structure of the guide for the welding wire that allows a low friction movement of the welding wire within the guide. The structure of the guide, according to the invention, is formed as several rolling bodies housed in the individual body, for example cylindrical balls or rollers.

According to a preferred embodiment, a flexible envelope is arranged around the guide, for example a flexible plastic tube. This prevents dust or other dirt particles from entering the guide and causing greater friction.

Other advantageous configurations of the invention emerge from the dependent claims.

Next, the invention is described by various examples and embodiments represented in the accompanying drawings.

- Figures 1 show a guide according to a first example, which does not fall within the claims;

- Figures 2 show a guide according to another example, which does not fall within the claims;

- Figures 3 show a guide according to a third example, which does not fall within the claims;

- Figures 4 show a guide according to a fourth example, which does not fall within the claims; 10

- Figures 5 show a guide according to a fifth example, which does not fall within the claims;

- Figure 6 shows a guide according to an example, which does not fall within the claims;

- Figures 7 show a guide according to a seventh example, which does not fall within the claims;

- Figures 8 show a guide according to an eighth example, which does not fall within the claims;

- Figures 9 show a guide according to a ninth example, which does not fall within the claims; fifteen

- Figure 10 shows a guide according to an embodiment of the invention;

- Figure 11 shows the guide of figure 10, showing an open individual element;

- Figure 12 shows a half of an individual element for the guide of figure 10; Y

- Figure 13 shows schematically a guide according to a tenth example, which does not fall within the claims. twenty

A guide is shown in Figure 1, in particular for a welding wire, composed of several individual elements 10. Each individual element has a body 14 with a spherical head 12 and a spherical bearing 16. The spherical bearing 16 (see also figure 1b) is configured in such a way that it can be inserted into the spherical head 12 of an adjacent individual element 10, that is to say, it automatically engages in it. In this way, a succession of several individual elements can be created which together forms the guide for the welding wire (see figures 1c, 1d and 1e).

In this case, each body 14 is formed by a base body 18 (see figure 1f) and an extension piece 20. The extension piece 20 is placed in the base body 18 in the area where the spherical head is then formed 12. Under the area covered by the extension piece 20 there are three notches 22 formed in the base body 18 (see Figures 1f, 1h, 1i and 1j). In each notch 22 a ball-shaped rolling body 24 is inserted (see figure 1k). The three three balls 24 define a guide structure for a welding wire 26 that is guided within the individual elements 10. The extension piece 20 ensures that the balls 24 cannot leave the recesses 22 outwards.

As can be seen in Figures 1c to 1e, each individual element 10 can pivot with respect to the adjacent individual element in the respective spherical joint. In this way, the guide of the welding wire formed by the 35 individual elements can be flexibly adapted to the path required at all times. The structure of the guide for the welding wire formed by the balls 24 ensures that it is guided with little friction within the guide, without high friction, the welding wire is scratched, nor can the individual elements be damaged. .

The length of the spherical bearing and / or the skirt of the base body 14 forming the spherical bearing is calculated in such a way that the maximum pivotability of an individual element with respect to the adjacent individual element is limited, namely, to the extent that the welding wire that runs along the bent guide to the maximum only comes into contact with the guide structure and not with the base bodies. This ensures that it is guided smoothly and that the base bodies are not destroyed.

The welding wire guide shown is characterized by a particularly compact structure. With a diameter of 45 of the welding wire of 1.9 mm, balls with a diameter of 4 mm can be used. The spherical head has an outside diameter of 11 mm, and the maximum diameter of the individual element is 16 mm with a total length of approximately 20 mm. Thanks to the interaction of the spherical bearing 16 with the spherical head 12, the individual elements are connected to each other in such a compact manner that no additional protection against dust penetrating from outside, etc. is necessary. fifty

A guide of the welding wire according to a second example is shown in Figure 2. For the known components of the previous example the same reference numbers are used, and in this sense it refers to the explanations

Previous songs

The difference with respect to the first example lies essentially in the configuration of the structure of the guide for the welding wire. In this case, five balls 24 are used as guide structure, which are inserted in a peripheral housing 30 (see Figure 2a). An opposite surface 32 (see figure 2b) is formed in the extension piece 20, which fits into an interlocking ring 34 of the base body 14. The extension piece 20, together with a surface suitably shaped in the body base 14, forms the spherical head 12 of the individual element 10. The balls 24 together form the structure of the guide for the welding wire 26 (see in particular Figure 2c), which is guided by the balls with little friction within the individual elements 10, even when the guide formed by the individual elements has a relatively tight curvature, as shown in Figure 2c. In this embodiment, the length of the spherical bearing and / or the skirt of the base body 14 that forms the spherical bearing 10 is also calculated such that the maximum pivotability of an individual element with respect to the adjacent individual element is limited , namely, to the extent that the welding wire that runs along the bent guide to the maximum only comes into contact with the structure of the guide and not with the base bodies.

Another example is shown in Figure 3. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations. fifteen

The example according to figure 3 differs from the example shown in figure 2 essentially in that a tread ring 40 made of a wear-resistant material is inserted into the base body 14. This acts in a manner similar to the rolling ring of a ball bearing and is completed by a counterpiece 42 that is placed on the raceway 40. The raceway 40 and the counterpart 42 are made of a wear-resistant material. You, for example steel. In the base body 14, the raceway ring 40 and the counterpart 42 are supported by the extension piece 20, which is placed on the base body 14. In this embodiment, the spherical head 12 of the base body 14 is also formed by the extension piece 20 together with a conveniently shaped base body surface section. The spherical bearing 16 corresponds to that of the first and second example. The structure of the guide for the welding wire formed in the third example corresponds essentially to the structure of the known guide of the second example. 25

A fourth example is shown in Figure 4. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations.

The example according to Figure 4 differs from the second example essentially in that for the structure of the guide, rolling bodies in the form of balls are not used, but rolling bodies in the form of cylindrical rollers 50. These are arranged opposite each other in pairs, the second pair being rotated 90 ° with respect to the first pair (see Figures 30 4a, 4b and 4c). The cylindrical rollers 50 of the first pair are supported on the cylindrical rollers 50 of the second pair. In the base body 14, guide surfaces 52 are formed for the cylindrical rollers 50 of the first pair (see figures 4d to 4f), while in the extension piece 20 opposite guide surfaces 54 (see figures 4g and 4h) are provided. As can be seen in Figure 4i, the cylindrical rollers 50 are held opposite each other in the base body when the extension piece 20 is placed on the base body 14. In this way, a structure 35 of the base body is defined the guide for welding wire 26.

It could also be envisaged to insert the rolling bodies into small flanges and / or clip-shaped bearing surfaces.

A fifth example is shown in Figure 5. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations.

The fifth example differs from the previous examples in that a closed ring 60 made of a low friction material, for example ceramic, is used as a guide structure for the hard solder wire. The ring 60 is fixedly anchored in the base body 14, in particular it is already cast in it. Thus, the spherical head 12 is only formed by the base body material 14. The ring 60, on its inner surface, has a rounded contour that widens with a gentle curvature to each side starting from the narrowest cross section cha. In this way, regardless of the angle at which the welding wire is guided by the ring 60, a smoothly rounded guide surface is achieved.

A simplified example using known rings 60 of the fifth example is shown in Figure 6. Each ring is provided with a peripheral recess on both sides on which a short tube section is placed. This tube is made of an elastically deformable material, for example plastic, in such a way that mobility in all directions is guaranteed. Therefore, each individual element is formed by a ring and a tube section. Unlike the previous 50 examples, in this case the mobility is not provided by the movement of a fixed individual element with respect to the adjacent one, but the elasticity of the individual elements, which ultimately results in a mobility of the individual elements with respect to each other.

A seventh example is shown in Figure 7. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations. 55

The seventh example differs from the fourth example in that the rolling bodies in the form of cylindrical rollers 50 are mounted on shafts 70. These are inserted behind clamping flanges 72 in the base body 14 and behind clamping flanges 74 in the workpiece. extension 20. On the one hand, the rolling bodies 50 can rotate freely

on shafts 70 with less friction. On the other hand, the axles can rotate freely with less friction between the clamping flanges and the base body and / or the extension piece. This guarantees a guide structure for the welding wire that works smoothly also when dirt accumulates in the area of the guide structure. Even when one of the support points, rolling body / axle and axle / clamping flanges, becomes harder due to dirt, the rest of the support point can continue to rotate with little friction. 5

The extension piece 20 is held in the base body 14 by two interlocking flanges 76.

According to a variant not shown, the rolling bodies can also be provided with small supporting appendages that are held behind the clamping flanges. In this case, the supporting appendages rotate behind the clamping flanges.

An eighth example is shown in Figure 8. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations.

The eighth example differs from the seventh example in that both pairs of cylinder-shaped rolling bodies are housed in an intermediate ring 80, which is provided with clamping flanges 72 and / or 74.

A ninth example is shown in Figure 9. For the known components of the previous examples the same reference numbers are used, and in this sense it refers to the previous explanations. fifteen

The ninth example differs from the eighth example in which the extension piece 20 has been removed. Instead, the intermediate ring 80 housing the rolling bodies has been configured so large that it forms the upper half of the spherical head 12. It is held in the base body 14 with two large interlocking flanges 76.

As a material for the base body 14 and also for the extension piece 12, plastic, preferably polyamide, is particularly suitable. In principle it is also possible to manufacture the base bodies with another material, for example metal or wood.

The second, fourth and seventh to ninth examples are especially suitable for the structure of the welding wire guide from the weld wire container to the transport rollers for the welding wire, that is, in the area where The welding wire is stretched. There it is important to provide a guide structure with bearings in the curvatures of the welding wire guide, since this reduces friction. 25 In this area of the welding devices, the dimensions of the welding wire guide are also not excessively important, such that the slightly larger outer diameter of the guide, due to the rolling bodies to be housed, does not have importance. In the area between the transport rollers and the welding head, the welding wire guide is preferably used according to the fifth example. There, the welding wire is pushed, so that the resulting friction is of secondary importance. On the other hand, the smaller outer diameter of the welding wire guide 30, which can be achieved thanks to the ring 60 fabricable with small dimensions, is of great importance.

An embodiment according to the invention is shown in Figures 10 to 12. In this embodiment, the welding wire guide is formed by a plurality of individual elements 10 coupled together in an articulated manner, namely, by a spherical joint-shaped connection, which allows the individual elements 35 to move in a determined distance from the adjacent individual element and also rotate about its longitudinal axis.

Each individual element 10 consists of two halves 90, joined together with a clip to form an individual element 10. Each half 90 has a section of quicionera 92, which extends in peripheral direction in 180 ° and a section of quicionera 94 that also It extends 180 °. In the embodiment, as can be seen in the figures, for the articulated connection between the individual elements no spherical segment is used that contains a maximum circle of the ball, but only a spherical layer is used, considered mathematically as head of bearing, which does not contain the maximum circle of the respective ball and is housed in a small section of quicionera.

As a guide structure for the welding wire, a total of four guide rollers 96, 98 are arranged on each individual element 10, which are placed opposite each other in pairs. Each guide roller is provided with a rotation axis, the rotation axes of the two guide rollers 96 being oriented perpendicular to the rotation axes of the two guide rollers 98. The rotation axes can be formed in one piece with the guide rollers or be separate components in which the guide rollers are introduced.

Both guide rollers 96 are housed in two separate halves 90 of the respective individual element. Instead, the guide rollers 98 are respectively housed in one of the halves 90 of the respective individual element. For this purpose, there are provided quick snap hooks 100 which, according to the invention, allow the respective guide roller to be inserted into the individual element from the outside, so that it automatically fits into it.

Within each individual element 10 guide surfaces 102 for the welding wire are provided, which ensure that the welding wire can be introduced into the guide. The guide surfaces ensure that the welding wire can be pushed through the individual elements placed one after the other without the more forward end of the welding wire being hooked anywhere.

In the embodiment according to the invention it is especially advantageous that the individual elements have a more or less square cross-section, in this case with rounded corners. The guide rollers 96, 98 protrude above the outer surface of the respective individual element, but not above a circular line, whose center is located in the central axis of the respective individual element and runs through the four corners of the cross section. This allows a coating to be placed on the guide, for example a plastic tube, so that dirt cannot enter the series of individual elements, which could impair the smooth movement of the guide rollers. In this sense, the guide rollers cannot come into contact with the inner wall of the lining, since they only protrude slightly above the outer surface of the respective individual element. This ensures that unwanted friction does not occur when the guide rollers rotate.

Another advantage of the embodiment according to the invention is that the guide rollers are visible from outside 10 when the coating is removed from the guide of the welding wire and therefore can be inspected without separating the individual elements from each other or even without disassembling them. . It is also advantageous that the guide rollers can be made with a larger diameter than for example in the case of the seventh example, since they are not completely housed within the individual elements, but can protrude above their outer surface . The large diameter of the guide rollers results in low friction, since the larger guide rollers rotate better than the smaller ones.

The assembly of the individual elements and the assembly of the individual elements to become a chain is carried out as follows: First, the two guide rollers 96 are placed in a half 90 of an individual element. Then, the second half is placed and fixed to the first half, so that the two guide rollers 96 are housed between both halves 90. The fixing of both halves with each other is carried out by means of suitable nailing means, in this case by means of flanges or clips 104. To position the two halves in front of each other, small positioning means (not shown) are provided, for example projections and cavities. Next, the guide rollers 98 are attached with clips to the two halves or have been previously mounted on them. Then, a half 90 of the following individual element is placed on the individual element already finished in such a way that its bearing head, composed of two sections of bearing head 94, rather, the segment formed of the spherical head 25, is housed in the section of quicionera 92 of the half 90 placed. After placing the second half 90, the segment of the bearing head of the previously assembled individual body is housed and held in the quicionera of the newly assembled individual body formed by the two sections of the quicionera 92. A special advantage is that the elements Individuals are fixed to each other inseparably. Unlike the previous embodiments, in which the spherical head of an individual element is inserted into the spherical bearing of the adjacent individual element 30 and can be removed again from it by applying a conveniently large force, the individual elements of the tenth form They are placed in a positive connection with each other, so that they can only be released again, separating the two halves 90.

The maximum angle of rotation of an individual element with respect to the adjacent individual element is determined by placing the opposite ends of the adjacent individual elements next to each other. Regardless of the rotation, each individual element can freely rotate about its longitudinal axis with respect to the adjacent individual element. Therefore, during operation, all the individual elements are oriented differently (but statistically evenly distributed), such that the welding wire is correctly and uniformly guided independently of the respective curvature of the guide.

A tenth example is shown schematically in Figure 13. This differs from the previous examples in that the individual elements 10 are no longer coupled to each other by authentic articulation, but only support each other in an articulated manner. For this purpose, each individual element is provided, at one end, with a cavity of the joint 120, on which a projection of the joint 122 of the adjacent individual element 10 rests. The surfaces turned against each other of the cavity of the joint 120 and of the projection of the joint preferably have the same curvature or at least essentially the same curvature. The front 124 of the individual elements are made in the form of a conical trunk, so that the individual elements can pivot with respect to each other without the projection of the joint having to be released from the cavity of the assigned joint. The joining of the individual elements in the longitudinal direction is guaranteed by a lining 126, which holds the elements arranged at the end of the chain formed by the individual elements and can apply the necessary retention force even in the longitudinal direction. As a coating, for example, a flexible fabric tube 50 or a plastic tube can be used.

As a guide structure, in the eleventh embodiment, guide rollers 96, 98 are also used which face each other in pairs. These are inserted from the outside into suitable housing openings and are held therein, for example, by interlocking flanges that act on the support shafts.

In the longitudinal direction, a channel for the welding wire limited by 55 guide surfaces 102 is extended for each individual element, which in turn is interrupted by the guide rollers 96, 98.

According to a variant not shown, instead of the projection of the joint in the individual elements a spherical head can be used, which fits into a suitable articulated quicionera of the adjacent individual element.

Claims (10)

1. Flexible guide, in particular for a welding wire, formed by a plurality of individual elements (10) connected to each other in an articulated manner, the individual elements (10) being able to pivot with respect to each other in any direction, characterized in that each individual element (10) is provided with a first and a second pair of guide rollers (96, 98), the axes of rotation of the first pair being oriented approximately perpendicular to the 5 axes of rotation of the second pair, the axes of support of at least two guide rollers (96, 98) in the body of the individual element (10) and the guide rollers (96, 98) being inserted in the body of the individual element (10) from the outside. 2. Flexible guide according to claim 1, characterized in that the individual elements (10) are connected to each other in an articulated manner as a spherical joint. 10 3. Flexible guide according to claim 2, characterized in that each individual element (10) has a spherical bearing (16) at one end and a spherical head (12) at the other end. 4. Flexible guide according to claim 3, characterized in that the spherical head of an individual element (10) is embedded in the spherical bearing (16) of an adjacent individual element (10). 5. Flexible guide according to claim 3 or claim 4, characterized in that the spherical head (12) is formed by an extension piece (20) placed in the base body (14) of the respective individual element (10). 6. Flexible guide according to claim 3 or claim 4, characterized in that the spherical head (12) is formed by an extension piece (20) in combination with a spherical segment-shaped part of the respective individual element (10). 7. Flexible guide according to claim 1, characterized in that the individual element (10) is formed by two halves fitted together. 8. Flexible guide according to one of the preceding claims, characterized in that the guide rollers (96, 98) protrude above the outer surface of the individual element (10). 9. Flexible guide according to one of the preceding claims, characterized in that each individual element (10) has a square cross-section, if necessary with rounded corners, and that the guide rollers 25 (96, 98) do not protrude above a line circular that runs through the four corners of the individual element (10). 10. Flexible guide according to one of the preceding claims, characterized in that the base body (14) is made of plastic.