Apparatus and Method for Butt-Welding Workpieces

Abstract

A butt-welding device and a method for butt welding workpieces, especially for double-upset resistance-pressure butt-welding of workpieces, particularly wires, strands and profiles, has first and second clamping members for receiving the ends of the workpieces that are to be joined. At least one clamping means can be moved between a starting position and a welding position. At least one deburring tool is provided for deburring the welded workpiece ends. In addition, at least one sensor is provided to determine the geometric dimensions of the workpieces that are to be joined, especially the diameter, the width or the height in the joining plane or substantially parallel thereto, wherein a control unit controls the movement of the clamping members and/or of the deburring tool as a function of the geometric dimension.

Claims

1. A butt-welding device (10) for butt welding workpieces (3, 4), particularly wires, strands and profiles, said device comprising: first (1) and second (2) clamping members for receiving ends (13, 14) of the workpieces (3, 4) that are to be joined, wherein at least one clamping member (1, 2) is configured to be moved between an initial position and a welding position; at least one deburring tool (5, 6) for deburring the workpiece ends (13, 14) after the workpiece ends are welded; at least one sensor (7, 8) configured to determine a geometric dimension of the workpieces (3, 4) selected from the group consisting of: diameter, width, height, and a combination thereof, in the joining plane or in a plane substantially parallel to the joining plane; and a control unit (19) configured to control movement of the clamping members (1, 2) and/or movement of the deburring tool (5, 6) as a function of the geometric dimension(s).

2. The device (10) according to claim 1, wherein the at least one sensor (7, 8) is a displacement sensor.

3. The device (10) according to claim 1, wherein each deburring tool (5, 6) is associated with one respective clamping member (1, 2) and is configured to be moved together with the associated clamping member (1, 2).

4. The device (10) according to claim 3, wherein, the deburring tool is configured to be moved in a same direction of motion of the associated clamping member.

5. The device (10) according to claim 1, wherein the deburring tool is adjustably held on a holder that is optionally connected to one the clamping member.

6. The device (10) according to claim 1, wherein each clamping member (1, 2) has two axially adjustable clamping jaws (15, 16, 17, 18) between which the workpiece (3, 4) can be clamped.

7. A method for double-upset resistance butt-press welding of workpieces (3, 4), comprising: a) inserting the workpieces (3, 4) having ends (13, 14) and defining end cross sections at the ends that are to be joined into respective first and second clamping members of a butt-welding device, b) bringing to a welding site defining a joining plane the ends (13, 14) of the workpieces (3, 4) that are to be joined, c) determining with at least one sensor at least one geometric dimension of the workpieces (3, 4) selected from the group consisting of: the diameter, width, height, and a combination of diameter, width or height, in the joining plane or substantially parallel to the joining plane before butt welding, d) butt welding the end cross sections of the ends (13, 14) of the workpieces (3, 4) that are to be joined, e) upsetting the weld (11) of the butt-welded workpiece (3, 4) at an elevated temperature in order to enlarge the cross section of the weld, f) reducing the enlarged cross section of the weld to a prescribed end cross section of the workpiece (3, 4) of with at least one deburring tool (5, 6), and g) actuating the at least one deburring tool (5, 6) as a function of the geometric dimension(s) of the workpieces (3, 4) that are to be joined.

8. The method according to claim 7, wherein for workpieces (3, 4) that are to be joined that have different geometric dimensions, the at least one deburring tool (5, 6) employed is associated with the workpiece (3, 4) having the larger geometric dimension.

9. The method according to claim 7, wherein: the at least one deburring tool (5, 6) is associated with at least one clamping member (1,2).

10. The method according to claim 7, wherein the at least one clamping member (1, 2) is moved independently of the deburring tool (5, 6).

11. The device (10) according to claim 1, wherein the workpieces comprise wires, strands and/or profiles.

12. The method according to claim 7, wherein the workpieces comprise wires, strands and/or profiles.

Description

DESCRIPTION OF THE DRAWINGS

[0031] In this context, the following is shown, at times schematically:

[0032] FIG. 1 the butt-welding device with two clamping members, without inserted workpieces,

[0033] FIG. 2 the device as shown in FIG. 1, with inserted workpieces, whereby the workpiece having the relatively larger diameter is situated on the right-hand side of the device,

[0034] FIG. 3 the device as shown in FIG. 2, whereby the workpiece having the relatively larger diameter is situated on the left-hand side of the device,

[0035] FIG. 4 the device as shown in FIG. 2, in a detailed view,

[0036] FIG. 5 method steps a) to j) for butt welding workpieces in a first arrangement, and

[0037] FIG. 6 method steps a) to j) for butt welding workpieces in a second arrangement.

DETAILED DESCRIPTION

[0038] For the sake of clarity, identical components or those having the same effect are provided with the same reference numerals in the figures shown and described below.

[0039] FIG. 1 shows a butt-welding device 10 without inserted workpieces 3, 4. Examples of workpieces 3, 4 for carrying out the method according to the invention employing a device 10 according to the invention as shown in FIGS. 2 to 6 comprise wire conductors 3, 4 or wires. These are unwound, for instance, from a supply coil and then fed hydraulically or pneumatically to clamping jaws 15, 16, 17, 18 that can be moved axially relative to each other and that are part of a first and second clamping member 1, 2 that can also serve to supply current.

[0040] Each of these clamping members 1, 2 having the clamping jaws 15, 16, 17, 18 is associated with a wire 3, 4, especially a wire end or workpiece end 13, 14 that is clamped by means of the clamping members 1, 2. The clamping members 1, 2 can be moved relative to each other between the resting position and the welding position, for instance, by means of a drive 9, so that the clamped wire ends 13, 14 can be moved towards each other horizontally until the wire ends 13, 14 meet. Naturally, it can be alternatively provided (in an embodiment not shown here) that the clamping members 1, 2 are aligned in such a way that they can be moved in the vertical direction.

[0041] The clamping jaws 15, 16, 17, 18 are used to butt weld wire ends 13, 14 of the wires 3, 4 that were previously neatly cut and that are to be joined to each other in a known manner (German Preliminary Published Application DE-OS 25 41 022). The welding burr 21 that is formed during the welding is likewise removed in a known manner (German Preliminary Published Application DE-OS 25 41 022) by the relative movement of the clamping jaws 15, 16, 17, 18 with the deburring tools 5, 6 that are arranged on them.

[0042] After the butt welding, the joint or weld 11 is upset at an elevated temperature, for instance, at least 450° C., in order to bring about a cross section enlargement, for example, of at least 40%.

[0043] The welding current needed for the welding procedure can be fed into the wire 3, 4 via the clamping jaws 15, 16, 17, 18 that are each arranged on the clamping members 1, 2.

[0044] Once the wire ends 13, 14 have been heated up in the edge areas by the welding current, the clamping members 1, 2 are moved once again relative to each other, a process in which the wire ends 13, 14 are joined and a welding burr 21 is formed around the weld seam or joint 11. The individual method steps are described in detail in FIGS. 5 and 6.

[0045] The deburring tools 5, 6 each comprise blade carriers 22 that are arranged on the clamping members 1, 2 and that have deburring blades 20 arranged on them. The deburring tools 5, 6 in the case here are fastened to the clamping members 1, 2 by screws. The blade carriers 22 can be moved together with the clamping members 1, 2 essentially parallel to the wire direction over the weld seam or joint 11.

[0046] If the deburring tool 5, 6 is always moved over the weld seam 11 exclusively from one side, completely irrespectively of the geometric dimensions of the workpieces 3, 4, as is the case in the state of the art, then drawbacks arise that are overcome by the device according to the invention and by the method according to the invention. After all, before the deburring tool 5, 6 starts the deburring procedure by means of the control unit 19, the sensors 7, 8 determine at least one geometric dimension—in the joining plane or essentially parallel thereto—of the workpieces 3, 4 that are to be joined.

[0047] In the present embodiment, the diameter of the wires 3, 4 that are to be joined is determined by means of the sensors 7, 8. However, it is likewise conceivable for the width or the height in the joining plane or essentially parallel thereto to be determined, especially in the case of profiled parts.

[0048] The sensors 7, 8 employed can be a displacement measuring system that measures a displacement employing potentiometric, optical or mechanical means, for instance, a cable control. It is likewise conceivable to use a displacement pickup consisting of a glass rod marked with a series of ultrafine lines that are optically scanned.

[0049] These sensors 7, 8 determine the geometric dimension of the workpieces 3, 4 in the joining plane or essentially parallel thereto. For instance, the sensors 7, 8 can be used to measure the necessary distance between each of the associated clamping jaws 15, 16, 17, 18 for clamping the workpieces 3, 4, so that the diameter of the appertaining wire 3, 4 can be determined on the basis of this data. The precision of this measurement can between at about 1/10 mm.

[0050] In this context, the sensor 7, 8 is arranged on the side at the top on a so-called jaw carrier, that is to say, on a mount of the device 10 for the clamping members 1, 2, as can be seen in FIGS. 1 to 3.

[0051] Particularly in order to re-adjust the deburring tool 5, 6, for instance, the deburring blade 20 arranged on the deburring tool 5, 6, the latter is adjustably held on a holder or blade carrier 22 that is optionally connected to the clamping member 1, 2. In this manner, the deburring tool 5, 6 can be re-adjusted, for example, if it shows signs of wear and tear that would cause to the properties of the deburring tool necessary for the deburring such as, for instance, the sharpness of the deburring blade 20, to no longer be sufficient.

[0052] The method steps for butt welding workpieces 3, 4 will be explained below on the basis of FIGS. 5 and 6.

[0053] FIG. 5 a) to j) depicts the method steps for butt welding two wires 3, 4, whereby in the present embodiment, the wire 3 that was inserted into the device 10 on the left-hand side 23 has a smaller diameter than the wire 4 that was inserted on the right-hand side 24.

[0054] Specifically, in the butt welding of the wires 3, 4 being presented here, the following steps are carried out: FIG. 5 a) inserting the first wire 4 into the device 10, b) securing the wire 4 by means of the clamping jaws 15, 16 of the first clamping member 1. Subsequently, in step c), the second wire 3 is inserted into the device 10 and then, in step d), clamped in place by means of the clamping jaws 17, 18.

[0055] Then, as shown in FIG. 5 e), the welding procedure takes place in a familiar manner. Subsequently, the weld is released in steps e) to h) so that the deburring procedure can take place.

[0056] Once the sensors 7, 8 have determined that the wire 4 that, in the present embodiment had been inserted on the right-hand side 24, has the relatively larger diameter than the other wire 2, the sensors 7, 8 emit a signal to this effect to the control unit 19. Then the clamping member 2 associated with the right-hand side 24 of the device 10, in other words, the side having the larger wire diameter, is moved in order for the deburring procedure to be carried out, as is shown in FIG. 5 i).

[0057] Finally, the clamping members 1, 2 release the welded wire; see FIG. 5 h).

[0058] The butt welding takes place in a manner similar to the case in which the wire 3 having the larger diameter is inserted on the left-hand side 23 instead of on the right-hand side 24 of the device 10. Consequently, the method steps of FIG. 6 a) to f) correspond to those of FIG. 5 a) to f).

[0059] Subsequently, the deburring is carried out as depicted in FIG. 6 f) to i). Since the wire 3 having the larger diameter was inserted on the left-hand side 23 of the device 10, the deburring is carried out from the left-hand side 23, as can be seen in FIG. 6 g) to i). Finally, in this embodiment as well, the welded wire 3, 4 is released and can then be removed; see FIG. 6 j).

[0060] Of course, it can also happen that the wires 3, 4 that are to be joined together do not display any, or else merely insignificant, differences in terms of their geometric dimensions, especially of the wire diameter. In this case, deburring always takes place from the right-hand side 24 of the device. Of course, as an alternative, it can also be provided for the left-hand side 23 to be actuated as a standard procedure.

[0061] In the embodiment according to FIGS. 5 and 6, the first wire 4 was first inserted onto the right-hand side 24 of the device 10. As set forth in the invention, however, it is also conceivable for the first wire 3, 4 to first be inserted on the left-hand side 23 of the device 10. In such a case, the method steps according to FIGS. 5 and 6 would be carried out analogously.

LIST OF REFERENCE NUMERALS

[0062] 1 first clamping member [0063] 2 second clamping member [0064] 3 workpiece [0065] 4 workpiece [0066] 5 deburring tool [0067] 6 deburring tool [0068] 7 sensor [0069] 8 sensor [0070] 9 drive [0071] 10 device [0072] 11 weld [0073] 12 stop [0074] 13 workpiece end [0075] 14 workpiece end [0076] 15 clamping jaw [0077] 16 clamping jaw [0078] 17 clamping jaw [0079] 18 clamping jaw [0080] 19 control unit [0081] 20 deburring blade [0082] 21 welding burr [0083] 222 blade carrier [0084] 23 left-hand side [0085] 24 right-hand side