INTERNAL WELDING OF PIPES AND PROFILES

Abstract

The invention relates to a device (1) for the internal welding of pipes and profiles, comprising a cantilever arm (2, 2a), which is secured to a suspension (3), which cantilever arm can be inserted into the pipe or profile to be welded and on which a welding head (4) is displaceably attached, the cantilever arm (2, 2a) further comprising at least one laser (5) and at least one camera (6). To avoid the disadvantageous effects of magnetism and heat on the position of the welding head (4), the invention proposes that a laser (5) is attached on the suspension (3), and a camera (6) for observing the laser beam (5a) is attached on the end of the cantilever arm (3) or on the welding head (4). A correction signal is calculated from the change in position of the laser beam (5a) observed with the camera (6) and forwarded to a control unit for adjusting the welding head (4) by means of displacement devices (8, 9).

Claims

1. Device (1) for internal welding of pipes and profiles, comprising a cantilever arm (2, 2a) which is attached to a suspension (3), which can be inserted into the pipe or profile to be welded and on which a welding head (4) is movably attached, wherein the cantilever (2.2a) further comprises a laser (5) and a camera (6), characterized in that a control device for moving the welding head (4) is present, one or more lasers (5) are attached to the suspension (3), one or more cameras (6) are attached to the welding head (4), wherein one or more laser beams (5a) are respectively directed at, and recognizable by the one or more cameras (6), an evaluation module is present, which is configured to evaluate changes (dX, dY) in the relative positions (X,Y) of the laser beams (5a) detected by the one or more cameras (6), to generate a signal from the changes in the relative position and to transmit the signal to the control device for moving the welding head (4).

2. Device according to claim 1, characterized in that two lasers (5) and two cameras (6) are attached.

3. Device according to claim 1 or 2, characterized in that the or each camera (6) is a matrix camera.

4. Device according to one or more of claims 1 to 3, characterized in that a projection surface (7) is arranged in the beam path between the one or more lasers (5) and the one or more cameras (6).

5. Device according to claim 4, characterized in that the projection surface (7) is a transparently colored plate.

6. Device according to one or more of claims 1 to 5, characterized in that additional sensors are present and connected to the evaluation module.

7. Device according to claim 6, characterized in that at least one of the additional sensors is a height sensor.

8. Method for moving a welding head (4) in a device (1) according to one or more of claims 1 to 7, comprising at least the following steps: detecting initial values (X, Y) of the position of the or each laser beam (5a) with the or each camera (6) in an initial state of the device (1), detecting deviations (dX, dY) in the position of the or each laser beam (5a) from the initial values (X, Y) during operation of the device (1), generating a signal for the control device from the detected deviations (dX, dY), forwarding the signal to the control device, which moves the welding head (4) as a function of the signal (8, 9) so that that the deviations (dX, dY) become smaller.

9. Method according to claim 8, characterized in that additional measured values or data from additional sensors are used to generate the signal.

10. Method according to claim 8 or 9, characterized by detecting initial values of the welding head position in an initial state of the device (1).

Description

[0026] Further features and details of the invention are set forth in the patent claims and the following description of the exemplary embodiment of the invention shown in the drawing. It is shown in:

[0027] FIG. 1 a schematic diagram of a possible embodiment of the device according to the invention in a plan view and a side view.

[0028] In the shown device 1, a cantilever arm 2 is attached to a suspension 3. The pipe or profile to be welded is not shown because it is not necessary for understanding the invention. However, the device 1 can be imagined as being situated in the middle of a pipe or profile. A deflection of the cantilever 2 as a result of magnetism or the effects of temperature is indicated by the dashed lines 2a. In the top view in the horizontal direction, in the side view in the vertical direction. At the end of the cantilever 2, a welding head 4 is mounted for movement in the vertical and horizontal directions perpendicular to the axis of the cantilever 3, wherein the welding head 4 itself is not shown. Two lasers 5 are attached to the suspension 3. The respective laser beams 5a are directed at two cameras 6 which are fastened to the end of the cantilever arm 3. In the beam path between the laser 5 and the camera 6, a plate 7, transparently colored, preferably in white, is attached, wherein a plate 7 can of course also be provided for each laser camera pair. The plate 7 serves as a projection surface for the laser beams 2a, for easy recognition of the laser beams by the cameras 6 as a point 7a and tracking of their relative positions in the horizontal X and vertical X directions. The deviations dX and dY are calculated from the different positions. Using a processor (not shown) and corresponding software, together an evaluation module, a signal is generated from the deviations and fed back to the control unit (also not shown). The control unit controls displacement devices 8 (vertical) and 9 (horizontal), which adjust the welding head 4 in such a way that the deviations dX and dY become smaller or, ideally, disappear. A laser beam point 7a can be seen in the detailed view of plate 7, which laser beam point, seen from camera 6, has deviated from a position X, Y to a position X+dX, Y+dY as a result of the deflection 2a.

[0029] In the shown example, the length of the cantilever 2 is given as 30 m. This is not to be understood as a limitation but is only intended to give an idea of the possible orders of magnitude. Of course, the lengths can be both shorter and longer. A possible torsion is not indicated in this drawing.

LIST OF REFERENCE NUMERALS

[0030] 1 internal welding device [0031] 2 cantilever [0032] 2a deflection of the cantilever [0033] 3 suspension [0034] 4 welding head [0035] 5 laser [0036] 5a laser beam [0037] 6 camera [0038] 7 projection surface [0039] 8 displacement device vertical [0040] 9 displacement device horizontal