DE8810131U1 - Welding device with sensor arrangement - Google Patents

Description

Weakening with sensor arrangement

The invention relates to a welding device with a sensor arrangement pre-oriented in the welding direction and rotatable about the axis of the welding torch for automatically monitoring and controlling the welding sensor position and the length of a welding line to be scanned, in particular in conjunction with an industrial robot.

Arrangements of this type are known, for example, from EU-A-01 08 539. In this state of the art, the welding torch is firmly _connected to the receiving head of the sensor arrangement, whereby this receiving head is mounted and driven in a housing so as to be rotatable about the longitudinal axis of the welding torch, which is connected to the end member of an industrial robot. The rotatability of the receiving head of the sensor arrangement has the purpose of allowing the scanning device of the sensor arrangement, which is arranged in front of the welding torch in the welding direction, to follow the theoretically predetermined welding path, regardless of the direction in which the path runs.

The fixed arrangement of the welding torch in the sensor assembly's mounting head means that the welding torch with the hose package attached to it must follow every rotary movement of the sensor's mounting head. Such rotary movements can be up to 360°. This results in considerable disadvantages. Firstly, the swivel drive for the sensor's mounting head has to accelerate a large mass and must be dimensioned accordingly. The rotation of the welding torch

As mentioned, this also affects the twisting of the hose package, which generates restoring moments, which in turn result in a positional offset of the sensor measurement value. Apart from this, the constant torsional stress on the hose package results in high levels of wear due to the twisting of the hoses.

The invention is therefore based on the object of finding a concept for the arrangement of welding torch and sensor which does not have the disadvantages mentioned and offers the possibility of connecting the welding torch and its hose package without any problem to the handling device, in particular an industrial robot, in order to avoid influences on the sensor values.

Based on the above-mentioned prior art, the essence of the invention is that the welding torch is arranged in a stationary manner in a housing held by an industrial robot or the like and the receiving head of the sensor arrangement is mounted and driven so as to be rotatable about the axis of the welding torch.

This inventive concept has numerous advantages. First of all, it is possible to use welding torches of standard types from well-known manufacturers. Due to the stationary arrangement of the welding torch, its hose package is also stationary. Its connection to the handling device, in particular the industrial robot, can be laid out in a defined manner according to the available space. Twisting and the resulting restoring forces cannot occur in the hose package of the welding torch according to the invention.

The mounting of the sensor head on the welding torch can be designed so precisely that on the one hand, a perfect centering of the welding torch and on the other hand, an exact position

mounting head to the welding torch.

As part of one embodiment of the invention, it is provided that the energy supply (e.g. signal/air and current supply) to the recording head of the sensor arrangement takes place via a cable spiral guided around the axis of rotation of the recording head or through openings arranged in the housing. This cable spiral can, for example, be a cable band which is wound around a stationary pin of the welding torch and is connected with one part to the fixed control unit and the other end to the scanning unit of the sensor arrangement. The relative rotation of this sensor arrangement with respect to the fixed welding torch, even with a 360° rotation, only leads to a loosening of the cable spiral without affecting its connection to the evaluation and control unit.

In one embodiment of the invention, the mounting of the sensor arrangement's receiving head is carried out by a double mounting in the housing and by an additional mounting on the part of the welding torch on the weld seam side. This ensures that even with a greater overall length of the receiving head and the welding torch, the receiving head is perfectly centrally guided.

In the drawing, the invention is shown in side view using an embodiment. Here, (1) merely symbolically designates the end part of an industrial robot or other handling device. A housing (2) is attached to this end part (1), which holds the welding torch (3) with its hose package (4) in a fixed position. The end part (1) of the industrial robot, the housing (2) and the welding torch (3) with its hose package (4) thus form a physical unit.

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The receiving head (5) is rotatably mounted in the housing (2) via the bearings (6) so that the axis of rotation (13) of the receiving head (5) coincides with the longitudinal axis of the welding torch (3) . An additional bearing (7) is located at the weld seam end (14) of the welding torch (3) opposite the receiving head (5) of the sensor.

The sensor's recording head (5) carries a device in front of the welding torch (3), viewed in the welding direction, that scans the area around the weld seam to be formed, for example a CCD camera (19) and laser elements (12). This scanning device, which can be of any design, is adjusted to the theoretical welding line using a standard, pre-designed robot control (IS). The recording head (5) can therefore be rotated about the rotation axis (13). Due to the advanced position of the scanning device (camera (19), laser element (12)) relative to the rotation axis (13), a swivel adjustment of the scanning device is required if the welding line deviates from the straight line.

This swivel adjustment is generated by a swivel gear (10) that is operated by a drive (9) that is located inside the housing (2). The swivel gear (10) rotates the sensor's pickup head (5) around the rotation axis (13). The individual phases of this rotation are pre-programmed and stored in the IR control. If, despite this swivel movement, an incorrect setting occurs due to the scanning of the area around the welding line, this is forwarded to the control of the industrial robot via the scanning device, e.g. laser element (12), and a correction of the robot position or path is effected.

Because the welding torch (3) with its hose package (4) is fixed in the housing (2) and thus cannot move relative to the end member (1) of the industrial robot, a flexible energy supply must be present between the sensing element, e.g. laser element (12), sensor electronics camera, of the recording head (5) of the sensor and the housing (2) or the end member (1) of the industrial robot, because the recording head (5) is rotatably mounted in the housing (2). This flexible energy supply is made possible by a cable spiral (8) which is connected to the control unit (17) on the robot side (15). The cable spiral (S), which can be designed as a ribbon cable, for example, is guided in a spiral around a pin (16) of the stationary welding torch (3) and is connected to the recording head (5) and thus to the sensor electronics via the energy supply (11).

Hit (20) are openings arranged in the housing (2) which enable a signal, air and/or power supply to the welding torch (3) or to the receiving head (5).

The drive (9), which is arranged in the housing (2), drives the sensor's recording head (5) via the belt drive (10) in a rotary movement around the rotation axis (13). This drive movement is pre-programmed.

From the example embodiment, it can be seen that the sensor's mounting head (5) can be rotated by any angle without affecting its energy supply. Since the welding torch (3) remains stationary and rigidly connected to the end member (1) of the industrial robot during each rotation of the mounting head (5), all of the disadvantages mentioned at the beginning are avoided.

parts list

1 End link industrial robot

2 housings

3 welding torches

4 Hose package

5 Sensor pickup head

6 Storage

7 Storage

S Kä&eläpxjiäie

9 Drive

10 Belt transmission

11 Energy supply

12 Laser link

13 Rotation axis

14 Weld side end of the welding torch

15 robot side 15 pins

17 Sensor control

18 Robot control IS CCD camera

20 through holes

Claims (4)

1) Welding device (3) with a sensor arrangement (5) arranged in the welding direction and rotatable about the axis (13) of the welding torch (3) for automatically monitoring and controlling the welding torch position along a welding line to be scanned, in particular in conjunction with an industrial robot, characterized in that the welding torch {3} is arranged in a stationary manner in a housing (2) held by the industrial robot (1) or the like and the receiving head (5) of the sensor arrangement is mounted and driven so as to be rotatable about the axis (13) of the welding torch (3). 2) Welding device according to claim 1, characterized in that the energy supply (e.g. signal, air and current supply) to the receiving head (5) of the sensor arrangement takes place via a cable spiral (8) guided around the axis of rotation (13) of the receiving head (5) or through passage openings (20) arranged in the housing (2). 3) Welding device according to claim 1 or 2, characterized in that the hose package (4) leading to the welding torch (3) is firmly connected to the associated part of the industrial robot. 4) Welding device according to claim 1 or one of the following, characterized in that the receiving head (5) of the sensor arrangement is rotatably mounted in the housing (2) and on the weld seam-side part (14) of the welding torch (3)