JPH0448548B2 - - Google Patents

Description

Claim 1: A device for performing circumferential welding on a round pipe, the device being able to be attached to the pipe and comprising a rotational drive body for imparting rotational movement about the pipe axis to the welding tool. , two rotary rollers 10 and 12 that are attached to the device and fixedly arranged at a constant interval from each other in the outer circumferential direction, a third drive roller 15 connected to a drive body 16, and a tube. a space between each roller 10, 12, 15 in the cross-sectional direction of the tube 1 and an insertion opening on the side having dimensions larger than the tube 1 when the drive roller 15 is at least partially rotated. A round tube welding device characterized by:

2. Device according to claim 1, characterized in that each fixed roller 10, 12 is designed as a pair of rollers 9, 10: 11, 12, respectively.

3 Each of the above rollers 9, 10, 12, 11, 15
3. The device according to claim 1, wherein the device is mounted on a ball bearing.

4. The device according to any one of claims 1 to 3, characterized in that the welding tool 21 is mounted on a rotatable arm 23.

5. Device according to claim 4, characterized in that the pivot arm (23) is biased by a spring (26).

6. Device according to claim 4 or 5, characterized in that the pivot arm (23) is rotatable about its longitudinal axis (25).

7 Adjustable stop 3 for said arm 23
7. A device according to any one of claims 4 to 6, characterized in that it has 5.

8. Since the welding tool 21 can rotate, especially
Claim 1, characterized in that it is attached to the arm 23 so as to be able to rotate over 360 degrees.
8. The device according to any one of paragraphs 7 to 7.

9 Current and inert gas piping 31, 30, 33,
9. A device according to claim 8, characterized in that 34, 35 pass through the pivot shaft 27.

10. The device according to any one of claims 1 to 9, characterized in that the amount of protrusion from the tube 1 is smaller than 6 centimeters.

11. According to any one of claims 1 to 10, characterized in that it has a removable extension shaft 36 and an additional roller 37 rotatably mounted on the extension shaft. The device described.

12. The rotating arm 13 for the fixed rollers 9, 10, 11, 12 and the drive roller 15 is arranged between the two plate members 3, 4 to which they are removably connected. 12. A device according to any one of claims 1 to 11, characterized in that:

13. Device according to any one of claims 4 to 12, characterized in that the arm 23 of the welding tool 21 is provided with various stops.

14. Apparatus according to any one of claims 4 to 13, characterized in that the arm 23 of the welding tool 21 is removably attached to the apparatus.

15 The arm 23 is provided in the plate members 3 and 4 and can be inserted into a notch that opens toward the outside and opens in the direction of extension of the tube,
15. The device according to claim 14, wherein the device is rotatably held by a notch surrounding the pivot shaft.

16. Device according to claim 15, characterized in that the pivot axis 45 is adjustable in the direction of the tube.

17. Device according to any one of claims 1 to 16, characterized in that the welding tool 21 projects laterally beyond one of the plate members 3, 4.

Description The present invention relates to an apparatus for circumferential welding on round tubes, which can be mounted on the tube and is equipped with a rotary drive for imparting a rotational movement about the tube axis to the welding tool. .

To weld round tubes together, circumferential welds often have to be made. At the same time, the available space around the tube is often very limited. For example, when installing pneumatic transport pipes, it is clearly intended and recommended that these pipes be installed as close to ceilings and walls as possible to avoid taking up unnecessarily large amounts of space. Additionally, several tubes are arranged next to each other so that they line up as close as possible to each other. As a result, the tube cannot be hand welded from all sides. Even more, it is often desirable to avoid the inaccuracies and non-uniformities of manual welding, preferably using automatic equipment.

Therefore, devices are known that have approximately the following mode of operation. The device is partially attached to the tube at the desired location. The part comprises a motor and a maximum longitudinal extension extending perpendicularly from the tube so that the motor can be used simultaneously as a handle. The motor drives a toothed ring of several parts placed around the tube to encircle it. The toothed ring is driven by a motor and a welding tool connected in turn to the toothed ring rotates around the tube, so that a circumferential weld is effected.

On the other hand, a drawback of the above device is that its structure is complex. It is cumbersome to open the toothed ring to position it around the tube and to subsequently close it to continue the toothed ring. Apart from the fact that if the toothed ring consisting of several parts is not complete, problems may arise in the drive through the toothed ring.
Finally, a motor that protrudes vertically from the tube requires a significant amount of space.

The object of the invention is to provide a device of the type mentioned at the outset, which has a similar construction, but operates more reliably and requires less space.

In order to solve the above problems, the device according to the present invention includes two rotary rollers arranged so as to be fixed at a constant interval from each other in the outer circumferential direction, and a third rotary roller coupled to a driving body. possible drive rollers, a space between each roller in the cross-sectional direction of the tube, and, when said drive roller is at least partially rotated, a lateral insertion opening having dimensions larger than the tube. ing.

The device therefore has a space in its center large enough to accommodate the tube. The space is limited to one side by the insertion port,
Further, the width of the insertion opening is larger than the diameter of the tube to be inserted so that the tube can be inserted into the space from here. At the same time, on the opposite side of the insertion port, the tube is
contact with fixed rotating rollers. Following this, the third roller is rotated towards the tube, so that the tube is held at three points by each roller. The third roller is connected to a drive which, when actuated, rotates the entire device around the fixed tube to effect welding.

At the same time, the maximum extension of the motor, which is usually an axial extension, can be parallel to the tube, so that no particularly complex force transmission is required, and the drive roller can be Can be placed directly on the axis.

Each roller must be reasonably long to prevent the welding equipment from tipping. However, it is advantageous to design each roller, in particular each fixed roller, as a pair of rollers. A stable mounting of the device is then obtained if the drive roller is arranged as a single roller between two rollers each consisting of a pair of rollers.

Preferably, each roller is mounted on a ball bearing so that very large driving forces are not required. The drive rollers are also suitably mounted on ball bearings external to the motor, so that the drive shaft of the motor is not subjected to lateral loads that could damage the motor.

Also preferably, the welding tool (welding head) is fixed to the pivot arm, so that the welding head can be easily pivoted away from the tube for checking, adjustment, etc. At the same time, if the pivot arm is spring-loaded, the welding tool can be brought to the desired distance from the workpiece, e.g.
If the protrusion touches the welding tool, as in the case of a damaged pipe, it can still be rotated away. By choosing the spring appropriately, the pivoting arm is not only spring-biased in the direction of the tube in the welding position, but also ensures that the welding tool maintains its position when pivoted away. In the open position, it is biased by a spring in the direction of the open position.

If the pivot arm can also pivot about its longitudinal axis, handling of the device is easier, and in particular the welding head can be accessed more easily.

If equipped with an adjustable stop for the arm, the device can be used for different welding conditions.
Welding heads of different sizes or wear of welding heads can be more easily accommodated. At the same time, on the one hand, the distance between the welding tool and the tube can be adjusted if the pivot arm approaches the stop provided on the frame of the welding device. However, the adjustment stop described above can also be mounted on the pivot arm and be brought into contact with the tube during operation.

If the welding tool is pivotally mounted on the arm, it can be set at different angles with respect to the tube surface, so that, for example, a socket can be welded to the tube. In particular, the welding tool can be rotated through 360° and is therefore particularly flexible in use.

The tubes are suitably welded together by shielded arc welding. At the same time, if the welding tool is rotatably mounted on the arm, if the current and inert gas pass through the axis of rotation, it will be costly and will also prevent the welding tool from rotating. There is no need to add any piping.

The device according to the invention is characterized in that it requires very little space. According to the invention, in its preferred embodiment, the amount of protrusion from the tube is less than 6 centimeters.

It will be appreciated that the above device can be used with tubes of different diameters. This is because the drive rollers can rotate and therefore the spacing between the three rollers welded to the tube can be freely selected over a wider range.

If the pivoting arms for the fixed roller and the drive roller are arranged between two removably connected plates, the above device is suitable especially for tubes of different diameters, i.e. It can also be used for pipes and pipes of fairly small diameter. To weld tubes of considerably larger or smaller diameter than previously, it is only necessary to replace the two plates.

Furthermore, if the device has a removable elongated shaft and an additional roller rotatably mounted on the elongated shaft, the device can It can also be used for tack welding, so that no additional tack welding equipment is required.

If the arm for mounting the welding tool is removably fixed to the device,
It is not even necessary to position the device on the pipe in order to perform the tack weld. For example, the arm together with the welding tool can be removed from the device for the purpose of performing tack welds or for other applications performed manually. In this way, the welding implement described above can be used in a particularly varied and flexible manner.

If said arm is inserted into a notch provided in the plate and open toward the outside and is retained by a notch that opens in the direction of extension of the tube and surrounds the pivot axis, On the one hand, the pivotability of the arm and, on the other hand, the removability are ensured.

At the same time, the pivot arm moves in the direction of the tube.
Alternatively, since it is biased toward the open position by a spring, the spring load acts and as a result of the open notch, it is pressed against the rotation shaft. To remove the arm, it is only necessary to pull it away from the pivot shaft against the spring load. If the pivot axis can also be adjusted in the direction of the tube, the exact position of the welding tool in the direction of tube extension can be easily adjusted.

Finally, various stops can be provided on the arm of the welding tool, which stops define a rest position in which the welding tool is at a greater distance than usual from the pipe to be welded. When said stop is rotated and pushed away, such as by laterally shifting, the welding tool is fixed by yet another stop and corresponds to the ideal distance for welding. get close to it. The second stop can also be placed directly on the pivot arm.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to a preferred embodiment with reference to the accompanying drawings.

In each drawing, FIG. 1 is an end view of the device according to the present invention as seen from the longitudinal direction of the tube, FIG. 2 is a side view of the device in FIG. 1, and FIG. 3 is a welding head and its fixing. 2, FIG. 4 is a detailed view of the welding head pivoting arm stopper seen from the same direction as FIG. 1, and FIG. 2, but showing the device with additionally mounted rollers, and FIG. 6 is a plan view showing another type of mounting of the pivoting arm of the welding tool.

1 and 2 illustrate a tube 1 provided with a weld line 2. FIG.

The device comprises two plate-like members 3 and 4, which partially surround the tube 1. The two plate-like members 3 and 4 are held at a constant distance from each other by several rod-like members 5, 6, 7, and 8. The rollers, in particular the two rollers near each of the plate members 3 and 4, are connected to the rod members 7 and 8.
is installed on. Rollers 9 and 10 are mounted on rod-shaped member 7, and rollers 11 (not shown) and 12 are mounted on rod-shaped member 8, and these rollers are mounted on ball bearings. The drive roller 15 and the drive motor 16 connected to the drive roller 15 have a rotatable lever arm 13;
It is rotatably attached to the rod-shaped member 5 by a bearing 14 disposed on the lever arm.
The rotational position can be set by a bolt 17 rotatably locked to the lever 13 at a portion 19, a spring 18 attached to the bolt 17, and a butterfly nut 20. 18 and butterfly nut 20 interact with an extension 21 attached to the rod-like member 6.

When inserting the tube 1, the drive roller 15 is first rotated upwards by the aforementioned rotation device. Then, after the tube 1 is inserted, the driving roller 15 is connected to the three rollers 10, 12 and 15.
is rotated downwards again until it contacts the tube in three places, so that the welding device can rotate around the tube once the motor 16 is activated.

Welding is performed by a welding head 21, which is supplied with inert gas and welding current through a hose 22. At the same time, the welding head 21 is mounted on a welding arm 23 which is rotatably mounted at a point 24 so that it can be pivoted upwards in FIG. At the same time, the rotation shafts 24 can be sequentially rotated around a rotation shaft 25 that is perpendicular to the rotation shafts 24 and attached to the plate-like member 3. As a result, as shown in FIG. The rotating arm 23 can not only be rotated upwardly, but also in the direction of the viewer, that is, in the lateral direction.

By means of a tension spring 26 attached to the plate 3 and the welding arm 23, the welding arm 23 and, therefore, the welding tool 21 are pulled downwards, in other words towards the tube. In the open position, by choosing the mounting position of the spring 26 appropriately, it can be ensured that the welding arm 23 remains in the open position.

Specifically, as shown in FIG. 3, the housing 23, which is separated at the bottom, is provided with an annular protrusion near the holes 27 and 28. The welding head 21 is located between the annular protrusions 55. The welding head 21 is held by a threaded member 56 which can rotate freely relative to the parts 23, 25 and is screwed into a corresponding threaded hole in the welding head 21. Inert gas is conducted through conduit 30-35, said conduit 30-3
5 branches into two conduits 54 within the housing 23, and each conduit 54 opens into an internal hole 58 of an annular projection 55. The threaded member 56 has an L-shaped hole 57, and when gas flows from the conduit 54 to the internal hole 58, it passes through the L-shaped hole 57 to the center of the welding head 21. hole 5
It can flow within 9. From here, gas can then flow out towards the outside of the welding head 21. The electrical connections from the welding head 21 to the power source are made in a similar manner, with the parts in contact with each other being electrically conductively connected to each other. In this way, the welding head 21 can be adjusted to different rotational positions without the use of hoses or wires and at the same time without impairing its rotational properties.

In FIG. 4, the device for adjusting the distance between the welding head 21 and the pipe to be welded is a plate member 4.
rather, it is supported directly by the tube to be welded. The reason for this is that in this way the distance from the tube to the welding head 21 can always be the same, even if the tube to be welded does not have an exact cylindrical shape. For this purpose, a plate 53 is provided which is assisted by a thumb screw 52 attached to the arm 23 of the welding head. By turning the thumbscrew 52, the plate 53 can be adjusted vertically in FIG. 4, thereby adjusting the distance between the welding head 21 and the tube.

The device shown in FIG. 5 differs from the embodiments previously described in that an additional shaft can be mounted on the rod-shaped member 7 or 8 by extending the rod-shaped member 7 or 8. Regarding the above-mentioned additional shafts, an additional shaft 36 for the rod-shaped member 7 is shown in FIG. At the shaft end of each of the additional shafts are located additional rollers, one of which is indicated at 37, also mounted on ball bearings. The cylindrical surface of the added roller corresponds to the extension of the cylindrical surface of each roller on the corresponding rod-shaped members 7 and 8. The mode of operation of this device is
It is as follows. If a further tube 39 is to be attached to an already completed section of the piping system (represented by tube section 38 in FIG. 5), tack welding must first be carried out. For this purpose, the device according to the invention is placed at the end of an already completed section 38 of the pipeline so that the welding head 21 is located at the section of the tube end 40 with which the new tube 39 is butted. Install. Arrange so that each fixed roller is located at the bottom. In this position, the rollers 15 are rotated and tightened so that the device is fixed to the tube end. Two additional shafts for the rods 7 and 8 are fitted, one of which is indicated at 37 in FIG.
9 form a support surface for the new tube 39 in such a way that they fuse together at the seam 40 without shifting. Then a tack weld is made on the bottom. Subsequently, the device is rotated 180° so that a tack weld is made on the top. Furthermore, when subsequently forming a continuous weld line, the additional shaft 36 can be removed again.
This is also necessary when welding near bent pipes, etc.

In the embodiment of FIG. 6, the pivot arm 23 of the welding tool 21 is mounted on the plates 3 and 4 and on the outside in a manner similar to the previously described embodiments (see, for example, FIG. 1). It is guided by notches 43 and 44 which are open toward the opposite direction. At the rear (i.e. the part remote from the welding tool 21), the arm 23 is provided with a transverse projection 44 having a notch opening towards the rear, the projection 44 having an L-shaped turn. The pivot shaft 45 can be stowed, so that its front end, and thus the pivot shaft 45, can be shifted forwards or backwards by means of a butterfly nut or the like. As a result, the rotating arm 23 can be easily removed from the device by pulling it forward and upward. On the other hand, the rotating arm 23 can be reattached to the device by pushing the notch of the protrusion 44 onto the rotating shaft 45.
This position remains stable because the spring 26 (see FIG. 2) exerts a rearwardly directed force.