JPS5914309B2 - Vertical welding method for inner and outer surfaces of pipes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is capable of longitudinally welding the inner and outer surfaces of a pipe to be welded, respectively, while moving a traveling cart carrying an arc welding head for the inner surface and an arc welding head for the outer surface in the axial direction of the pipe to be welded. The present invention relates to a method for vertical joint welding of inner and outer surfaces of pipes to be welded.

Generally, when manufacturing pipes (mainly circular pipes) by bending thick steel plates, the pipe to be welded and the welding head are moved relative to each other in the longitudinal direction (in the axial direction of the pipe), while the inner and outer surfaces of the pipe are bent vertically. It is welded continuously.

In this case, if the welding head is fixed and the pipe is moved, the weight of the pipe will increase as the pipe becomes longer or larger in diameter, making it unavoidable that the pipe moving device will become larger. . Furthermore, in order to prevent the formation of defective welds during welding, it is necessary to make the relative speed between the tube and the welding head as uniform as possible, so if the tube is moved, the speed will be extremely high. A powerful mobile device is required. Moving the pipe has the disadvantage that it is troublesome to create a pipe moving device and increases production costs, so generally the pipe is fixed during welding, and the welding head is often configured to move in the longitudinal direction of the pipe. . Conventionally, in this type of welding method, as shown in FIG. An external welding head 15 is supported on a traveling carriage v which supports a guide rail 2' and runs on a guide rail 2'.

To perform welding, first insert the inner surface welding head 7 into the inside of the pipe to be welded located at the welding position W1, perform vertical joint welding on the inner surface of the pipe, and then turn the pipe approximately 180 degrees at that position. The tube is rotated to position the position to be welded at the top, and longitudinal joint welding of the outer surface of the pipe is performed using the outer surface welding head 15.
Conventionally, longitudinal welding of the inner and outer surfaces has been carried out using a device such as that shown in FIG.
The tube is moved to the welding position, rotated approximately 180 degrees, the position to be welded is located at the top, and the welding head 15 performs longitudinal joint welding on the outer surface. However, these methods are uneconomical because it is necessary to arrange one traveling carriage for inner welding and one for outer welding. In addition, in the device shown in Fig. 1, the tube loading and unloading directions are limited to the Xl, X2, and Y2 directions, and in the device shown in Figure 2, the tube loading and unloading direction is limited to the X1 direction or the X2 direction for the welding position light. Since the pipes are limited, handling of the pipes is inconvenient, and installation is sometimes difficult, especially when welding equipment needs to be installed in an existing building. In addition, in FIG. 1, if the traveling trolley 1'' for the outside surface is sufficiently retracted in the X1 direction or the X2 direction, and the traveling rail 21 is placed sufficiently downward (Z1 direction), the pipe to be welded It can also be transported to the side of the traveling truck f, but in this case, the traveling rail 2'' becomes longer than necessary, and various methods are required to prevent the traveling rail, the pipe to be welded, and the pipe handling device from interfering with each other. It was a hassle because it required consideration. SUMMARY OF THE INVENTION An object of the present invention is to propose a vertical joint welding method for inner and outer surfaces of a pipe that eliminates the above-mentioned conventional drawbacks.

Embodiments of the present invention will be described in detail below with reference to the drawings.
3 to 6 show an apparatus for carrying out the method of the present invention. In these figures, reference numeral 1 denotes a running cart with a drive source that runs on a guide rail 2. One end of the elongated beam 3 is carried and a frame 4 is supported.

A guide roll 5 is pivotally supported at the lower part of the free end of the long beam 3, a support roll 6 which can be raised and lowered is rotatably supported, and a welding head 7 for the inner surface is supported. Note that in the present invention, the term "welding head" refers to the welding torch 8 and the welding torch position adjustment device 9, but may also include the feeding device 12 for the welding wire 11 in some cases. There is also. The position adjustment device 9 is a well-known device that adjusts the position of the welding torch up and down, left and right, and front and rear as necessary. A device that can be adjusted to the desired angle is used. Reference numeral 13 denotes a pipe to be welded, which is provided with a groove 131 into which the guide roll 5 is fitted, and is disposed at the inner welding position W1 so that its axis is substantially parallel to the moving direction of the traveling carriage 1.

A tab plate 13a is temporarily attached to the end of the joint portion of the pipe 13 as necessary to prevent welding defects at the end. Reference numeral 14 denotes an auxiliary trolley that supports the support roll 6 in order to position the free end of the long beam 3 up and down when the guide roll 5 comes off the pipe to be welded 13;
Reference numeral 5 designates an external welding head supported by the frame 4, and the welding head 15 is supported so as to be movable up and down in the vertical direction (Z direction) and movably adjustable in the longitudinal direction (Y direction).

It should be noted that the welding torch 16 of the welding head 15 for the outer surface is different from the welding torch 8 of the welding head 7 for the inner surface than the pipe to be welded 13.
are arranged with a corresponding distance 1 in a direction perpendicular to the axis of. Reference numerals 17 and 17 are rotating devices having turning rolls for rotating the pipe to be welded 13 around its central axis, and in the illustrated example, an inner welding position W1 and an outer welding position W
2 and Wl, and an intermediate position W3 adjacent to W2, and the rotation center of the rotation devices 17, 17 located at the intermediate position W3 is the central axis of the welded pipe 13 located at the outer surface welding position W2. is set to approximately match.

Further, reference numerals 18 and 18 are transfer devices having conveyor rolls arranged at positions W2 and W3 in order to move the pipe to be welded 13 in the axial direction. At the inner welding position W1 and the outer welding position W2 of the pipe 13 to be welded, the welded part is at the 6 o'clock position (see FIG. 5) and 1 with respect to the center of the pipe.
The welding torch is placed at the 2 o'clock position (see Figure 6), and in either case, welding is performed with the welding torch facing downward. In this specification, when the pipe to be welded 13 is at the inner surface welding position W1, the pipe to be welded is called the first pipe to be welded, and when the pipe to be welded 13 is at the outer surface welding position W2, the pipe to be welded is called the first pipe to be welded. The pipe is called a second welded pipe. Next, a welding method of the present invention using the above-mentioned apparatus will be explained. First, in FIGS. 3 to 7, the tube to be welded 13 is transferred by an appropriate device (not shown) and brought into the inner surface welding position W1. Thereafter, the pipe 13 to be welded is rotated by the rotating device 17 and arranged so that the part to be welded is located at the lowest position as shown in FIG. Next, the support roll 6 is lowered and the auxiliary trolley 1
After the free end of the long beam 3 is positioned in the vertical direction by contacting the long beam 3 with the long beam 4, the traveling carriage 1 is caused to travel in the X1 direction. At this time, the auxiliary trolley 14 is also
move in the direction. The auxiliary truck 14 stops when it comes into contact with the tab plate 13a provided on the pipe to be welded 13, but the traveling truck 1 continues to travel further in the X1 direction. Furthermore, tab plate 1
3a is omitted, the auxiliary truck 14
It comes into contact with the end of 3 and stops. When the welding torch 8 is located at the end of the pipe to be welded 13 in the 131. In this state, welding is carried out while the traveling trolley 1 is traveling in the X2 direction.
At the end of the direction, before the guide roll 5 is detached from the pipe to be welded 13 or its tab plate 13a, the support roll 6 is lowered to engage with a receiving member disposed on the auxiliary cart 14. Even if it comes off the pipe to be welded, the welding head 7 will not be displaced in the Z direction. Thereafter, the traveling trolley 1 is positioned at the end in the X2 direction, and the welding work is completed. In addition, when the traveling cart 1 is traveling in the X1 direction, that is, when it is traveling, the support roll 6 is in contact with the welded pipe 13 as shown in FIG. 7, and the guide roll 5 is not in contact with the welded pipe 13. It's summery.

Further, when the traveling carriage 1 is traveling in the X2 direction, that is, during welding, the guide roll 5 is fitted into the groove 131 of the pipe to be welded 13, and the welding head is positioned with respect to the welding line. After welding of the inner surface is completed in this way, the pipe to be welded 13 is moved to an intermediate position indicated by the symbol W3 in FIG. let

Then, the pipe to be welded is rotated by the rotating device 17 so that the pipe to be welded is placed at the top. Further, while the pipe to be welded 13 whose inner surface has been welded is transferred from the inner welding position W1 to the outer welding position W1, the pipe to be welded next to be welded next is placed at the inner welding position W1. Next, welding is carried out in the same manner as the inner surface welding described above, but in this case, the outer surface of the tube to be welded 13 is welded with the welding torch 16 of the outer surface welding head 15 while the traveling carriage 1 is traveling in the X1 direction.

In this case, the inner surface welding head 7 moves inside the pipe to be welded at the W1 position toward the end in the X direction. After welding the outer surface is completed or when the traveling truck 1 is located at the end in the Make sure that the wire 11 does not come into contact with the pipe to be welded 13 or the already welded part. Then, when the traveling carriage 1 is traveling in the X2 direction, the inner surface vertical joint welding of the pipe at the welding position W1 is performed in the same manner as described above. Thereafter, vertical joint welding of the inner and outer surfaces of the pipe to be welded is performed alternately in the same manner as above. In the above embodiment, the support roll 6
Although the guide rolls 5 are not necessarily necessary, they are useful when the pipe to be welded is extremely long compared to the cross-sectional area of the pipe.

Furthermore, if a plurality of welding torches are provided in the welding heads for the inner surface and the outer surface, respectively, welding can be reliably performed in one welding operation.

In addition, in the above explanation, it was explained that the pipe to be welded to which the outside surface is welded is immediately placed at the W2 position after passing through the intermediate position after the completion of the internal welding. It is also possible to store the welded pipe once at the W3 position and then transfer it from W3 to W1-{3 after the second internal welding is completed. In this way, the rotating device 17 can position the position to be welded at the top of the pipe at the intermediate position W3 which is not affected by the traveling carriage during welding. In this case, since the welding position of the pipe to be welded transferred from the position W3 to the position W2 is located approximately near the top of the pipe, the outer surface welding work can be performed extremely quickly. Particularly, the larger the diameter of the pipe, the more time is required for the rotating device 17 to rotate the pipe to be welded, so it is advantageous to provide an idler position as a handling position for the pipe to be welded.

Furthermore, if the outer surface is welded after the inner surface welding is performed as described above, it is possible to automatically weld along the groove 131 on the inner surface of the tube, where it is difficult to confirm the line to be welded from the outside. Further, when welding the outside surface, the line to be welded can be easily checked while being welded from the outside, and the pipes to be welded can be vertically welded on the inside and outside surfaces sequentially from the first one, so it is easy to implement equipment.

It is also possible to perform internal welding after external welding.

In this case, if the welding conditions are selected so that the penetration during welding on the outside does not extend to the groove 131 and welding is performed on the outside, this bead can prevent burn-through during welding on the inside. Furthermore, automatic welding can be performed along the groove portion 131, which is advantageous. Furthermore, the inner and outer surfaces can be simultaneously welded while the traveling carriage is traveling toward the pipe to be welded.

In this case, after welding the inner and outer surfaces, the traveling carriage is moved away from the pipe to be welded, so that the welding time required for the -cycle can be shortened. Further, after the traveling cart is moved toward the pipe to be welded and then moved, the inner surface and the outer surface can be simultaneously welded while the traveling cart is moved in a direction away from the pipe to be welded.

By doing this, not only can the welding time required for one cycle be shortened, as is the case when welding is carried out while the traveling cart is traveling toward the pipe to be welded, but also the welding head will not wander above the weld bead after welding. Therefore, there is an advantage that the welding head, wiring, etc. are not affected by the heat retained in the welding bead. In addition, if the structure is such that the outer surface welding is performed when the traveling truck approaches the pipe to be welded, and the inner welding is performed when the traveling truck moves away from the tube, the inner and outer surfaces are welded by the forward and backward movements of the traveling truck. If welding is performed separately, it is easy to set the reciprocating speed of the traveling carriage to a speed suitable for external welding and internal welding, and it is easy to select each welding condition.

As described above, according to the method of the present invention, inner welding and outer welding are performed during one reciprocation of the traveling trolley.
This has the advantage of shortening the travel time of the trolley, which causes work loss, and greatly reducing the work time required for welding.

Furthermore, since both internal and external welding are carried out using only one traveling trolley, not only can equipment costs be reduced, but there is also the advantage that there are no restrictions on the direction in which pipes to be welded can be brought in and out. This method has the advantage of making it possible to vertically weld the inner and outer surfaces of pipes in places where space is limited, such as inside a building.

[Brief explanation of the drawing]

Figures 1a and 2 are plan views showing different examples of devices for carrying out the conventional welding method, and Figure 1b is the same as Figure 1a.
, FIG. 3 is a front view showing an example of an apparatus for carrying out the method of the present invention, FIG. 4 is a plan view of FIG. 3, and FIGS. 5 and 6 are taken along V-V in FIG. Line and -line cross-sections,
FIG. 7 is a partially enlarged sectional view of FIG. 3. 1... Traveling trolley, 3... Long beam,
7...Welding head for inner surface, 8...Welding torch, 11...Welding wire, 13...
・Pipe to be welded, 15... External welding head, 16
...Welding torch, 17... Rotation device,
18... Transfer device.

Claims (1)

[Scope of Claims] 1. In a pipe welding method for vertically welding the inner and outer surfaces of a pipe from the inner and outer sides, a first pipe to be welded is located at an inner surface welding position and a second pipe is located at an outer surface welded position. The pipes to be welded are spaced apart from each other in the axial direction and are arranged parallel to each other with their respective axes separated by a predetermined distance, and an external welding head is provided on the side of one traveling vehicle, and the welding head is provided in the direction of movement of the traveling vehicle. An inner surface welding head is provided in front of the traveling truck via a long beam extending in parallel, and the traveling truck is made to reciprocate once to longitudinally weld the inner and outer surfaces of the first and second pipes to be welded, respectively. A welding process is performed, and then the pipe to be welded at the inner welding position or the outer welding position is transported to the outer welding position or the inner welding position, and a new pipe to be welded is carried into the inner welding position or the outer welding position. A vertical joint welding method for the inner and outer surfaces of a pipe, characterized in that the inner and outer surfaces of the pipe are sequentially welded. 2. In the welding step, when the traveling carriage moves toward or away from the pipe to be welded, the inner surface welding head and the outer surface welding head perform simultaneous welding according to claim 1. Method for welding longitudinal joints on the inner and outer surfaces of pipes. 3 In the welding step, when the traveling cart moves in a direction approaching the pipe to be welded, welding is performed by either the inner surface welding head or the outer surface welding head, and the traveling cart moves in the direction away from the pipe to be welded. Claim 1 in which welding is performed by the other welding head when moving.
Method for welding vertical joints on the inner and outer surfaces of pipes as described in . 4 In the welding step, when the traveling cart moves in a direction approaching the pipe to be welded, welding is performed by the welding head for the outer surface, and when the traveling cart moves in the direction away from the pipe to be welded, welding is performed by the welding head for the inner surface. A method for vertical joint welding of inner and outer surfaces of a pipe according to claim 3, which performs the following.