JPS62197300A - Tack straightening device for steel pipe - Google Patents

Abstract

PURPOSE:To surely straighten the unconformity of the seam part of a steel pipe by pressing the inner peripheral face of the steel pipe so as to offset the synthetic force of the pressure by a pressing roll and by providing the means which moves the pressing roll in the radial direction by other pressing roll. CONSTITUTION:A knife plate 33 is inserted to the seam part with a steel pipe A is expanded by a opener roll 53, when the steel pipe A is transferred into a tack welding line. The unconformity of the seam part is straightened with a pressing roll 47 and cage roll 55 pressing the seam part with further transfer of the steel pipe A. After straightening the tack welding is performed. Since the pressing roll 47 constitutes the moving means and arranged 120 deg. apart on the inner face of the steel pipe A the synthetic force of the pressure becomes zero. The unconformity of the seam part of the steel pipe can surely be straightened by this device.

Description

DETAILED DESCRIPTION OF THE INVENTION <Technical Field to Which the Invention Pertains> The present invention relates to a tack welding device for steel pipes that corrects irregularities in seams in advance before tack welding of welded steel pipes.

<Prior art> Generally, welded steel pipes are manufactured by forming a steel plate into a cylindrical shape by press forming using a UO press, etc., then tack welding the seam of the steel pipe, and then main welding. There is.

However, as shown in FIG. 8, after the steel pipe A is formed into a cylindrical shape, the edges at the seam portion S are separated from each other due to the spring bank after exiting the zero press. Also, the edges may be uneven due to irregularities in wall thickness, etc. This phenomenon is noticeable when the wall thickness of the steel pipe is small and the diameter is large.

If these differences in level or separation occur, good tack welding or main welding cannot be achieved. Therefore, at the time of tack welding, correction is performed using a correction device so that the offset m is 0.5 or less and the seam ρ is 0.1 or less.

Conventionally, as the above-mentioned correction device, one shown in FIG. 9 is known.

This is equipped with a pair of opener rolls 2 (see Figure 13) for expanding the steel pipe at the tip of the base 1 (on the right side in the figure), and a roll 3 and a pressure roll 4 on the base 1. There is. A knife plate 5 is connected to the base 1, and this knife plate 5 has an arm 6 that moves up and down.
The base body 1 is connected to the arm 6 so that the base body 1 moves up and down as the arm 6 moves up and down. On the other hand, a press roll 1o and a cage roll 12 are provided on a support base 7.8 facing the collar roll 3 and press roll 4.

Now, when the steel pipe A formed into a cylindrical shape is carried into the tack welding line, turning rollers (not shown) rotate the steel pipe in the circumferential direction so that the seam part is on top. Then, as it is transported to the steel pipe, the seam portion S (see FIG. 10) is expanded by the opener roll 2. As the steel pipe A is conveyed, the knife plate 5 is inserted into the expanded seam S, and as shown in FIG. 11, the roll 3 and presser roll 10 press the seam S. go. Furthermore, as shown in FIG. 12, the pressure roll 4 and the cage roll 12 press the seam part S, and the irregularity of the seam part S is corrected.

After the above correction, as shown in FIG.
．． 13, the expanded steel pipe A is closed so as to maintain a perfect circle, and is tack welded at point P.

FIG. 14 shows another conventional straightening device, in which a base body 16 is connected to a knife plate 15, a link 17 is attached to this base body 16, and a straightening roll 18 is attached to one end of the link 17. On the other hand, the other end of the link 17 is connected to the rond 20 of the cylinder 19, and when the rond 2° is stretched, the seam part is pressed by the straightening roll 18 and the cage roll 12 to correct irregularities in the seam part. There is.

Note that 21 is a holding roll.

<Problems to be Solved by the Invention> However, in the straightening device shown in FIG. 9, the collar 3a of the collar roll 3 is pushed from both edges of the seam portion S and worn, and the edges are also damaged. There was a problem with getting it on. Furthermore, since the substrate 1 is held cantilevered by the knife plate 5, the pushing up effect of the support roll 4' is limited to the substrate 1.
Even if we strengthen the system, we cannot expect enough. Furthermore, since the cage roll 13 is disposed adjacent to the knife plate 5 and the expanded steel pipe A is rapidly compressed, there is a problem that the steel pipe A is distorted. In addition, it is necessary to provide an elevating device that moves the base 1 up and down, and if the elevating device raises the base 1 to a higher position, the steel pipe A
The entire weight of the collar roll 3 is applied to the collar roll 3, which causes many problems such as the collar roll 3 being easily damaged and making it difficult to adjust the height position of the base body 1.

Further, in the straightening device shown in FIG. 14, since the holding roll 21 and the straightening roll 18 are used to expand the steel pipe using the cylinder 19, the effect of straightening the offset is large. However, with this device, once the edges overlap, as shown when the offset is small,
The drawback was that it could not be undone.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a temporary fixing device that can exert a strong pushing-up effect and can easily correct misalignment and overlapping of seams. shall be.

<Means for solving the problem> The structure of the present invention that achieves the above object is a device that is inserted into a cylindrical steel pipe and restrains the steel pipe from the inside so that the seams of the steel pipe match. , while pressing the seam part from within the steel pipe, a push roll is provided so as to be movable in the radial direction, and the inner circumferential surface of the steel pipe is pressed so that the combined force with the pressing force of the push roll is offset, and the radial Another push roll movable in the direction is provided, and a moving means for moving the push roll in the radial direction is provided.
Function> Each roll is arranged so that the combined force of the pushing force of the push roll and the pushing force of other push rolls is zero, so each roll can be installed at a large distance from the knife plate. However, the pushing effect of the push roll does not decrease.

<Embodiment> FIG. 1 shows a partially sectional side view of a temporary fixing device according to an embodiment of the present invention, and FIG. 2 shows its II-I
[A cross-section in the direction of arrows, a plane view in FIG. 3, and an explanatory view of the corrected state in FIGS. 4, 5, and 6.

In FIG. 1, reference numeral 31 denotes an arm fixed to a frame 32, and this arm 31 has a knife plate 1-330''.
It is attached by bolts 34. Further, a body 35 is detachably attached to the knife plate 33 with bolts 36. A hole 3ja is formed in the body 35, a rod 37 movable in the direction of arrow A is attached to the hole 35a, and a screw is formed at the rear of the rod 37,
Furthermore, the rotating shaft 39 that engages with this screw on the body 35
As shown in FIG. 2, the rod 37 is moved in the direction of arrow A by rotation of a handle 40 provided on the rotating shaft 39.

On the other hand, support members 41.42 are provided at the tip of the rod 37 and at a predetermined distance rearward from the tip, and the support members 41.42 extend along the circumferential direction of the rod 37, as shown in FIG. They are installed in three locations separated by 120'. Link members 44 and 45 are pivotally connected to these support members 41 and 42, and both ends of a storage stand 46 having a U-shaped cross section are pivotally connected to the tips of the link members 44 and 45. A base 48 on which a plurality of rolls 47 are installed is housed.

The storage table 46 is provided with a disc spring 49 that causes the base 48 to protrude from the storage table 46 and press the push roll 47 against the inner circumferential surface of the steel pipe A. On the other hand, the tip of the link member 45 and the body 35 are linked together by a link member 51, so that when the rod 37 moves to the left in the drawing, the storage stand 46 expands outward.

Further, an opener roll 53 for expanding the steel pipe A is provided at the tip of the body 35.

In addition, 55 is a cage roll that closes the expanded steel pipe A so as to maintain a perfect circle. Also, the rod 351 and the rotating shaft 39.
Handle 40. The link members 44, 45, 51, etc. constitute a moving means for expanding and contracting the push roll 47.

Next, the operation of the embodiment constructed as described above will be explained.

As in the past, when the steel pipe A is carried into the tack welding line, the steel pipe A is transferred with the seam portion facing upward (see FIG. 4). Then, the steel pipe A is opened by the opener roll 53.
is expanded, and as the knife plate 33 is moved, the knife plate 33 is inserted into the seam portion. When the steel pipe A is further transferred to the position indicated by the solid line, the push rolls 47 and the cage rolls 55 press the seam S, as shown in FIGS. 5 and 6, to correct the irregularity of the seam S. To go. At this time, since the push roll 47 has a cushion provided by the disc spring 49, the seam portion S is gradually corrected starting from the push roll 47 at the right end (in FIG. 1). After the correction, tack welding is performed at P.

Since the seam portion is corrected at a position far away from the knife plate 33, the seam portion can be corrected without difficulty. In addition, the push roll 47 has a diameter of 120 mm on the inner circumferential surface of the steel pipe A.
Since they are arranged at positions separated by ', the resultant force of the pressing force by the pressing rolls 47 becomes zero.

Therefore, the pressing force of the push roll 47 can be increased, and the seam portion can be reliably corrected.

When the steel pipe A has a large diameter, when the handle 40 shown in FIG. 2 is turned and the rod 37 is moved to the left (in FIG. 1), the storage stand 46 is moved outward as shown in FIG. spread. In this way, irregularities in the seam portion of a large diameter steel pipe can be corrected in the same manner as described above.

<Effects of the Invention> As described above, according to the present invention, even if the push roll is installed at a position far away from the knife plate, the pushing up effect of the push roll can be large, so that distortion does not occur in the steel pipe. It is possible to reliably correct irregularities in the seam portion without causing any damage. Furthermore, since no brim roll is used, the brim does not wear out and the edges of the seam are not damaged by the brim, unlike conventional methods. Furthermore, since no elevating device is used, the structure is simpler.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view of one embodiment of the present invention, and FIG.
Fig. 3 is a plan view, Fig. 4 is an end view of the steel pipe, Fig. 5 is an explanatory diagram showing the position of the push rolls in the steel pipe, and Fig. 6 is the push rolls and An explanatory diagram showing the relationship between cage rolls and steel pipes, Fig. 7 is an explanatory diagram when used for large diameter steel pipes, Fig. 8 is an explanatory diagram showing misalignment of the seam, and Fig. 9 is an explanatory diagram showing conventional straightening. A schematic cross-sectional view of the device; FIG. 10 is an explanatory view of expanding the seam portion; FIGS. 11 to 13 are explanatory views showing correction of the seam portion; FIG. 14 is a schematic cross-sectional view of another conventional correction device; FIG. 15 is an explanatory diagram showing irregularities in the seam portion. In the drawing, 33 is a knife plate, 35 is a body, 37 is a rod, 39 is a rotating shaft, 44, 45 is a link member, 46 is a storage stand, 47 is a push roll, 48 is a base, 53 is an opener roll, A is the steel pipe, and S is the seam part. Figure 3 Kuku Figure 4 Figure 5 Figure 8 Figure 9 Figure 1O Figure 1I Figure 12 Figure 13 Figure 14 Figure 1, j 15th factor

Claims (1)

[Claims] This is a device that is inserted into a cylindrical steel pipe and restrains the steel pipe from the inside so that the seam portion of the steel pipe coincides with the steel pipe. is provided to press the inner circumferential surface of the steel pipe so that the resultant force with the pressing force from the push rolls is offset, and another push roll that is movable in the radial direction is provided, and further, the push roll is moved in the radial direction. A temporary fixing straightening device for steel pipes, characterized by being provided with a moving means for moving the pipes.