JPH07314186A - Distorting device for pipe butt welds - Google Patents

Abstract

(57) [Summary] [Purpose] Weld pipe butt welds accurately and in a short time. [Structure] An elongated body 3 has a plurality of arms 4 whose ends are rotatably connected by hinges 5, and rollers 6 rotatably provided on each hinge 5. A hydraulic jack 7 is provided between both ends of the elongated body 3. A long body 3 is formed on the peripheral surface of the pipe butt welded portion 2.
Wrap around and extend the rod of the hydraulic jack 7. The movement of the arms 4 in the tightening direction by the hydraulic jack 7 is smooth because each roller 6 rotates. On the outer peripheral surfaces of the tubes 2a and 2b, a correction pressure averaged at equal intervals corresponding to the intervals of the rollers 6 is applied. The force applied to the pipe butt welded portion 2 is directed toward the center of the pipe with the roller 6 as a fulcrum. The distortion of the pipe butt welds 2 is corrected, and the joining accuracy of the ends of both pipes to be butted is extremely high. The pipe butt welded portions 2 are temporarily welded at a plurality of positions between the adjacent distortion correcting rollers 6,6. After that, the strain relief device 1 is removed from the pipe butt welding portion 2 and main welding is performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strain relief device for a pipe butt welded portion which improves the accuracy of welding by eliminating the step at the butted portion due to the distortion of the pipe when the pipes are abutted and welded. Is.

[0002]

2. Description of the Related Art When butt welding steel pipes and steel pipes,
If there is a distortion at the end of the pipe and there is a step on the joint surface,
Not only is it difficult to weld, but the welding strength is also reduced.
However, according to the Japanese Industrial Standards, the manufacturing error of the steel pipe is recognized up to ± 1/100 of the diameter, and if there is an error of this degree, an unacceptable step is generated in the butt welded part of the steel pipe, and the welding accuracy is high.・ Problems occur in strength.

Therefore, conventionally, in order to correct the distortion of the pipe butt welded portion, a method of removing the distortion of the pipe butt welded portion as shown in FIGS. 7 and 8 has been used. According to this method, first, a pair of steel pipes 100 and 101 to be welded are abutted against each other, and the portions 100a and 101a of the respective steel pipes 100 and 101 which are distorted outward as indicated by broken lines in the figure are corrected. , 101a, the base portion 102a of the receiving metal fitting 102 is welded to the steel pipes 101, 100 on the opposite side. Tip part 10 of the receiving metal fitting 102
2b opposes the distorted portions 100a and 101a at a predetermined interval. Then, a camber 103, which is a wedge-shaped member, is driven between the distorted portions 100a and 101a and the tip portion 102b of the receiving metal fitting 102. The portion that is distorted toward the outside of the tube is deformed and corrected toward the inside.

[0004]

According to the above-mentioned modification of the conventional pipe butt welded portion, when the camber is driven at one place, a step is formed at another place due to the influence.
Therefore, in order to remove the strain, it is necessary to weld metal fittings at a plurality of places and drive the camber, which causes a problem that it takes time and labor.

An object of the present invention is to enable the welding of a pipe butt welded portion with high accuracy and in a short time.

[0006]

According to another aspect of the present invention, there is provided a strain relief device for a pipe butt welded portion, wherein a bendable elongated body wound around the pipe butt welded portion is provided with a predetermined interval. A plurality of supporting members that are provided and a tightening unit that applies a force in the center direction of the pipe to the pipe butt-welding portion with the supporting member serving as a fulcrum by drawing the elongated body.

According to a second aspect of the present invention, there is provided a strain relief device for a pipe butt welded portion, wherein the elongated body has a plurality of plate-shaped members and respective plate-shaped members. It is characterized by comprising a hinge connecting members.

According to a third aspect of the present invention, there is provided a strain relief device for a pipe butt welding portion, wherein the elongated body is made of a flexible strip-shaped member. It has a feature.

According to a fourth aspect of the present invention, there is provided a strain relief device for a pipe butt welding portion, wherein the support member is rotatably attached to the elongated body. It is characterized by being a roller.

[0010]

The elongated body is wound around the pipe butt welded portion, and a plurality of supporting members provided on the elongated body are brought into contact with the pipe butt welded portion. Tighten the long body by tightening means. With the support member serving as a fulcrum, a force in the direction of the center of the pipe is applied to the pipe butt weld, and the distortion of the pipe butt weld is corrected.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A strain relief device 1 of a first embodiment will be described with reference to FIGS. First, the strain relief device 1 of the present embodiment
Includes a bendable elongated body 3 wound around the pipe butt welded portion 2 of the pair of pipes 2a and 2b. This long body 3
This is a link structure in which the ends of the arm members 4 that are plate-shaped members are rotatably connected by a hinge 5 and connected. The pair of arms 4 is a pair, and the ends of the arms 4 of each adjacent pair are alternately connected by hinges 5 so as to be rotatable.

A strain correcting roller 6 as a supporting member is provided on each hinge 5 of the arm 4 so as to be rotatable coaxially with the hinge 5.

A hydraulic jack 7 is provided between both ends of the elongated body 3 as a fastening means for fastening the elongated body 3 to the peripheral surface of the pipe butt welded portion 2. That is, one end of a pair of outer arms 8 is rotatably connected to the arm 4 and the distortion correcting roller 6 at one end of the elongated body 3 around the hinge 5. In addition, one end of a pair of inner arms 9 is rotatably connected to the arm 4 and the strain correcting roller 6 at the other end of the elongated body 3 around the hinge 5. The outer arm tree 8 and the inner arm tree 9 are configured to be able to slide while crossing each other.

A jack fixing plate 10 and a slip prevention pin 11 are provided at the other end of the outer arm tree 8 which is a free end. The bottom portion of the barrel of the hydraulic jack 7 is fixed to the jack fixing plate.

A jack reaction force plate 12 and a slip-prevention pin 13 are provided at the other end of the inner arm 4 which is a free end. The tip of the rod of the hydraulic jack 7 is fixed to the jack reaction force plate 12.

When the elongated body 3 is wound around the peripheral surface of the pipe butt welded portion 2 and the hydraulic jack 7 is driven to extend the rod, the elongated body 3 is squeezed and the pipes are abutted with the distortion correcting roller 6 as a fulcrum. A force is applied to the welded portion 2 toward the center of the pipes 2a and 2b.

A fine adjustment unit 14 is provided at a position opposite to the hydraulic jack 7 in the elongated body 3 connected in a substantially annular shape with the hydraulic jack 7 interposed therebetween. The arm in this position is replaced with a pair of substantially U-shaped connecting members 16 each having a nut portion 15 having a different thread direction.
Both connecting members 16, 16 are connected by a fine adjustment screw 17. When the fine adjustment screw 17 is rotated, the pair of connecting members 16 and 16 move in opposite directions. By adjusting the distance between the pair of connecting members 16 and 16 with the fine adjustment screw 17, the length of the elongated body 3 wound around the peripheral surface of the pipe butt welded portion 2 can be finely adjusted.

In the above construction, the width of the arm 4 and the diameter of the strain correcting roller 6 are appropriately determined according to the diameter of the pipes 2a and 2b to which the present strain relief device 1 is applied. When the present strain relief device 1 is wound around the pipe butt welded portion 2 as shown in FIG. 2, the diameter of the circumferential line where the strain correcting roller 6 contacts the pipes 2a and 2b is larger than the outer diameter of the pipes 2a and 2b. When the elongated body 3 is tightened, the diameter of the circumferential line where the distortion correcting roller 6 contacts the tubes 2a and 2b becomes smaller than the original outer shape of the tube. Also, when the long body 3 is tightened, the arms 4
Is designed not to contact the tubes 2a and 2b.

Next, a method of using the strain relief device 1 for the pipe butt welded portion 2 will be described. First, the pair of tubes 2a and 2b are butted. As shown in FIGS. 2 and 3, the apparatus 1 is installed so that the distortion correction roller 6 straddles the butt welded portion 2.

The hydraulic jack 7 is operated to tighten the elongated body 3. The arm 4 of the elongated body 3 moves in the tightening direction by the force of the hydraulic jack 7. The movement is smooth because each distortion correction roller 6 rotates. Further, an average correction pressure is applied to the outer peripheral surfaces of the tubes 2a and 2b at equal intervals corresponding to the intervals of the distortion correction rollers 6. The force applied to the pipe butt welded portion 2 is directed toward the center of the pipes 2a and 2b with the distortion correcting roller 6 as a fulcrum. Therefore, the distortion of the pipe butt welded portion 2 is corrected, and both pipes 2a to be abutted,
The joining accuracy of each end of 2b becomes extremely high.

Depending on the standard, steel pipes and the like may have different outer diameters even if they have the same nominal diameter. In such a case, the fine adjustment screw 17 of the fine adjustment unit 14 is used to perform adjustment so that the tube can be properly tightened by the elongated body 3.

In the state where the distortion of the pipe butt welded portion 2 is corrected, the pipe butt welded portion 2 is provided between the adjacent strain correction rollers 6 and 6 as indicated by the symbol W in FIG.
Is temporarily welded at appropriate multiple points. The tentative welding is performed at a position or a position where at least the distortion of the pipe butt welded portion 2 can be maintained.

After the temporary welding, the strain relief device 1 is removed from the pipe butt welding portion 2. After that, main welding is performed.

In the first embodiment, the hydraulic jack 7 is used as the fastening means for the elongated body 3. When the diameter of the pipe to be joined is small, the tightening force of the elongated body 3 does not have to be large, and therefore, instead of the hydraulic jack 7, a tightening means having the same structure as the fine adjustment unit 14 may be provided.

In the first embodiment, the distortion correcting roller 6 is used as the supporting member, but the supporting member for transmitting the tightening force of the tightening means to the pipe need not be a rotatable roller. For example, a cylindrical member that does not rotate may be used, or a member other than a cylindrical member may be used as long as it can uniformly transmit pressure to the pipe.

Further, in the first embodiment, the distortion correcting roller 6 is provided coaxially with the hinge 5 of the arm 4; however, as in the second embodiment shown in FIG. A shaft 21 different from the hinge 5 of the arm 4 may be rotatably provided at a portion slightly away from the center. In FIG. 4, the same components as those in the first embodiment are designated by the reference numerals used in the description of the first embodiment, and the description thereof will be omitted.

Next, a third embodiment will be described with reference to FIGS. The strain relief device 31 includes a pair of pipes 2a,
As the bendable elongated body wound around the pipe butt welded portion 2 of 2b, a large number of flexible belts 32, which are belt-shaped members, are provided.
have.

An annular portion 33 is formed at both ends of each belt 32. A pair of narrow belts 32a, 32a arranged in parallel at a predetermined interval and the pair of belts 32
A rather wide belt 32b having a width corresponding to the distance between a and 32a is alternately connected to the roller 34, which is a supporting member, by inserting the annular portion 33 therethrough. As shown in FIG.
The belt 32 has an annular shape which is wound around the entire circumference of the tubes 2a and 2b as a whole. Further, as shown in FIG. 6, the pipe butt welded portion 2 can be visually recognized from the gap between the pair of narrow belts 32a, 32a. These belts 32 are nonflammable, flexible, and have sufficient strength.

As shown in FIG. 5, a fastening means 40 having a structure similar to that of the fine adjustment section 14 is provided on a part of the belt 32. When the fine adjustment screw 17 is rotated in this tightening means, the pair of connecting members 16 and 16 each having the nut portion 15 move in mutually opposite directions. By this fine adjustment screw 17, the pair of connecting members 1
When the distances 6 and 16 are close to each other, the belt 32 is tightened, and the rollers 34 press the pipe butt welded portions 2 of the pipes 2a and 2b via the annular portion 33 of the belt 32.

The rollers 34 are provided on the outer peripheral surfaces of the tubes 2a and 2b.
The average correction pressure is applied at equal intervals corresponding to the intervals of. The force applied to the pipe butt welded portion 2 is directed toward the center of the pipes 2a and 2b with the roller 34 as a fulcrum. Therefore, the distortion of the pipe butt welded portion 2 is corrected, and the joining accuracy of the ends of the pipes 2a and 2b to be butted is extremely high.

In the first and second embodiments described above, the elongated body 3 wound around the pipe butt welded portion 2 is formed by connecting plate-like link members such as arms 4, and the third embodiment. In the example, the flexible and bendable belt 32 has a long body. However, the structure of the long body of the present invention is not limited to these. The elongated body in the present invention may have any structure as long as it can be wound around the pipe butt welded portion and can evenly clamp the pipe when tightened. For example, a belt-shaped member such as a chain that is a transmission member can be used.

[0032]

According to the strain relief apparatus for a pipe butt welded portion according to the present invention, the elongated body wound around the pipe butt welded portion is tightened so that the support member of the elongated body makes it uniform toward the center of the pipe. Different stresses can be applied to the weld.

Therefore, according to the present invention, it is possible to apply an average correction pressure to the peripheral surface of the pipe butt welded portion at a uniform interval by a simple operation, and it is possible to surely correct the distortion of the pipe butt welded portion with high accuracy. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a front view of a first embodiment of the present invention viewed from a direction parallel to an axis of a pipe to be butt-welded.

FIG. 2 is a side view of the first embodiment of the present invention.

FIG. 3 is a partially enlarged view of an embodiment of the present invention.

FIG. 4 is a front view of the second embodiment of the present invention as seen from a direction parallel to the axis of the butt-welding tubes.

FIG. 5 is a front view of the third embodiment of the present invention as seen from a direction parallel to the axis of the butt-welding tubes.

FIG. 6 is a side view of the third embodiment of the present invention.

FIG. 7 is a front view showing a conventional method for removing distortion from a pipe butt welded portion as seen from a direction parallel to the axis of the pipe to be butt welded.

FIG. 8 is a cross-sectional view showing a conventional method for removing distortion from a pipe butt welded portion as seen from a direction orthogonal to FIG. 7.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Strain relief device 2 Pipe butt welded parts 2a, 2b Pipe 3 Long body 4 Arms as plate member 5 Hinge 6 Strain correction roller as support member 7 Hydraulic jack as tightening means 20 Roller as support means

Claims (4)

[Claims] 1. A bendable elongated body wound around a pipe butt welded portion, a plurality of support members provided at predetermined intervals in the elongated body, and the support member by drawing the elongated body. A strain relief device for a pipe butt weld portion having a tightening means for applying a force in the direction of the center of the pipe to the pipe butt weld portion with the fulcrum as a fulcrum. 2. The strain relief device for a pipe butt welded portion according to claim 1, wherein the elongated body comprises a plurality of plate-shaped members and a hinge connecting the plate-shaped members. 3. The strain relief device for a pipe butt welded portion according to claim 1, wherein the elongated body is made of a flexible strip-shaped member. 4. The strain relief device for a pipe butt welded portion according to claim 1, wherein the support member is a roller rotatably attached to the elongated body.