JP2001300760A - Method of forming bevel of pipe body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of machining of a pipe end and a method of forming a bevel by assembly, by which method a precise bevel is formed. SOLUTION: In a machining process of the pipe end the end face of the pipe end is cut and formed in a state that the end part is made in a nearly cylindrical form by fixing a clumping jig on the pipe end of each pipe from outer face side and giving pressing force to the pipe end, thus the bevel face is formed. In the assembly process of the bevel, the form of the end part of each pipe is surely reproduced in the same form as that of each pipe given in the machining process of the pipe end of each pipe by butting the end part of each pipe in a state that the clumping jig is kept fixed in, for example, the machining process of the pipe end. By reproducing in this way the form of the end part of each pipe in the assembly process of bevel in the same form as given in the machining process of the pipe end, the bevel is assembled while keeping the flatness of the end face of each pipe with a very high precision in the same level given in the machining process of the pipe end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a high-precision groove in welding a pipe body, for example, in all-position welding of a steel pipe peripheral joint by electron beam welding and laser beam welding.

[0002]

2. Description of the Related Art A pipeline for transporting gas or the like is formed by connecting a plurality of steel pipes by forming a butt-welded joint. Butt weld joints are MAG (metal active gas) welding, MIG (metal inert gas) welding, TIG (tungste)
In general, it is formed by inert gas welding or the like, but in recent years, in order to speed up the welding operation, high energy density welding such as electron beam welding and laser beam welding has been adopted.

[0003] In high energy density welding such as electron beam welding, the joint can be formed by one or several welding operations by assembling an I groove by utilizing the characteristics of deep penetration. Since the beam diameter of the emitted electron beam is small and the width of the fusion zone is small, the accuracy required for the groove, especially the root gap, needs to be almost zero. That is, as the plate thickness increases, the width of the fusion zone becomes relatively smaller than the penetration depth, and the required groove accuracy becomes severer. In particular, in the case of the above-mentioned all-position welding in which the pipes are butt-butted and welded over the entire circumference, the beam diameter is reduced to prevent the molten metal from dripping by its own weight.
The melt width must be reduced to about mmφ or less, and higher groove accuracy is required. For example, in a butt joint of a steel pipe having a thickness of 19 mm, a root gap needs to be about 0.2 mm or less at an I groove for performing all-position backside welding by electron beam welding.

FIG. 31 is a front view showing a pipe end processing apparatus 1 for explaining a conventional pipe end processing method, and FIG.
2 is a side view shown from the left side of FIG. In the pipe end processing apparatus 1, the cutting means 2 and the clamp means 3 include a base 4
It is provided in. The cutting means 2 is provided with a face plate 6 for holding the cutting tool 5 so as to be rotatable. The clamp means 3 is provided with a pair of clamp portions 7, 8 in which a V-shaped recess is formed so as to face each other. Using this pipe end processing apparatus 1, the pipe body 9 is clamped by the clamps 7 and 8, the face plate 6 is driven to rotate, and the pipe body 9 is cut by the blade 5 to form the pipe end face 10. I have.

FIG. 33 is a sectional view showing a groove assembling apparatus 11 for explaining a conventional method of assembling a pipe.
FIG. 34 is a side view seen from the left side of FIG. The groove assembling apparatus 11 has a pair of clamp bodies 12 and 13 and pulling means 14. One clamp body 12
A clamp ring 15 formed by connecting two semicircular frame members; four clamp bolts 16 provided at equal intervals in the circumferential direction on the clamp ring 15; And 24 staggered adjusting bolts 17 provided at equal intervals. The other clamp body 1
3 has the same configuration as the one clamp body 12. In each of the clamp bodies 12, 13, the ends of the respective clamp bolts 16 are brought into contact with the outer surface of the tubular body 9 and the tubular body 22 having the same configuration, and the respective tubular bodies 9, 22 are clamped from the outer surface side. Can be.

The pulling means 14 has four turnbuckles 18, and each turnbuckle 18 has two bolt members 20 screwed to one nut member 19, and each bolt member 20 is prevented from rotating. By rotating the nut member 19 in the state, the bolt members 20 can be displaced toward and away from each other. Each of the turnbuckles 18 is provided so that each of the bolt members 20 is connected to each of the clamp bodies 12 and 13.
The four clamp rings 15 are connected at equal intervals in the circumferential direction while being prevented from rotating, whereby the clamp bodies 12 and 13 can be connected so that the distance between them can be changed.

[0007] Each of the clamp bodies 1 is
2 and 13 clamp the ends of the tubes 9 and 22 having the end faces 10 formed as described above, and pull the clamps 12 and 13 by the pulling means 14 to pull the respective tubes 9 and 22. 22 and pull the pipes 9, 22 against each other.
A groove 24 can be formed. The axial gap between the end faces 10 which is the root gap of the I groove 24 can be adjusted by the amount of pulling by the pulling means 14. The radial displacement of the ends of the tubes, which are misaligned between the tubes 9 and 22, is adjusted by adjusting the amount of protrusion of the misalignment adjusting bolt 17 so that the tube located on the radially outward side is radially inward. It can be corrected by pressing it toward one side. As described above, in the conventional technique, a groove is formed by a groove forming method in which the pipe end machining cutting method in FIG. 31 and the groove assembling method in FIG. 33 are combined.

[0008]

As described above, in each groove forming method of the prior art, each pipe is formed by a pipe end processing step of a pipe end face and a pipe assembly step (groove assembling step). Since clamping conditions such as the position of the clamp and the clamping force when the body is clamped are different, a difference occurs in the amount of deformation of the end portion of the tube caused by the clamping, and a high-precision groove cannot be assembled. The pipe end face is deformed in the axial direction when the pipe end is deformed in the radial direction, but can be formed into an end face having a high flatness by the pipe end processing method as described above. However, this is only the flatness achieved in the clamped state of the pipe end processing step 2. When the pipe end is clamped in the groove assembling step under different clamping conditions from the pipe end processing step, the deformation of the pipe end is That is, since the amount of deformation in the axial direction is different, the flatness is significantly reduced.

In the cutting shown in FIGS. 31 and 32, the clamp of the tube 9 is intended only to prevent the rotation of the tube 9 against the rotational force applied to the tube 9 from the blade 5. The clamping force is small, the clamping position is also the contact position of the clamping parts 7, 8 and is not equally spaced in the circumferential direction, and no consideration is given to how the tube end is deformed by such clamping. . 33 and 34, each tube 9 must be strongly drawn, so that it is clamped with a large clamping force and the clamp position is closer to the tube end face than in the tube end processing step. And are equally spaced in the circumferential direction.
Further, after the clamp is performed in this manner, the pipe body is partially pressed and deformed by a misalignment bolt to correct misalignment.

As described above, since the purpose of clamping the pipe body is completely different between the pipe end processing step and the groove assembling step, clamping is performed by a clamping device having a different configuration. Are different. As a result, the shape of the end portion of the tube is different, and the groove is assembled in a state where the flatness of the end surface of the tube is extremely low, which causes a problem that the groove accuracy is extremely low. For example, the plate thickness is 19 mm, and the average diameter is 762.
In the case where a 1% oval cylindrical tube is deformed into a true cylindrical shape by being clamped, according to an analysis, it has been found that ± 0.
An irregularity of 14 mm, and thus a difference of 0.28 mm in the axial position between the peaks and valleys on the end face of the tube. In such a state, the root gap cannot always be reduced to about 0.2 mm or less as described above even if the pipes are butted.

An object of the present invention is to provide a groove having a groove processing step and an assembling step capable of forming a high-precision groove, which can be suitably carried out also for high energy density welding such as electron beam welding. It is to provide a forming method.

[0012]

SUMMARY OF THE INVENTION The present invention is a method of assembling a groove to form a welded joint by abutting the ends of two tubes, wherein the end of each tube is machined. In the step, the end of each tube is cut in a state where the end is formed into a predetermined shape by applying a pressing force from the outer surface side of each tube, and in the assembly process of each tube, the end of each tube is The shape of the part
A groove forming method for a pipe body, characterized in that a groove is assembled by reproducing the same shape as the shape of the pipe end processing step and abutting ends of the respective pipe bodies.

According to the present invention, each pipe is pressed from the outer surface side and the end is formed into a predetermined shape, and the end of each pipe is cut to form an end face. When the end of each tube has a predetermined shape, the end face of each tube is
It becomes a plane with extremely high flatness. The end of each tube body thus cut is reproduced in the same shape as that of the tube end processing step, and the ends are abutted. When assembling the groove by abutting the parts, the end face of each tube is a plane with extremely high flatness. Therefore, the root gap of the groove formed from the end surfaces of the two pipes can be extremely small, and a highly accurate groove can be formed. Therefore, the present invention can also be suitably performed for high energy density welding such as electron beam welding and laser beam welding. Furthermore, in making the end of each tube body a predetermined shape,
Since the pressing force is applied from the outer surface side, it is possible to adjust the pressing force in a large working space outside the tube, and it is easy to work to shape the end of each tube into a predetermined shape. It is.

Further, in the present invention, in the pipe end processing step of each pipe body, each end of each pipe body is cut by clamping from the outer surface side of each pipe body, The end of the tube is clamped under the same clamping conditions as at least the clamping position and the clamping force in the tube end processing step, and the ends are assembled to form a groove.

According to the present invention, in the tube end machining step of each tube, the end of each tube is cut and clamped from the outer surface side, and the end of each tube is cut in the assembly process of each tube. Since the parts are clamped and butted under the same clamping conditions as the clamping conditions of the pipe end processing step, when assembling a groove by abutting the ends of the respective pipes, the shape of the end of each pipe is: The shape is the same as when the end of each tube is cut. In this way, the shape of the end of each pipe body in the pipe end processing step and the assembling step can be made identical, and the groove can be assembled with the flatness of the end face of each pipe body being extremely high. The tip can be formed with high precision.

Further, in the present invention, in the tube end processing step of each tube, the end of each tube is corrected to a true cylinder or a shape very close to a perfect cylinder by clamping from the outer surface side of each tube. Each end of each tube is cut, and in the process of assembling each tube, the end of each tube is clamped from the outer surface side and straightened into a true cylinder or a shape very close to a perfect cylinder, The groove is assembled by aligning the axes of the pipes and abutting them.

According to the present invention, in the tube end processing step of each tube, the end of each tube is clamped from the outer surface side and the end is corrected to a true cylinder or a shape very close to a perfect cylinder. In the assembly process of each tube body, each part is cut and clamped from the outer surface side, and the end of each tube body is corrected into a true cylinder or a shape very close to a perfect cylinder, Since the axes are aligned and butted, when assembling the groove with the ends of each tube abutting, the shape of the end of each tube is the same as the shape when the end of each tube is cut . In this way, the shape of the end of each pipe body in the pipe end processing step and the assembling step can be made identical, and the groove can be assembled with the flatness of the end face of each pipe body being extremely high. The tip can be formed with high precision. Further, by making the shape of the end of each tube in the tube end processing step and the assembling process into a true cylinder or a shape very close to a true cylinder, the shape of the end of each tube in the assembling process is included in the tube end processing step. It is easy to reproduce in the shape of. In addition, even if the respective pipes are displaced in the circumferential direction, there is no large difference in the amount of misalignment, and the assembling work of the groove is easy.

Further, in the present invention, in the tube end processing step of each tube, a clamp jig is mounted from the outer surface side of each tube and clamped, and in this state, the end of each tube is cut and processed. In the assembling process of each tube, a groove is assembled by abutting the ends of each tube with the clamp jig attached in the tube end processing step still attached to the end of each tube. Features.

According to the present invention, in the tube end processing step of each tube, a clamp jig is mounted from the outer surface side, clamped and cut, and the clamp jig mounted in the tube end processing step is attached to each tube. Since the ends of each tube are abutted while being attached to the end of the body, when the ends of each tube are abutted and the groove is assembled, the shape of the end of each tube is Therefore, the shape of the end of each tube body is exactly the same as when it is cut. In this way, the shape of the end of each pipe in the pipe end processing step and the assembling step can be surely made the same, and the flatness of the end face of each pipe can be reliably maintained in an extremely high state to make a groove. Can be assembled, and the groove can be reliably formed with high precision. Furthermore, in the tube assembly process, much work for reproducing the end shape of each tube is not required, so that workability is improved.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a flow chart showing a procedure of an operation according to a method for forming a groove of a tubular body, specifically a groove forming and assembling method according to an embodiment of the present invention, and FIG. FIG. 4 is a diagram showing a procedure of a groove preparation and an assembly operation of No. 1;
FIG. 2A is a front view of the tubular body 41 before correction, and FIG.
(2) is a right side view of the tube 41 viewed from the right side of FIG. 2 (1), FIG. 2 (3) is a left side view of the tube 42 before correction, and FIG. It is the front view of the pipe body 42 seen from the right side of 2 (3). FIG. 2 (5) shows the tube body 4 having the end portion 43 corrected.
1 is a front view, FIG. 2 (6) is a right side view of the tube 41 viewed from the right side of FIG. 2 (5), and FIG.
FIG. 2 (8) is a front view as seen from the right side of FIG. 2 (7). FIG. 2 (9) is a front view showing the pipe body 41 having the pipe end processed, and FIG.
0) is a front view showing the pipe body 42 whose pipe end has been processed. FIG. 2 (11) is a cross-sectional view showing a cross section perpendicular to the axis of the pipe 41 in a state where the pipes 41 and 42 are abutted, and FIG.
FIG. 2 is a front view showing a state where the pipes 41 and 42 are abutted, and FIG. 2 (13) is a cross-sectional view showing a cross section perpendicular to the axis of the pipe 42 where the pipes 41 and 42 are abutted.

The groove forming method of the present invention is a method for forming a groove 40 for forming a butt-welded joint and connecting a plurality of steel pipes in forming a pipeline for transporting gas or the like. is there. In other words, for example, the groove 40 is assembled after the end portions 43 and 44 of two pipes 41 and 42 such as steel pipes are assembled. Specifically, in the pipe end processing step, a pressing force is applied to the ends 43, 44 of the respective pipe bodies 41, 42 from the outer surface side, and the ends 43, 44 are provided.
With the 44 in a predetermined shape, the end faces of the pipes 43 and 44 are cut, respectively, and in the groove assembling step of assembling the pipes, the ends 43 and 44 of the pipes 41 and 42 are formed. Reproduce the shape to the same shape as the shape of the pipe end processing process,
The groove 44 is assembled and formed by abutting the ends 43, 44 of the respective tubes 41, 42.

More specifically, the operation of forming the groove includes a pipe end processing step of forming the end faces 45, 46 of the pipe bodies 41, 42, and the pipe bodies 41, 42 after the pipe end processing step.
And a groove assembling step of assembling a groove by abutting 42. In step s0, a groove forming operation is started in, for example, a factory, and is performed from a pipe end processing step. Each tube 4
Since it is extremely difficult to form the tubes 1 and 42 in a true cylindrical shape, the tube 41 is, for example, shown in FIGS.
As shown in (2), the shape of the cross section perpendicular to the axis L2 is elliptical, and is a uniform elliptic cylinder in the axial direction. As shown in FIGS. 2 (3) and 2 (4), the pipe body 42 also has an elliptical cross section perpendicular to the axis L3, and has a uniform elliptic cylindrical shape in the axial direction. The nominal outer diameter of each of the housings 41 and 42 is, for example, 762 mm. Each of the tubes 41 and 42 as shown in FIGS. 2 (1) to 2 (4) is prepared.
The operation is started in step s0.

In step s1, the ends 43, 44 of the respective tubes 41, 42 are formed into a predetermined shape. The predetermined shape is not particularly limited, and may be, for example, a true cylindrical shape. Specifically, as shown in FIG. 2 (5), a clamp body 47 is attached to the end portion 43 of the tube 41 from the outer surface side and clamped, and as shown in FIG. Or, it is corrected to a shape very close to a perfect cylinder. As in the case of the tube 41, the tube 42 is also shown in FIG.
As shown in FIG. 2, a clamp body 48 is attached to the end portion 44 from the outer surface side and clamped, and as shown in FIG.
4 is corrected to a true cylinder or a shape very close to a perfect cylinder.

Here, in the present invention, the true cylinder means a cylinder whose outer shape (outer peripheral shape) is a perfect circle in a cross section perpendicular to the axis, and the perfect circle is represented by the following equation (1). It means a shape with the indicated roundness of 0%.

Roundness = (maximum diameter−minimum diameter) / average diameter (1) The maximum diameter is the maximum outer diameter, and data obtained by measuring the outer peripheral radius from the virtual center over the entire circumference. , A circumscribed perfect circle having a minimum diameter determined based on the measurement result, and the diameter is defined as the maximum diameter. The minimum diameter is a minimum outer diameter, and a minimum perfect circle concentric with the maximum perfect circle, that is, an inscribed perfect circle concentric with the maximum perfect circle is obtained, and the diameter is defined as the minimum diameter. The average diameter is the average outer diameter, which is the diameter obtained by adding the maximum diameter and the minimum diameter and dividing by two. Also, in the present invention, a shape that is very close to a perfect cylinder means a shape whose cross section perpendicular to the axis is very close to a perfect circle, and a shape that is very close to a perfect circle is represented by the formula (1). Is a shape having a roundness greater than 0%, for example, 0.3% or less.

As described above, in step s1, FIG.
As shown in FIG. 2 (8), the end 4 of each of the pipes 41, 42
3 and 44 are formed into a predetermined shape.
2 (9) by cutting the end portions 43, 44 of
Then, end faces 45 and 46 are formed as shown in FIG. Specifically, taking the tube 41 as an example, FIG.
As shown in (5), when the end portion 43 of the tubular body 41 is straightened, the flat end surface is deformed as shown in FIG. In this case, an end face 45 which becomes a flat surface at the time of correction is formed. Similarly, the end portion 44 of the tube body 42 is also cut to form an end surface 46 that is flat when straightened. Such steps s1 and s2
Is included in the pipe end processing step.

In the above-described pipe end processing step, each end 4
Although it has been described that the cutting process of the end portions 43 and 44 is performed after the straightening of each of the pipes 3 and 44,
After the first end 43 is straightened and cut, the end 44 of the other tube 42 may be straightened and cut. Although only the one ends 43 and 44 in the axial direction of the pipes 41 and 42 have been described, when the pipeline is formed as described above, the other ends of the pipes 41 and 42 are also required. Cutting is performed in the same manner, and after both ends are similarly corrected, cutting is performed.

After the tube processing step, the process proceeds to the tube moving step.
Specifically, at the factory, the end 4 of each pipe 41, 42
After the cutting of the pipes 3 and 44, the pipes 41 and 42 are carried into the laying site in step s3. After the respective tubes 41 and 42 have been carried in the tube moving process, the process proceeds to the groove assembling process.

In the groove process, at step s4, each pipe 4
The ends 43 and 44 of the pipes 1 and 42 have the same shape as that in the pipe end processing step. Specifically, as shown in FIGS. 2 (9) and 2 (10), the shape is corrected to a true cylinder or a shape very close to a perfect cylinder. Such correction of the end portions 43 and 44 may be performed by using the above-described clamp bodies 47 and 48 or a device similar thereto to reproduce the shape. Each clamp 4 installed in the pipe end processing step
If the pipes 7 and 48 are carried to the site while being mounted, the ends 43 and 44 of the pipes 41 and 42 at that time are reproduced in the shape in the pipe end processing step, and the step s
In step 4, no special operation is required.

Thus, in step s4, each end 43,
44 is re-corrected, or carried in with the clamp bodies 47 and 48 mounted in the pipe end processing step, and each end 4
After reproducing the shapes of Nos. 3 and 44 to the shapes in the pipe end processing step, in step s5, FIGS.
As shown in 3), the ends 43, 44 of the tubes 41, 42 are drawn together so that the ends 43, 44 face each other and the tubes 41, 42 are brought closer to each other. By abutting the ends 43 and 44 in this manner, the groove 40 is assembled as shown in FIG.
Then, the process proceeds to step s6 to complete the groove forming work. The steps s4 and s5 constitute a groove assembly process. After the groove 40 is formed in this way, the groove 40 is welded in a welding process to form a joint.

FIG. 3 is a front view showing the pipe end processing apparatus 50 for explaining the pipe end processing method in the pipe end processing step, and FIG. 4 is shown as viewed from the cutting plane line IV-IV in FIG. FIG. 5 is a cross-sectional view taken along line VV of FIG. 3. In the pipe end processing device 50, a cutting means 51 and a holding means 52 are provided on a base 53. The cutting means 51 has a face plate 55 for holding a cutting tool 54 and a driving unit 56 for driving the face plate to rotate. A tool post 57 is provided on the outer peripheral portion of the face plate 55, and a tool (bite) 54 is held on the tool post 57. The drive unit 56 can rotationally drive the face plate 55 about the axis L1 and can drive the face plate 55 in the axial direction.

The holding means 52 has a pair of holding portions 58 and 59 in which a V-shaped recess is formed, and a support portion 60 having rollers. The holding portions 58 and 59 are provided so as to face each other at a position facing the face plate 55, and the end portion 43 is provided with the face plate 5.
5 and the axis L2 of the tube body 41 is
The tube 41 can be sandwiched from the outside and held so as to coincide with the rotation axis L1 of. In addition, the support portion 60
The height of the tube 41 is adjusted so that the axis of the tube 41 is guided to a height substantially close to the holding center of the tube holders 58 and 59. Since each holding portion has a V-shaped concave portion, it has an automatic centering function of the tube body 41 when the tube body 41 is sandwiched. The centering function can work effectively.

Using this pipe end processing apparatus 50, the pipe body 41 is held by the holding portions 58 and 59, and the face plate 55 is rotationally driven and axially displaced and driven. 43 can be cut to form an end face 45. In the pipe end processing step constituting the groove forming method according to the present invention, a clamp body 47 is attached to the end portion 43 from the outer surface side, and the end portion 43 is corrected to a predetermined shape, for example, a true cylindrical shape by clamping, In this state, the face plate 55 is driven to rotate, and the end 43 is cut. The clamp body 47 presses the pipe body 41 from the outer surface side at positions equidistant in the circumferential direction along a plane perpendicular to the axis L2 of the pipe body 41 to correct the end 43. The position where the tube body 41 is pressed by the clamp body 47 (the center position of the pressed portion) is
The position is a distance D1 from the formed end face 45 in the axial direction. If the nominal outer diameter (target outer diameter at the time of manufacture) is, for example, 762 mm, the distance D1 is
For example, it is 120 mm. As described above, the pipe body 41 is cut in a state where the end portion 43 has a predetermined shape, and the end face 45 is formed. In FIG. 3, the clamp body 47 is independently mounted closer to the end face than the holding position of each holding portion 58, 59 of the holding means 52, but it is not always necessary to be independent. May be done.

Although the procedure for cutting the tube 41 has been described with reference to FIGS. 3 to 5, other tubes, for example, the tube 42, are similarly cut to form the end surface 46. .

FIG. 6 is a side view showing a specific structure of the clamp body 47, and FIG. 7 is a front view of the clamp body 47 shown from the left side in FIG. Here, FIG. 6 shows a state viewed from the near side with respect to the paper surface of FIG. The clamp body 47, which is a clamp jig, includes a clamp ring 62 and a plurality of clamp bolts 63. The clamp ring 62
It may be formed integrally, or may be formed by connecting a plurality of arc-shaped ring members. In each case, the whole shape is an annular shape. In the present embodiment,
The three ring members 64 are connected to each other. The clamp bolt 63, which is a press fitting as a pressing member,
For example, twelve are provided and arranged at equal intervals in the circumferential direction of the clamp ring 62.

FIG. 8 is an enlarged front view showing the vicinity of the connecting portion of the ring member 64 in FIG. 7, and FIG. 9 is a side view showing one circumferential end of the ring member 64 viewed in the circumferential direction. .
The ring member 64 is made of, for example, high-strength steel, and has a main body 65 and connecting portions 66 and 67 provided at both ends in the circumferential direction.
And The main body 65 is configured such that an arc-shaped outer peripheral wall 68 and an arc-shaped inner peripheral wall 69 are connected by a connecting wall 70 arranged at intervals in the circumferential direction. The outer peripheral wall 68 and the inner peripheral wall 69 are connected to the axis L of the clamp ring 62.
4 in the circumferential direction.

The connecting portion 66 is fixed to one end of the main body 65 in the circumferential direction. The connecting portion 66 has a projecting portion 71 projecting from the main body 65 to both sides in the axial direction, and has a main body 6 at an intermediate portion in the radial direction with respect to the axis L4.
The surface opposite to 5 has a protrusion 72 protruding away from the main body 65. Each of the overhang portions 71 is formed with, for example, two insertion holes 73.

The connecting portion 67 is fixed to the other end of the main body 65 in the circumferential direction. The connecting portion 67 has a projecting portion 74 projecting from both sides of the main body portion 65 in the axial direction, and has a main body portion 6 at an intermediate portion in the radial direction with respect to the axis L4.
A concave portion 7 recessed so that a surface opposite to the surface 5 approaches the main body portion 65;
Five. In each overhang portion 74, an insertion hole 76 is provided.
For example, two are formed at a time.

Each of the ring members 64 is provided so that one end in the circumferential direction abuts on the other end in the circumferential direction of the other ring member 64, and the protrusion 72 is provided so as to fit into the recess 75. As a result, the ring members 64 are positioned so that their positions in the radial direction do not shift. In this state, the connecting portion 66 is connected to the connecting portion 66 by using a connecting bolt 77 commonly inserted into the insertion holes 73 and 76 of the projecting portions 71 and 74 and a nut 78 screwed to the connecting bolt 77. , 67 are fastened to each other so that each ring member 64 is detachably connected.

The clamp ring 62 formed by connecting the ring members 64 is connected to the outer peripheral wall 6 of the ring member 64.
8 extends along the true cylindrical surface around the axis L4, and the inner peripheral wall 69 of each ring member 64 extends along the true cylindrical surface around the axis L4. In other words, the ring member 64 is formed in a true cylindrical shape. The clamp ring 62 has higher rigidity at least in the radial direction than the tube body 41, and in the present embodiment, has higher rigidity not only in the radial direction but also in the axial direction and the circumferential direction.

FIG. 10 is an enlarged sectional view showing the vicinity of the clamp bolt 63 of FIG. 7, FIG. 11 is a sectional view taken along the section line XI-XI of FIG. 10, and FIG. 1
FIG. 13 is a plan view seen from the upper side of FIG. 1, and FIG. 13 is a cross-sectional view partially cut away as seen from the upper side of FIG. 11. Four clamp bolts 63 are provided for each ring member 64,
It is arranged between each connecting wall 70. Connection wall 7 at a position where each clamp bolt 63 of each ring member 64 is provided
A nut holding portion 80 is provided on the outer peripheral side of the inner peripheral wall 69 between the outer peripheral walls 68, the inner peripheral wall 69, and the nut retaining portion 80. The insertion hole 8 extends along one radial line L5 passing through the axis L4.
1, 82 and 83 are formed respectively. Each clamp bolt 63 is provided so as to pass through each of the insertion holes 81 to 83.

The nut holding portion 80 is formed with a concave portion 84 having an approximately elliptical inner surface which is open toward the inner side, and a nut 85 having an approximately elliptical outer diameter is formed in the concave portion 84.
Are fitted so that rotation about the one-radius line L5 is prevented. The nut 85 is a cover 86
Is prevented from falling outside. A clamp bolt 63 is screwed to the nut 85, and the clamp bolt 63 can adjust its position in the radial direction with respect to the clamp ring 62 by rotating around the one-radius line L5. The amount of protrusion of the clamp pad 88 provided at the distal end from the clamp ring 62 radially inward can be adjusted.

The clamp bolt 63 is made to protrude inward in the radial direction from the clamp ring 62, and the distal end portion, that is, the clamp pad 88 is brought into contact with the outer peripheral surface of the tube 41 as shown by a virtual line in the drawing. The tube 41 can be clamped. At this time, the clamp pad 88 is
1 while being in contact with the outer peripheral surface of
3 is projected radially inward, so that the pipe 41
Can be corrected by pressing inward in the radial direction. The clamp bolt 63 has a hexagonal hole 89 in a head 87 on the outer peripheral side of the clamp ring 62, and can be rotated using a hexagonal wrench.

The amount of displacement of each clamp bolt 63 in the radial direction of the clamp ring 62 by one rotation around its axis is the same.
Can be displaced by the same amount by rotating the same number of revolutions. Therefore, it is possible to make each clamp bolt 63 project from the true cylindrical clamp ring 62 inward in the radius by the same amount. Thus, when the clamp body 47 is attached to the tube body 41, the clamp bolts 63 are made to protrude while maintaining the same amount of protrusion from the clamp ring 62, so that the clamp bolts 63 project radially outward of the tube body 41. Each of the clamp bolts 63 abuts on the tube 41 from a bolt facing the expanded portion.
Are projected until all of them come into contact with the tube 41, so that the contact portion of the tube 41 can be corrected into a true cylinder, specifically, a shape in which the outer peripheral surface is a true cylinder. At this time, the axis L4 of the clamp body 47 and the axis L2 of the tube 41 are coaxial.

By changing the amount of protrusion of each clamp bolt 63, the shape can be corrected to another shape different from a true cylinder, for example, an elliptical shape, a substantially triangular shape, and other substantially polygonal shapes.

In such a clamp body 47, a plurality of, for example, six locking members 90 in this embodiment are provided at equal intervals in the circumferential direction. Each locking member 90 is provided to be fixed to the connecting wall 70, two for each ring member 64. Each locking member 90 has a substantially rectangular locking hole 91 that penetrates in the axial direction of the clamp ring 62 and is long in the circumferential direction.

FIG. 14 is a side view showing a specific structure of the clamp body 48, and FIG. 15 is a front view of the clamp body 48 shown from the right side of FIG. Here, FIG.
In FIG. 3, the tube 41 is replaced by the tube 42, and the clamp 47 is replaced by the clamp 48, which is shown in a state viewed from the back side with respect to the paper surface. As shown in FIG.
13 have the same configuration as that of the clamp body 47 shown in FIG. 13, the same reference numerals are given to portions having the same configuration, and detailed description will be omitted. Although the clamp body 48 itself is configured similarly to the clamp body 47, the clamp body 4
8 is provided with a pulling cylinder 93 instead of the locking member 90.

The clamp body 48 is also a clamp body 4
7, each of which has a clamp bolt 63,
When the clamp body 48 is mounted on the tube 2, the clamp bolts 63 are made to protrude while maintaining the same amount of protrusion from the clamp ring 62, so that each of the clamp bolts 63 protrudes radially outward of the tube 42. By contacting the tube 42 from the facing bolt and projecting until all of the clamp bolts 63 abut the tube 42,
The contact portion of the tube body 42 can be corrected into a true cylinder, specifically, a shape in which the outer peripheral surface is a true cylinder. At this time, the axis L6 of the clamp body 48 and the axis L3 of the tube 42 are coaxial.

By changing the amount of protrusion of each clamp bolt 63, the shape can be corrected to another shape different from a true cylinder, for example, an elliptical shape, a substantially triangular shape, and other substantially polygonal shapes.

The number of pulling cylinders 93 is the same as the number of locking members 90, and therefore a plurality of pulling cylinders 93, for example, six in the present embodiment.
And are arranged at equal intervals in the circumferential direction. Each pulling cylinder 93 is connected to each of the ring members 64 by two,
It is provided fixed at 0. Each pulling cylinder 93
The base end of the cylinder tube 94 is fixed to the connection wall 70 and is provided from the clamp ring 62 along the axial direction. Each pulling cylinder 93 has a piston 95 capable of being driven to expand and contract with respect to a cylinder tube 94 by hydraulic oil, and a locking piece 96 is provided at a tip end thereof. The clamp body 48 is mounted such that each pulling cylinder 93 projects from the clamp ring 62 toward the end surface 46.

FIG. 16 shows a state in which each of the pipes 41 and 42 is butted by using a groove assembling apparatus 100 to form a groove 40 in order to explain a groove assembling method in the groove assembling process. FIG. Each end 4 as described above
The pipes 41 and 42 on which the pipes 3 and 44 have been processed are butted against each other using the groove assembling apparatus 100. Groove assembly device 1
Reference numeral 00 denotes each of the clamp bodies 47 and 48 and the pulling means 1.
01, and the pulling means 101 is configured to include the locking member 90 and the pulling cylinder 93 described above.

In this embodiment, each tube 4
When the pipe ends are machined at the factory, the clamp bodies 47 and 48 constituting the groove assembling apparatus 100 used when butting the pipes 1 and 42 are mounted on the pipe bodies 41 and 42, respectively, and cutting is performed. The clamp bodies 47 and 48 are carried to the site while being attached to the pipes 41 and 42, respectively.
The respective tubes 41 and 42 are butted. Each tube 41, 42
Each of the clamp bodies 47 and 48 is
Are brought together by pulling them together.

FIG. 17 is a view showing a specific structure of the pulling means 101, FIG. 17 (1) is a side view seen from the clamp body 47 side, and FIG. FIG. 17C is a cross-sectional view showing the structure, and FIG.
It is a side view shown seen from the side. The connecting wall 70 of the clamp body 47 connects one end in the axial direction of the outer peripheral wall 68 and the inner peripheral wall 69. The clamp body 47 is clamped by arranging one side in the axial direction on the end face 45 side of the tubular body 41. The connecting wall 70 of the clamp body 47 has a substantially rectangular recess 10 on the other axial side of the portion where the locking member 90 is provided.
3 is formed, and a fitting hole 104 is formed at the center of the recess 103 so as to be inserted in the axial direction.

The locking member 90 is a rhombic plate-shaped member, and is provided so as to close the fitting hole 104 from the other side in the axial direction of the clamp body 47 in a state of being fitted into the recess 103. The locking member 90 is, for example, a fixing bolt 10
5 and is fixed to the connecting wall 70. The locking member 90 is formed with the locking hole 91 as described above. The locking hole 91 partially opens the fitting hole 104 on the other axial side of the clamp body 47.

The connecting wall 70 of the clamp body 48 connects one end in the axial direction of the outer peripheral wall 68 and the inner peripheral wall 69. The clamp body 48 is clamped by disposing one axial side on the end surface 46 side of the tube 42. A substantially rectangular recess 103 is formed in the connection wall 70 of the clamp body 48 on the other side in the axial direction of the portion where the pulling cylinder 93 is provided, and is inserted in the axial direction at the center of the recess 103. A fitting hole 104 is formed. Each of the clamp bodies 47 and 48 has the same configuration as described above, and the same reference numerals are given to the respective recesses and the respective fitting holes.

Cylinder tube 9 of pulling cylinder 93
Reference numeral 4 denotes a substantially cylindrical shape, and has a rhombus-shaped mounting portion 106 protruding radially outward at a base end portion. The cylinder tube 94 is fitted so as to pass through the fitting hole 104,
The free end is provided so as to protrude from the fitting hole 104 to one side in the axial direction of the clamp body 48 in a state where the mounting portion 106 is fitted into the recess 103.
8 and is fixed to the connecting wall 70.

The piston 95 of the pulling cylinder 93 is the main body of the hydraulic cylinder, and has a piston tube 109 and a piston rod 110. The piston 95 is inserted into the cylinder tube 94 from the base end side, and the male thread portion 111 provided on the base portion of the piston tube and the female thread portion provided on the inner wall of the cylinder tube 94 mesh with each other. It is fixed by a tube 94. The piston 95 not only protrudes the piston rod portion 110 straight by pressurization due to the guide groove provided inside the piston tube 109, but also projects the piston rod portion 110 to the shaft 90 degrees with respect to the shaft in the end stroke of the protruding. It has a mechanism to rotate degrees. This mechanism also works when the rod part is retracted, the rod part is retracted while rotating in the first stroke of retraction from the most protruding state, and after rotating 90 degrees, the remaining stroke continues as it is and completes Drawn into.

The locking piece 96 of the drawing cylinder 93 has a substantially rectangular plate shape, and is provided at the tip of the rod portion 110 of the piston 95. The longitudinal dimension of the locking piece 96 is smaller than the longitudinal dimension of the locking hole 91 and larger than the width dimension, and the width dimension of the locking piece 96 is larger than the width dimension of the locking hole 91. Is also small. Therefore, when the locking piece 96 is in the same direction in which at least its longitudinal direction is arranged in the same direction as the longitudinal direction of the locking hole 91 (FIG. 1).
7 (1) is in the arrangement state indicated by the imaginary line), it can pass through the locking hole 91. The locking piece 96 has a locking hole 91 at least in the longitudinal direction.
17 (1) when it is arranged in the same direction as the width direction (when it is in the arrangement state indicated by the solid line in FIG. 17A).
Cannot pass through the locking hole 91, and the locking member 90
Can be locked by.

Such a pulling means 101 is provided for each pipe 4
In a state where the end faces 45 and 46 are opposed to each other, the clamp bodies 47 and 48 are drawn so as to approach each other.

More specifically, first, the rod portion 110 of the piston 95 is completely protruded in the entire stroke, and the locking piece 96 is rotated by 90 degrees. Next, the fitting hole 104 of the clamp body 47
The cylinder tube 94 is inserted into the
The locking piece 96 is inserted through the No. 0 locking hole 91. Here, the piston 95 has the rod portion 110 completely protruding, and the locking piece 9
6 is rotated by 90 degrees, and is fixed to the cylinder shoe in an angle-adjusted state so that it can be inserted without contacting the engaging holes 91 of the engaging members 90 facing each other. At this time, the amount of protrusion of the rod portion 110 from the locking hole is set to be equal to or longer than the rotation stroke of the rod portion. Then, piston 9
When the fifth rod portion 110 is retracted, the locking piece 96 completes the 90-degree rotation just before passing through the locking hole.

Next, the locking piece 96 is connected to the locking member 9 as described above.
The piston 95 is retracted as shown by the solid line in FIG. As a result, in a state in which the locking piece 96 is locked to the locking member 90 on the other side in the axial direction of the clamp body 47, the picitone 95 is retracted, and the clamp bodies 47 and 48 come closer to each other. Gravitate. In the present embodiment, the clamp bodies 47 and 48 are drawn as far as possible. In other words, the clamp bodies 47 and 48 are pulled until the end faces 45 and 46 of the pipe bodies 41 and 42 abut and the clamp bodies 47 and 48 can no longer be drawn. By pulling each of the clamp bodies 47 and 48 by the pulling means 101 in this way, the groove assembling apparatus 100 can abut the respective pipes 41 and 42 and assemble the groove 40. Thereby, the groove 40 is formed.

FIG. 18 is a front view showing a state in which the pipes 41 and 42 are abutted with each other. FIG. 19 is a cross-sectional view showing an enlarged section XIX of FIG. The accuracy of the groove 40 formed by assembling the pipes 41 and 42 against each other is determined by the end faces 45 and 46 of the pipes 41 and 42.
The root gap G1, which is the distance between the pipes, and each pipe 41, 4
The accuracy is determined by the amount of misalignment G2, which is the amount of deviation of the outer peripheral surface in the radial direction, and the smaller the variation in the circumferential direction, the higher the accuracy.

When the groove 40 is assembled in accordance with the groove forming method of the present invention as described above, each of the pipes 41 and 42 is held in a shape in which each end 43 and 44 is cut. Can be matched. As described above, the tubular body processing apparatus 50 can perform cutting with extremely high flatness even if it is generally commercially available.
46 is, for example, 0.1 mm
The end face can be formed as follows. Therefore, each end face 4 when each pipe body 41, 42 is butted.
5, 46 also have very high flatness.

Further, since the pulling means 101 draws the clamp bodies 47 and 48 as much as possible as described above,
The pipes 41 and 42 are pulled and fixed until the end faces 45 and 46 abut at least at three or more positions in the circumferential direction. When the pipes 41 and 42 are abutted and fixed in this manner, the flatness of the end faces 45 and 46 is extremely high as described above, and thus the root gap G1 has a very small variation in the circumferential direction. In each of the tubes 41 and 42 having such dimensions, the maximum value can be set to, for example, 2.5 mm or less.

When the clamp bodies 47 and 48 are pulled, the free end of the cylinder tube 94 is fitted in the fitting hole 104 of the clamp body 47. As a result, the clamp bodies 47, 48 are positioned in the circumferential direction and the radial direction, and the respective clamp bodies 47, 48 are positioned.
48 are arranged coaxially. Therefore, each clamp body 4
Tubes 41, 42, which are coaxial with 7, 48, respectively, are coaxially arranged. As described above, the pipes 41 and 42 are arranged coaxially, and the end portions 43 and 44 are in a state of being a true cylinder or a very true cylinder. Therefore, the misalignment amount G2 has a very small variation in the circumferential direction. In the small tubes 41 and 42 described above, the maximum value can be set to, for example, 1.6 mm or less.

Here, when the clamp bodies 47 and 48 are pulled toward each other, the outer diameter of the cylinder tube 94 and the fitting hole 104 of the clamp body 48 are increased in order to increase the coaxiality of the clamp bodies 47 and 48. Reduce the dimensional difference with the inner diameter,
The mounting position accuracy of the pulling cylinder 93 is increased, and the outer diameter of the cylinder tube 94 and the fitting hole 10 of the clamp body 47 are increased.
The configuration is such that the dimensional difference from the inner diameter of 4 is small, and the positioning accuracy is high. Thereby, each clamp body 4
The coaxiality of 7, 48 increases, and the coaxiality of each tube 41, 42 increases.

Further, if the above-mentioned dimensional accuracy is achieved in all the pulling cylinders 93, the pulling operation becomes difficult. Therefore, two or more pulling cylinders 93, for example, two pulling cylinders arranged in a one-diameter line shape are used. For the cylinder 93, the dimensional accuracy is as described above, and for the other drawing cylinders 93, the diameter of the cylinder tube 94 is reduced.
May be made larger in dimensional difference from the inner diameter. Thus, the clamp bodies 47 and 48 can be positioned with high accuracy by some of the pulling cylinders 93, and the other pulling cylinders 93 have the free ends of the cylinder tubes 94 in the fitting holes 104 of the clamp bodies 47. Since it fits easily, pulling work becomes easy.

The free end of the cylinder tube 94 of each pulling cylinder 93 is formed to be inclined like a truncated cone whose end face expands toward the base end. As a result, the free end of the cylinder tube 94 is inserted into the fitting hole 10 as described above.
4, the cylinder tube 94 is guided by the clamp body 47 and is easily fitted, thereby facilitating the pulling operation.

For example, when assembling the groove 40 to form a welded joint of the pipes 41 and 42 for forming a pipeline, a highly accurate groove 40 can be obtained by the above-described method. Can be. In other words, according to the groove forming method of the present embodiment, each of the pipes 41, 42
In the tube end processing step, the end portions 43 and 44 are cut and formed into end surfaces in a state where the end portions are formed into a predetermined shape by being pressed from the outer surface side.
4 has a predetermined shape, the end surfaces 45, 46
Is a plane with extremely high flatness. Each of the pipes 41, 42 formed by cutting and forming the end faces 45, 46 in this manner.
In the groove assembling process, the shape of the end portions 43 and 44 is reproduced to be the same shape as the shape of the tube end processing process. At this time, the end surfaces 45 and 46 of the respective tube bodies 41 and 42 have extremely flatness. It is a high plane. As described above, in the groove assembling process, the end portions 43 and 44 of the pipes 41 and 42 can be abutted with the end faces 45 and 46 having extremely high flatness. When assembling the groove 40 in this manner, the accuracy of the root gap G1 is almost governed by the assembling accuracy. Therefore, if a groove assembling apparatus having high accuracy is used, the root gap G1 can be made uniform in the circumferential direction and can be set in a predetermined dimensional range. But,
When it is desired that the root gap is as small as possible in the case of electron beam welding or laser beam welding, the ends 43 and 44 of the pipes 41 and 42 may be pressurized and brought into close contact with each other. Can be done very easily. If the shape of each end 43, 44 is the same or similar, the axis L2, L3 of each tube 41, 42 is accurately matched by the groove assembling device, so that the misalignment amount G2 is also reduced. It can be made uniform in the circumferential direction, and the average amount of misalignment can be minimized without partially correcting the amount of misalignment.

In order to form the end portions 43 and 44 into a predetermined shape, a pressing force is applied from the outer surface side. The work can be performed in a large work space outside the body, and the work for forming the end portions 43 and 44 into a predetermined shape is easy.

In the pipe end processing step, each pipe 41,
The end portions 43 and 44 of the 42 are formed into a predetermined shape, and this is achieved by clamping with the clamp bodies 47 and 48 attached to the outer surface side. In this state, the end portions 43 and 44 are cut. In the groove assembling step, the pipes 41 and 42 are clamped under the same clamp conditions as those of the pipe end processing step, so that the pipes 41 and 42 abut each other. Parts 43, 4
The shape of No. 4 is reproduced in the same manner as the shape obtained when the ends 43 and 44 are cut. In this way, by making the clamping conditions the same in the pipe end processing step and the groove assembling step, the high precision end face flatness obtained during cutting can be reproduced at the time of assembly without impairing Grooves can be assembled. In this case, the clamping conditions include, for example, the mounting position of the clamp body 47, the number of clamp locations for pressurized deformation, the amount of protrusion of the clamp bolt at each pressurized position, and the like.

When the ends 43 and 44 of the pipes 41 and 42 are formed into a predetermined shape in the pipe end processing step and the groove assembling step, the predetermined shape can be a perfect cylinder or a shape very close to a perfect cylinder. .

In this case, the true cylindrical shape has a simple shape and is symmetrical with respect to the axis, so that the shape can be easily reproduced. Actually, each pipe 41, 42
Only at the end faces 45, 46 of the respective end portions 43, 44, it is necessary to confirm that the shape is a perfect circle or a very perfect circle. Therefore, the clamp conditions in the pipe end processing step and the groove assembly step are not necessarily the same. Even if it is not necessary, the shape of the end portion can be made the same and it can be easily reproduced.

When the predetermined shape in each step of forming the groove is a true cylinder or a shape very close to a perfect cylinder,
In the groove assembly process, the axis L of each clamped tube is
2 and L3, the root gap G1
In addition, the amount of misalignment G2 can be easily minimized. In general, when the circumferences of the pipes to be welded are different, the misalignment amount G unless one of the pipes is plastically deformed.
2 cannot be made zero. However, if the shape of the pipe end is a perfect circle or a shape very close to a perfect circle, the misalignment amount G2 resulting from the difference in the circumferential length is made uniform in the circumferential direction by matching the axial axes of the ends of the pipes. can do.

In the case where the pipe ends are aligned and the pipe ends are abutted, even if each pipe body is displaced in the circumferential direction, there is no large difference in the amount of misalignment, and the assembling work of the groove is easy. Become. Therefore, in the pipe end processing step, the pipe end of each pipe is corrected to a true cylinder or a shape very close to a true cylinder, and cutting is performed. When straightening is performed, for example, a groove assembly device having a roundness correcting function including the clamp bodies 47 and 48, a shaft centering function, and a pulling function is used.
0 can be assembled with high precision.

Also, in the pipe end machining step, the clamp bodies 47, 48 attached to the ends 43, 44 from the outer surface side in order to form the pipe end into a predetermined shape are not removed even after the end of the cutting.
The state may remain in the state of being mounted even during the pipe moving step, and the process may shift to the groove assembling step. In such a case, each end 4
Since the shape of each of the end portions 43 and 44 can be reliably set to the same predetermined shape as that at the time of cutting, the flatness of each of the end surfaces 45 and 46 at the time of cutting is improved. The groove 40 can be assembled while being held. Therefore, the groove 40 can be reliably assembled with high accuracy. Further, in the groove assembling step, the step of forming the pipe end portion into a predetermined shape is not required, so that the workability of the groove assembling is improved.

The present inventor performed a numerical analysis in order to examine the relationship between the clamping conditions and the deformed state of the tube body in correcting the roundness of the tube end using the same clamp jig as each of the clamp bodies 47 and 48. FIG. 20 shows the target tube 1 in the analysis.
70 and a position from the end of the tube to which displacement due to pressurization is added from the outer surface side and an additional range. FIG.
Indicates the pressing position in the circumferential direction.

In the deformation analysis, as shown in the front view of FIG. 20 (2), the outer diameter d1 in the long axis direction is 766 mm, the outer diameter d2 in the short axis direction is 758 mm, and the average outer diameter dm is 7 mm.
An elliptical cylindrical pipe (steel pipe) 170 having a maximum radius difference Δr of 2 mm with respect to a true cylindrical shape of 62 was used. This tube 17
The roundness of the outer shape at the 0 end face is about 1%, the plate thickness of this tubular body 170 is 19 mm, and the end face 171 is a plane perpendicular to the axis of the tubular body 170.

The pressing position, which is the clamping position, is shown in FIG.
As shown in the side view of (1), there are a plurality of positions on the circumference where the axial distance D10 from the end surface 171 is 120 mm.
The dimension a1 in the axial direction is 40 mm, and the dimension a2 in the direction perpendicular to the diameter line and the axis passing through the pressing position is 50 mm.
Was displaced toward the axis from the outer surface side toward the axis. The pressing positions are equally spaced in the circumferential direction, and an eight-point clamp that presses at eight points including the intersection with the long axis 172 of the outer peripheral surface shown in FIG. 21A, and a length of the outer peripheral surface shown in FIG. Analysis was performed for each of two cases: a 12-point clamp in which the intersection with the shaft 172 was located at the center of the pressure point.

In the analysis, the outer peripheral surface shape of the tubular body 170 was analyzed in a plurality of clamp states in which the amount of clamping, that is, the amount of protrusion of the end of the press fitting realized by the clamp bolt similar to the clamp bolt 63 described above, was different. .
In each case, a non-corrected state (non-pressed state) in which the end of the press fitting is on a cylindrical surface having a diameter of 766 mm circumscribing the tube 170, and each press fitting is protruded 1 mm radially inward from the uncorrected state. 1mm straightened state and 2mm in which each pressing fitting is projected 2mm inward in the radial direction from the uncorrected state
In a straightened state, a 4 mm straightened state in which each push fitting protrudes 4 mm inward in the radial direction from the non-straightened state, and a 6 mm straightened state in which each push fitting is projected 6 mm inward in the radial direction from the uncorrected state. The diameter was determined.

FIG. 22 is a graph showing an analysis result of the eight-point clamp shown in FIG. FIG. 22A shows the outer diameter of the end face 171 corresponding to the welding portion.
(2) is an end face 17 which is a pressing position, which is a position of a press fitting.
The outer diameter at a distance D10 from 1 is shown. In each graph, the horizontal axis represents the angle around the axis with respect to this major axis, with the major axis perpendicular to the axis taken as 0 degree, and the vertical axis represents the tube 1
Shows a diameter of 70. Further, in each graph, in FIG. 21B, the angle from the long axis 172 to the short axis 173 is shown.
The diameter in the 90-degree angle range θ1 to the upper angle position is shown. Each line 180a, 180b shows the diameter in the uncorrected state, each line 181a, 181b shows the diameter in the 1 mm corrected state, and each line 182a, 182b shows 2m.
m shows the corrected state, and each line 183a, 183b is 4 mm
A straightened state is shown, and each line 184a, 184b shows a 6mm straightened state.

As is clear from FIG. 22, in the uncorrected state and the 1 mm corrected state, the correction is insufficient, the ellipse is maintained at the end face 171 and the pressing position, and the outer diameter varies. In the 2 mm straightened state, an appropriate straightening has been performed. The outer diameter at the end face 171 and the pressing position does not vary, and the roundness of the outer shape is 0.1% or less. Could be corrected to a shape very close to a perfect cylinder. Further, in the 4 mm straightened state and the 6 mm straightened state, the correction is excessive at the end face 171 and the pressing position,
The pressing position becomes concave inward in the circumferential direction,
The outer diameter varied.

FIG. 23 is a graph showing an analysis result of the 12-point clamp shown in FIG. 21 (2). FIG. 23A shows the outer diameter of the end face 171 corresponding to the welding portion, and FIG.
3 (2) is an end surface 1 which is a pressing position, which is a position of a press fitting.
The outer diameter at a position of a distance D10 from 71 is shown. In each graph, the horizontal axis indicates an angle around the axis with respect to the major axis as 0 degree with respect to the major axis perpendicular to the axis, and the vertical axis indicates the diameter of the tube 170. Each graph shows the diameter in the above-mentioned angle range θ1. Each line 190a, 190b
Indicates the diameter in the uncorrected state, and each line 191a, 191b
Indicates the diameter in the 1 mm straightened state, and each line 192a, 19
2b shows a 2 mm straightened state, and each line 193a, 183
b shows a 4 mm straightened state, and each line 194a, 194b
Indicates a 6 mm straightened state.

As is clear from FIG. 23, in the uncorrected state and the 1 mm corrected state, the correction is insufficient, the elliptical shape is maintained at the end face 171 and the pressing position, and the outer diameter varies. In the 2 mm straightened state, an appropriate straightening has been performed. The outer diameter at the end face 171 and the pressing position does not vary, and the roundness of the outer shape is 0.1% or less. Could be corrected to a shape very close to a perfect cylinder. In the 4 mm straightened state and the 6 mm straightened state, at the pressing position, the pressing position is concave inward in the circumferential direction, and the outer diameter is varied.
In No. 1, as in the 2 mm straightened state, there was no variation in the outer diameter, the roundness of the outer shape was 0.1% or less, and the shape near the end face could be straightened to a shape very close to a perfect cylinder. In the 4 mm straightened state and the 6 mm straightened state, the outer diameter becomes smaller as a whole at the pressing position, and the outer diameter becomes larger at the end face 171 as the straightening amount (projection amount of the press fitting) corresponding to the above-mentioned clamping amount becomes larger. Has grown.

According to the results of the analysis shown in FIGS. 22 and 23, even if the elliptic cylinder of about 1% was analyzed,
It has been shown that the tube end can be corrected to a substantially round shape by roundness correction at a position about 120 mm from the tube end. Regarding the number of clamp points, it was shown that in both the 8-point clamp and the 12-point clamp, if the clamp portion was corrected to a substantially perfect circle, the pipe end would also have a substantially perfect circular shape. Regarding the number of clamps, when the clamp portion is further deformed by pressing from a perfect circle, in the case of the eight-point clamp, the portion corresponding to the clamp position in the tube end shape is dented,
In the two-point clamp, a result was obtained in which the pipe end maintained a substantially perfect circular shape despite the depression of the clamp portion. From this result, it can be seen that a 12-point clamp is more advantageous than a 8-point clamp for obtaining a perfect circular shape at the end of the tube, with respect to the tube dimensions to be analyzed.

FIG. 24 is a graph showing the displacement of the end face in the tube axis direction in the 2 mm straightened state in the (8 point clamp, 12 point clamp) analysis of each case described above. The horizontal axis is
The clockwise angular position is shown in a state facing the end face 171 from one intersection point with the long axis 172 of the tubular body. This horizontal axis is shown in FIG. 20 (2) such that the uppermost position of the tube is at 0 degree. The vertical axis indicates the amount of displacement of the end face in the axial direction (the amount of displacement from a predetermined reference position). A line with a mark 195 indicates the displacement of the 8-point clamp, and a line with a mark △ indicates the displacement of the 12-point clamp.

As is clear from FIG. 25, each line 195,
Reference numeral 196 substantially overlaps on the graph, and in each case, when the end is corrected to a state very close to a true cylinder, the end face is deformed in substantially the same manner. The maximum displacement of the end face is about ± 0.14 mm, and the maximum displacement of the end face in the axial direction (tube end flatness) is about 0.28 mm.
Therefore, when cutting the end portion, the end surface is formed by cutting the elliptical shape as shown in FIG. 20 while maintaining the outer shape as shown in FIG. 20, and the outer shape of the end surface becomes a perfect circle in the groove assembling process. Therefore, if the shape of the end portion is different between the pipe end processing and the groove assembling, the root gap cannot form a groove with a precision suitable for electron beam welding or the like. Very likely. Therefore, as in the present invention, it is necessary to reproduce the shape of the end portion at the time of pipe end processing and at the time of groove assembly, and to increase the flatness of the end face, and thereby, it is possible to obtain a high precision suitable for electron beam welding and the like. A high groove can be formed.

The inventor of the present invention processed a steel pipe having a thickness of 19 mm and an average outer diameter of 762 mm according to the method of the present invention as described above, and measured the flatness of the end face. In processing the end of the steel pipe, 12 points are clamped at a position where the axial distance from the formed end face is 120 mm using the same clamp body as each of the clamp bodies 47 and 48, and the end portion is formed into a true cylindrical shape. And flat-cut. One example of the measurement results is shown in FIGS.

FIG. 25 is a graph showing the flatness measured while the end after the pipe end processing is straightened into a true cylindrical shape, and FIG. 26 is the flatness measured by removing the clamp body after the pipe end processing. FIG. In each of the graphs of FIGS. 25 and 26, the horizontal axis represents the angular displacement around the axis of the steel pipe, and the vertical axis represents the amount of displacement of the end face in the axial direction (the amount of displacement from a predetermined position). As shown by the line 197 in FIG. 25, in the corrected state, the maximum displacement (deviation) of the end face is about 0.1 mm.
In contrast, as shown by line 198 in FIG.
When the correction is released, the maximum displacement of the end face is about 0.2 mm. Thus, it was confirmed that the clamp condition of the pipe end greatly affected the flatness of the pipe end face.

The present inventor measured the accuracy of a groove formed by performing the above-described groove forming method of the present invention. The two steel tubes used to form the groove had a thickness of 19 mm
And a steel pipe having an average outer diameter of 762 mm. Using each of such steel pipes, at a position where the axial distance from the end face formed by pipe end processing is 120 mm, a straight cylindrical shape is formed into a 12-point clamp by the same clamp bodies as the clamp bodies 47 and 48 described above. The ends are straightened, the pipe ends are machined (plane cutting), and the two uncapped tubes are clamped using the same apparatus as the groove assembling apparatus 100 in the same clamp conditions as in the pipe end machining. And the ends were corrected into a true cylindrical shape and butted, and the groove was assembled and formed. The root gap and misalignment of this groove were measured. FIG. 27 shows the measurement results of the accuracy of the groove formed in this embodiment.

FIG. 27A is a graph showing the amount of misalignment of a groove formed by one embodiment, and FIG. 27B is a graph showing the root gap of a groove formed by one embodiment. is there. In FIG. 27 (1) and FIG. 27 (2), the horizontal axis indicates the angular position around the axis of the steel pipe.
In FIG. 7 (1), the vertical axis indicates the amount of misalignment.
In (2), the vertical axis indicates the route gap. FIG.
As shown by the line 185 in (1), the amount of misalignment is at most less than 1.5 mm, and as shown by the line 186 in FIG. 27 (2), the root gap is at most 0.10 mm. In this way, a groove with extremely high precision can be formed.

In order to compare the groove forming method of the present invention with the method of the prior art, the present inventor formed the groove without reproducing the pipe end shape in the assembling process according to the conventional groove forming method. The accuracy of the groove was measured. The two steel pipes used for forming the groove are the same steel pipes as those used in the examples. Using such steel pipes, without roundness correction, pipe end processing (plane cutting processing) is performed in a state of being simply clamped for fixing, and these two pipes are formed in the same manner as the groove assembly apparatus 100. Using a device, it was straightened into a true cylindrical shape, butted, and a groove was assembled and formed. The root gap and misalignment of this groove were measured. FIG. 28 shows the measurement results of the accuracy of the groove formed in this comparative example.

FIG. 28A is a graph showing the amount of misalignment of a groove formed by one embodiment, and FIG. 28B is a graph showing the root gap of a groove formed by one embodiment. is there. In FIG. 28 (1) and FIG. 28 (2), the horizontal axis indicates the angular position around the axis of the steel pipe.
In FIG. 8 (1), the vertical axis indicates the amount of misalignment.
In (2), the vertical axis indicates the route gap. FIG.
As shown by the line 187 in (1), the amount of misalignment is 2 m at the maximum.
m, and the root gap is at most 0.20 mm as indicated by the line 188 in FIG. 28 (2). As described above, the precision of the groove is lower than that of the embodiment, and particularly, the root gap is twice as large as that of the embodiment of the present invention.

In the examples and comparative examples shown in FIGS. 27 and 28, each tube is a tube having a relatively good roundness of about 0.4% in the outer shape on the end face. As for the flatness of the end face in the clamped state after the pipe end processing, the displacement amount (displacement amount) in the axial direction was about 0.1 mm or less, and the accuracy was secured. From the measurement results of the groove accuracy of the above Examples and Comparative Examples using such a tubular body, by forming the groove according to the groove forming method of the present invention, high precision that could not be obtained by the conventional method It was confirmed that a groove could be formed.

FIG. 29 is a cross-sectional view showing another pipe end processing apparatus 200 for explaining a pipe end processing method according to another embodiment of the present invention. FIG. 30 is a sectional view taken along line XXX of FIG. −
It is sectional drawing seen from XXX. Portions having the same configuration as in the above-described embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the pipe end processing apparatus 200, a cutting means 201 and a fixing means 202 are connected by a connecting body 203.
The cutting means 201 includes a face plate 205 for holding the blade 204.
And a driving unit 206 that rotationally drives the face plate. Face plate 2
A tool post 207 is provided on an outer peripheral portion of the tool 05, and a tool (bite) 204 is held on the tool post. The drive unit 206 can rotationally drive the face plate 205 about the axis L10.

The fixing means 202 has three fixing legs 208, 209 and 210 which can be displaced in conjunction with each other in the radial direction. Each of the fixed legs 208 to 210 is held by a holding portion 211 connected by a connecting body 203 so as to be coaxial with the face plate 205, and can be driven to be displaced in the radial direction with respect to the axis L1. This fixing means 202 is
1, the fixed legs 208 to 210 of the handle 212 disposed outside the pipe body are displaced radially outward to abut against the inner peripheral surface of the pipe body 41.
So that the end 43 faces the face plate 205 and the pipe 41
Can be held on the tube 41 so that the axis L2 of the flat plate 205 coincides with the rotation axis L10 of the face plate 205.

Using this pipe end processing apparatus 200, the cutting means 201 is held on the pipe 41, and the face plate 205 is axially displaced while being rotationally driven.
Can be cut to form an end face 45. Even with such a pipe end processing apparatus 200, it is possible to cut the respective end portions 43 and 44 similarly to the pipe end processing apparatus 50 described above. Such a device can also cut the end of a pipe body at a welding site, thereby improving convenience.

In the above embodiment, the groove assembling apparatus 10
In a state where each of the clamp bodies 47 and 48 constituting the first part 0 are mounted and clamped, the respective end parts 43 and 44 are cut and carried to the welding site while being mounted, and the pipe bodies 41 and 42 are mounted.
Can be assembled to form a groove. However, after the cutting (pipe end processing), the respective clamp bodies 47 and 48 are temporarily removed, and the respective pipe bodies 41 and 42 are carried to the site, and the clamp bodies 47 and 48 are again provided. Is attached and clamped.
4 may be reproduced. Further, the clamp jigs are separate from the clamp bodies 47 and 48, and have the same clamping ability as the clamp bodies 47 and 48, specifically, the same rigidity, the same clamp force, and the same number of points. Each end 43, using a clamp jig that can press
After clamping and cutting 44, each clamp body 4
Alternatively, the end portions 43 and 44 may be clamped and abutted with each other by attaching 7, 48. Even in this manner, in the groove assembling process, it is possible to reproduce the shape of each end 43, 44 in the tube end processing process.

When the shape of the end portion is reproduced by using different jigs as described above, the clamp position, that is, the number of clamps (the number of pressed portions) is made the same as described above, and the arrangement interval is made the same. The shape can be easily reproduced by making the axial distance from the end face to be formed the same.

The above embodiments are merely examples of the present invention, and the configuration can be changed within the scope of the present invention. For example, the number of divisions of the clamp body as the clamp jig may be two or three or more, and the number of clamp bolts is not limited as long as it is three or more.
Further, the tubular body does not necessarily need to be corrected into a true cylinder, and may have another shape such as a substantially polygonal shape. Further, for example, the material and dimensions of the tube are not limited to the exemplified materials and dimensions, and the groove may be assembled by abutting other tubes. Not only a groove for electron beam welding but also a groove for other welding such as MIG welding as described in connection with the prior art may be formed. The purpose is not limited to the formation of a pipeline for transporting gas, but may be a pipeline for mailing oil, or may be for the purpose of forming other industrial products and structures. In addition to the I groove, another groove such as a V groove, a Y groove and a U groove may be assembled.

[0101]

As described above, according to the present invention, when assembling a groove by abutting each tube in the tube assembly process, the end face of each tube is obtained by cutting in the tube end machining process. The flatness is as high as the required flatness, the root gap of the groove formed by the two end faces can be extremely small, and a highly accurate groove can be formed. Therefore, high energy density welding can be suitably performed. Further, since the pressing force is applied from the outer surface side, it is easy to form the end of the tube into a predetermined shape.

Further, according to the present invention, the shape of the end portion of the tube can be reproduced by making the clamping conditions the same in the tube processing step and the assembling step, and a high-precision groove can be formed. be able to.

Further, according to the present invention, in the pipe end processing step and the assembling step, by forming the end of the pipe into a true cylinder or a shape very close to a perfect cylinder, it is possible to form a groove with high precision. This facilitates the operation of forming the high-precision groove.

Further, according to the present invention, a groove is formed by abutting the respective pipe bodies in a state in which the clamp jig mounted in the pipe end processing step is mounted as it is, so that the shape of the end portion can be reliably reproduced. This makes it easy to form a high-precision groove reliably and easily.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a groove forming method according to an embodiment of the present invention.

FIG. 2 is a view showing a groove forming method of FIG. 1;

FIG. 3 is a front view of a pipe end processing apparatus 50 showing a pipe end processing method.

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a cross-sectional view taken along the line VV of FIG. 3;

6 is a side view showing the clamp body 47. FIG.

FIG. 7 is a front view showing a clamp body 47;

FIG. 8 is an enlarged front view showing the vicinity of a connection point of the ring member 64.

FIG. 9 is a side view showing one circumferential end of the ring member 64 in the circumferential direction.

FIG. 10 is a sectional view showing a clamp bolt 63;

FIG. 11 is a cross-sectional view taken along line XI-XI of FIG. 10;

FIG. 12 is a plan view showing a clamp bolt 63 as viewed from above in FIG. 11;

FIG. 13 is a sectional view showing the clamp bolt 63 as viewed from above in FIG. 11;

14 is a side view showing the clamp body 48. FIG.

15 is a front view showing the clamp body 48. FIG.

16 is a front view showing the groove assembling apparatus 100. FIG.

FIG. 17 is a diagram showing a drawing means 101.

FIG. 18 is a front view showing the butted state of the respective tubes 41 and 42.

FIG. 19 is an enlarged sectional view showing a section XIX of FIG. 18;

FIG. 20 is a diagram showing a pressurizing condition for correction analysis.

FIG. 21 is a diagram showing a pressing position in a circumferential direction.

FIG. 22 is a graph showing an analysis result of an 8-point clamp.

FIG. 23 is a graph showing an analysis result of a 12-point clamp.

FIG. 24: 2 mm for 8-point and 12-point clamps
It is a graph which shows the amount of displacement of the end face in a correction state.

FIG. 25 is a graph showing measurement results of the end face of the tubular body.

FIG. 26 is a graph showing measurement results of the end face of the tubular body.

FIG. 27 is a graph showing measurement results of groove accuracy according to one embodiment.

FIG. 28 is a graph showing measurement results of groove accuracy of a comparative example.

FIG. 29 is a front view showing a cutting apparatus 200 of a cutting method according to another embodiment of the present invention.

FIG. 30 is a cross-sectional view taken along line XXX-XXX of FIG. 29.

FIG. 31 shows a cutting apparatus 1 according to a conventional cutting method.
FIG.

FIG. 32 is a cross section showing the cutting apparatus 1.

FIG. 33 is a cross-sectional view showing a groove assembling apparatus 11 in a conventional tube assembly method.

34 is a side view of the groove assembling apparatus 11. FIG.

[Explanation of symbols]

 40 Groove 41, 42; 170 Tube 43, 44 End 45, 46; 171 End 47, 48 Clamp 50, 200 Pipe end processing device 62 Clamp ring 63 Clamp bolt 90 Lock member 91 Lock hole 93 Pull cylinder DESCRIPTION OF SYMBOLS 100 Groove assembly apparatus 101 Pulling means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tsutomu Tomita 2-4-1 Hamamatsucho, Minato-ku, Tokyo World Trade Center Building Kawasaki Heavy Industries, Ltd., Tokyo Head Office (72) Inventor Akio Nishida Harima-cho, Kako-gun, Hyogo 8 Niijima Kawasaki Heavy Industries Co., Ltd. Harima Plant (72) Inventor Toshinori Iwase 8 Harima Town, Kako-gun, Hyogo Prefecture Kawashima Heavy Industries Co., Ltd. Harima Plant F-term (reference) 3J022 EA42 EB14 EC17 EC22 ED22 FB12 GA04 GA13 GB90

Claims (4)

[Claims] 1. A method of processing and assembling a groove in order to form a welded joint by abutting ends of two pipes, wherein an outer surface of each pipe is formed in a pipe end processing step of each pipe. The end of each tube is cut in a state in which the end is given a predetermined shape by applying a pressing force from the side, and in the assembly process of each tube, the shape of the end of each tube is changed to the tube end. Reproduce the same shape as the shape of the processing process,
A groove forming method for a tube, comprising assembling a groove by abutting ends of the respective tubes. 2. In the pipe end processing step of each pipe body, an end portion of each pipe body is cut and clamped from the outer surface side of each pipe body, and in the assembling step of each pipe body, each of the pipe bodies is cut. The opening of the pipe body according to claim 1, wherein the end is clamped under the same clamping conditions as at least a clamping position and a clamping force in the pipe end processing step, and the groove is assembled by abutting. Prior forming method. 3. In the tube end processing step of each tube, each tube is clamped from the outer surface side of each tube, and the end of each tube is straightened to a true cylinder or a shape very close to a perfect cylinder. In the process of assembling each tube, each tube is clamped from the outer surface to correct the end of each tube into a true cylinder or a shape very close to a perfect cylinder. 3. The groove forming method for a tubular body according to claim 1 or 2, wherein the groove is assembled by matching the axes of the grooves. 4. In the pipe end processing step of each pipe, a clamp jig is mounted from the outer surface side of each pipe and clamped, and in this state, the end of each pipe is cut and processed. In the assembling step, the groove is assembled by abutting the ends of the respective tubes while the clamp jig attached in the tube end processing step is still attached to the ends of the respective tubes. The method for forming a groove of a tubular body according to claim 1.