JP2018176244A - Pipe joining device and pipe joining method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pipe joining device and a pipe joining method by which good joining can be realized by friction stir welding even if ends of a pipe, which is configured from a material having a thick wall and a high strength, are joined.SOLUTION: A pipe joining device comprises: a probe which is pushed into a joint part of two pipes and performs friction stir welding; a joint tool which comprises the probe at a tip thereof; a rotating mechanism which rotates the joint tool around a central axis of a metal pipe; a device body which is provided with the rotating mechanism; and an axial movement part which is so configured as to be capable of freely advancing and retracting in a direction along the central axis of the pipe with respect to the device body. The device body comprises a first clamp mechanism which holds one pipe. The axial movement part comprises a second clamp mechanism which holds the other pipe.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a joining apparatus for butting and joining pipes, and more particularly to a pipe joining apparatus and pipe joining method for joining pipes by friction stir welding.

  Conventionally, in pipeline construction work, pipes are butt-joined in the axial direction. For example, a pipe (newly installed pipe) whose both ends are not fixed is joined to a pipe (an existing pipe) in which one end is joined and fixed to a pipe already laid. At this time, a groove is formed at each end of the butted tubes, and a predetermined gap is held between the ends of the tubes, and for example, MAG (Metal Active Gas) welding is performed from the outer periphery of the tube. Fusion welding is performed. When performing such welding, the process of holding the pipe in a predetermined position and preparing it in a weldable state, the process of welding, and the process of removing the apparatus to be welded require a large amount of welding to weld one pipe joint. It took a long time. In particular, since a relatively thick steel pipe is used for the pipeline, the welding process took a great deal of time. In addition, since pipeline welding is performed outdoors, it is necessary to take measures against wind during operation, and the influence on welding workers such as electric shock, arc light and pneumoconiosis has been a problem.

  On the other hand, friction stir welding (FSW; Friction Stir Welding) which can join metal materials easily compared with fusion welding, such as mug welding, attracts attention. In friction stir welding, a welding tool having a cylindrical projection called a probe on the tip surface is used. When the probe is pressed against the joint and the jointing tool is rotated about the central axis, frictional heat is generated between the probe and the material of the joint to soften the material and the probe is buried in the material. The material around the probe causes plastic flow due to the rotation of the probe, and the material is joined when the joining tool is moved along the joining line.

  As what joins metal tubes together by friction stir welding, what utilized friction stir welding as a joining apparatus of a metal tube is disclosed by patent document 1, for example. The metal pipe joining apparatus includes a joining tool, moves the joining tool circumferentially along the inner circumferential surface of the metal pipe, joins the two metal pipes, and is disposed inside the metal pipe. Friction stir welding is performed from the inside. By friction stir welding, the time for metal pipe bonding can be shortened, no windbreak measures become necessary, and the influence on workers during bonding can be reduced.

International Publication No. 2013/172244

  However, when friction stir welding is performed by butting the ends of the metal tubes, the probe of the welding tool is embedded in the joint and the probe is rotated. Depending on the construction conditions, so-called rotational deformation may occur in which the front of the joint line opens. Therefore, rotational deformation occurs at the time of friction stir welding, and there is a problem that the construction can not be continued when the welding line is opened. In addition, in the case of friction stir welding, in order to cause the material of the joint to plastic flow, it is necessary to make the ends of the metal pipe contact as uniformly as possible. However, since the end of the metal pipe can not be processed into an ideal flat surface for the convenience of production, there is a problem that the ends of the metal pipe must be brought into contact with each other with high accuracy in order to perform friction stir welding. there were. In addition, since friction stir welding is performed by plastic flow, the tolerance for the difference in the joint of the pipe is smaller than that of the mag welding in which the metal is melted and joined. Therefore, in the case of friction stir welding, it was necessary to reduce the difference in the joint between the tubes.

  Furthermore, in consideration of safety, a relatively thick steel pipe is used as a metal pipe used for a pipeline or the like. In friction stir welding of such metal tubes, in order to cause plastic flow of the material of the joint, it is necessary to increase the number of revolutions of the probe and to increase the pressing force to press the jointing tool against the joint. Therefore, in order to suppress rotational deformation, there is a problem that it is necessary to restrain by a larger force. In the joining apparatus disclosed in Patent Document 1, for example, in a relatively thin pipe made of a low strength light metal pipe, even if friction stir welding is possible, for example, a thick metal pipe used in a pipeline There were limits to joining together.

  The present invention has been made to solve the above-mentioned problems, and it is possible to achieve good bonding even when the ends of tubes made of relatively thick and high-strength materials are joined. An object of the present invention is to provide a pipe joint device and a pipe joint method.

  A pipe joining apparatus according to the present invention comprises a probe that is pushed into a joint of two pipes and is subjected to friction stir welding, a joining tool provided with the probe at its tip, and a rotation mechanism that rotates the joining tool around the central axis of the pipe. And a device body provided with the rotation mechanism, and an axial moving unit configured to be movable back and forth in a direction along the central axis of the pipe with respect to the device body, the device body comprising A first clamp mechanism for holding the tube is provided, and the axial movement unit is provided with a second clamp mechanism for holding the other tube.

  Further, according to the pipe joint device according to the present invention, a probe which is pushed into a joint portion of two pipes and performs friction stir welding, a bonding tool provided with the probe at the tip, a device main body provided with the bonding tool, and the bonding The apparatus includes: a rotation mechanism configured to rotate a tool around the apparatus body; and an axial movement unit configured to be movable back and forth in a direction along the central axis of the rotation mechanism with respect to the apparatus body. The first clamp mechanism is configured to be movable back and forth in the radial direction of the rotation track of the rotation mechanism, and the second moving mechanism is configured to be movable in the radial direction of the rotation track of the rotation mechanism. Equipped with

  Further, in the pipe joining method according to the present invention, the probe provided in the pipe joining device is aligned with the end face of the existing pipe, and the first clamp mechanism provided in the pipe joining device is brought into contact with the inner circumferential surface of the existing pipe A pipe bonding apparatus installation step of fixing a bonding apparatus inside the existing pipe, and a second clamp mechanism provided in the pipe bonding apparatus disposed inside a new pipe to be connected to the existing pipe, the second clamp mechanism A new pipe fixing step of bringing the new pipe into contact with the inner peripheral surface of the new pipe and fixing the new pipe to the pipe joining device; moving the second clamp mechanism to the first clamp mechanism side; Pressing the probe rotated from the inside into the joint formed by bringing the end face of the new pipe into contact and applying a load, and bringing the end face of the existing pipe and the end face of the new pipe into contact with each other Before along the junction And friction stir welding step of performing friction stir welding by moving the probe, but with a.

  According to the present invention, when friction stir welding a tube made of a relatively thick and high-strength material, the opening of the joint and the level difference of the joint caused by pushing the probe into the joint are suppressed, and the accuracy is achieved. Good bonding can be done. In addition, it is possible to join pipes with simple equipment at the site where pipes are connected.

It is a schematic diagram of the state which installed the pipe joining apparatus concerning Embodiment 1 in the metal pipe. It is a schematic diagram which shows the AA cross section of FIG. It is a schematic diagram which shows the contact part of a clamp head and a metal pipe. FIG. 6 is an explanatory view of a metal pipe joining method using the pipe joining device according to the first embodiment. FIG. 6 is an explanatory view of a metal pipe joining method using the pipe joining device according to the first embodiment. FIG. 6 is an explanatory view of a metal pipe joining method using the pipe joining device according to the first embodiment. FIG. 6 is an explanatory view of a metal pipe joining method using the pipe joining device according to the first embodiment. FIG. 6 is an explanatory view of a metal pipe joining method using the pipe joining device according to the first embodiment. It is explanatory drawing of the metal pipe joining method which uses the pipe joining apparatus concerning Embodiment 2 of this invention. It is explanatory drawing of the metal pipe joining method which uses the pipe joining apparatus concerning Embodiment 2 of this invention. It is the figure which looked at the clamp band of FIG.9 and FIG.10 from the pipe-axis direction. It is an enlarged view of the junction part 99 periphery of FIG.

  The pipe joining apparatus according to the present invention is mainly used in friction stir welding of two pipes. Hereinafter, an embodiment of a pipe joining apparatus according to the present invention will be described by taking the case of joining two metal pipes as an example.

Embodiment 1
FIG. 1: is a schematic diagram of the state which installed the pipe bonding apparatus 100 concerning Embodiment 1 in the metal pipe. FIG. 1: represents typically the pipe joining apparatus 100 installed in the inside of the metal pipe 80,90 in which the end surface 81,91 was abutted. The metal tubes 80 and 90 are arranged, for example, such that the tube axes 83 and 93 are in the horizontal direction. However, the arrangement of the tube shafts 83 and 93 is not limited to the horizontal direction, and the posture of the metal tubes 80 and 90 can be appropriately changed depending on the installation environment. In the following description, in particular, the metal pipe 80 may be described as the existing metal pipe 80, and the metal pipe 90 may be described as the new metal pipe 90. One end of the existing metal pipe 80 is joined and fixed to the already installed metal pipe. The new metal pipe 90 is a metal pipe joined to the existing metal pipe 80, and its both ends are not fixed in the state before joining. The metal pipes 80 and 90 correspond to the "pipe" of the present invention, the existing metal pipe 80 corresponds to the "existing pipe" of the present invention, and the new metal pipe 90 corresponds to the "new pipe" of the present invention.

  The pipe joint device 100 is used, for example, to join metal pipes 80 and 90 used for pipelines buried underground. In the first embodiment, a steel pipe is used as the metal pipe 80, 90, and in consideration of the strength against a pressure in the pipe and the earthquake resistance, for example, a relatively thick one having a thickness of 10 mm or more is used.

  The pipe bonding apparatus 100 is installed inside the metal pipes 80, 90, and bonds the joint portion 99 from the inside of the metal pipes 80, 90. According to the pipe bonding apparatus 100, since the metal pipes 80 and 90 can be bonded without the need for a device or the like installed outside, it is necessary to provide a large space around the bonding portion 99 when bonding the metal pipes 80 and 90. Absent. For example, in the connection of a pipeline buried in the ground, it is not necessary to excavate only the periphery of the joint portion 99 widely to secure a work space, and it is possible to reduce the work time required for laying the pipeline.

  The pipe joining apparatus 100 includes an apparatus main body 70 provided with a joining tool 40. The welding tool 40 has a probe 41 at its tip. The probe 41 is rotated at a high speed and pushed into the bonding portion 99, and bonds using the frictional heat of the material forming the bonding portion 99 and the probe 41. The apparatus main body 70 is provided with a rotation mechanism 74. The rotation mechanism 74 rotates the welding tool 40 around the device body 70. By rotating the rotation mechanism 74 around the device body 70, the probe 41 provided on the welding tool 40 moves along the welding portion 99 while being pushed into the welding portion 99. The joint 99 is joined by friction stir welding by rotating the probe 41 around the joint 99 in the circumferential direction of the metal tubes 80 and 90.

  The device body 70 includes a roller 50 in contact with the inner circumferential surface 82 of the metal tube 80 and a third clamp mechanism 30 configured to apply a load to the inner circumferential surface 82 of the metal tube 80. The roller 50 is provided so as to protrude outward from the apparatus main body 70 in accordance with the inner diameter of the metal pipe 80. When the roller 50 contacts the inner circumferential surface 82 of the metal tube 80 and rolls, the apparatus main body 70 can easily move the inside of the metal tube 80 in the direction along the tube axis 83. The third clamp mechanism 30 is configured such that the clamp head 31 can be advanced and retracted outward from the apparatus main body 70. The device body 70 can be fixed to the inside of the metal tube 80 by pressing the clamp head 31 against the inner circumferential surface 82 of the metal tube 80.

  In addition, the device main body 70 includes the first clamp mechanism 10 in the vicinity of the welding tool 40. It is desirable that the first clamp mechanism 10 be provided as close as possible to the joined end surface 81 of the metal tube 80. The first clamp mechanism 10 includes a clamp head 11 which protrudes outward from the device body 70 and is retractable. Furthermore, the clamp head 11 is configured to be movable forward and backward in the radial direction of the rotation path of the rotation mechanism 74. The clamp heads 11 are equally disposed circumferentially around the apparatus body 70. The first clamp mechanism 10 presses the clamp head 11 against the inner circumferential surface 82 of the metal pipe 80 to fix the device body 70 inside the metal pipe 80. Desirably, the first clamp mechanism 10 fixes the apparatus main body 70 so that the rotation center of the rotation mechanism 74 and the pipe axis 83 of the metal pipe 80 coincide with each other. In addition, the clamp head 11 is brought into contact with the inner peripheral surface 82 at a position close to the end surface 81 of the metal tube 80, and a load is applied to the inner peripheral surface 82 of the metal tube 80. Correct the shape. The shape correction process of the end of the metal tube 80 will be described later.

  The pipe joining apparatus 100 has an axial moving unit 71 which can be advanced and retracted from the apparatus body 70 in the direction along the pipe axis 83 of the metal pipe 80. In other words, the axial direction moving unit 71 is configured to be movable in the direction along the central axis of rotation of the rotation mechanism 74 with respect to the apparatus main body 70.

  The axial moving unit 71 includes a second clamp mechanism 20. The second clamp mechanism 20 includes a clamp head 21 which protrudes outward from the axial movement unit 71 and is movable back and forth. Furthermore, the clamp head 21 is configured to be able to advance and retract in the radial direction of the rotation path of the rotation mechanism 74. The clamp head 21 presses the clamp head 21 against the inner circumferential surface 92 of the metal tube 90 to fix the metal tube 90 to the axial movement portion 71. The axial direction moving unit 71 can move the second clamp mechanism 20 in a direction approaching the first clamp mechanism 10 while fixing the metal pipe 90 to the second clamp mechanism 20. The tube bonding apparatus 100 includes a drive unit (not shown), and the drive unit moves the axial movement unit 71 such that the second clamp mechanism 20 moves closer to or away from the first clamp mechanism 10. Further, as shown in FIG. 1, in a state where the end face 81 of the metal pipe 80 and the end face 91 of the metal pipe 90 are in contact, the drive unit is capable of applying a load in the direction of pressing the end faces together. A load is generated in a direction to attract the axial direction moving portion 71 to 70. The second clamp mechanism 20 also brings the clamp head 21 into contact with the inner circumferential surface 92 at a position close to the end surface 91 of the metal tube 90, and applies a load to the inner circumferential surface 92 of the metal tube 90 to join the metal tubes 90. The shape of the end being

  The second clamp mechanism 20 moves to the side closer to the first clamp mechanism 10, and the end face 81 of the metal pipe 80 and the end face 91 of the metal pipe 90 contact each other, and the load which mutually presses between the end face 81 and the end face 91 Preferably, the center of the second clamp mechanism 20 is configured to be coaxial with the central axis of the first clamp mechanism 10 when it is engaged. Further, the central axis of the second clamp mechanism 20 and the central axis of the first clamp mechanism may be coaxially positioned. For example, the apparatus main body 70 is provided with a guide for supporting the movement of the axial movement part 71, and the axial movement part 71 is configured to move parallel to the central axis of the first clamp mechanism 10.

  A cable 72 for supplying power or the like for driving the pipe bonding apparatus 100 is connected to the metal pipe 90 side of the pipe bonding apparatus 100. The cable 72 extends from the axial movement portion 71 side to the other end of the metal pipe 90 and is drawn to the outside.

Next, shape correction of the ends of the metal tubes 80 and 90 will be described.
FIG. 2: is a schematic diagram which shows the AA cross section of FIG. The first clamp mechanism 10 applies a load by bringing the clamp head 11 attached to the end of the rod 12 into contact with the inner circumferential surface 82 of the metal tube 80. The outer peripheral surface of the clamp head 11 has a shape obtained by dividing the cylindrical surface into an arbitrary number. In the first embodiment, the outer peripheral surface of the clamp head 11 has a shape obtained by dividing a cylindrical surface having the same radius as the inner peripheral surface 82 of the metal tube 80 into twelve. The first clamp mechanism 10 presses the clamp head 11 toward the inner circumferential surface of the metal pipe 80 by, for example, hydraulic pressure, and applies a load uniformly over the entire circumference of the inner circumferential surface 82. The second clamp mechanism 20 is also configured in the same manner as the structure of the first clamp mechanism 10 shown in FIG. That is, the B-B cross section of FIG. 1 is the same as that of FIG.

  FIG. 3 is a schematic view of the contact portion between the clamp head 11 and the metal tube 80. As shown in FIG. FIG. 3 is a view of a part of the end face 81 of the metal pipe 80 as seen from the direction along the pipe axis. FIG. 3A shows a state before the first clamp mechanism 10 contacts the inner circumferential surface 82 of the metal tube 80. FIG. 3B shows a state in which the clamp head 11 of the first clamp mechanism 10 is in contact with the inner circumferential surface 82. In FIG. 3C, a load is applied from the clamp head 11 to the inner circumferential surface 82. The shape of is corrected.

  The metal pipe 80 is, for example, a welded steel pipe. In the welded steel pipe, the cross-sectional shape is not formed in a perfect circle for manufacturing convenience, and there are a portion where the inner circumferential surface 82 protrudes with respect to the true circle and a portion where the inner circumferential surface 82 is recessed. The welded steel pipe is formed by deforming a steel strip into a circular shape in the width direction and welding the end portions in the width direction of the steel strip. Therefore, the shape of the welded steel pipe is corrected in order to remove the deformation due to the influence of the residual stress or the like of the welded portion. When the inner circumferential surface 82 of the metal tube 80 is seen in detail, it is distorted, for example, in a polygonal shape due to the shape of the jig used for the correction.

  When the metal pipe 80 and the metal pipe 90 are joined with the cross-sectional shape as shown in FIG. 3A, a step (difference) occurs on the inner peripheral surface and the outer peripheral surface of the joint portion 99. If the inner and outer peripheral surfaces of the joint portion 99 are joined while having a level difference, the joint depth (the throat thickness) of the metal pipes 80 and 90 in the tube sheet thickness direction becomes uneven, and the circumference of the metal pipes 80 and 90 Bonding strength varies depending on the position of the direction. Moreover, there is a possibility that the metal tubes 80 and 90 joined may be damaged etc. starting from the level difference which remained after joining. Therefore, as in the tube bonding apparatus 100 according to the first embodiment, the friction stir welding is performed on the bonding portion 99 while correcting the cylindrical shape of the end portions of the metal pipe 80 and the metal pipe 90, thereby producing the bonding portion 99. Staggering can be suppressed, and good joint quality can be secured.

  As shown in FIG. 3, the outer peripheral surface 13 of the clamp head 11 has a shape obtained by dividing the cylindrical surface by an arbitrary number in the circumferential direction. In the first embodiment, the outer circumferential surface 13 is formed to be a cylindrical surface equal to the inner diameter of the metal pipe 80. As shown in FIG. 3B, in a state where the outer peripheral surface 13 of the clamp head 11 is in contact with the inner peripheral surface 82 of the metal tube 80 and no load is applied to the inner peripheral surface 82, A contact portion 84 and a clearance 85 are formed between the outer circumferential surface 13 and the inner circumferential surface 82 of the metal tube 80. Here, the first clamp mechanism 10 presses the clamp head 11 against the inner circumferential surface 82 of the metal pipe 80 by a force such as oil pressure. Since the clamp head 11 is configured to have higher rigidity than the metal tube 80, the inner circumferential surface 82 of the metal tube 80 is gradually corrected in the shape following the outer circumferential surface 13 of the clamp head 11.

  As shown in FIG. 2, the clamp head 11 preferably has a plurality of clamp heads 11 arranged along the inner circumferential surface 82 of the metal tube 80 without any gap as much as possible, but is limited to this form. It is not a thing. Each clamp head 11 may be installed at a predetermined distance between adjacent clamp heads 11. Moreover, in FIG. 2, although the clamp head 11 is arrange | positioned in 12 circumferential directions equally, this division number can also be set suitably.

  The second clamp mechanism 20 is also configured in the same manner as the first clamp mechanism 10, and the shape of the end portion of the metal tube 90 is corrected according to the outer peripheral surface 23 of the clamp head 21.

  4-8 is explanatory drawing of the metal pipe joining method which uses the pipe joining apparatus 100 which concerns on Embodiment 1. FIG. A metal pipe joining method using the pipe joining apparatus 100 according to the first embodiment will be described using FIGS. 4 to 8.

  As shown in FIG. 4, first, the pipe joining apparatus 100 is installed inside the existing metal pipe 80. The existing metal pipe 80 forms a joint 99 by abutting one end face 81 shown in FIG. 4 to the end face 91 of the new metal pipe 90. The other non-illustrated end face of the existing metal pipe 80 is joined to another metal pipe.

  Since the pipe bonding apparatus 100 is provided with the roller 50 installed so as to project outward from the apparatus main body 70, the roller 50 is in contact with the inner peripheral surface 82 inside the existing metal pipe 80 and is rolled along the pipe axis. It is movable in the other direction. At this time, the pipe bonding apparatus 100 is adjusted such that the tip end of the probe 41 is aligned with the end surface 81 of the existing metal pipe 80 in the pipe axis direction.

  When the tip of the probe 41 is disposed at an appropriate position, the third clamp mechanism 30 provided in the apparatus body 70 is brought into contact with the inner circumferential surface 82 of the existing metal pipe 80 to apply a load. Thus, the device body 70 is fixed to the inner circumferential surface 82 of the existing metal pipe 80. The new metal pipe 90 is inserted from the end face 91 side with the axial moving part 71 projecting from the end face 81 of the existing metal pipe 80 so that the end face 91 of the new metal pipe 90 faces the end face 81 of the existing metal pipe 80 It is arranged. The new metal pipe 90 is movably supported, for example, by being supported in a suspended state or supported on a table, depending on the installation environment.

  As shown in FIG. 5, the first clamp mechanism 10 is operated when the device body 70 is fixed at a proper position. The first clamp mechanism 10 applies a load by bringing the clamp head 11 into contact with the inner circumferential surface 82 of the existing metal pipe 80. The load by which the first clamp mechanism 10 pushes the inner circumferential surface 82 is set higher than the load by which, for example, the third clamp mechanism 30 presses the inner circumferential surface 82, whereby the center of the first clamp mechanism 10 is the existing metal The pipe jointing apparatus 100 is positioned so as to be located on the pipe axis 83 of the pipe 80. At the same time as the pipe bonding apparatus 100 is positioned, the inner peripheral surface 82 of the existing metal pipe 80 is corrected in shape along the outer peripheral surface 13 of the clamp head 11. The process of installing the pipe joining apparatus 100 shown in FIGS. 4 and 5 in the existing metal pipe 80 is called a pipe joining apparatus installation process.

  The third clamp mechanism 30 may release the clamp when the first clamp mechanism 10 is actuated and a load is applied from the clamp head 11 to the inner circumferential surface 82 in the pipe bonding apparatus installation step. Alternatively, the third clamp mechanism 30 may release the load immediately before the clamp head 11 applies a load to the inner circumferential surface 82. Further, in the pipe bonding apparatus 100, the first clamp mechanism 10 may be provided without providing the third clamp mechanism 30 in the device main body 70. If the first clamp mechanism 10 corrects the shape of the end of the existing metal pipe 80 and can position the existing metal pipe 80 and the apparatus main body 70, the roller 50 and the third clamp mechanism 30 are It is not limited to the form shown in the form 1, and other forms can be taken.

  Next, the new metal pipe 90 is fixed to the pipe joining apparatus 100. This process is called a new metal pipe fixing process. As shown in FIG. 6, the second clamp mechanism 20 provided in the axial movement unit 71 is operated. The second clamp mechanism 20 also has a structure similar to that of the first clamp mechanism 10, and applies a load by bringing the clamp head 21 into contact with the inner circumferential surface 92 of the new metal pipe 90. The new metal pipe 90 is, for example, suspended and supported, and is movably supported. Therefore, when the clamp head 21 contacts the inner circumferential surface 92 and a load is applied, the position of the new metal pipe 90 is determined such that the center of the second clamp mechanism 20 is on the pipe axis 93 of the new metal pipe 90. At the same time when the position of the new metal pipe 90 is determined, the shape of the inner circumferential surface 92 of the new metal pipe 90 is corrected along the outer circumferential surface 23 of the clamp head 21.

  When the position of the new metal pipe 90 with respect to the pipe joining apparatus 100 is determined, the end face 81 of the existing metal pipe 80 and the end face 91 of the new metal pipe 90 are brought into contact with each other. This process is called a joint pressure process. As shown in FIG. 7, the pipe joining apparatus 100 drives the axial direction moving unit 71 by the drive unit, and moves the second clamp mechanism 20 in a direction approaching the first clamp mechanism 10. Then, the end face 81 of the existing metal pipe 80 and the end face 91 of the new metal pipe 90 come into contact, but the drive part continues to drive the axial moving part 71 even when the end face 81 and the end face 91 come in contact. The end face 81 and the end face 91 are mutually pressurized by a load.

  Next, friction stir welding is performed while pressing the end face 81 of the existing metal pipe 80 and the end face 91 of the new metal pipe 90. This process is called a friction stir welding process. As shown in FIG. 8, the bonding tool 40 moves the probe 41 from the inside to the outside of the metal tubes 80 and 90, rotates the probe 41 at high speed around the central axis of the probe 41, and bonds the probe 41. Push into section 99. At this time, as shown in FIG. 8, the joint 99 applies a load in a direction to open the joint 99 at a position where the probe 41 is pushed. That is, a load is applied in the direction of arrow 1 shown in FIG. The existing metal pipe 80 is fixed because it is already joined to another metal pipe, but the new metal pipe 90 falls in the direction of arrow 2 shown in FIG. Try to move.

  However, the existing metal pipe 80 and the new metal pipe 90 are circumferentially fixed by the first clamp mechanism 10 and the second clamp mechanism 20, and a second clamp is further provided between the axially moving portion 71 and the apparatus main body 70. A load is applied in the direction in which the mechanism 20 approaches the first clamp mechanism 10. Therefore, even if the probe 41 moves along the joint 99 and a load is applied in the direction to open the joint 99, the existing metal pipe 80 and the new metal pipe 90 keep the end face 81 and the end face 91 pressed against each other. It is held. As a result, the existing metal pipe 80 and the new metal pipe 90 are friction stir welded as they are in the initial positional relationship in which the end face 81 and the end face 91 are butted.

  The welding tool 40 rotates around the metal pipes 80 and 90 in the circumferential direction of the metal tubes 80 and 90 along the joint 99 by the rotation mechanism 74 while keeping the probe 41 pressed into the joint 99. Thus, the bonding portion 99 is bonded by friction stir welding. It is desirable that the rotation center of the rotation mechanism 74 be configured to be located on an imaginary line connecting the center of the first clamp mechanism 10 and the center of the second clamp mechanism 20, for example. According to this configuration, the probe 41 can move along the inner circumferential surfaces 82, 92 of the metal tubes 80, 90 without changing the amount of pressing into the joint 99.

<Function effect>
As described above, the pipe joining apparatus 100 is installed in the metal pipes 80 and 90, and friction stirs and joins the joint portion 99 from the pipe. Thereby, joining of two pipes becomes possible, without arranging an apparatus etc. in a field by the side of the perimeter around joint part 99, for example, can reduce a range which excavates in a pipe buried under the ground. In addition, the pipe joining apparatus 100 fixes the metal pipe 80 to the first clamp mechanism 10 and fixes the metal pipe 90 to the second clamp mechanism 20 so that the pipe axis of the metal pipe 80 and the pipe axis of the metal pipe 90 93 can be positioned to be coaxially positioned. Thus, it is not necessary to provide a support structure for positioning the metal pipe 80 and the metal pipe 90 around the metal pipes 80, 90. Further, since the positioning is performed using the inner circumferential surfaces 82 and 92 of the metal pipes 80 and 90, the end surface 81 of the metal pipe 80 forming the joint portion 99 and the end surface 91 of the metal pipe 90 can be accurately butted. Furthermore, the clamp head 11 of the first clamp mechanism 10 is corrected such that the cross-sectional shape of the end of the metal tube 80 approaches a perfect circle by contacting the inner peripheral surface 82 of the metal tube 80 and applying a load thereto. The clamp head 21 of the second clamp mechanism 20 also corrects the cross-sectional shape of the end of the metal tube 90 in the same manner. As a result, the joint portion 99 between the metal pipe 80 and the metal pipe 90 can suppress the level difference, and also suppress the dispersion of the joint depth (throat thickness) in the tube sheet thickness direction, and ensure good joint quality. it can.

  When the end face 81 of the metal pipe 80 and the end face 91 of the metal pipe 90 are butted, the axial direction moving part 71 is moved to the apparatus main body 70 side. By the movement of the axial movement unit 71, the second clamp mechanism 20 approaches the first clamp mechanism 10 side, and the end surface 81 and the end surface 91 come in contact with each other. Even after the end face 81 and the end face 91 contact, the axial moving part 71 is driven to move to the apparatus main body 70 side, and the end face 81 and the end face 91 are held in a mutually pressurized state. Thereby, it is possible to face the load in the direction to open the joint 99 when the probe 41 is pushed into the joint 99, and the metal pipe 80 and the metal pipe 90 have the end face 81 and the end face 91. Friction stir welding can be performed while maintaining the contact state. In particular, when joining a relatively thick steel pipe used in a pipeline or the like, the pressing load of the probe 41 is also high, so the force to open the joint 99 is large, but the pipe joining apparatus 100 is used. Thus, the contact between the end face 81 and the end face 91 can be maintained. In the first embodiment, the metal pipes 80 and 90 have been described as an example, but the material of the pipes is not limited to only metal.

Second Embodiment
In the second embodiment, in addition to the method of joining the metal tubes 80 and 90 using the tube joining apparatus 100 of the first embodiment, the clamp bands 60 are used to join the metal tubes 80 and 90. In the following, the second embodiment will be described focusing on the changes from the first embodiment. Items not particularly described in the second embodiment are the same as in the first embodiment, and the same functions and configurations are described using the same reference numerals.

  FIG.9 and FIG.10 is explanatory drawing of the metal pipe joining method which uses the pipe joining apparatus 100 based on Embodiment 2 of this invention. FIG. 11 is a view of the clamp band 60 of FIGS. 9 and 10 as viewed from the direction of the tube axes 83 and 93. FIG. FIG. 9 is the same as FIG. 7 except that a clamp band 60 is added to the outer surface of the metal tubes 80, 90. In FIG. 10, a clamp band 60 is additionally installed on the outer surface of the metal tubes 80 and 90 as compared with FIG.

  As shown in FIG. 9, the position of the new metal pipe 90 with respect to the pipe bonding apparatus 100 is determined, and the joint pressure application process for bringing the end face 81 of the existing metal pipe 80 and the end face 91 of the new metal pipe 90 into contact is completed. The clamp band 60 is attached to the outer periphery of the joint 99. Clamp band 60 is provided so as to surround the outer peripheral surface of the portion where existing metal pipe 80 is pressurized by first clamp mechanism 10 and the portion where new metal pipe 90 is pressurized by second clamp mechanism 20. It is done. The clamp band 60 may be attached before the joint pressing step is completed.

  As shown in FIG. 11, the clamp band 60 is configured by combining ones of the cylinders divided along the central axis. In the second embodiment, the clamp band 60 is configured by combining the band parts 61 and 62 divided into two, but may be further divided into a large number. One band component 61 has flat portions 63 provided at both ends with the flat portion parallel to the central axis. The other band component 62 is also configured similarly to the one band component 61. The band parts 61 and 62 are fixed by the fixing member 65 with the flat portions of the flat plate portion 63 and the flat plate portion 64 in contact with each other.

  FIG. 12 is an enlarged view of the vicinity of the joint 99 of FIG. The welding tool 40 is omitted in FIG. The clamp band 60 is attached with the inner circumferential surfaces 66 and 67 in contact with the outer circumferential surfaces of the existing metal pipe 80 and the new metal pipe 90 or with a minute gap. The inner diameter dimensions of the inner circumferential surfaces 66 and 67 of the clamp band 60 are set to be, for example, slightly larger than the outer diameter dimensions of the existing metal pipe 80 and the new metal pipe 90. By setting in this manner, as shown in FIG. 12 (b), in the state where the clamp band is installed, as shown in FIG. Can be used to correct misplacement. The clamp band 60 is composed of band parts 61 and 62 divided into two along the central axis of the cylindrical shape, and the flat plate portion 63 and the flat plate portion 64 are used by tightening the fixing member 65 and connecting them.

<Function effect>
In the existing metal pipe 80 and the new metal pipe 90, the probe 41 is pushed into the joint 99 while the clamp band 60 is installed on the outer peripheral side of the joint 99, and friction stir welding is performed. The shapes of the existing metal pipe 80 and the new metal pipe 90 are corrected by the first clamp mechanism 10 and the second clamp mechanism 20 from the inner peripheral side, and are further surrounded by the clamp band 60 from the outer peripheral side. The clamp band 60 plays a role of keeping the existing metal pipe 80 and the new metal pipe 90 which are to be radially expanded by being pressurized by the first clamp mechanism 10 and the second clamp mechanism 20 from the inner circumferential side within a predetermined range. . Furthermore, since the existing metal pipe 80 and the new metal pipe 90 are pressurized from the inner peripheral side and the inner peripheral side, even if the probe 41 is pushed into the joint portion 99 and a force to open the joint portion 99 is applied. The joint 99 can be kept in contact with each other. That is, the new metal pipe 90 which is going to move so as to fall down in the direction of the arrow 2 shown in FIG. 11 can be held at the initial position.

  Reference Signs List 1 arrow, 2 arrow, 10 first clamp mechanism, 11 clamp head, 12 rod, 13 outer circumferential surface, 20 second clamp mechanism, 21 clamp head, 23 outer circumferential surface, 30 third clamp mechanism, 31 clamp head, 40 welding tool , 41 probes, 50 rollers, 60 clamp bands, 61 band parts, 62 band parts, 63 flat plate parts, 64 flat plate parts, 65 fixing members, 66 inner circumferential surface, 67 inner circumferential surface, 70 device main body, 71 axial direction moving portion , 72 cable, 74 rotation mechanism, 80 (existing) metal pipe, 81 end face, 82 inner circumferential surface, 83 pipe axis, 84 contact portion, 85 clearance, 90 (newly installed) metal pipe, 91 end face, 92 inner circumferential surface, 93 pipe axis, 99 joints, 100 pipe joining equipment.

<Function effect>
In the existing metal pipe 80 and the new metal pipe 90, the probe 41 is pushed into the joint 99 while the clamp band 60 is installed on the outer peripheral side of the joint 99, and friction stir welding is performed. The shapes of the existing metal pipe 80 and the new metal pipe 90 are corrected by the first clamp mechanism 10 and the second clamp mechanism 20 from the inner peripheral side, and are further surrounded by the clamp band 60 from the outer peripheral side. The clamp band 60 plays a role of keeping the existing metal pipe 80 and the new metal pipe 90 which are to be radially expanded by being pressurized by the first clamp mechanism 10 and the second clamp mechanism 20 from the inner circumferential side within a predetermined range. . Furthermore, since the existing metal pipe 80 and the new metal pipe 90 are pressurized from the inner peripheral side and the inner peripheral side, even if the probe 41 is pushed into the joint portion 99 and a force to open the joint portion 99 is applied. The joint 99 can be kept in contact with each other. That is, the new metal pipe 90 which is going to move so as to fall down in the direction of the arrow 2 shown in FIG. 10 can be held at the initial position.

Claims (14)

A probe that is pushed into the joint of two tubes and friction stir welded;
A welding tool provided with the probe at its tip;
A rotation mechanism for rotating the welding tool around a central axis of the pipe;
An apparatus body provided with the rotation mechanism;
An axial moving unit configured to be movable back and forth in a direction along the central axis of the pipe with respect to the apparatus main body;
The device body is
A first clamp mechanism for holding one of the tubes;
The axial moving unit is
A pipe joining apparatus comprising a second clamp mechanism for holding the other of the pipes. A probe that is pushed into the joint of two tubes and friction stir welded;
A welding tool provided with the probe at its tip;
An apparatus body provided with the welding tool;
A rotation mechanism for rotating the welding tool around the device body;
An axial movement unit configured to be movable back and forth in a direction along the central axis of the rotation mechanism with respect to the apparatus main body;
The device body is
A first clamp mechanism configured to be movable forward and backward in a radial direction of a rotation path of the rotation mechanism;
The axial moving unit is
A pipe joining apparatus, comprising: a second clamp mechanism configured to be movable back and forth in a radial direction of a rotation track of the rotation mechanism. The axial moving unit is
The pipe joint device according to claim 1, wherein the second clamp mechanism moves in a direction approaching the first clamp mechanism.   The drive part which generates a load in a direction in which the second clamp mechanism approaches the first clamp mechanism between the axial movement unit and the apparatus main body is further provided. Pipe joint device as described. The first clamp mechanism and the second clamp mechanism are
And a clamp head which is movable back and forth in the radial direction of the rotation path of the rotation mechanism,
The clamp head is
The pipe joint device according to any one of claims 1 to 4, wherein a load is applied to the inner peripheral surface at the end of the pipe, and the shape of the end is corrected to a shape along the outer peripheral surface of the clamp head. . The first clamp mechanism and the second clamp mechanism are
Comprising a plurality of said clamp heads,
The outer peripheral surface of the clamp head is
The pipe joint device according to claim 5, wherein a cylindrical surface is formed in a shape divided in an arbitrary number in a circumferential direction of the cylindrical surface, and a load is applied to the inner peripheral surface of the pipe. The device body is
The pipe joint device according to any one of claims 1 to 6, further comprising a third clamp mechanism that fixes the device body inside one of the tubes. The device body is
The pipe joint device according to any one of claims 1 to 7, further comprising a roller provided to project outward from the device body and guiding the device body along the inner circumferential surface of the tube. The center of the second clamp mechanism is
The pipe joint device according to any one of claims 1 to 8, arranged coaxially with the central axis of the first clamp mechanism. The rotation center axis of the rotation mechanism is
The pipe joint device according to any one of claims 1 to 9, arranged on an imaginary line connecting a center of the first clamp mechanism and a center of the second clamp mechanism. The rotation center axis of the rotation mechanism is
The pipe joint device according to any one of claims 1 to 10, which is disposed coaxially with the central axis of the first clamp mechanism and the central axis of the second clamp mechanism. The probe provided in the pipe joining apparatus is aligned with the end face of the existing pipe, and the first clamp mechanism provided in the pipe joining device is brought into contact with the inner circumferential surface of the existing pipe to fix the pipe joining apparatus inside the existing pipe. Pipe joint installation process,
A second clamp mechanism provided in the pipe joining apparatus is disposed inside a new pipe to be joined to the existing pipe, the second clamp mechanism is brought into contact with the inner circumferential surface of the new pipe, and the new pipe is connected to the pipe A new pipe fixing step of fixing to a joining device,
A joint pressing step of moving the second clamp mechanism to the first clamp mechanism side and bringing the end faces of the existing pipe and the new pipe into contact with each other to apply a load;
Friction stir welding is performed by pressing the probe rotated from the inside into a joint formed by bringing the end face of the existing pipe and the end face of the new pipe into contact with each other and moving the probe along the joint to perform friction stir welding. And a pipe joint method comprising:   The pipe joining method according to claim 12, wherein the friction stir welding step is performed while bringing the end faces of the existing pipe and the new pipe into contact with each other and applying a load thereto.   The pipe joining method according to claim 12 or 13, wherein a clamp band surrounding the outer peripheral surface of the joint of the existing pipe and the new pipe is installed.

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