WO2013172244A1 - Metal pipe joining device and metal pipe joining method using same - Google Patents

Abstract

A joining device (10) that butts together and joins metal pipes by means of friction stir welding from the interiors of the metal pipes, and that addresses the problems of preventing the generation of opening defects at the inner surface of the metal pipes and of preventing the generation of sputter when the pipes are butted together and joined, said joining device being equipped with: a friction stir unit (20), which has a joining tool (22) at the tip of which is formed a probe (21) that is pushed into the parts to be joined, a retaining jig (25) that holds the joining tool (22) so as to be capable of moving in the direction of the central axis (R) of the joining tool, and a first motor (30) that rotates the joining tool (22) around the central axis (R) via the holding jig (25); a pressing part (35), which presses the joining tool (22) in the direction of the central axis (R); and a circumferential direction movement unit (40), which has a tubular case (41) to one end of which the holding jig (25) and the pressing part (35) are attached, and a second motor (44) that moves the joining tool (22) in the circumferential direction along the inner circumferential surface of the metal pipes (11), via the case (41).

Description

Metal pipe joining apparatus and metal pipe joining method using the same

The present invention relates to a joining apparatus and joining method for butt-joining metal pipes, and more particularly to a joining apparatus for joining butt-joining metal pipes by friction stir welding from the inside of the metal pipe and a joining method of metal pipes using the joining apparatus. .
This application claims priority based on Japanese Patent Application No. 2012-112671 filed in Japan on May 16, 2012, the contents of which are incorporated herein by reference.

As one method for joining metal materials, a friction stir welding method is conventionally known. In the friction stir welding method, a cylindrical joining tool having a projection called a probe on the tip surface is used. By pressing the probe against the joint portion of the material to be joined while rotating the joining tool around the central axis, frictional heat is generated between the probe and the material, the material is softened, and the probe is buried in the material. This causes plastic flow in a form in which the material around the probe is dragged by the rotation of the probe. The base materials are joined by moving the joining tool along the joining line while maintaining the rotation and pressurization of the joining tool.
Compared with arc welding, the friction stir welding method has a) small residual stress and strain at the joint, b) a smooth bead surface and excellent fatigue strength, and c) less defects such as bubbles and cracks. It has the following features.

For example, in Patent Document 1, metal pipes are coaxially butted against each other, and a joining tool provided with a probe concentrically at the tip is pushed in while rotating, and relatively moved in the circumferential direction. The butt portion is joined by a friction stir welding method to obtain a pipe joined body, and the pipe joined body thus obtained is inflated by the pressure of the incompressible fluid filled therein, and the desired shape is obtained. Techniques for manufacturing molded tubes are disclosed.

Moreover, in patent document 2, it is a discontinuous cylindrical shape by presence of the butting part extended in an axial direction obtained by bending the outer peripheral surface of a cylindrical core material into the cylindrical shape from the board | plate material different from a core material. A clad tube having a desired outer diameter is obtained by mandrel extrusion of the obtained composite billet after manufacturing the composite billet by covering the cylindrical outer shell material exhibiting A forming technique is disclosed.

In Patent Document 3, the shoulder surface of the welding tool is formed into a truncated cone, a probe protruding from the shoulder surface is provided, and a spiral groove is formed on the shoulder surface, whereby the posture of the welding tool with respect to the workpiece is changed. In addition, a joining tool capable of obtaining stable joining quality is disclosed.

JP 2004-042049 A JP 2007-313541 A JP 2007-301579 A

In piping that transports fluids such as natural gas containing a large amount of hydrogen sulfide, etc., the inner surface of the piping becomes highly corrosive, so there is a defect that opens on the inner surface of the piping in the butt joint between the end surfaces of the metal pipe used as piping. , Stress corrosion cracking starting from the defect may occur.

On the other hand, when arc welding is performed from the inner surface of a metal pipe, the occurrence of the defect can be prevented, but spatter generated during welding adheres to the inner surface of the pipe, and stress corrosion cracking starting from the spatter may occur. For this reason, the work of spatter removal after welding is required.

The present invention has been made in view of such circumstances, and a metal pipe joining apparatus that does not cause an opening defect on the inner surface of the metal pipe when splicing and joining the metal pipes and does not generate spatter during joining. An object of the present invention is to provide a method for joining metal pipes using a metal.

A metal pipe joining device according to the present invention is a metal pipe joining device that joins end faces of coaxially arranged metal pipes, and a probe that is pushed into a joined portion between the end faces of two metal pipes. A joining tool formed at a distal end; a holder that holds the joining tool so as to be movable in a central axis direction of the joining tool; and a first tool that rotates the joining tool around the central axis via the holder. A friction stirrer having a drive unit, a pressing unit that presses the welding tool in the direction of the central axis of the welding tool, and press-fits the probe into the welded part; and the first drive unit, A cylindrical casing having a holder and the pressing portion attached to one end thereof, and a second casing that moves the joining tool in a circumferential direction along the inner peripheral surface of the metal pipe via the casing. Circumferential direction with drive And a dynamic part, a joining device of the metal pipe to be joined by friction stir welding the metal pipe from the inside of the metal pipe.

This joining apparatus includes a first drive unit that rotates a joining tool having a probe at a tip thereof around a central axis thereof, a pressing unit that presses the joining tool in the direction of the central axis of the joining tool, and the joining tool that is attached to a metal pipe. A second drive unit that moves in the circumferential direction along the inner circumferential surface. The probe is inserted into the metal pipe, the first drive unit is driven to rotate the welding tool around its central axis, and the pressing tool is pressed in the direction of the central axis of the welding tool by the pressing unit. Is pressed against the bonded portion, frictional heat is generated between the probe and the bonded portion, the bonded portion is softened, and the probe is buried in the bonded portion. Then, plastic flow occurs in a form in which the material around the probe is dragged by the rotation of the probe. By driving the second drive unit while maintaining the rotational speed and the pressing force of the welding tool and moving the welding tool in the circumferential direction along the inner peripheral surface of the metal pipe, the metal pipes are caused by plastic flow. Integrated and joined.

In the metal pipe joining device according to the present invention, the reaction force that rolls on the inner peripheral surface of the metal pipe against the reaction force generated when the joining tool is pressed in the central axis direction of the joining tool. A force receiving roller is preferably provided.

According to the said structure, since the reaction force which generate | occur | produces when pressing a joining tool with a press part and pressing a probe on to-be-joined part can be received with a reaction force receiving roller, the state which pressed the joining tool is maintained. However, the welding tool can be stably moved in the circumferential direction along the inner peripheral surface of the metal pipe.

In the metal pipe joining device according to the present invention, the housing includes a front housing in which the holder and the pressing portion are attached to one end, and a rear housing in which the first driving unit is incorporated. And the front housing and the rear housing are connected by an Oldham shaft coupling that allows decentering (parallel error) and declination (angle error), and the first drive unit and the first drive The rotating shaft that transmits the rotational force of the parts may be connected by a universal shaft joint that allows a declination.

The metal pipe may be bent in a direction different from the axis within the straightness tolerance. Therefore, even when the central axis of the metal pipe joining device according to the present invention is aligned with the axis of the metal pipe, the joining tool is placed in the circumferential direction along the inner circumferential surface of the metal pipe at the joint location of the metal pipe. An angle difference is generated between the rotating shaft and the axis of the metal pipe when moving, and the following problems may occur.
a. Some of the reaction force receiving rollers do not contact the inner surface of the metal pipe, and a reaction force moment is generated.
b. The probe cannot be pressed at an appropriate angle, for example, perpendicular to the inner surface of the metal pipe, resulting in poor quality joints.
c. The pressing position of the probe deviates from the joining position, and a portion that is not joined in the circumferential direction of the metal pipe occurs.

In this configuration, the housing is divided into a front housing and a rear housing, the front housing and the rear housing are connected by an Oldham shaft joint, and the first driving unit and the first driving unit are connected to each other. Since the rotary shaft that transmits the rotational force is connected by a universal shaft joint, even if the metal pipe is bent halfway, the tolerance of the metal pipe can be absorbed by these shaft joint portions. Therefore, occurrence of the above problem can be suppressed.

Further, the metal pipe joining apparatus according to the present invention preferably includes a first adjusting mechanism for adjusting a travel angle of the joining tool and a second adjusting mechanism for adjusting a work angle of the joining tool. .

The first adjustment mechanism includes a plate portion disposed between the joining tool, the holder, the pressing portion, and the housing, and a bolt that fastens the plate portion and the housing. It is preferable that the plate portion is formed with a long hole through which the bolt is inserted, and the long hole allows the rotation of the plate portion with respect to the housing with the tip of the probe as a fulcrum. .

The second adjustment mechanism is input from the angle detection means including a first sensor for measuring the angle of the joined portion and a second sensor for measuring the angle of the joining tool. You may comprise the calculating means which calculates the said workpiece | work angle based on a value, and the actuator which adjusts the inclination of the center axis | shaft of the said joining tool based on the calculation result of the said calculating means. In this case, it is preferable that the actuator is provided in the Oldham shaft coupling and adjusts the inclination of the central axis of the welding tool by driving the actuator in the central axis direction of the housing.

In this configuration, the angle of the center axis of the welding tool can be freely changed with the tip of the probe as a fulcrum. For this reason, the friction stir welding can be performed after adjusting the contact angle (travel angle, workpiece angle) between the welding tool and the bonded portion to be an appropriate value. Therefore, the problem as described in the above b occurs, the generation of burrs, the reduction in thickness, and the generation of processing marks called grooves can be suppressed, and good bonding quality can be realized.

Further, the metal pipe joining device according to the present invention preferably includes a third adjusting mechanism that corrects a deviation between a joining line between the metal pipes and a course of the joining tool.

The third adjustment mechanism includes a third sensor that detects the joining line, and a calculation unit that calculates a deviation amount between the joined portion and the course of the joining tool based on a detection value of the third sensor. And a direction changing portion that changes a course of the joining tool in accordance with the amount of deviation.

In this configuration, even when the path of the welding tool and the bonding line are misaligned, the path of the welding tool 22 can be corrected by the third adjustment mechanism 91. In addition, it is possible to detect the deviation between the path of the joining tool and the joining line (joining location) repeatedly using the camera 92 and the calculation means, correct the rotation, and rotate the probe on the joining line. For this reason, it is prevented that the above-mentioned problem c occurs and the bonding strength is lowered. As a result, high joining accuracy can be obtained.

In the metal pipe joining method according to the present invention, the metal pipe joining device described above is inserted into the metal pipe, and the metal pipes are butt-joined by friction stir welding from the inside of the metal pipe.

The present invention includes a first drive unit that rotates a welding tool having a probe at a tip about its central axis, a second drive unit that moves the welding tool in a circumferential direction along the inner peripheral surface of the metal pipe, and A metal pipe joining apparatus having a pressing portion that presses the joining tool in the direction of the central axis of the joining tool and a metal pipe joining method using the same, so that the metal pipes are connected to each other by friction stir welding from the inside of the metal pipe. Butt-joining is possible. For this reason, when the metal pipes are butt-joined, there is no opening defect on the inner surface of the metal pipe, no spattering occurs at the time of joining, and post-treatment after joining becomes unnecessary.

It is a schematic diagram which shows the side cross section of the joining apparatus of the metal pipe which concerns on the 1st Embodiment of this invention. It is the schematic diagram which shows the cross section which looked at the same joining apparatus from the axial direction of the metal pipe. It is a schematic diagram which shows the side cross section of the joining apparatus of the metal pipe which concerns on the 2nd Embodiment of this invention. It is a perspective view of an Oldham shaft coupling. It is a disassembled perspective view of an Oldham shaft coupling. It is the fragmentary sectional view which showed the detail of the projection part provided in the hub. It is a schematic diagram which shows the side cross section of the joining apparatus of the metal pipe which concerns on the 3rd Embodiment of this invention. It is a schematic diagram which shows a mode that the board part of FIG. 6 and the joining tool were seen from the axial direction front side. In FIG. 7A, it is a schematic diagram which shows a mode that the board part and the joining tool were rotated. It is a perspective view of an Oldham shaft coupling. It is a disassembled perspective view of an Oldham shaft coupling. It is the schematic diagram which looked at the mode of the Oldham shaft coupling and joining tool at the time of adjusting a work angle with the 2nd adjustment mechanism from the direction orthogonal to the central axis of a case and a joining tool. It is a schematic diagram which shows the side view of the joining apparatus of the metal pipe which concerns on the 4th Embodiment of this invention. It is the schematic diagram which shows the cross section which looked at the same joining apparatus from the axial direction of the metal pipe. It is the schematic diagram which looked at the mode of the Oldham shaft coupling and joining tool when the course of a joining tool was corrected with the 3rd adjustment mechanism from the central axis direction of the joining tool. It is a perspective view of the Oldham shaft coupling which concerns on the modification of the 4th Embodiment of this invention. It is a disassembled perspective view of an Oldham shaft coupling.

Embodiments embodying the present invention will be described with reference to the drawings.

[Metal Pipe Joining Device According to First Embodiment]
FIG. 1 is a side cross-sectional view of a metal pipe joining device 10 (hereinafter, simply referred to as “joining device”) according to the first embodiment of the present invention, and the joining device 10 is a shaft of a metal pipe 11. A cross section viewed from the direction is shown in FIG.
In the following, for convenience of explanation, it is assumed that the metal pipe 11 is arranged so that its tube axis (axial core) is in the horizontal direction, and the butt joint side along the tube axis direction of the metal pipe 11 (see FIG. The left side in FIG. 1 is called the “front” side, and the opposite side is called the “rear” side. In the direction perpendicular to the tube axis, the side on which the probe 21 is located when the joining apparatus is stopped is referred to as the “lower” side, and the opposite side is referred to as the “upper” side.

The joining device 10 is a device that butt-joins metal pipes 11 from the inside of the metal pipe 11 by friction stir welding, and a joining tool in which a probe 21 press-fitted into a joined portion 12 (see FIG. 2) is formed at the tip. Friction stirrer 20 that rotates 22 around its central axis R, and pressing unit 35 that presses the welding tool 22 in the direction of the central axis R (in the radial direction outside the metal pipe 11) and press-fits the probe 21 into the welded part 12. And a circumferential direction moving portion 40 that moves the joining tool 22 (probe 21) in the circumferential direction along the inner peripheral surface of the metal pipe 11.

The friction stirrer 20 includes a columnar joining tool 22, a probe 21 that is coaxial with the central axis R of the joining tool 22, protrudes from one end surface of the joining tool 22, a holder 25 that holds the joining tool 22, A first motor 30 (first drive unit) that rotates the welding tool 22 around the central axis R via the holder 25 is provided.

The bonding tool 22 and the probe 21 include, for example, polycrystalline cubic boron nitride (PCBN) or PCBN having a strength higher than that of the metal pipe 11 at a temperature higher than the melting point of the member to be bonded and the carbon steel material constituting the metal pipe 11. An alloy material with a tungsten composite material is used.

The holder 25 has a substantially cylindrical chuck member 23 having a fitting hole (not shown) into which the joining tool 22 is fitted at the center of one end surface, and is externally fitted to the chuck member 23, with the central axis R as a rotation axis. And a cylindrical member 24 that is rotatable. The probe 21, the bonding tool 22, the chuck member 23, and the cylindrical member 24 have a central axis R as a common central axis.
On the inner surface of the cylindrical member 24, a protrusion 24a extending in the direction of the central axis R is formed. The chuck member 23 is movable in the direction of the central axis R in the cylindrical member 24 with the protruding portion 24 a as a guide, and rotates together with the cylindrical member 24.

The pressing part 35 is installed immediately above the cylindrical member 24 and moves the chuck member 23 in the direction of the central axis R to press-fit the probe 21 into the joined part 12 and press-fit the probe 21 into the joined part 12. A plurality of reaction force receiving rollers 38 that roll on the inner peripheral surface of the metal pipe 11 against the reaction force generated at that time (see FIG. 2).
The tip of the rod 36 of the hydraulic cylinder 37 is inserted into a cylindrical connecting member 23 a connected to the upper end of the chuck member 23. The tip of the rod 36 and the connecting member 23a (chuck member 23) are connected via a ball bearing 33, and the rod 36 does not rotate when the chuck member 23 rotates.
The reaction force receiving roller 38 is movable in the radial direction of the metal pipe 11.

The circumferential direction moving part 40 is disposed on a cylindrical casing 41 in which the holder 25 and the pressing part 35 are attached to one end part (front face part), and the other end side (rear face side) of the casing 41. A second motor 44 (second drive unit) is provided for rotating the body 41 about the central axis S as a rotation axis.

A first motor 30 that rotates the holder 25 around the central axis R of the welding tool 22 is installed inside the housing 41. The first motor 30 is installed such that a shaft (not shown) is positioned on the central axis S of the housing 41, and a rotating shaft 28 to which a bevel gear 27 is attached is connected to the shaft via a connecting member 29. ing. The central axis S and the central axis R are orthogonal to each other and exist in the same plane.
On the other hand, a follower roller 42 is attached to the outer peripheral surface of the casing 41 so as to roll on the inner peripheral surface of the metal pipe 11 and move in the radial direction of the metal pipe 11.

The cylindrical member 24 constituting the holder 25 is covered with an outer shell member 31 attached to the front surface of the housing 41. A tapered roller bearing 32 is interposed between the cylindrical member 24 and the outer shell member 31 so that the cylindrical member 24 can rotate about the central axis R as a rotation axis. A bevel gear 26 that meshes with a bevel gear 27 that transmits the rotational force of the first motor 30 is provided around the outer peripheral surface of the cylindrical member 24.
When the first motor 30 is driven, the rotational force of the rotary shaft 28 connected to the first motor 30 is transmitted from the bevel gear 27 to the cylindrical member 24 via the bevel gear 26, and the cylindrical member 24 together with the chuck member 23 has the central axis R. Rotate around the axis of rotation.
Note that a driven roller 39 is attached to the outer surface of the outer shell member 31 so as to roll on the inner peripheral surface of the metal pipe 11 and move in the radial direction of the metal pipe 11 (see FIG. 2).

The second motor 44 is fixed in the metal pipe 11 by a support member 45 so that a shaft (not shown) is positioned on the central axis S of the housing 41. The casing 41 and the second motor 44 are connected via a connecting member 43.
When the second motor 44 is driven, the housing 41 and the holder 25 and the pressing portion 35 attached to the front surface of the housing 41 rotate about the central axis S (see FIG. 2). That is, the probe 21 (joining tool 22) moves in the circumferential direction along the inner peripheral surface of the metal pipe 11.

Next, a method of joining the metal pipes 11 using the joining device 10 having the above configuration will be described.
(1) The joining apparatus 10 is placed in the metal pipe 11 so that the center axis R of the joining tool 22 is located in a joining surface (a surface orthogonal to the tube axis of the metal pipe 11) where the end faces of the metal pipe 11 are abutted. Insert into. At that time, the reaction force receiving roller 38, the driven rollers 39 and 42, and the support member 45 provided in the joining device 10 are retracted inward in the radial direction of the metal pipe 11.
(2) After the central axis R of the joining tool 22 is disposed within the joining surface of the metal pipe 11, the reaction force receiving roller 38, the driven rollers 39 and 42, and the support member 45 are moved outward in the radial direction of the metal pipe 11. . Then, the reaction force receiving roller 38 and the driven rollers 39 and 42 are brought into contact with the inner peripheral surface of the metal pipe 11, and the second axis so that the central axis S of the housing 41 is positioned on the tube axis of the metal pipe 11. The motor 44 is fixed in the metal pipe 11 by the support member 45.

(3) The first motor 30 is driven to rotate the welding tool 22 around its central axis R, and the rod 36 of the hydraulic cylinder 37 is moved to press the probe 21 against the welded part 12, thereby joining the joined part 12. The probe 21 is buried (press-fitted) therein, and a plastic flow is generated in the bonded portion 12. The second motor 44 is driven and the probe 21 (joining tool 22) is moved along the joining line (the part where the end faces of the metal pipe 11 are butted together) while maintaining the rotational speed and pressing force of the joining tool 22. Thus, the inner peripheral surface side of the metal pipe 11 is joined.

According to the metal pipe joining apparatus 10 according to the first embodiment, the first motor 30 for rotating the joining tool 22 having the probe 21 at the tip thereof around the central axis R, and the joining tool 22 within the metal pipe 11. Since the second motor 44 that moves in the circumferential direction along the circumferential surface and the pressing portion 35 that presses the welding tool 22 in the direction of the central axis R of the welding tool 22 (outside in the radial direction of the metal pipe 11) are provided. The end surfaces of the metal pipe 11 can be joined from the inside of the metal pipe 11 by friction stir welding. Therefore, when joining the metal pipes 11, there is no opening defect on the inner surfaces of the metal pipes, no spattering occurs at the time of joining, and post-treatment after joining becomes unnecessary.

Further, according to the joining apparatus 10, the reaction force generated when the joining tool 22 is pressed by the pressing portion 35 and the probe 21 is pressed against the joined portion 12 can be received by the reaction force receiving roller 38. The welding tool 22 can be stably moved in the circumferential direction of the metal pipe 11 while maintaining the pressed state of the welding tool 22.

[Metal Pipe Joining Device According to Second Embodiment]
FIG. 3 shows a side cross-section of the metal pipe joining device 18 according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as the joining apparatus 10 which concerns on 1st Embodiment, and description is abbreviate | omitted.

In the joining device 18, the shaft of the first motor 30 and the rotary shaft 28 that transmits the rotational force of the first motor 30 are connected by the universal shaft joint 14 that allows the deflection angle, and the center of the shaft of the first motor 30. The angle formed between the shaft and the central axis of the rotary shaft 28 is variable. The declination is an angle formed between the shaft of the first motor 30 and the rotating shaft 28.

Moreover, in the joining apparatus 18, the housing | casing 46 rotated by the 2nd motor 44 is the cylindrical front housing | casing 46a with which the holder 25 and the press part 35 were attached to the one end part, and the 1st motor 30 is incorporated. And a cylindrical rear casing 46b. And the front housing | casing 46a and the rear housing | casing 46b are connected by the Oldham shaft coupling 13 which accept | permits eccentricity and a declination. The decentering means that the central axis of the front casing 46a and the central axis of the rear casing 46b are not on the same straight line, and the declination is the center axis of the front casing 46a and the rear casing 46b. This is the angle between the central axis.

4A and 4B are a perspective view and an exploded perspective view of the Oldham shaft coupling 13 that allows the eccentricity and the deflection angle.
The Oldham shaft coupling 13 includes a cylindrical first hub 15 having two first protrusions 15a formed on one end face and a cylindrical second hub 16 having two second protrusions 16a formed on one end face. And a columnar slider 17 disposed between the first hub 15 and the second hub 16.
The first hub 15, the slider 17, and the second hub 16 are arranged along the tube axis of the metal pipe 11 so as to be coaxially arranged in this order. At this time, the first hub 15 and the second hub 16 are arranged with the first protrusion 15a and the second protrusion 16a facing the slider 17 side.
A first groove 17a into which the first protrusion 15a is fitted is formed on one end face of the slider 17 facing the first hub 15 side, and the other end face facing the second hub 16 side is formed on one end face facing the first hub 15 side. A second groove 17b into which the second protrusion 16a is fitted is formed.

The pair of first projecting portions 15 a are formed so that their tip portions protrude toward the slider 17 side along the central axis of the first hub 15, and the first projecting portion 15 a is sandwiched between the first central axis of the first hub 15. It arrange | positions so that the radial direction of the hub 15 may be opposed.
The pair of second protrusions 16 a are formed so that the tip ends protrude toward the slider 17 side along the center axis of the second hub 16, and the second protrusion 16 a is sandwiched between the second axis and the second axis. It arrange | positions so that the radial direction of the hub 16 may be opposed.
The first hub 15 and the second hub 16 are configured so that the pair of first protrusions 15 a and the pair of second protrusions 16 a are alternately arranged at equal intervals along the circumferential direction of the slider 17. 17 is disposed with a 17 therebetween.
The tip portions of the pair of first protrusions 15a are each formed in a disk shape that bulges in a circular shape when viewed from the side. In that case, the front-end | tip part of a pair of 1st projection part 15a is formed so that surfaces may oppose on both sides of the center axis | shaft of the 1st hub 15. As shown in FIG. The tip portions of the pair of second projecting portions 16a are also formed in the same manner as the pair of first projecting portions 15a.
On the other hand, the first groove 17a and the second groove 17b formed in the slider 17 are each formed in a circular shape in a side view corresponding to the shape of the first protrusion 15a and the second protrusion 16a on the groove bottom side. Therefore, the first imaginary line X that penetrates the center of the two first grooves 17 a on the groove bottom side along the radial direction of the slider 17 and the center of the two bottom grooves 17 b on the groove bottom side of the slider 17 The second virtual lines Y that penetrate each other in the radial direction are orthogonal to each other in a cross shape in a plane parallel to the end face of the slider 17.
And the front-end | tip part of the 1st projection part 15a fits in the 1st groove | channel 17a, and the front-end | tip part of the 2nd projection part 16a fits in the 2nd groove | channel 17b, The 1st hub 15, the slider 17, and The second hub 16 is connected with a gap between the end faces.

As shown in FIG. 5, the base end portions of the first protrusion portion 15a and the second protrusion portion 16a are inserted into the recessed portions 15b and 16b formed on the end surfaces of the first hub 15 and the second hub 16, respectively. ing. And the spring 19 is interposed in the compressed state between the base end part of these 1st projection parts 15a and the 2nd projection part 16a, and the bottom face of the recessed parts 15b and 16b. Thereby, the first protrusion 15a and the second protrusion 16a are each urged toward the slider 17.

The first protrusion 15 a of the first hub 15 slides along the first groove 17 a of the slider 17 to absorb the eccentricity in the direction of the first groove 17 a (first imaginary line X direction). The one protrusion 15 a rotates around the first imaginary line X of the first groove 17 a of the slider 17 to absorb the declination around the first groove 17 a (around the first imaginary line X). Similarly, the second protrusion 16a of the second hub 16 slides along the second groove 17b of the slider 17 to absorb the eccentricity in the direction of the second groove 17b (second imaginary line Y direction). The sixteen second protrusions 16 a rotate around the second imaginary line Y of the second groove 17 b of the slider 17 to absorb the declination around the second groove 17 b (around the second imaginary line Y).

With the above configuration, the joining device 18 can absorb the tolerance of the metal pipe 11 by the Oldham shaft joint 13 and the universal shaft joint 14 even if the metal pipe 11 is bent in the middle. Therefore, an angular difference is generated between the rotating shaft and the axis of the metal pipe 11 when the joining tool 22 is moved in the circumferential direction along the inner peripheral surface of the metal pipe 11 at the joint portion of the metal pipe 11. There is no.

[Metal Pipe Joining Device According to Third Embodiment]
FIG. 6 shows a cross-sectional side view of a metal pipe joining device 50 according to the third embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as the joining apparatus 18 which concerns on 2nd Embodiment, and description is abbreviate | omitted.

The joining device 50 is different from the joining device 18 according to the second embodiment in that it includes a travel angle and workpiece angle adjustment mechanism. That is, the joining device 50 sets the contact angle between the center axis R of the joining tool 22 and the joined portion 12 in a plane orthogonal to the center axis S and in a plane passing through the center axis S and the center axis R (center axis S). And a mechanism for adjusting in the plane in which the central axis R extends. Hereinafter, these adjustment mechanisms will be described in detail.

FIG. 7A is a view showing a first adjustment mechanism 61 that adjusts the travel angle, and is a view of the joining tool 22 of FIG. 6 and a plate portion 62 described later as viewed from the front side in the axial direction. The travel angle refers to an angle formed by the central axis R of the welding tool 22 and the tangential direction of the bonded portion 12 at the contact point between the probe 21 and the bonded portion 12. That is, the first adjusting mechanism 61 adjusts the travel angle by adjusting the inclination angle of the central axis R in the plane orthogonal to the central axis S.

The first adjustment mechanism 61 includes an annular plate portion 62 disposed between the joining tool 22, the holder 25, the pressing portion 35, and the front housing 46a, and the plate portion 62 and the front housing 46a. And a bolt 63 for connecting.

The plate part 62 presses the probe 21 against the joining tool 22, the holding tool 25, the pressing part 35, that is, the joined part 12, which is disposed in front of the plate part 62 (left side in FIG. 6), and plastically flows to the joined part 12. It is connected with the member which generates. For example, the plate portion 62 is connected to the outer member 31 covering the holder 25 via the tapered roller bearing 32. Thereby, the joining tool 22, the holder 25, and the pressing part 35 are connected to the front housing 46a via the plate part 62.
In the first adjustment mechanism 61, the relative position of the joining tool 22 with respect to the circumferential movement unit 40 is orthogonal to the central axis S by fastening the front housing 46 a and the plate part 62 using the bolts 63. It is possible to adjust in the plane.

A plurality of long holes 62 a for inserting the bolts 63 are formed in the plate portion 62. The plurality of long holes 62 a are formed at intervals in the circumferential direction of the plate portion 62. Each elongated hole 62a is defined by a curved surface including two parallel cylindrical surfaces. The cylindrical surface has a central axis that passes through the tip T of the probe 21 and is parallel to the central axis S.
That is, each long hole 62a is formed long along the rotation direction so as to allow rotation of the plate portion 62 with the tip T of the probe 21 as a fulcrum in a plane orthogonal to the central axis S. . At this time, the lengths of the elongated holes 62a are different depending on the formation position (depending on the distance from the tip T of the probe 21).

In such a first adjustment mechanism 61, as shown in FIG. 7B, the plate portion 62 can be rotated within the range in which the long hole 62a is formed with the tip T of the probe 21 as a fulcrum. It is possible to adjust the fixing position of the plate part 62 with respect to the body 46a.

Specifically, after a plurality of bolts 63 inserted through the long holes 62a are screwed into a bolt hole (not shown) of the front housing 46a in a loosened state, the plate portion 62 is moved with the tip T of the probe 21 as a fulcrum. Rotate. As a result, the inclination of the central axis R of the welding tool 22 changes in a plane orthogonal to the central axis S, and the front housing 46a and the plate portion 62 are relatively positioned so that the travel angle becomes an angle suitable for friction stir welding. The position is adjusted. Thereafter, the travel angle can be maintained at an angle suitable for joining by fastening the bolt 63 to fix the plate portion 62 to the front housing 46a.

Next, the second adjustment mechanism 71 that adjusts the work angle will be described. The work angle refers to an angle formed by the central axis R of the joining tool 22 and the radial direction of the metal pipe 11 at the contact point between the probe 21 and the metal pipe 11. In other words, the work angle is an angle formed by a normal line passing through the welded portion 12 and the tube axis of the metal pipe 11 and the central axis R of the welding tool 22, and the degree of inclination of the welding tool 22 with respect to the normal line. It is an angle shown.
The second adjustment mechanism 71 changes the angle of the central axis R of the welding tool 22 in a plane passing through the central axis S and the central axis R. As shown in FIGS. 6, 8 </ b> A, and 8 </ b> B, the second adjustment mechanism 71 includes an actuator 78, an angle detection unit 81, and a calculation unit 85.

The angle detection means 81 will be described with reference to FIG. The angle detection unit 81 includes a first sensor 82 and a second sensor 83. The first and second sensors 82 and 83 measure the angle of the metal pipe 11 (the joined portion 12) and the angle of the joining tool 22, respectively.

The first sensor 82 is attached to the outer peripheral surface of the ring 84 attached to the outer peripheral surface of the metal pipe 11. The ring 84 is composed of two halved rings. By fastening the two halved rings with bolts or the like with the flanges (not shown) of the halved rings facing each other, the outer periphery of the joint line of the metal pipe 11 It is attached to the surface. Thus, the metal pipe 11 is fixed by the ring 84 in a state where the metal pipe 11 is abutted, so that when the welding tool is pressed against the metal pipe, it is possible to prevent the bonded portion from spreading in a trumpet shape with the pressing. The first sensor 82 is disposed on the outer side of the ring 84 on the side (upper side) opposite to the position of the welding tool 22 when the welding device 50 is stopped. The second sensor 83 is attached to the vicinity of the welding tool 22, specifically, to the outer shell member 31.

The first sensor 82 measures the angle of the metal pipe 11 (the angle of the tube axis (or radial direction) of the metal pipe 11 with respect to the direction of gravity). The second sensor 83 measures the installation angle of the bonding apparatus 50 (the angle of the central axis S (or R) with respect to the direction of gravity). As the first and second sensors 82 and 83, for example, an angle sensor or a sensor that measures a shape by a light cutting method or the like can be used. The measured angle is transmitted from the first and second sensors 82 and 83 to the calculation means 85.

The calculating means 85 calculates the work angle based on the difference between the angles measured by the first and second sensors 82 and 83. Then, the calculation means 85 drives an actuator 78 of the Oldham shaft coupling 73 described below based on the calculated work angle. Thereby, the work angle is adjusted.

8A and 8B are a perspective view and an exploded perspective view for explaining the Oldham shaft coupling 73. FIG. The Oldham shaft joint 73 includes a first hub 75, a second hub 76, and a slider 77, similarly to the Oldham shaft joint 13 according to the second embodiment. The 1st hub 75 is the same composition as the 1st hub 15 of Oldham shaft coupling 13, and a pair of 1st projection parts 75a are provided in the end surface.

The second hub 76 has a recess 76a extending along the central axis. An actuator 78 is fitted and fixed to the recess 76a.

The actuator 78 includes a cylindrical cylinder tube 78a extending along the central axis of the second hub 76, a piston 78b sliding inside the cylinder tube 78a, and a hydraulic pump (not shown) connected to the cylinder tube 78a. It is a hydraulic cylinder provided. The piston 78b reciprocates along the central axis of the second hub 76 by driving the hydraulic pump to change the hydraulic pressure in the cylinder tube 78a.
The actuator 78 is not limited to a hydraulic cylinder, and for example, an air cylinder or an electric actuator may be used. The tip of the piston 78b has the same shape as the tip of the second protrusion 16a in the second embodiment.

The second hub 76 is provided with a second protrusion 76b at a portion located on the opposite side of the recessed portion 76a in the radial direction across the central axis of the second hub 76. Unlike the first protrusion 75a and the piston 78b, the second protrusion 76b is formed integrally with the second hub 76. The distal end portion of the second projecting portion 76b has the same shape as the distal end portion of the second projecting portion 16a in the second embodiment, and the through hole is positioned on the axis of the second imaginary line. Is formed.

The slider 77 is formed with two first grooves 77a in which the first protrusions 75a are fitted, a second groove 77b in which the pistons 78b are fitted, and a recess 77c in which the second protrusions are fixed. Among these, the 1st groove | channel 77a and the 2nd groove | channel 77b are the same shapes as the 1st groove | channel 17a and the 2nd groove | channel 17b of the Oldham shaft coupling 13 of 2nd Embodiment.
Therefore, a line connecting the centers of the two first grooves 77a is a first imaginary line X ′, a line connecting the centers of the second grooves 77b and the recesses 77c is a second imaginary line Y ′, and both these imaginary lines are In a plane parallel to the end surface of the slider 77, the cross is orthogonal to the cross.

A bolt hole is formed in the recess 77c at a position corresponding to the through hole of the second protrusion 76b when the tip of the second protrusion 76b is disposed in the recess 77c. The second hub 76 and the slider 77 are connected by inserting the bolt 76c through the through hole of the second protrusion 76b and screwing it with the bolt hole of the recess 77c. At this time, the second protrusion 76b is not completely fixed to the recess 77c, but is attached in a state in which vertical movement and inclination with respect to the recess 77c are allowed. A pin may be used instead of the bolt 76c.

The Oldham shaft joint 73 as described above is attached so that the positions of the second protrusion 76 b and the welding tool 22 coincide with each other in the circumferential direction of the welding device 50. As shown in FIG. 9, the actuator 78 is driven in a state where the probe 21 is disposed on the joined portion 12, so that the axial end surface of the Oldham shaft coupling 73 is on the front side or in the plane passing through the central axes R and S. Tilt backwards.
As a result, the central axis R of the welding tool 22 is tilted forward or rearward with the tip T of the probe 21 as a fulcrum. That is, the work angle can be adjusted by changing the inclination of the joining tool 22 with respect to the normal passing through the joined portion 12 and the tube axis of the metal pipe 11.

Next, a method for adjusting the travel angle and the work angle in the joining apparatus 50 including the first adjustment mechanism 61 and the second adjustment mechanism 71 will be described.
(1) First, adjustment is performed using the first adjustment mechanism 61 so that the travel angle is within an appropriate range in a state where the joining device 50 is installed outside the metal pipe 11. This appropriate range is determined from the joining conditions such as the shape of the joining tool 22 (probe 21) and the material of the metal pipe 11. The actual travel angle of the joining device 50 is obtained from the shape of the metal pipe 11 and the shape of the joining device 50. By rotating the plate portion 62 with the tip T of the probe 21 as a fulcrum so that the travel angle is within an appropriate range, the mounting position of the plate portion 62 with respect to the front housing 46 a is adjusted, and the plate portion is adjusted by the bolt 63. 62 is fixed to the front housing 46a.

(2) After adjusting the travel angle, the joining device 50 is installed inside the metal pipe 11 so that the joining tool 22 contacts the joined portion 12. At this time, a ring 84 is attached to the outer peripheral surface of the metal pipe 11, and a first sensor 82 is attached to the ring 84. A second sensor 83 is attached to the outer shell member 31. In this state, the rod 36 of the hydraulic cylinder 37 is moved to press the probe 21 against the joined portion 12.
(3) Next, the second adjustment mechanism 71 is used to adjust the work angle to be within the appropriate range. This appropriate range is determined by the shape of the joining tool 22 (probe 21) and the material of the metal pipe, and is input to the computing means 85 in advance. The angle measured by the first sensor 82 and the second sensor 83 is transmitted to the calculation means 85. The calculation means 85 obtains the work angle at that time based on the input angle.

(4) When the work angle obtained by the calculation means 85 is within the appropriate range inputted in advance, the actuator 78 is locked and the piston 78b is restricted from moving. On the other hand, when the work angle obtained by the calculation means 85 is not within the appropriate range input in advance, the calculation means 85 calculates a deviation amount between the work angle and the appropriate range. The calculation means 85 drives the actuator 78 based on the deviation amount, and adjusts the work angle to be within an appropriate range. The procedure after calculation of the workpiece angle in (3) is repeated, and when the workpiece angle falls within the appropriate range, the actuator 78 is locked and the piston 78b is restricted from moving.
(5) The joining apparatus 50 is driven and the metal pipes 11 are joined to each other by the method of the first embodiment.

According to the metal pipe joining device 50 according to the third embodiment, the angle of the central axis R of the joining tool 22 can be freely rotated with the tip T of the probe 21 as a fulcrum. For this reason, the friction stir welding can be performed after adjusting the contact angle (travel angle, work angle) between the welding tool 22 and the bonded portion 12 to be an appropriate value. Thereby, generation | occurrence | production of a burr | flash, thickness reduction, and generation | occurrence | production of a process mark can be suppressed, without using the joining tool of a special shape. Further, even when the metal pipe 11 is warped in the tube axis direction or has a shape defect such as a trumpet shape, the probe 21 and the to-be-joined portion 12 are at an appropriate angle (work angle, travel angle). Can be contacted. As a result, good bonding quality can be realized.

Note that the second adjustment mechanism 71 in the third embodiment is not limited to the above configuration. For example, although the Oldham shaft coupling 73 includes one actuator 78, another concave portion 76a may be provided instead of the second protrusion 76b, and the second actuator 78 may be attached thereto. In addition, the installation positions of the first and second sensors 82 and 83 are not limited to the positions shown in FIG. 6, and may be any positions where the angles of the metal pipe 11 and the welding tool 22 can be measured. What is necessary is just to arrange | position in the vicinity and the vicinity of the joining tool 22. However, it is preferable that the first sensor 82 and the second sensor 83 have the same direction in which the angle is measured with respect to the direction of gravity (for example, the axial direction, the radial direction, etc.). In this case, the calculation means 85 can obtain the work angle only by calculating the difference between the values measured by the first and second sensors 82 and 83.

[Metal Pipe Joining Device According to Fourth Embodiment]
FIG. 10 shows a side cross section of a metal pipe joining device 90 according to a fourth embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the same component as the joining apparatus 50 which concerns on 3rd Embodiment, and description is abbreviate | omitted.

The joining device 90 includes a third adjusting mechanism 91 that corrects the position of the probe 21 and the position of the joined portion 12 (joining line) during friction stir welding, and the joining device 50 according to the third embodiment. Is different. That is, the joining device 90 includes a third adjustment mechanism 91 that corrects the position of the probe 21 on the inner peripheral surface of the metal pipe 11. Hereinafter, the third adjusting mechanism 91 will be described in detail with reference to FIGS.

The third adjusting mechanism 91 includes a camera 92, a direction changing unit 93, and a calculation unit (not shown).
The camera 92 is disposed on the path of the welding tool 22, that is, in the forward direction of the welding tool 22 as a sensor for detecting the bonding line. An image photographed by the camera 92 is input to a calculation unit (not shown) (may also be used as the calculation unit 85 of the third embodiment). The calculation means determines whether or not the path of the welding tool 22 is out of the bonding line from the input image, and operates the direction changing unit 93 based on the result. Here, the path of the welding tool 22 refers to the path of the tip T of the probe 21 when the welding tool 22 moves on the inner peripheral surface of the metal pipe 11 while maintaining the center of rotation at that moment.

The direction changing section 93 includes a steering roller 94, a rack 96, a pinion 95, and a motor (not shown). The steering roller 94 adjusts the traveling direction of the tip of the probe 21. In the present embodiment, of the four reaction force receiving rollers 38, two of the four reaction force receiving rollers 38 located on the side close to the joining tool 22 (the right side in FIG. 10) in the traveling direction of the joining tool 22 are used as the steering roller 94. is doing. For this reason, the steering roller 94 also functions as a reaction force receiving roller that receives a reaction force generated when the probe 21 is pressed against the bonded portion 12.

The pinion 95 is connected to a motor (not shown), and the rotation of the motor is input. The pinion 95 is disposed so as to mesh with a rack 96 disposed so as to be reciprocally movable in parallel with the tube axis of the metal pipe 11, and the pinion 95 and the rack 96 constitute a rack and pinion mechanism. Steering rollers 94 are respectively connected to both ends of the rack 96, and the direction of the steering roller 94 is changed by moving the rack 96 in the longitudinal direction (the tube axis direction of the metal pipe 11).

Next, a method for correcting the advancing direction of the welding tool 22 using the third adjusting mechanism 91 in the welding apparatus 90 will be described.
(1) The travel angle and workpiece angle of the welding tool are adjusted by the same method as in the third embodiment.
(2) The welding tool 22 is rotated about its central axis R by the same method as in the first embodiment, and the probe 21 is pressed against the probe 21 to be buried in the joint 12 (press-fit). ) To generate plastic flow.

(3) The second motor 44 is driven, and the probe 21 (joining tool 22) is moved in the circumferential direction along the inner peripheral surface of the metal pipe 11. At this time, the following operations (3-1) to (3-3) are repeated until the probe 21 is rotated 360 degrees and all the joining lines are joined.
(3-1) The joining line is photographed by the camera 92 disposed in front of the probe 21 (joining tool 22) in the traveling direction, and the photographed data (image) is transmitted to the calculation means.
(3-2) The computing means calculates a deviation amount between the course of the probe 21 (joining tool 22) and the joining line based on the input data.

(3-3) If there is no deviation or the deviation amount can be ignored, the process returns to (3-1). On the other hand, in the case where the deviation is not negligible, the direction changing unit 93 is driven to change the path of the probe 21 (joining tool 22) in a direction in which the deviation is eliminated.
Specifically, the arithmetic means controls the motor to rotate the motor by a necessary amount of rotation, and the rotation of the motor transmitted to the pinion 95 is converted into a linear motion of the rack 96 by the rack and pinion mechanism. Thereby, the direction of the roller 94 for steering can be changed, and the course of the probe 21 (joining tool 22) can be changed. At this time, as shown in FIG. 12, the first hub 75 of the Oldham shaft coupling 73 moves in accordance with the change in the path of the probe 21 (joining tool 22). Absorption is possible at the connection between the hub 75 and the slider 77.
After the direction of the steering roller 94 is changed, the process returns to (3-1).

According to the metal pipe joining device 90 according to the fourth embodiment, even when the course of the joining tool 22 and the joining line are deviated, the course of the joining tool 22 is corrected by the third adjusting mechanism 91. Can do. Further, the deviation between the course of the joining tool 22 and the joining line is repeatedly detected using the camera 92 and the calculation means, and the probe 21 is reliably run (rotated) along the joining line while appropriately correcting the deviation. be able to. For this reason, it can prevent that friction stir welding is performed in the state where the probe 21 and the joining line do not match, and friction stir welding is performed in the state where the joining line and the probe 21 do not match, thereby preventing the joining strength from being lowered. Is done. As a result, good bonding quality can be realized.

Also, in the joining device 90, since the steering roller 94 has the function of a reaction force receiving roller, it is not necessary to provide both separately. Then, since the reaction force is applied to the steering roller 94, the steering roller 94 is prevented from sliding on the inner peripheral surface of the metal pipe 11, so that the correction by the third adjustment mechanism 91 is appropriately performed. .

In addition, the direction change part 93 in the 3rd adjustment mechanism 91 is not limited to the above-mentioned structure. For example, as shown in FIGS. 13A and 13B, the Oldham shaft coupling 73 according to the third embodiment may be configured with an Oldham shaft coupling 93A including an actuator 98 instead of the two first protrusions 75a.

The Oldham shaft coupling 93A includes a first hub 97, a second hub 76, and a slider 77. The second hub 76 and the slider 77 have the same configuration as the Oldham shaft coupling 73. The first hub 97 includes two actuators 98. The actuator 98 has the same shape and configuration as the actuator 78 of the second hub 76, and the tip end of the piston 98b of the actuator 98 is the first groove of the slider 77, respectively. Fits 77a.

Next, a method for correcting the advancing direction of the welding tool 22 using a third adjusting mechanism including the Oldham shaft coupling 93A will be described. In the third adjusting mechanism, the following operation is repeated until the probe 21 is rotated 360 degrees and the joining line is completely joined.
(1) Data obtained by photographing the joining line with the camera 92 disposed in front of the traveling direction of the probe 21 (joining tool 22) is transmitted to the calculation means.
(2) The calculation means calculates a deviation amount between the expected path of the probe 21 (joining tool 22) and the joining line based on the input data.

(3) If there is no deviation or the deviation amount can be ignored, the process returns to (1). If the deviation is not negligible, the actuator 98 of the Oldham shaft coupling 93A is driven to change the path of the probe 21 (joining tool 22) in a direction to eliminate the deviation. Specifically, the required drive amounts of the two actuators 98 are calculated by the calculation means, and an instruction to drive the actuators 98 is given. The two actuators 98 are driven to change the direction of the first hub 97 (see FIG. 12). As a result, the path of the probe 21 (joining tool 22) is changed. Then return to (1).

Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the above-described embodiments, and is considered within the scope of the matters described in the claims. Other embodiments and modifications are also included. For example, in the above embodiment, the second drive unit is disposed in the metal pipe. However, the shaft that connects the housing and the second drive unit is lengthened so that the second drive unit is outside the metal pipe. You may arrange in. In the fourth embodiment, the third adjustment mechanism is used in combination with the first and second adjustment mechanisms of the third embodiment, but the third adjustment mechanism is used in the second embodiment. The third adjusting mechanism may be used alone in combination with the form.

In this invention, the 1st drive part which rotates the joining tool which has a probe at the front-end | tip to the surroundings of the central axis, the 2nd drive part which moves a joining tool to the circumferential direction along the internal peripheral surface of a metal pipe, and A metal pipe joining device having a pressing portion that presses the joining tool in the direction of the central axis of the joining tool and a metal pipe joining method using the same, and the end face of the metal pipe by friction stir welding from the inside of the metal pipe They can be joined together. Therefore, when joining the end surfaces of the metal pipes, there is no opening defect on the inner surface of the metal pipe, no spattering occurs at the time of joining, and post-treatment after joining becomes unnecessary. In addition, by providing the first to third adjusting mechanisms, it is possible to realize good bonding quality.

10, 18 Joining device (metal pipe joining device)
DESCRIPTION OF SYMBOLS 11 Metal pipe 12 Joint part 13 Oldham shaft coupling 14 Universal shaft coupling 15 1st hub 15a 1st projection part 15b Recessed part 16 2nd hub 16a 2nd projection part 16b Recessed part 17 Slider 17a 1st groove | channel 17b 2nd groove | channel 19 Spring 20 Friction stirring part 21 Probe 22 Joining tool 23 Chuck member 23a Connection member 24 Cylindrical member 24a Projection part 25 Holder 26, 27 Bevel gear 28 Rotating shaft 29, 43 Connecting member 30 First motor (first drive part)
31 outer shell member 32 tapered roller bearing 33 ball bearing 35 pressing portion 36 rod 37 hydraulic cylinder 38 reaction force receiving rollers 39, 42 driven roller 40 circumferential direction moving portions 41, 46 housing 46a front housing 46b rear housing 44 Second motor (second drive unit)
45 Support members R, S Center axis

Claims (10)

1. A metal pipe joining device for joining end faces of metal pipes arranged on the same axis,
   A joining tool in which a probe to be pushed into a joined portion between the end faces of the metal pipe is formed at the tip, a holding tool that holds the joining tool movably in the central axis direction of the joining tool, and the holding tool A friction stirrer having a first drive for rotating the welding tool about the central axis;
   A pressing portion that presses the joining tool in the direction of the central axis of the joining tool and press-fits the probe into the joined portion;
   A cylindrical housing in which the first driving unit is built in, and the holder and the pressing unit are attached to one end, and the joining tool is placed on the inner peripheral surface of the metal pipe via the housing A circumferentially moving portion having a second drive portion that is moved circumferentially along the circumferential direction;
   A metal pipe joining device for joining a metal pipe by friction stir welding from the inside of the metal pipe.
2. The metal pipe joining device according to claim 1, wherein the metal pipe is rolled on an inner peripheral surface of the metal pipe against a reaction force generated when the joining tool is pressed in a central axis direction of the joining tool. Metal pipe joining device with force receiving roller.
3. The metal pipe joining apparatus according to claim 1 or 2, wherein the housing includes the front housing in which the holder and the pressing portion are attached to one end, and the first driving unit. A rear housing, and the front housing and the rear housing are connected by an Oldham shaft coupling that allows eccentricity and declination,
   An apparatus for joining metal pipes, wherein the first drive unit and a rotary shaft that transmits the rotational force of the first drive unit are connected by a universal shaft joint that allows a declination.
4. In the metal pipe joining device according to claim 3,
   A first adjusting mechanism for adjusting a travel angle of the welding tool;
   And a second adjusting mechanism for adjusting a work angle of the joining tool.
5. The metal pipe joining device according to claim 4,
   The first adjustment mechanism includes a plate portion disposed between the joining tool, the holder, the pressing portion, and the housing, and a bolt that fastens the plate portion and the housing.
   The plate portion is formed with a long hole through which the bolt is inserted,
   An apparatus for joining metal pipes, in which rotation of the plate portion with respect to the housing with the tip of the probe as a fulcrum is allowed by the long hole.
6. The metal pipe joining device according to claim 4 or 5,
   The second adjustment mechanism includes an angle detection unit including a first sensor that measures an angle of the joined portion and a second sensor that measures an angle of the joining tool;
   Arithmetic means for calculating the workpiece angle based on a value input from the angle detection means;
   An apparatus for joining metal pipes, comprising: an actuator for adjusting an inclination of a central axis of the joining tool based on a calculation result of the computing means.
7. The metal pipe joining device according to claim 6,
   The said actuator is provided in the said Oldham shaft coupling, The joining apparatus which adjusts the inclination of the center axis | shaft of the said joining tool by driving the said actuator to the center axis direction of the said housing | casing.
8. The metal pipe joining device according to any one of claims 3 to 7,
   A joining apparatus provided with the 3rd adjustment mechanism which correct | amends the shift | offset | difference of the joining line of the said metal pipes, and the course of the said joining tool.
9. The metal pipe joining device according to claim 8,
   The third adjusting mechanism includes a third sensor that detects the joint line;
   An arithmetic means for calculating a deviation amount between the joined portion and the course of the joining tool based on a detection value of the third sensor;
   A direction changing unit that changes a course of the welding tool according to the amount of deviation;
   A joining apparatus comprising:
10. A method for joining metal pipes, wherein the metal pipe joining device according to any one of claims 1 to 9 is inserted into the metal pipe, and the metal pipes are butt joined together by friction stir welding from the inside of the metal pipe. .

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