JP2021074751A - Joint method and joint device - Google Patents

Abstract

To provide a technology that can control an oxide film from being formed at an inner surface of a joining part as much as possible (control oxide film from being formed at pipe inner surface of joint part as much as possible) in joining a pipe to a pipe, and can be readily executed at low cost.SOLUTION: A device for joining a pipe A to a pipe B includes: holding means for holding the pipes A, B while being erected; inert gas supply means for supplying an inert gas into the pipes A, B held by the holding means and being in an abutment state; and welding means disposed while being opposed to an abutment position of the pipe A to the pipe B.SELECTED DRAWING: Figure 1

Description

The present invention relates to a joining technique.

Various welding devices have been proposed. For example, a welding head in which a closing plug is TIG welded to the tube groove of a cut heat transfer tube among the heat transfer tubes inserted into a narrow portion between a plurality of tubes in which a plurality of heat transfer tubes are installed, and an operation unit. The welding head is moved and swiveled via the moving swivel mechanism portion by the operation from, and the closing plug is arranged at the pipe groove portion, and the torch is supplied with the wire from the wire supply tip holding portion at the time of TIG welding. A welding head setting mechanism unit that sets the welding position of the closing plug, a wire supply device that supplies wires to the wire supply tip holding portion, and a power supply device that supplies power for welding to the torch of the welding head. By a command from the remote control and the inert gas supply device that supplies the inert gas that shields and protects the pipe groove and the closing plug from the atmosphere during TIG welding to the pipe groove and the closing plug. A torch rotation motor that controls the flow rate of the wires supplied from the wire supply device, the welding power supplied from the power supply device, and the inert gas supplied from the inert gas supply device, and drives the torch. A welding device including a control device for controlling and positioning the torch at the welding position of the closing plug has been proposed (Japanese Unexamined Patent Publication No. 2018-202462). The outline of the welding apparatus of this proposal is shown in FIG. In FIG. 2, 11 is a heat transfer tube, 14 is a tube groove, 15 is a closing plug, 17 is a welding head, 18 is a closing plug holding part, 19 is a torch, 20 is a wire, 21 is a wire supply tip holding part, and 22. Is a torch rotation motor, 23 is a welding head setting mechanism, 24 is a moving swivel mechanism, 25 is an operation unit, 26 is a wire supply device, 27 is a control device, 28 is a remote control, 29 is a power supply device, and 30 is an inert device. A gas supply device, 31 is a gas supply pipe, and 32 is an electric wire. A closing plug 15 is TIG welded to the tube groove portion 14 of the heat transfer tube 11 cut out of the heat transfer tubes 11 by the welding head 17, and the welding head setting mechanism unit 23 moves and turns the welding head 17 by operation from the operation unit 25. The closing plug 15 is arranged in the groove portion 14 of the pipe, and the torch 19 is set to the welding position of the closing plug 15 in a state where the wire 20 is supplied from the wire supply tip holding portion 21 at the time of TIG welding. The closing plug 15 can be TIG welded to the tube groove portion 14 of the heat transfer tube 11 even in a narrow portion that cannot be entered.

JP-A-2018-20462

By the way, for example, when the Ti pipe A and the Ti pipe B are welded together, the pipes A and B are arranged in the horizontal direction. That is, the abutting surface (joining surface) between the pipe A and the pipe B was in the vertical direction. The welding torch (TIG torch) is arranged outside the joint surface. At the time of welding, the pipe is fixed, and the welding torch rotates along the circumference of the pipe to perform welding.

During the welding, an inert gas (for example, Ar gas) is supplied. The inert gas is supplied into the pipes A and B. The supply of the inert gas (Ar gas) is to prevent the formation of an oxide film.

When the Ti pipe A and the Ti pipe B were welded as described above, the quality of the welded portion was inferior. For example, if the welded portion on the inner surface side of the pipe is discolored or an oxide film is formed, the strength of the welded portion is lowered, and in some cases, the oxide film may be peeled off. In particular, the welded portion is inferior in surface smoothness and has a rough surface (having irregularities). Therefore, the oxide film on the surface of the welded portion is easily peeled off. There was a risk that the composition of the release film would be mixed with the substance transported in the tube. When the substance transported in the tube is called a drug, it is difficult if a substance different from the drug is mixed in the drug. From this point of view, the demand for suppressing the formation of an oxide film on the inner surface of the pipe (inner surface of the welded portion) has been extremely strict.

However, there has been a limit to the quality improvement (quality improvement in which an oxide film is not formed on the inner surface of the pipe at the welded portion).

Therefore, the first problem to be solved by the present invention is to suppress the oxide film formed on the inner surface of the joint as much as possible at the time of joining the pipe to the pipe (as much as possible to form the oxide film on the inner surface of the pipe of the joint). It is to propose a technology that can be suppressed).

The second problem to be solved by the present invention is to propose a technique for solving the first problem at low cost and easily.

The third problem to be solved by the present invention is to propose a technique that does not cause a problem in welding strength even if the technique for solving the first problem is implemented.

The study for solving the above-mentioned problems has been enthusiastically promoted by the present inventor. The experiment was repeated over and over again. However, it did not reach the customer's required quality (suppressing the formation of an oxide film on the inner surface of the pipe at the joint). It was wondered if the quality of the inert gas (Ar gas) supplied to the inside of the pipe was inferior. However, the same result was obtained with the highest quality Ar gas available. I wondered if it would be impossible to have a joint quality higher than this.

Through repeated trial and error, it is revealed that even if Ar gas is flowed into the pipe, the oxygen gas that originally existed in the pipe is not sufficiently discharged (extruded). Came to get. Upon examination, the density of Ar gas was 1.784 g / L (standard state), and _{the density of oxygen (O 2} ) gas was 1.429 g / L (standard state). Incidentally, the density of nitrogen (N ₂ ) gas is 1.250 g / L, the density of Ne gas is 0.900 g / L, and the density of hydrogen (H ₂ ) gas is 0.0899 g / L. Therefore, even if Ar gas is poured into the horizontally arranged pipe, the large density Ar mainly flows to the lower side in the horizontal pipe, and the small density oxygen (O ₂ ) drifts to the upper side in the horizontal pipe. As a result, I came to think that _{oxygen (O 2) in the pipe might have remained.}

Based on these findings, I thought that if the pipe was erected and Ar gas was supplied from the bottom to the top of the pipe, the oxygen gas in the pipe would be effectively discharged. It is.

Even if Ne gas is used instead of Ar gas, _{the density of oxygen (O 2} ) gas is 1.429 g / L and the density of Ne gas is 0.900 g / L, which is the same as that of Ar gas. On the contrary, oxygen gas drifted to the lower side in the horizontal pipe, and it was thought that the oxygen gas discharge would be insufficient.

Based on the above findings, the present invention has been achieved.

The present invention
It is a method of joining pipe A and pipe B,
We propose a joining method in which the pipe A and the pipe B are abutted against each other, an inert gas is supplied into the upright pipe, and welding is performed at the abutment portion.

The present invention proposes the above-mentioned joining method, in which an inert gas, which is a gas having a density higher than that of oxygen gas, is preferably supplied from the lower side to the upper side in the pipe.

The present invention proposes the above-mentioned joining method, preferably the joining method in which the inert gas is Ar.

The present invention proposes the above-mentioned joining method, preferably a joining method in which an inert gas, which is a gas having a density lower than that of oxygen gas, is supplied from above to below in the pipe.

The present invention is the bonding method, preferably, the inert gas is supplied into the tube via a transport path including a flexible tube, and the flexible tube is a polyvinyl alcohol or an ethylene-vinyl alcohol copolymer. , Polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high density polyethylene, butyl rubber, polypropylene, and at least one or more selected from the group of Teflon. We propose a joining method.

The present invention proposes the above-mentioned joining method, preferably the joining method in which the pipe is made of Ti.

The present invention proposes the above-mentioned joining method, preferably a joining method in which the pipe is made of stainless steel.

The present invention
It is a joining device between pipe A and pipe B,
A holding means for holding the pipes A and B in an upright position,
The inert gas supply means, in which the inert gas is supplied into the butt tubes A and B held by the holding means,
We propose a joining device including welding means arranged so as to face each other at the abutting position between the pipe A and the pipe B.

The present invention proposes the joining device, preferably the inert gas supply means, which supplies an inert gas having a density higher than that of oxygen gas from the lower side to the upper side in the pipe.

The present invention proposes the joining device, preferably the inert gas supply means, which supplies an inert gas having a density smaller than that of oxygen gas from the upper side to the lower side in the pipe.

The present invention is the joining apparatus, preferably, the inert gas supply means is provided with a transport path having a flexible tube at least partially, and the flexible tube is made of polyvinyl alcohol or ethylene-vinyl alcohol. At least one or more selected from the group of copolymers, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high density polyethylene, butyl rubber, polypropylene, and Teflon are used. We propose a joining device that is composed of

The present invention is the joining device, preferably further comprising moving means, the welding means moving around a standing pipe held by the holding means by the action of the moving means. We propose a joining device.

The present invention proposes the joining device, preferably the joining device in which the pipe is made of Ti.

The present invention proposes the joining device, preferably the joining device in which the pipe is made of stainless steel.

The present invention is the above-mentioned joining device, and preferably, the present invention proposes the above-mentioned joining device used in the above-mentioned joining method.

The formation of an oxide film inside the pipe at the welded part could be suppressed very much. Therefore, it is difficult for the oxide film powder to be mixed with the substance transported inside the pipe. It is extremely preferable for joining transport pipes of substances such as chemicals, which are strictly required to be mixed with substances other than the target substance.

The technique of the present invention does not cause a special cost increase, and can be carried out inexpensively and easily.

Welding was also beautiful. For example, gravity is evenly applied to the welded portion during welding, and the welded portion does not protrude into the inside of the pipe.

Basic schematic diagram of the welding apparatus of the present invention Schematic diagram of conventional welding equipment

Hereinafter, embodiments of the present invention will be described.

The first invention is a method. The method is a method of joining pipe A and pipe B. The tubes A and B are round tubes. It may be a circular tube. An elliptical tube may be used. It may be a square tube. The cross-sectional shape of the pipe may be any shape. Since the pipe A and the pipe B are joined, it is preferable that the inner shape of the butt portion between the pipe A and the pipe B is the same. Of course, it is preferable that the outer shape is the same. However, this requirement is not mandatory. It suffices if the butt portion has a butt surface. The tubes A and B are made of, for example, pure titanium or a titanium alloy (simply abbreviated as Ti). For example, it is made of stainless steel. Of course, it is not limited to Ti and stainless steel. Ti is an active metal. Therefore, an oxide film is likely to be formed during welding. Therefore, it is proposed to cover the target part (the part where the oxide film is not formed) with an inert gas for the purpose of preventing the formation of the oxide film when welding the Ti material. Therefore, the present invention is applied to any active metal that easily forms an oxide film during welding. In the joining method, the pipe A and the pipe B are butted at the time of joining. The pipe A and the pipe B are temporarily fixed, for example, for the convenience of work. However, temporary fixing is not essential. The pipe A and the pipe B are in a standing state. The standing state is most preferably a vertical (vertical) standing state. However, an inclination of about ± 30 ° with respect to the vertical direction (vertical direction) will be allowed. More preferably, an inclination of about ± 15 ° with respect to the vertical direction will be allowed. More preferably, an inclination of about ± 5 ° with respect to the vertical direction will be allowed. The standing state does not have to be the standing state over the entire length of the pipes A and B. In addition to the case where the pipes A and B in the joined state are in a straight line, for example, they may have a substantially U-shape, a substantially L-shape, or a substantially “shape, abbreviated” shape. It suffices if the vicinity of the joint (welded portion) (for example, a length of about ± 2.5 cm (total 5 cm) in the vertical direction from the abutting surface) is in a standing state. The inert gas is supplied into the pipes A and B in the standing state. Welding is performed at the abutting portion between the pipe A and the pipe B.

The inert gas was preferably Ar gas. He and Ne can also be considered as the inert gas. However, He and Ne have a lower density (specific gravity) than Ar. Considering the ability to discharge oxygen gas, Ar gas was preferred as the inert gas used in the present invention. That is, it will be understood that the heavier gas (Ar) has a higher ability to push out the oxygen gas than the oxygen gas. Ar is the most abundant in the atmosphere next to _{N 2} and O _2. Ar is also cheaper than He and Ne. Nitrogen gas is also known as an inert gas. However, when the pipe was made of Ti, Ar gas was preferred as the inert gas.

When the inert gas is _{Ar having a density higher than that of O 2} and N ₂ , the inert gas is preferably transported (supplied) (flowed) in the pipe from the lower side to the upper side. The oxygen gas discharge capacity (efficiency) in the pipe was higher when the gas was flowed from the bottom to the top. When Ar gas is flowed from above to downward, since Ar gas has a higher density (specific gravity) than oxygen gas, oxygen gas easily escapes upward, and the oxygen gas discharge capacity (efficiency) is inferior accordingly. .. On the contrary, when the inert gas is _{He, Ne having a density lower than that of O 2} and N ₂ , the inert gas is preferably transported (supplied) (flowed) in the pipe from above to below. ). The oxygen gas discharge capacity (efficiency) in the pipe was higher when the gas was flowed from the upper side to the lower side. When He and Ne gas are flowed from the bottom to the top, the density (specific gravity) of the He and Ne gas is smaller than that of the oxygen gas, so it is difficult for the oxygen gas to be pushed upward, that is, the He and Ne gas. Is _{easier to move upward than O 2} gas, and the oxygen gas discharge capacity (efficiency) is inferior accordingly.

A flexible tube is preferably used for the transport path (part or all) of the inert gas. It is not realistic to construct a transport path for an inert gas using only metal pipes. Of course, a metal pipe may be partially used. At this time, if the inert gas is poured from the upper side to the lower side of the pipe, the flexible tube must be arranged at a high position. This is very disturbing. From this point of view, it was preferable that the inert gas was transported (supplied) (flowed) in the pipe from the lower side to the upper side.

The flexible tube includes, for example, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high-density polyethylene, butyl rubber, polypropylene, and Teflon. At least one or two or more selected from the above are used. More preferably, polyvinyl alcohol (O ₂ permeability coefficient is 0.00006. H ₂ O permeability coefficient is 19.), Ethylene vinyl alcohol copolymer (O ₂ permeability coefficient is 0.0001.), Polyvinylidene chloride (O). ₂ Permeability coefficient is 0.0053. H ₂ O transmission coefficient is 1.), High-density polyethylene (O ₂ transmission coefficient is 0.4. H ₂ O permeability coefficient is 12.), Polypropylene (O ₂ transmission coefficient is 2.). 2. At least one or more selected from the group of _{H 2} O transmission coefficient 65.) And Teflon (O ₂ transmission coefficient 4.9. H _{2 O transmission coefficient 33.) Is used.} It is composed. A material having an O ₂ permeability coefficient of 10 or less (further, 5 or less) is preferable. Preferably, _{H 2} O permeability coefficient of 300 or less (further, 100 or less, more further 50 or less) material. The unit of the transmission coefficient is (× 10 ^-10 cm ³ (STP) / (cm ² · s · cm Hg)). By using the material, it is _{difficult for the O 2} or H ₂ O gas to enter the inert gas transported in the flexible tube.

The second invention is an apparatus. The device is a joining device for pipe A and pipe B. The tubes A and B are round tubes. It may be a circular tube. An elliptical tube may be used. It may be a square tube. The cross-sectional shape of the pipe may be any shape. Since the pipe A and the pipe B are joined, it is preferable that the inner shape of the butt portion between the pipe A and the pipe B is the same. Of course, it is preferable that the outer shape is the same. However, this requirement is not mandatory. It suffices if the butt portion has a butt surface. The tubes A and B are made of, for example, Ti. For example, it is made of stainless steel. Of course, it is not limited to Ti and stainless steel. Ti is an active metal. Therefore, an oxide film is likely to be formed during welding. For this reason, it has been proposed to cover the target portion (the portion where the oxide film should not be formed) with an inert gas for the purpose of preventing the formation of the oxide film when welding the Ti material. Therefore, the present invention is applied to any active metal that easily forms an oxide film during welding. It can be understood from the above that the apparatus of the present invention is suitable for joining Ti pipes. The device comprises holding means. The holding means holds the pipes A and B in an upright position. If the pipe A and the pipe B are temporarily fixed, the holding means may only hold one of the pipes A and B. The holding means is, for example, a clamp. It may have any structure. The device comprises welding means. The welding means is provided corresponding to the abutting position between the pipe A and the pipe B. The welding means is, for example, a TIG welding device. For example, a MIG welding device. For example, an inert gas arc welding device. For example, plasma welding (Plasma)
It is an arc welding) device. For example, an electron beam welding device. For example, it is a laser beam welding device. For example, a resistance welding device. Any type of welding equipment may be used. The device comprises an inert gas supply means. The inert gas supply means supplies the inert gas into the butt tubes A and B held by the holding means.

The device preferably comprises means of transportation. By the action of the moving means, the welding means moves (rotates: rotates) around the standing pipe held by the holding means. As a result, welding is performed over the entire circumference of the pipes A and B.

The device preferably comprises an inert gas recovery means. The inert gas recovery means recovers the gas (mixed gas of inert gas and air) discharged from the tip of the pipe located above or below the pipes A and B. Since oxygen is contained in the recovered gas, the recovered gas cannot be used as it is in the present invention. However, when Ar is used as the inert gas, the Ar concentration in the recovered gas is much higher than the Ar concentration in the atmosphere. The cost of recovering Ar from the recovered gas is lower than the cost of purifying Ar from the atmosphere.

_{When the inert gas has a density higher than that of O 2} and N ₂ , the inert gas supply means directs the inert gas into the butt tubes A and B, preferably from bottom to top. Is configured to supply. The reason is as described above. Assuming that the pipe A is arranged on the pipe B, the inert gas is poured into the pipe through the hole on one end side of the pipe B. A gas (atmosphere such as oxygen or an inert gas) is discharged from the hole on the other end side of the pipe A through the inside of the pipe.

The inert gas is preferably Ar. The reason is as described above.

The inert gas supply means (inert gas transport path) has a flexible tube at least in part. Without the flexible tube, the degree of freedom of the device is extremely poor. The constituent materials of the flexible tube include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high-density polyethylene, butyl rubber, polypropylene, and Teflon. One or more selected from the group is used. More preferably, at least one or more selected from the group of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, high density polyethylene, polypropylene, and Teflon is used.

The above method (welding) is performed using the above device.

Hereinafter, specific embodiments will be described. However, the present invention is not limited to the following embodiments. Various modifications and applications are also included in the present invention as long as the features of the present invention are not significantly impaired.

FIG. 1 is a basic schematic view (partly in cross section) of the welding apparatus of the present invention.

The welding apparatus of the present invention was assembled by devising a commercially available welding apparatus (trade name: POLYSOUDE).

In FIG. 1, reference numeral 1 denotes tube A. 2 is a tube B. In FIG. 1, the tube 2 is partially cut out (part is a cross section). The tube 1 is drawn on a straight tube. The tube 2 is drawn on a substantially L-shaped tube. As described above, the pipes 1 and 2 may be a straight line extending from the abutting surface 3 between the pipe 1 and the pipe 2 to about 2 to 3 cm.

The pipe 1 and the pipe 2 are temporarily fixed (not shown) on the abutting surface 3.

4 is a clamp. The clamp 4 holds the tube 1 (and / or the tube 2). The pipe 1 is maintained in a vertical (vertical) posture by the clamp 4. Since the pipe 1 stands in the vertical direction by the clamp 4, the upper side (one end side) 2a of the pipe 2 also maintains the vertical posture.

Reference numeral 5 denotes a flexible tube made of Teflon. One end side of the flexible tube 5 is connected to the other end side 2b of the tube 2. An inert gas flow path is connected to the Ar tank 6. At least a part of the flow path is made of flexible resin. All of the flow paths may be made of flexible resin, but some of them may be made of metal or inorganic material. The other end side of the flexible tube 5 is connected to the flow path connected to the Ar tank 6. The Ar gas in the Ar tank 6 is supplied (transported) into the pipe 2 via the flexible tube 5. The outlet side of tube 1 is squeezed with a packaging tube (not shown). The inert gas flowing through the tubes 2 and 1 is blown out from the packaging tube. Therefore, the abutting portion between the pipe 2 and the pipe 1 is effectively filled with the inert gas.

Reference numeral 7 is a welding torch. The welding torch 7 is arranged to face the abutting surface 3 between the pipe 1 and the pipe 2. The welding torch 7 can be rotated around the pipes 1 and 2 by a moving means (rotating means: rotating means: not shown).

Welding work by the welding apparatus having the above configuration will be described. First, the Ar gas in the Ar tank 6 was supplied (transported) into the pipe 2 via the flexible tube 5. The supplied Ar gas was discharged from the throttle port of the packaging tube connected to the pipe 1. _{Along with this, the gas of the atmospheric components (O 2} , N _2, etc.) existing in the pipes 2 and 1 was discharged from the pipe 1. About 100% of the gas in tubes 1 and 2 became Ar gas. After this, a welding torch 7 was used and welding was performed. The welding torch 7 rotated around the pipes 1 and 2. Along with this, the butt surface 3 was welded over the entire circumference. At the time of this welding, the inner surfaces of the pipes 1 and 2 in the welded portion are covered with Ar gas. _{O 2} and N ₂ gas are not present at the weld (near the butt surface 3). Therefore, an oxide film caused by welding could not be formed in the vicinity of the abutting surface 3 on the inner surface side of the pipes 1 and 2. Welding was done cleanly. For example, gravity was evenly applied to the welded portion during welding, and the welded portion protruded less into the inside of the pipe.

1 Tube A
2 Tube B
3 Butt surface between pipe 1 and pipe 2 (welded part)
4 Clamp (holding means)
5 Flexible tube (inert gas transport path in the inert gas supply means)
6 Ar tank 7 Welding torch (welding means)

Claims (15)

It is a method of joining pipe A and pipe B,
A joining method in which the pipe A and the pipe B are butted against each other, an inert gas is supplied into the upright pipe, and welding is performed at the butted portion. The joining method according to claim 1, wherein the inert gas, which is a gas having a density higher than that of oxygen gas, is supplied from the lower side to the upper side in the pipe. The joining method according to claim 1 or 2, wherein the inert gas is Ar. The joining method according to claim 1, wherein the inert gas, which is a gas having a density lower than that of oxygen gas, is supplied from above to below in the pipe. The inert gas is supplied into the tube via a transport path including a flexible tube.
The flexible tube is included in the group of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high density polyethylene, butyl rubber, polypropylene, and Teflon. The joining method according to any one of claims 1 to 4, wherein at least one or two or more selected from the above are used. The joining method according to any one of claims 1 to 5, wherein the pipe is made of Ti. The joining method according to any one of claims 1 to 5, wherein the pipe is made of stainless steel. It is a joining device between pipe A and pipe B,
A holding means for holding the pipes A and B in an upright position,
The inert gas supply means, in which the inert gas is supplied into the butt tubes A and B held by the holding means,
A joining device including welding means arranged so as to face each other at an abutting position between the pipe A and the pipe B. The joining device according to claim 8, wherein the inert gas supply means supplies an inert gas having a density higher than that of oxygen gas from the lower side to the upper side in the pipe. The joining device according to claim 8, wherein the inert gas supply means supplies an inert gas having a density smaller than that of oxygen gas from the upper side to the lower side in the pipe. The inert gas supply means is provided with a transport path having a flexible tube at least in part.
The flexible tube is included in the group of polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyacrylonitrile, polyvinylidene chloride, polyethylene terephthalate, nylon resin, vinyl chloride resin, polylactic acid, high density polyethylene, butyl rubber, polypropylene, and Teflon. The joining device according to any one of claims 8 to 10, wherein at least one or two or more kinds selected from the above are used and configured. It will be equipped with more means of transportation
The joining device according to any one of claims 8 to 11, wherein the welding means moves around a standing pipe held by the holding means by the action of the moving means. The joining device according to any one of claims 7 to 12, wherein the pipe is made of Ti. The joining device according to any one of claims 8 to 12, wherein the pipe is made of stainless steel. The joining device according to any one of claims 8 to 14, which is used in the joining method according to any one of claims 1 to 7.

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