JP6964530B2 - Pipe joining structure and joining method - Google Patents

Description

The present invention relates to a pipe joining structure and a joining method.

For example, as shown in FIG. 8A, the truss boom of a crane has a structure in which a branch pipe 103 is diagonally joined to a main pipe 101. In order to join the branch pipe 103 to the main pipe 103, the branch pipe 103 is diagonally butted against the peripheral surface of the main pipe 101, and the butted portion is welded to join. Therefore, as shown in FIG. 8B, a welded portion 105 is formed at the butt portion.

In addition, as another technique for joining pipes to each other, the core is inserted into the branch pipe until the cut surface of the core is slightly exposed from the cut surface of the branch pipe, and the branch pipe is inserted into the core. There is a method in which the peripheral surface of the main pipe and the cut surface of the core are butted against each other and the outer peripheral portion to be in contact with the pipe is welded after being temporarily fixed (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2001-58264

By the way, in the joint structure in which the branch pipe is abutted against the peripheral surface of the main pipe and welded, as shown in FIG. 8B, it is difficult to weld the inner peripheral side of the branch pipe 103, so that the inner peripheral side of the branch pipe 103 is welded. An unwelded portion G may be formed in the pipe, and the joint strength between the main pipe 101 and the branch pipe 103 may not be sufficiently secured.
Further, since the branch pipe 103 is diagonally joined to the main pipe 101 (the axis Ob of the branch pipe 103 is inclined with respect to the axis Oa of the main pipe 101), the joint portion between the main pipe 101 and the branch pipe 103 Is also inclined with respect to the axis Ob of the branch pipe 103. Therefore, when a load in the axial direction Ob direction acts on the branch pipe 103, a load in the shear direction acts on the joint portion. In particular, since there is an unjoined portion G in the joint portion, the joint strength is lowered with respect to the load in the shearing direction.

In the joining structure described in Patent Document 1, since the branch pipe and the main pipe are joined using a core, it is necessary to separately prepare the core, and the cut surface of the core is the main pipe. It is necessary to process it according to the peripheral surface of the pipe, which causes an increase in cost.

An object of the present invention is to provide a pipe joining structure and joining method capable of ensuring sufficient joining strength while suppressing costs as much as possible and easily joining.

The present invention has the following configuration.
(1) A pipe joining structure in which the second pipe is joined to the first pipe.
A cylindrical joint is formed on the peripheral surface of the first pipe, and a tubular joint is formed.
The end face of the second pipe is abutted against the end face of the joint and joined by welding.
The joint is a joint structure of a pipe made of a laminated model in which a welded bead obtained by melting and solidifying a filler metal is laminated on the peripheral surface of the first pipe.
(2) A pipe joining method for joining the second pipe to the first pipe.
A joint forming step of forming a cylindrical joint on the peripheral surface of the first pipe, and
A joining process in which the end face of the second pipe is abutted against the end face of the joint and joined by welding.
Including
In the joint forming process
A method for joining a pipe in which a welded bead obtained by melting and solidifying a filler metal is laminated on the peripheral surface of the first pipe to form the tubular joint.

According to the present invention, it is possible to provide a pipe joining structure and joining method capable of ensuring sufficient joining strength while suppressing costs as much as possible and easily joining.

It is a perspective view of the joint part which shows the joint structure of the pipe of this invention. It is sectional drawing of the joint part which shows the joint structure of the pipe of this invention. It is a schematic schematic block diagram of the manufacturing system which forms a joint by laminated molding. It is sectional drawing of the joint part explaining the joint formation process in the joint method of a pipe. It is sectional drawing of the joint part explaining the joint formation process in the joint method of a pipe. It is sectional drawing of the joining part explaining the joining process in the joining method of a pipe. It is a perspective view of the joint portion which shows the joint structure of the pipe which concerns on modification 1. FIG. It is sectional drawing of the joint part which shows the joint structure of the pipe which concerns on modification 1. FIG. It is a perspective view of the joint portion which shows the joint structure of the pipe which concerns on modification 2. FIG. It is a perspective view of the joint portion which shows the joint structure of the pipe which concerns on modification 3. FIG. It is sectional drawing of the joint part which shows the joint structure of the pipe which concerns on modification 3. FIG. It is sectional drawing of the joint part which shows the joint structure of the pipe which concerns on a comparative example. It is a perspective view of the joint part which shows the joint structure of the conventional pipe. It is sectional drawing of the joint part which shows the joint structure of the conventional pipe.

Hereinafter, a pipe joining structure and a joining method according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3C.

As shown in FIGS. 1A and 1B, the pipe joining structure of the present embodiment is a joining structure of a first pipe 51 which is a main pipe and a second pipe 53 which is a branch pipe. These first pipe 51 and second pipe 53 are, for example, pipe members constituting a truss boom of a crane, and both are formed in a cylindrical shape. Further, the second pipe 53 is obliquely joined to the peripheral surface of the first pipe 51 via a joint 55. Therefore, the axis Ob of the second pipe 53 is inclined with respect to the axis Oa of the first pipe 51 (see FIG. 1B).

The joint 55 is made of a laminated model formed on the peripheral surface of the first pipe 51 by the laminated modeling device 11 described later, and is formed from the joint portion 57 fixed to the peripheral surface of the first pipe 51 and the joint portion 57. It has a joint cylinder portion 59 extending diagonally along the joint direction of the second pipe 53. The joint cylinder portion 59 has a wall thickness substantially the same as that of the second pipe 53. The joint portion 57 has a cross-sectional shape in which the wall thickness gradually increases from the joint cylinder portion 59 side toward the joint side with the first pipe 51.

The second pipe 53 is joined to the joining cylinder portion 59 in a state where the second pipe 53 is abutted against the end face thereof. The joint surface 65, in which the end surface of the joint cylinder portion 59 and the end surface of the second pipe 53 are abutted and joined, is a plane perpendicular to the axis Ob of the second pipe 53. Further, a tapered portion 59a is formed on the outer peripheral side of the end portion of the joining cylinder portion 59. As a result, a groove 61 is formed around the joint portion between the joint cylinder portion 59 and the second pipe 53, and by welding at the groove 61, the joint cylinder portion 59 and the second pipe 53 of the joint 55 are formed. Is joined by a welded portion 63.

Next, a laminated modeling device for modeling the joint 55 will be described. FIG. 2 is a schematic schematic configuration diagram of a manufacturing system in which joints are formed by laminated molding.

The manufacturing system 100 includes a laminated modeling device 11 and a controller 15 that controls the laminated modeling device 11 in an integrated manner.

The laminated modeling device 11 includes a welding robot 19 having a torch 17 on a tip shaft, and a filler material supply unit 23 that supplies a filler metal (welding wire) M to the torch 17. The torch 17 holds the filler metal M in a state of protruding from the tip.

The controller 15 includes a CAD / CAM unit 31, an orbit calculation unit 33, a storage unit 35, and a control unit 37 to which these are connected.

The welding robot 19 is an articulated robot, and the filler metal M is continuously supplied to the torch 17 provided on the tip shaft. The position and posture of the torch 17 can be arbitrarily set three-dimensionally within the range of the degree of freedom of the robot arm.

The torch 17 has a shield nozzle (not shown), and shield gas is supplied from the shield nozzle. The arc welding method used in this configuration may be either a consumable electrode type such as shielded metal arc welding or carbon dioxide arc welding, or a non-consumable electrode type such as TIG welding or plasma arc welding. It is appropriately selected according to the situation.

For example, in the case of the consumable electrode type, a contact tip is arranged inside the shield nozzle, and the filler metal M to which the melting current is supplied is held by the contact tip. The torch 17 generates an arc from the tip of the filler metal M in a shield gas atmosphere while holding the filler metal M. The filler metal M is fed from the filler metal supply unit 23 to the torch 17 by a feeding mechanism (not shown) attached to a robot arm or the like. Then, when the filler metal M that is continuously fed is melted and solidified while moving the torch 17, a linear welded bead 25 that is a melt-solidified body of the filler metal M is formed.

The heat source for melting the filler metal M is not limited to the above-mentioned arc. For example, a heat source by another method such as a heating method using both an arc and a laser, a heating method using plasma, and a heating method using an electron beam or a laser may be adopted. When heating by an electron beam or a laser, the amount of heating can be controlled more finely, the state of the welded bead can be maintained more appropriately, and the quality of the laminated structure W can be further improved.

After creating the shape data of the laminated model W to be manufactured, the CAD / CAM unit 31 divides the laminated model W into a plurality of layers and generates layer shape data representing the shape of each layer. The trajectory calculation unit 33 obtains the movement trajectory of the torch 17 based on the generated layer shape data. The storage unit 35 stores data such as the generated layer shape data and the movement locus of the torch 17.

The control unit 37 drives the welding robot 19 by executing a drive program based on the layer shape data stored in the storage unit 35 and the movement locus of the torch 17. That is, the welding robot 19 moves the torch 17 while melting the filler metal M with an arc based on the movement locus of the torch 17 generated by the trajectory calculation unit 33 in response to a command from the controller 15. FIG. 2 shows a state in which a welded bead 25 is formed by a torch 17 on the peripheral surface of the first pipe 51 and laminated to form a laminated model W composed of a joint 55.

Next, a method of joining the first pipe 51 and the second pipe 53 will be described. 3A and 3B are cross-sectional views of a joint portion for explaining the joint forming process in the pipe joining method, and FIG. 3C is a cross-sectional view of the joining portion for explaining the joining step in the pipe joining method.

(Joint formation process)
First, in the manufacturing system 100, the filler metal M is melted while the torch 17 is moved by the drive of the welding robot 19 along the movement locus of the torch 17 generated from the set layer shape data, and the melted filler metal is melted. The material M is supplied on the peripheral surface of the first pipe 51. Then, a tubular joint 55 having a joint portion 57 and a joint tubular portion 59 made of a laminated model W in which the welding beads 25 are laminated is formed. At this time, as shown in FIG. 3A, first, the joint portion 57 on the first pipe 51 side is formed perpendicular to the axis Oa of the first pipe 51. When the wall thickness of the joint portion 57 is thicker than the bead width of the welded bead 25, the joint portion 57 may be formed by a plurality of rows of welded beads 25 on the peripheral surface of the first pipe 51. Further, as shown in FIG. 3B, the joint cylinder portion 59 is formed so as to be continuous with the joint portion 57 and inclined with respect to the first pipe 51.

At that time, as is clear from FIG. 3B, the lengths of the joint cylinder portion 59 along the axis Ob are different in the circumferential direction (in the figure, the left side portion of the joint cylinder portion 59 is longer than the right portion. Therefore, the joint cylinder portion 59 first has an annular weld bead 25 formed at the same height in the direction perpendicular to the axis Oa of the first pipe 51 until the end face of the shortest portion is reached. Laminate while shifting diagonally. After that, an arc shape formed at the same height in the direction perpendicular to the axis Oa of the first pipe 51 so as to form the portion of the joint cylinder portion 59 on the longer side. The welded beads 25 of the above are laminated while being gradually shortened to form up to the end face of the joint cylinder portion 59.

Alternatively, after shaping the joint portion 57, the joint cylinder portion 59 changes the posture of the first pipe 51 so that the direction of the axis line Occ of the joint cylinder portion 59 faces upward, and the length of the joint cylinder portion 59 is the longest. While gradually lengthening the arc-shaped welded bead 25 from the position, the welded bead 25 is laminated until an annular welded bead 25 can be formed. Then, in the above posture, the annular weld beads 25 are laminated up to the end of the joint cylinder portion 59.

Further, the wall thickness of the joint cylinder portion 59 is substantially the same as that of the second pipe 53, and is formed to be thinner than the joint portion 57. Further, the joint cylinder portion 59 is formed so that the end surface is perpendicular to the axis line Occ.
The joint portion 57 and the joint cylinder portion 59 can be arbitrarily laminated as long as a desired shape can be obtained.

After that, the end surface of the joint cylinder portion 59 is smoothed by machining or the like on the formed joint 55, and a tapered portion 59a serving as a groove 61 is formed on the outer peripheral side of the end portion of the joint cylinder portion 59.

(Joining process)
As shown in FIG. 3C, the end face of the second pipe 53 is abutted against the end face of the joint cylinder portion 59 of the joint 55. Then, a groove 61 is formed on the outer peripheral side at the abutting portion between the joint cylinder portion 59 and the second pipe 53. After that, by welding the formed groove 61, the joint cylinder portion 59 of the joint 55 and the second pipe 53 are joined by the welded portion 63 of the groove 61 (see FIG. 1B). At this time, the joint cylinder portion 59 of the joint 55 and the second pipe 53 are joined on a plane orthogonal to the axis Ob of the second pipe 53. That is, the end surface of the joint cylinder portion 59 is a plane perpendicular to the axis line Occ. Therefore, by joining the second pipe 53 to the joint cylinder portion 59 of the joint 55, the axis lines Ob and Occ of the second pipe 53 and the joint cylinder portion 59 are matched, and the second pipe 53 and the joint cylinder portion are matched. It will be joined at the joining surface 65 orthogonal to the axes Ob and Occ of 59.

As described above, according to the present embodiment, the tubular joint 55 made of the laminated model W in which the welding beads 25 obtained by melting and solidifying the filler metal M are laminated is formed on the peripheral surface of the first pipe 51. , The end face of the second pipe 53 is abutted against the end face of the joint 55 and joined by welding.

Therefore, as compared with the case where the second pipe 53 is abutted against the peripheral surface of the first pipe 51 and directly welded, the unwelded portion G can be eliminated as much as possible, and a joint structure having high joint strength can be obtained. Moreover, since the tubular joint 55 and the second pipe 53 are welded and joined, the joining can be facilitated, and robot welding using a robot or the like can also be easily supported. Further, it is not necessary to make the end face shape of the second pipe 53 a complicated shape according to the peripheral surface shape of the first pipe 51, and the manufacturing cost of the second pipe can be suppressed.

Further, in the joint 55, the joint portion 57 fixed to the peripheral surface of the first pipe 51 is formed to have substantially the same wall thickness as the second pipe 53, and the joint portion 59 extends in the axis Ob direction of the second pipe 53. It is said to be thicker than. Therefore, the load capacity at the joint portion of the joint 55 with the first pipe 51 can be increased, and a higher strength joint structure can be obtained.

Moreover, the joint cylinder portion 59 of the joint 55 is inclined with respect to the first pipe 51. Therefore, by joining the second pipe 53 to the joining cylinder portion 59, the second pipe 53 can be easily and diagonally joined to the first pipe 51.

Further, the joining cylinder portion 59 and the second pipe 53 are joined by a joining surface 65 orthogonal to the axis Ob of the second pipe 53. Therefore, even if an axial load acts on the second pipe 53, it is possible to suppress the generation of a shear load generated at the joint between the joint 55 and the second pipe 53, and the load bearing capacity can be further improved.

Next, various modifications will be described.
(Modification example 1)
As shown in FIGS. 4A and 4B, in the first modification, the second pipe 53 is joined perpendicularly to the first pipe 51. In this case, the joint 55 formed in the first pipe 51 is formed by laminating the welding beads 25 so that the joint cylinder portion 59 stands vertically from the joint portion 57.

Also in the case of this modification 1, since the second pipe 53 is joined to the joint 55 laminated and shaped on the peripheral surface of the first pipe 51, a joining structure having high joining strength can be obtained. Further, it is not necessary to make the end face shape of the second pipe 53 a complicated shape according to the peripheral surface shape of the first pipe 51, and the cost for joining can be suppressed.

(Modification 2)
As shown in FIG. 5, in the second modification, the second pipe 53 made of a square pipe is joined perpendicularly to the first pipe 51 made of a square pipe. In this case, the joint 55 formed in the first pipe 51 has a square tubular shape having the same cross-sectional shape as the second pipe 53, and the welding beads 25 are laminated so as to stand vertically from the peripheral surface of the first pipe 51. It will be formed.

Also in the case of this modification 2, since the second pipe 53 is joined to the joint 55 laminated and formed on the peripheral surface of the first pipe 51, a joining structure having high joining strength can be obtained.

(Modification example 3)
As shown in FIGS. 6A and 6B, in the modified example 3, a plurality of (two in this example) joints 55 are formed by laminated molding so as to partially overlap the peripheral surface of the first pipe 51. The joint tube portion 59 extends in different directions. A second pipe 53 is joined to each of the plurality of joining cylinders 59. These joint cylinder portions 59 extend from the joint portion 57 formed on the peripheral surface of the first pipe 51. The joint portion 57 on which each joint cylinder portion 59 is formed is formed on the peripheral surface of the first pipe 51 so that a part thereof intersects.

In this modification 3, in the joint forming step, the welded beads 25 are laminated to form a plurality of joints 55 in which a part thereof overlaps. Specifically, a plurality of joint portions 57 are formed on the peripheral surface of the first pipe 51 so as to partially intersect with each other, and further, a plurality of joint cylinder portions extending in different directions from the respective joint portions 57. Form 59. After that, in the joining step, the second pipe 53 is joined to each of the plurality of joining cylinders 59.

Here, FIG. 7 shows a joining structure of a comparative example in which a plurality of second pipes 53 are directly joined to the peripheral surface of the first pipe 51.

As shown in FIG. 7, one second pipe 53 is joined perpendicularly to the first pipe 51, and the other second pipe 53 is a combination of the first pipe 51 and one second pipe 53. It is joined to both and extends diagonally. Also in the case of this joint structure, an unwelded portion G is generated on the inner peripheral side of each of the second pipes 53. Further, in this structure, it becomes difficult to weld the second pipes 53 to each other in the narrow gap portion S. As a result, in this joint structure, it becomes difficult to obtain a sufficient load capacity, and the end face shape of the other second pipe 53 becomes more complicated, which further increases the cost.

On the other hand, also in the modified example 3, a plurality of second pipes 53 can be joined to the first pipe 51 with high strength via a laminated joint 55. Further, by increasing the number of laminated weld beads 25 to lengthen the length of each joint cylinder portion 59 extending from each joint portion 57, each of the joint cylinder portions 59 and the second pipe 53 is joined. It is possible to separate the parts and make it easier to weld. Moreover, a part of the joint portion 57 in which a part of the joint 55 intersects and a part of the joint cylinder portion 59 on one side become ribs 57a, and the load bearing capacity can be further improved. In this case, the rib 57a is joined to the peripheral surface of the first pipe 51 by welding and is formed inside the joint 55. That is, a part of the joint portion 57 and a part of one joint cylinder portion 59 form a rib 57a, and the rib 57a is formed inside the other joint cylinder portion 59.

It should be noted that the present invention is not limited to the above-described embodiment, and those skilled in the art may modify or apply the invention based on the combination of the configurations of the embodiments with each other, the description of the specification, and the well-known technique. Is also the subject of the present invention and is included in the scope for which protection is sought.

As described above, the following matters are disclosed in this specification.
(1) A pipe joining structure in which the second pipe is joined to the first pipe.
A cylindrical joint is formed on the peripheral surface of the first pipe, and a tubular joint is formed.
The end face of the second pipe is abutted against the end face of the joint and joined by welding.
The joint is a joint structure of a pipe made of a laminated model in which a welded bead obtained by melting and solidifying a filler metal is laminated on the peripheral surface of the first pipe.
According to the joint structure of this pipe, a tubular joint made of a laminated molded product obtained by laminating welded beads obtained by melting and solidifying a filler metal is formed on the peripheral surface of the first pipe, and a second joint is formed on the end surface of the joint. The end faces of the pipes are abutted and joined by welding.
Therefore, as compared with the case where the second pipe is abutted against the peripheral surface of the first pipe and directly welded, the unwelded portion can be eliminated as much as possible, and a joint structure having high joint strength can be obtained. Moreover, since the cylindrical joint and the second pipe are welded and joined, the joining can be facilitated, and robot welding using a robot or the like can also be easily supported.
Further, it is not necessary to make the end face shape of the second pipe a complicated shape according to the peripheral surface shape of the first pipe, and therefore, the manufacturing cost of the second pipe can be suppressed.

(2) The joint has a joint portion fixed to the peripheral surface of the first pipe and a joint cylinder portion extending from the joint portion in the axial direction of the second pipe.
The pipe joint structure according to (1), wherein the joint cylinder portion has substantially the same wall thickness as the second pipe, and the joint portion is formed to be thicker than the joint cylinder portion.
According to the joint structure of this pipe, the joint is a joint cylinder portion in which the joint portion fixed to the peripheral surface of the first pipe is formed to have substantially the same wall thickness as the second pipe and extends in the axial direction of the second pipe. It is said to be thicker than. Therefore, the load capacity at the joint with the first pipe in the joint can be increased, and a higher-strength joint structure can be obtained.

(3) The joint cylinder portion of the joint is inclined with respect to the first pipe,
The pipe joining structure according to (2), wherein the second pipe joined to the joint is joined obliquely to the first pipe.
According to the joint structure of this pipe, the joint cylinder portion of the joint is inclined with respect to the first pipe. Therefore, by joining the second pipe to the joining cylinder portion, the second pipe can be easily and diagonally joined to the first pipe.

(4) The pipe joining structure according to (2) or (3), wherein the joining cylinder portion of the joint and the second pipe are joined on a plane orthogonal to the axis of the second pipe.
According to the joining structure of this pipe, the joining cylinder portion and the second pipe are joined at a plane orthogonal to the axis of the second pipe. Therefore, even if an axial load acts on the second pipe, it is possible to suppress the generation of a shear load generated at the joint between the joint and the second pipe, and the load bearing capacity can be further improved.

(5) The joint has a plurality of joint cylinders extending in different directions, and the second pipe is joined to the plurality of joint cylinders, respectively, from any one of (2) to (4). The pipe joint structure described in 1.
According to this pipe joining structure, a plurality of second pipes can be joined with high strength via a joint formed in a laminated manner with respect to the first pipe. Further, by increasing the length of each joint cylinder portion by increasing the number of laminated weld beads, the joint portion between each joint cylinder portion and the second pipe can be separated to facilitate welding.
(6) The pipe according to any one of (1) to (5), wherein the joint is joined to the peripheral surface of the first pipe by welding and has ribs formed inside the joint. Joint structure.
According to the joint structure of this pipe, ribs are formed inside the joint. Therefore, the load bearing capacity of the joint can be increased.

(7) A pipe joining method for joining the second pipe to the first pipe.
A joint forming step of forming a cylindrical joint on the peripheral surface of the first pipe, and
A joining process in which the end face of the second pipe is abutted against the end face of the joint and joined by welding.
Including
In the joint forming process
A method for joining a pipe in which a welded bead obtained by melting and solidifying a filler metal is laminated on the peripheral surface of the first pipe to form the tubular joint.
According to this pipe joining method, a tubular joint made of a laminated molded product obtained by laminating welded beads obtained by melting and solidifying a filler metal is formed on the peripheral surface of the first pipe, and a second joint is formed on the end surface of the joint. The end faces of the pipes are abutted and joined by welding.
Therefore, as compared with the case where the second pipe is abutted against the peripheral surface of the first pipe and directly welded, the unwelded portion can be eliminated as much as possible, and the joint can be joined with high joining strength. Moreover, since the cylindrical joint and the second pipe are welded and joined, the joining can be facilitated, and robot welding using a robot or the like can also be easily supported. Further, it is not necessary to make the end face shape of the second pipe a complicated shape according to the peripheral surface shape of the first pipe, and therefore, the manufacturing cost of the second pipe can be suppressed.

(8) In the joint forming step,
The joint having a joint portion fixed to the peripheral surface of the first pipe and a joint cylinder portion extending from the joint portion in the axial direction of the second pipe is formed.
The method for joining a pipe according to (7), wherein the joint cylinder portion is formed to have a wall thickness substantially the same as that of the second pipe, and the joint portion is formed to be thicker than the joint cylinder portion.
According to this pipe joining method, the joint portion fixed to the peripheral surface of the first pipe is formed to have substantially the same wall thickness as the second pipe and is thicker than the joint cylinder portion extending in the axial direction of the second pipe. And. Therefore, the load capacity at the joint with the first pipe in the joint can be increased, and a higher-strength joint structure can be obtained.

(9) In the joint forming step, the second pipe is joined obliquely to the first pipe by forming the joint so that the joint cylinder portion is inclined with respect to the first pipe (). 8) The method for joining pipes.
According to this pipe joining method, the joint is formed so that the joint cylinder portion of the joint is inclined with respect to the first pipe. Therefore, by joining the second pipe to the joining cylinder portion, the second pipe can be easily and diagonally joined to the first pipe.

(10) The pipe according to (8) or (9), wherein in the joining step, the joining cylinder portion of the joint and the second pipe are joined on a plane orthogonal to the axis of the second pipe. Joining method.
According to this pipe joining method, the joining cylinder portion and the second pipe are joined at a plane orthogonal to the axis of the second pipe. Therefore, even if an axial load acts on the second pipe, it is possible to suppress the generation of a shear load generated at the joint between the joint and the second pipe, and the load bearing capacity can be further improved.

(11) In the joint forming step, the joint having a plurality of joint cylinders extending in different directions is formed.
The method for joining a pipe according to any one of (8) to (10), wherein the second pipe is joined to a plurality of the joining cylinders in the joining step.
According to this pipe joining method, a plurality of second pipes can be joined with high strength via a joint formed in a laminated manner with respect to the first pipe. Further, by increasing the length of each joint cylinder portion by increasing the number of laminated weld beads, the joint portion between each joint cylinder portion and the second pipe can be separated to facilitate welding.
(12) The method according to any one of (8) to (11), wherein in the joint forming step, the peripheral surface of the first pipe is joined by welding and has ribs formed inside the joint. How to join pipes.
According to this pipe joining method, the peripheral surface of the first pipe is joined by welding and has ribs formed inside the joint. As a result, the load bearing capacity of the joint can be increased.

25 Welding bead 51 First pipe 53 Second pipe 55 Joint 57 Joint 59 Joint cylinder 65 Joint surface M Welding material Oa, Ob, Occ Axis line W Laminated model

Claims (10)

It is a pipe joining structure in which the second pipe is joined to the first pipe.
A cylindrical joint is formed on the peripheral surface of the first pipe, and a tubular joint is formed.
The end face of the second pipe is abutted against the end face of the joint and joined by welding.
The joint, the circumferential surface of the first pipe, Ri Do a laminate shaped article obtained by laminating the weld bead obtained by melting and solidifying the filler material,
The joint is joined to the peripheral surface of the first pipe by welding and has ribs formed inside the joint.
Pipe joint structure. The joint has a joint portion fixed to the peripheral surface of the first pipe and a joint cylinder portion extending from the joint portion in the axial direction of the second pipe.
The pipe joint structure according to claim 1, wherein the joint cylinder portion has substantially the same wall thickness as the second pipe, and the joint portion is formed to be thicker than the joint cylinder portion. The joint cylinder portion of the joint is inclined with respect to the first pipe,
The pipe joining structure according to claim 2, wherein the second pipe joined to the joint is joined obliquely to the first pipe. The pipe joining structure according to claim 2 or 3, wherein the joining cylinder portion of the joint and the second pipe are joined on a plane orthogonal to the axis of the second pipe. The joint according to any one of claims 2 to 4, wherein the joint has a plurality of joint cylinders extending in different directions, and the second pipe is joined to the plurality of joint cylinders. Pipe joint structure. It is a pipe joining method that joins the second pipe to the first pipe.
A joint forming step of forming a cylindrical joint on the peripheral surface of the first pipe, and
A joining process in which the end face of the second pipe is abutted against the end face of the joint and joined by welding.
Including
In the joint forming process
A welded bead obtained by melting and solidifying a filler metal is laminated on the peripheral surface of the first pipe to form the tubular joint, and the inside of the joint is welded to the peripheral surface of the first pipe. Forming ribs joined by,
How to join pipes. In the joint forming process
The joint having a joint portion fixed to the peripheral surface of the first pipe and a joint cylinder portion extending from the joint portion in the axial direction of the second pipe is formed.
The method for joining a pipe according to claim 6 , wherein the joint cylinder portion is formed to have substantially the same wall thickness as the second pipe, and the joint portion is formed to be thicker than the joint cylinder portion. In the joint forming step, by the joint tube portion relative to the first pipe forming the joint so as to be inclined, to claim 7 for joining diagonally the second pipe to the first pipe The method of joining the pipes described. The method for joining a pipe according to claim 7 or 8 , wherein in the joining step, the joining cylinder portion of the joint and the second pipe are joined on a plane orthogonal to the axis of the second pipe. In the joint forming step, the joint having a plurality of joint cylinders extending in different directions is formed.
The method for joining a pipe according to any one of claims 7 to 9 , wherein in the joining step, the second pipe is joined to each of the plurality of joining cylinders.

Images