JP6996543B2 - Multi-threaded thread joints, steel pipes with joints, structures, construction methods of structures, design methods and manufacturing methods of multi-threaded threaded joints - Google Patents

Description

The present invention includes a multi-threaded joint consisting of an inner joint pipe having two or more male threads and an outer joint pipe having two or more female threads, a steel pipe with a joint to which the multi-threaded joint is attached, and a steel pipe with a joint. The present invention relates to a structure composed of a plurality of connected structures, a method of constructing the structure, and a method of designing and manufacturing a multi-threaded threaded joint.

Structures made of steel pipes used for foundations of structures and prevention of landslides (for example, steel pipe piles, steel pipe sheet piles, steel pipe sheet pile walls connecting steel pipe sheet piles, steel pipe columns, steel pipe beams, etc.) are required depending on the construction conditions. The length may reach several tens of meters. On the other hand, when transporting these steel pipe structures to the construction site, it is not possible to transport long structures due to traffic restrictions. Therefore, they are carried in increments of several meters, which is a length that can be transported, and are joined during construction (including casting) at the construction site.

As a method of joining a structure made of steel pipes at a construction site, a threaded joint as disclosed in Patent Document 1 is used. Threaded joints are attached to each end of the steel pipe to be joined, and the steel pipes are joined by rotational fitting at the construction site to construct a structure made of steel pipes.

In the threaded joint disclosed in Patent Document 1, by making the threaded portion a multi-threaded screw, the amount of rotation required for fitting can be reduced, the fitting time can be reduced, and the workability can be improved. In particular, when applying a threaded joint to a steel pipe for a steel pipe sheet pile that has a connecting joint that connects adjacent steel pipes, other steel pipe sheet piles within the radius of gyration of the connecting joint may interfere, so it is necessary for fitting. It is effective to reduce the amount of rotation.

Japanese Unexamined Patent Publication No. 10-31028

When applying a threaded joint to a steel pipe for a steel pipe sheet pile, the position of the connecting joint of the upper steel pipe and the lower steel pipe must be in the same position when the fitting of the upper and lower steel pipes is completed. In this respect, in the case of a multi-threaded threaded joint, there are as many thread tips as there are threads, and there are as many fitting start positions as there are threads. Therefore, it is necessary to start the fitting from the fitting start position which is the correct position when the fitting is completed. Therefore, the multi-threaded threaded joint is provided with an alignment mark at the correct fitting start position.

When the threaded joint is applied to a steel pipe for a steel pipe sheet pile, the upper and lower connecting joint positions are matched when the fitting is completed by starting the fitting according to the alignment mark.
However, even if the alignment mark is provided, the mistake of the fitting start position due to human error cannot be completely eliminated. It can be seen that the connecting joint positions of the above were inconsistent and the fitting start position was incorrect.
In this case, the completed fitting is rotated in the reverse direction again to remove the fitting, the fitting position is aligned, and the fitting is refitted. It causes a defect.

The present invention has been made to solve such a problem, and has a structure in which a multi-threaded screw joint capable of eliminating a fitting error, a steel pipe with a joint to which the multi-threaded screw joint is attached, and a plurality of steel pipes with a joint are connected. It is an object of the present invention to provide a method of constructing a body and a structure, and a method of designing and manufacturing a multi-threaded threaded joint.

(1) The multi-threaded threaded joint according to the present invention is attached to the end of a steel pipe and is composed of an inner joint pipe having a male thread and an outer joint pipe having a female thread. A multi-threaded joint that is a multi-threaded screw with two or more threads.
The thread of a specific one of the multi-threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. It is characterized by having different shapes.

(2) Further, in the above-mentioned (1), the thread for one specific thread and the corresponding thread bottom have a thread and a thread with a gap in the joint axial direction of the thread bottom of another thread and a thread. It is characterized by being the same as the bottom.

(3) Further, in the above-mentioned (1) or (2), the specific one thread and the corresponding thread bottom have the same height as the other thread and the thread bottom. It is characterized by being different.

(4) Further, in the above-mentioned (1) or (2), the thread for one specific thread and the corresponding thread bottom have a different thread width from other threads and thread bottoms. It is characterized by that.

(5) Further, in the above-mentioned (1) or (2), the thread of the specific one thread and the corresponding thread bottom have a different screw angle from the other threads and the thread bottom. It is characterized by that.

(6) The steel pipe with a joint according to the present invention is formed by attaching the inner joint pipe and the outer joint pipe in the multi-threaded screw joint according to any one of (1) to (5) above to one end and the other end. It is a feature.

(7) The structure according to the present invention is characterized by comprising the multi-threaded screw joint according to any one of (1) to (5) above and a plurality of steel pipes connected by the multi-threaded screw joint. It is something to do.

(8) A method for constructing a structure according to the present invention, which is a method for constructing a structure according to (7) above, in which the rotation of one of the steel pipes with a joint to be connected is restrained, and the other joint steel pipe is restrained. It is characterized in that the multi-threaded threaded joint of the above is aligned with the multi-threaded threaded joint of the steel pipe with one of the above and is rotationally fitted.

(9) The method for designing a multi-threaded threaded joint according to the present invention comprises an inner joint pipe having a male thread and an outer joint pipe having a female thread attached to the end of a steel pipe, and the inner joint pipe and the outer joint pipe. Screws are a design method for multi-threaded screws with two or more threads.
The thread of a specific one of the multi-threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. It is characterized in that the shape is designed to have a different shape.

(10) The method for manufacturing a multi-threaded threaded joint according to the present invention comprises an inner joint pipe having a male thread and an outer joint pipe having a female thread attached to the end of a steel pipe, and the inner joint pipe and the outer joint pipe. A method for manufacturing a multi-threaded thread joint in which the thread is a multi-threaded thread with two or more threads.
The thread of a specific one of the multi-threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. It is characterized in that the shapes are formed into different shapes.

In the multi-threaded threaded joint according to the present invention, the thread for a specific one of the multi-threaded threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe are other threads. And since the pitch is the same as that of the thread bottom and the thread shape is different, the thread cannot be fitted unless the specific corresponding thread and the thread bottom are in a matable state. Therefore, misfitting can be reliably prevented.

It is a side view of the state before fitting of the multi-threaded screw joint which concerns on this embodiment. It is a figure which shows the side surface of the state at the time of completion of fitting of the multi-threaded screw joint which concerns on this embodiment through the inside. FIG. 3 (a) is an enlarged view showing a part of the state in which the multi-threaded threaded joint is fitted in the correct position, FIG. 3 (a) shows the fitted state of other screw shapes, and FIG. 3 (b) shows the fitted state. It is a fitted state of a specific thread shape. It is explanatory drawing for demonstrating that the multi-threaded screw joint shown in FIG. 3 cannot be fitted when it tries to fit at an erroneous position. It is a conceptual diagram of the fitting start position of a male thread and a female thread when 8 thread joints are seen from the upper part. It is explanatory drawing explaining another aspect 1 of a screw shape, FIG. 6 (a) is the fitting state of other screw shapes, and FIG. 6 (b) is the fitting state of the specific 1 thread shape. Is. It is explanatory drawing for demonstrating that the multi-threaded screw joint shown in FIG. 6 cannot be fitted when it tries to fit at an erroneous position. It is explanatory drawing explaining another aspect 2 of a screw shape, FIG. 8 (a) is the fitting state of other screw shapes, and FIG. 8 (b) is the fitting state of the specific 1 thread shape. Is. It is explanatory drawing for demonstrating that the multi-threaded screw joint shown in FIG. 8 cannot be fitted when it tries to fit at an erroneous position.

As shown in FIGS. 1 and 2, the multi-threaded threaded joint 1 according to the present embodiment is attached to the end of the upper steel pipe 3 and has an inner joint pipe 7 having a male screw 5 and a lower steel pipe 9. The inner joint pipe 7 and the outer joint pipe 13 are made of an outer joint pipe 13 attached to an end and having a female thread 11, and the threads of the inner joint pipe 7 and the outer joint pipe 13 are a multi-threaded threaded joint 1 which is a multi-threaded thread having two or more threads. The pipe 7 and the outer joint pipe 13 have threads 5as and 11as for a specific one of the multi-threaded threads (parts shown by diagonal lines in FIGS. 1 and 2) and corresponding thread bottoms 11bs and 5bs. Be prepared. The thread 5as, 11as and the corresponding thread bottoms 11bs, 5bs are characterized in that they have the same pitch as the other threads 5a, 11a and the thread bottoms 11b, 5b, but have different screw shapes. It is something to do.

<Steel pipe>
The steel pipes 3 and 9 constitute piles, and the upper steel pipe 3 in the figure constitutes an upper pile and the lower steel pipe 9 constitutes a lower pile.
In the present embodiment, the inner joint pipe 7 having the male screw 5 is fixed to the upper steel pipe 3 by welding, and the outer joint pipe 13 having the female screw 11 is fixed to the lower steel pipe 9 by welding.
However, the inner joint pipe 7 may be fixed to the lower steel pipe 9, and the outer joint pipe 13 may be fixed to the upper steel pipe 3.

<Inner fitting pipe, outer fitting pipe>
The inner joint pipe 7 is formed with a male screw 5 composed of two or more multi-threaded threads. Further, the outer joint pipe 13 is formed with a female screw 11 made of two or more multi-threaded threads having the same number of threads as the inner joint pipe 7.
Then, the threads 5as and 11as for a specific one of the multi-threaded threads and the corresponding thread bottoms 11bs and 5bs provided in the inner joint pipe 7 and the outer joint pipe 13 are the other thread 5a. The pitch is the same as that of 11a and the screw bottoms 11b and 5b, but the screw shape is different.
Therefore, if the fitting start positions of the specific strips of the inner joint pipe 7 and the outer joint pipe 13 do not match, the rotary fitting cannot be performed. In other words, as shown in FIG. 2, rotary fitting can be performed only when the fitting start positions of the specific ones are the same.

As an example of the thread shape of a specific thread 5as, 11as and the corresponding thread bottom 11bs, 5bs, the height of the thread 5as, 11as and the corresponding thread bottom 11bs, 5bs is different from the others. Different ones are mentioned, and this will be described with reference to FIGS. 3 and 4.

FIG. 3A shows threads 5a, 11a, and thread bottoms 11b, 5b other than the specific one thread, and is in a state of being properly fitted. As an example, the height h of the thread 11a of the appropriately fitted female thread 11 is 4.0 mm, and the radial clearance c ₁ between the thread bottom 5b of the male thread 5 and the thread bottom 5b is 0.5 mm.
Further, FIG. 3B shows a specific thread of thread 5as, 11as, thread bottom 11bs, and 5bs, and is in a state of being properly fitted. As an example, the thread height H of the female thread 11 for this specific thread 11 is 2.0 mm, and the clearance C ₁ between the thread bottom 5 bs of the male thread 5 is 0.5 mm.

The screw pitch P is 10 mm for both other screw shapes and specific one-row screw shapes. The thread pitch P is the axial distance from the end of the thread bottom of the male thread 5 in one thread to the starting position of the thread bottom of the next male thread 5 in one thread, or from the end of the thread of the female thread 11 in one thread. This is the axial distance to the starting position of the next thread.
In the case of a single-threaded screw, the screw pitch means the distance traveled by the screw when it makes one rotation, but in the case of a multi-threaded screw, the distance traveled when it makes one rotation differs depending on the number of threads of the screw, so it is constant. Since the screw pitch as the distance cannot be defined, it is defined as above.

As shown in FIG. 3B, even for a specific thread, if the male thread 5 and the female thread 11 are one specific thread, the fitting can be started, and the inner joint pipe 7 having the male thread 5 can be started. The outer joint pipe 13 having the female screw 11 can be rotationally fitted.
However, when a specific one thread and another thread try to fit, as shown in FIG. 4, the thread bottom 5 bs (H + C ₁ ) of 2.5 mm including the clearance C ₁ of the male thread 5 which is the specific thread 5 is included. ), The thread 11a of the female screw 11 having a screw height h of 4.0 mm, which is another female screw 11, is located, and cannot start fitting due to interference.

It should be noted that the difference in thread height must be a clearance c ₁ or more in order to prevent the specific screw of one thread from fitting with another screw. For example, the relationship between the height H of a specific thread 5as and 11as, the height h of other threads 5a and 11a, the _other thread bottoms 5b and 11b and the clearance c1 of the threads 11a and 5a is , H> H + c ₁ or H> h + c ₁ .

FIG. 5 is a conceptual diagram of the screw start positions of the male screw 5 and the female screw 11 when the threaded joint of the eight threads is viewed from above. In the figure, the black circle indicates the fitting start position of the screw other than the specific one thread, and the star mark indicates the fitting start position of the specific one thread.
In FIG. 5A, all the screws on which a specific one is not formed are normal, and the male screw 5 and the female screw 11 can start fitting if the positions of the black circles match. .. FIG. 5 (b) shows a specific strip formed, and in this case, as shown in FIG. 5 (b), if the positions of the star marks on the male screw 5 and the female screw 11 are the same, the fitting is performed. Can be started. In the state shown in FIG. 5B, the relationship between the black circles is the state shown in FIG. 3A, and the relationship between the stars is the state shown in FIG. 3B.

FIG. 5 (c) shows that a specific row is formed as in FIG. 5 (b), but since the fitting start position of the male screw 5 and the fitting start position of the female screw 11 do not correspond to each other. , Cannot start mating. The relationship between the star mark and the black circle in FIG. 5C is as shown in FIG.

In this way, the specific thread 5as, 11as and the corresponding thread bottoms 11bs, 5bs are the same as the other thread 5a, 11a and the thread bottoms 11b, 5b, but the pitch is the same but the thread shape is different. By doing so, since the fitting cannot be started unless the position corresponds to the corresponding position, it is possible to surely prevent the erroneous fitting.
That is, if the alignment mark is attached to the position where the mating start positions of the specific strips match, rotational mating can be performed if the mating position is correct, and the alignment is assumed by human error. If you make a mistake, you cannot start mating. Therefore, it is immediately known that the fitting start position is incorrect, and the construction efficiency can be improved as compared with the case where the rotary fitting is redone due to the incorrect fitting.

In the above description, the heights of the specific thread threads 5as and 11as and the corresponding thread bottoms 11bs and 5bs are set to be different from the others, but the present invention relates to this. It is not limited, and in short, it is sufficient to form one specific screw having a screw shape that cannot be fitted with other screws, and an embodiment for making a specific one screw shape different from other screw shapes is, for example, , Other aspects 1, 2 and the like described below can be mentioned.

<Other aspect 1>
In another aspect 1, the thread pitches of a specific thread 5as, 11as and the corresponding thread bottoms 11bs, 5bs are the same as those of the other threads 5a, 11a and thread bottoms 11b, 5b. , The screw widths are different, and this will be described with reference to FIGS. 6 and 7.
FIG. 6A shows other thread threads 5a, 11a, and thread bottoms 11b, 5b, and is in a state of being properly fitted. As an example, the thread width w of the appropriately fitted female thread 11 is 3.4 mm, and the axial clearance c ₂ between the male thread 5 and the thread bottom 5b is 0.5 mm.
Further, FIG. 6B shows a specific thread of thread 5as, 11as, thread bottom 11bs, and 5bs, and is in a state of being properly fitted. As an example, the thread width W of the female thread 11 for this specific thread is 2.4 mm, and the axial clearance C ₂ between the male thread 5 and the thread bottom 5 bs is 0.7 mm.
The screw pitch P is 10 mm for both other threads and a specific thread.

As shown in FIG. 6B, the corresponding thread 5as, 11as and the thread bottom 11bs, 5bs can be fitted to each other even for a specific one, and the inner joint pipe 7 having the male thread 5 can be fitted. The outer joint pipe 13 having the female thread 11 can be fitted.
However, when a specific thread 1 screw and another screw try to fit, as shown in FIG. 7, the clearance C ₂ of the male screw 5 which is the specific thread 5 is included and the thickness is 3.1 mm (W + C ₂ ). The thread 11a of the female thread 11 having a thread width w of 3.4 mm, which is another female thread 11, is located at the thread bottom 5bs, and interferes with each other to start fitting the inner joint pipe 7 and the outer joint pipe 13. Can not do it.

It should be noted that the difference in thread width must be a clearance of c ₂ or more in order to prevent the specific screw of one thread from fitting with another screw. For example, the relationship between the width W of the specific thread 5as and 11as, the width w of the other threads 5a and 11a, the other thread bottoms 5b and 11b and the clearance c ₂ of the threads 11a and 5a is w> W + c ₂ . Or, the relationship is W> w + c ₂ .

<Other aspect 2>
In another aspect 2, the specific one thread threads 5as and 11as and the corresponding thread bottoms 11bs and 5bs have the same pitch as the other thread threads 5a and 11a and the thread bottoms 11b and 5b. The screw angles are different, and this will be described with reference to FIGS. 8 and 9. Note that the different screw angles mean that both the cases where the flank angles on both sides of the thread are different and the cases where the flank angles on one side are different are included.

FIG. 8A shows the other threads 5a and 11a and the thread bottoms 11b and 5b, and is in a state of being properly fitted. As an example, the flank angle α on the lower side in the figure of the thread 11a of the female screw 11 and the thread bottom 5b of the male screw 5 that are properly fitted is set to about 10 °. As a result, the screw width w of the female screw 11 is 3.4 mm, and the axial clearance c ₂ between the male screw 5 and the screw bottom 5b is 0.5 mm.

Further, FIG. 8B shows a specific thread of thread 5as, 11as, thread bottom 11bs, and 5bs, and is in a state of being properly fitted. As an example, the lower flank angle β in the figure of the thread 11 as of the female screw 11 for this specific thread and the thread bottom 5 bs of the male screw 5 is set to about 20 °. As a result, the screw width W of the female screw 11 is 2.2 mm, and the axial clearance C ₂ between the male screw 5 and the screw bottom 5 bs is 0.6 mm.
The screw pitch P is 10 mm for both other threads and a specific thread.

As shown in FIG. 8B, the corresponding thread 5as, 11as and the thread bottom 11bs, 5bs can be fitted to each other even for a specific one, and the inner joint pipe 7 having the male thread 5 can be fitted. The outer joint pipe 13 having the female thread 11 can be fitted.
However, when the specific one-threaded screw and the other screw are to be fitted, as shown in FIG. 9, the thread 11a of the other female screw 11 is formed at the thread bottom 5bs of the specific one-threaded male screw 5. When they are positioned, they cannot be fitted because they interfere with each other due to the difference in flank angle, and the inner joint pipe 7 and the outer joint pipe 13 cannot be fitted.

Also in the present invention, it is better to have a guideline for starting fitting, and it is preferable to provide an alignment mark. Even if the alignment mark is provided, misfitting may occur due to a human error, but by applying the present invention, such a human error can be reliably prevented.
Further, since the change in the screw shape for a specific row in the present invention can be manufactured by changing the cutting blade and the cutting program without significantly increasing the conventional cutting process, the present invention is a low-cost screw. It can be said that the misfitting of the above can be prevented.

Although parallel screws were targeted in the above example, it can also be applied to tapered screws, and misfitting can be prevented without problems even with tapered screws.
If the fitting position on the outer joint pipe 13 side cannot be confirmed without looking into the front side from the upper part due to the large diameter, the thread of the outer joint pipe 13 can be visually checked from the upper side by making it different from the others. It becomes easy to determine the fitting position.

In the other form 1 described above, the axial clearance (gap) C ₂ of a specific thread and the corresponding thread bottom is 0.7 mm, and the thread and the corresponding thread bottom are threaded. In the other form _{2, the axial clearance (gap) C 2 of} a specific thread and the corresponding thread bottom is 0.6. In mm, an example is shown in which the joint axial clearance c2 between the other thread and the corresponding thread _bottom is 0.5 mm.
However, the multi-threaded threaded joint of the present invention is attached to the end of a steel pipe constituting the structure, and when a load is applied, all the threads are evenly contacted in the axial direction to transmit the load. Is more preferable.
Therefore, the axial clearance (gap) C ₂ of a specific thread and the corresponding thread bottom is the same as the joint axial clearance c ₂ of the thread and the corresponding thread bottom. Is more preferable.

Further, in the above embodiment, the description has been made using a parallel screw (a screw whose thread is on the outer surface or the inner surface of the cylinder), but the scope of the present invention is not limited to the parallel screw. The present invention can obtain the same effect even in the case of a tapered screw (a screw having a thread on the outer surface or the inner surface of the cone).

Further, in the above embodiment, the multi-row screw joint to be attached to the end of the steel pipe has been described, but this multi-row screw joint constitutes a steel pipe pile, a steel pipe sheet pile, a steel pipe column, a steel pipe beam, etc. in advance at a factory or the like. A steel pipe with a joint can be constructed by attaching it to the end of the steel pipe by welding or the like.

Then, at a construction site or the like, by connecting a plurality of multi-threaded screw joints of steel pipes with joints, structures such as steel pipe piles, steel pipe sheet piles, steel pipe sheet pile walls connecting steel pipe sheet piles, steel pipe columns, and steel pipe beams are formed. be able to. That is, these structures include a multi-threaded threaded joint described in the above embodiment and a plurality of steel pipes connected by these multi-threaded threaded joints.
When forming these structures, the multi-threaded threaded joint of the other jointed steel pipe is aligned with the multi-threaded threaded joint of the one of the jointed steel pipes while the rotation of one of the steel pipes with joints to be connected is restrained. It suffices to rotate and fit.
For example, when the structure is a steel pipe pile or a steel pipe sheet pile, one steel pipe with a joint may be placed in the ground first, the other steel pipe with a joint may be joined, and then the casting may be repeated.
For example, when the structure is a steel pipe sheet pile wall, a steel pipe with a joint provided with one connecting joint is first driven into the ground while being connected by a connecting joint next to another steel pipe with a joint already in the ground. It may be installed, the other steel pipe with a joint is joined, the positions of the connecting joints are aligned, and then the casting is repeated.
At this time, the method of placing the steel pipe with a joint in the ground is not particularly limited, and any of the Nakadori pile method, the steel pipe soil cement pile method, the rotary pile method, the vibration method, the striking method and the like can be applied.

Since the multi-threaded screw joint of the present invention can reliably prevent misfitting, the connecting joint positions of the upper and lower steel pipe sheet piles do not differ when the rotary fitting is completed as in the case of steel pipe sheet piles, and the rotary fitting is performed. There is no need to redo, and construction efficiency is improved.

Further, in the above description, the multi-threaded threaded joint has been described as an invention of the product, but the multi-threaded threaded joint is designed by the following design method.
A multi-threaded joint that is attached to the end of a steel pipe and consists of an inner joint pipe with male threads and an outer joint pipe with female threads, and the threads of the inner joint pipe and the outer joint pipe are two or more multi-threaded threads. It is a design method of
The thread of a specific one of the multi-threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. Design with different shapes.

Further, the multi-threaded threaded joint described as the invention of the product is manufactured by the following manufacturing method.
A multi-threaded joint that is attached to the end of a steel pipe and consists of an inner joint pipe with male threads and an outer joint pipe with female threads, and the threads of the inner joint pipe and the outer joint pipe are two or more multi-threaded threads. It is a manufacturing method of
The thread of a specific one of the multi-threads and the corresponding thread bottom provided in the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. Form different shapes.

1 Multi-thread thread joint 3 Upper steel pipe 5 Male thread 5a Thread (others)
5b screw bottom (others)
5as thread (specific)
5bs screw bottom (specific)
7 Inner joint pipe 9 Lower steel pipe 11 Female thread 11a Thread (Other)
11b Thread bottom (others)
11as thread (specific)
11bs screw bottom (specific)
13 Outer fitting pipe

Claims (9)

It is attached to the end of a steel pipe that constitutes a structure and consists of an inner joint pipe having a male thread and an outer joint pipe having a female thread. A multi-threaded threaded joint
The thread of a specific one of the multi-threads and the corresponding thread bottom provided by the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. A multi-threaded threaded joint characterized by a different shape and the same axial clearance between the thread and the thread bottom as other threads and the thread bottom . The multi-threaded threaded joint according to claim 1, wherein the specific one thread and the corresponding thread bottom are different in height from other threads and thread bottoms. The multi-threaded threaded joint according to claim 1, wherein the specific one-threaded thread and the corresponding threaded bottom have a different thread width from other threaded threads and threaded bottoms. The multi-threaded threaded joint according to claim 1, wherein the specific one thread and the corresponding thread bottom have a different thread angle from other threads and thread bottoms. A steel pipe with a joint, wherein the inner joint pipe and the outer joint pipe in the multi-threaded screw joint according to any one of claims 1 to 4 are attached to one end and the other end. A structure comprising the multi-threaded screw joint according to any one of claims 1 to 4 and a plurality of steel pipes connected by the multi-threaded screw joint. The method for constructing the structure according to claim 6 , wherein the multi-threaded screw joint of the other joint steel pipe is connected to the multi-threaded joint of the one jointed steel pipe in a state where the rotation of one of the jointed steel pipes to be connected is restrained. A method of constructing a structure, which comprises aligning with a threaded joint and rotating and fitting. It is attached to the end of a steel pipe that constitutes a structure and consists of an inner joint pipe having a male thread and an outer joint pipe having a female thread. A method of designing a multi-threaded threaded joint,
The thread of a specific one of the multi-threads and the corresponding thread bottom provided by the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. A method for designing a multi-threaded threaded joint, characterized in that the shape is different and the joint axial clearance between the thread and the thread bottom is designed to be the same as that of other threads and the thread bottom . It is attached to the end of a steel pipe that constitutes a structure and consists of an inner joint pipe having a male thread and an outer joint pipe having a female thread. A method of manufacturing a multi-threaded threaded joint,
The thread of a specific one of the multi-threads and the corresponding thread bottom provided by the inner joint pipe and the outer joint pipe have the same pitch as the other threads and the thread bottom. A method for manufacturing a multi-threaded threaded joint, characterized in that the shapes are formed differently and the joint axial gap between the thread and the thread bottom is formed to be the same as that of other threads and the thread bottom .

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