JP5880421B2 - Steel pipe joint, steel pipe joint structure, and steel pipe joint method - Google Patents

Description

  The present invention relates to a steel pipe joint, a steel pipe joining structure, and a steel pipe joining method for joining steel pipes.

Steel pipe piles are usually used as long foundation support materials by joining upper and lower piles by threaded joints, other mechanical joints, or field welding. The threaded joint is formed by forming a male screw made of a taper screw or the like at the end of the steel pipe pile, and screwed into a socket having a female screw or an enlarged diameter portion or the like (for example, see Patent Document 1). Such threaded joints are cumbersome and expensive. In addition, field welding is greatly influenced by the weather, and there is a difficulty in securing qualified welding personnel.
Moreover, what is called a key-type thing is also known as an example of another mechanical coupling (for example, refer patent documents 2-4). However, this key type has a problem that since the key needs to be provided in the joint portion, the portion becomes thick and the product weight increases.

As a steel pipe joining structure that solves the above problems, those described in Patent Documents 5 to 7 are known.
This steel pipe joining structure consists of a female cylinder and a male cylinder that have a pile axial direction crimping end face and can be inserted into and removed from each other, and the female cylinder is arranged in the circumferential direction with an interval between them on the inner surface of the entrance side. The inner cylinder has a plurality of inner surface protrusions that are loosely fitted to the outer peripheral surface of the male cylinder. The male cylinder is arranged alternately with the inner surface protrusions on the outer surface of the charging end, and the outer diameter is loosely connected to the inner peripheral surface of the female cylinder. A plurality of outer surface projections, each of the inner surface projection and the outer surface projection having a taper on the back end face, and the taper comes into contact with each other when the male cylinder is inserted into the female cylinder and rotated about its axis. It is characterized by a taper for connecting and fixing.

Japanese Patent No. 3747594 Japanese Patent No. 3158081 Japanese Patent No. 3329781 Japanese Patent No. 3336430 Japanese Patent No. 3598052 Japanese Patent No. 4456427 Japanese Patent No. 3896318

However, in the steel pipe joint structures described in Patent Documents 5 to 7, the inner surface protrusion and the outer surface protrusion respectively provided on the male and female cylinders are formed by cutting the inner surface and the outer surface of the cylinder. In addition, there is a problem in that it is necessary to cut the left and right side surfaces of the inner surface protrusion and the outer surface protrusion and the total four surfaces of both the back side and the inlet side with high accuracy, which increases the processing cost.
In addition, when joining a male cylinder and a female cylinder respectively provided at the joining end of a steel pipe to be joined, it is necessary to insert the male cylinder into the female cylinder and then rotate the male cylinder around its axis Therefore, it was necessary to separately apply a rotational force to the steel pipe from the outside.

  The present invention has been made in view of the above circumstances, can reduce the processing cost, and when joining steel pipes, the steel pipes can be rotated without applying a rotational force to the steel pipes from the outside. An object of the present invention is to provide a steel pipe joint, a steel pipe joint structure, and a steel pipe joint method.

In order to achieve the above object, a female-side steel pipe joint according to the present invention includes a female cylinder provided at a joining end portion to be joined to the steel pipe, and an inner circumferential surface of the female cylinder along the inner circumferential surface. A spiral female-side ridge that extends so as to intersect the axial direction of the cylinder and is provided at a predetermined interval in the circumferential direction;
A female-side engaging portion is formed on a surface of the female-side ridge facing the inner side in the axial direction of the steel pipe, and a surface of the female-side ridge facing the outer side in the axial direction of the steel pipe is along the female-side ridge. female side inclined surface extending Te is formed,
The female engagement portion is formed in a step shape having an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction,
The width of the orthogonal contact surface in the circumferential direction is B (mm), the height of the orthogonal contact surface from the inner peripheral surface of the female cylinder is H (mm), the number of the orthogonal contact surfaces is N,
The plate thickness of the steel pipe is t (mm), the diameter of the steel pipe is D (mm),
When the shortest length between the orthogonal contact surface and the female inclined surface is L1 (mm), the inclination angle of the female protrusion is θ (°), and the thickness of the female cylinder is T (mm). The following expression is satisfied .
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
L1 ≧ H · (3) ^1/2 -Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the long-term allowable tensile strength of the steel pipe determined from the yield value of the steel material is F1 / 1.5,
The long-term allowable bearing strength of the steel pipe joint (F2 / 1.1)
N · B ≧ πD.

  In the present invention, the female side engaging portion is formed on the surface facing the inner side in the axial direction of the steel pipe of the female side ridge provided on the inner peripheral surface of the female cylinder, and the outer side in the axial direction of the steel pipe of the female side ridge. Since the female-side inclined surface extending along the female-side protrusion is formed on the surface facing the surface, the processing cost of the steel pipe joint can be reduced. In other words, the female side engaging portion and the female side inclined surface can be formed by cutting the two surfaces of the female side ridges, the surface facing the inner side in the axial direction and the surface facing the outer side in the axial direction. Processing cost can be reduced.

Further, the male steel pipe joint of the present invention has a male cylinder provided at a joining end portion to which the steel pipe is to be joined, and an outer circumferential surface of the male cylinder so as to intersect the axial direction of the male cylinder along the outer circumferential surface. And a plurality of spiral male side ridges provided at predetermined intervals in the circumferential direction,
A male side engaging portion is formed on a surface of the male side ridge facing the inner side in the axial direction of the steel pipe, and a surface of the male side ridge facing the outer side in the axial direction of the steel pipe is along the male side ridge. male-side inclined surface extending Te is formed,
The male engagement portion is formed in a step shape having an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction,
The width of the orthogonal contact surface in the circumferential direction is B (mm), the height of the orthogonal contact surface from the outer peripheral surface of the male cylinder is H (mm), the number of the orthogonal contact surfaces is N,
The plate thickness of the steel pipe is t (mm), the diameter of the steel pipe is D (mm),
When the shortest length between the orthogonal contact surface and the male inclined surface is L1 (mm), the inclination angle of the male protrusion is θ (°), and the thickness of the male cylinder is T (mm). The following expression is satisfied .
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
L1 ≧ H · (3) ^1/2 -Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the long-term allowable tensile strength of the steel pipe determined from the yield value of the steel material is F1 / 1.5,
The long-term allowable bearing strength of the steel pipe joint (F2 / 1.1)
N · B ≧ πD.

  In the present invention, the male engagement portion is formed on the surface facing the inner side in the axial direction of the steel pipe of the male ridge provided on the outer peripheral surface of the male cylinder, and the outer side in the axial direction of the steel pipe of the male ridge is formed. Since the male-side inclined surface extending along the male-side protrusion is formed on the facing surface, the processing cost of the steel pipe joint can be reduced. In other words, by cutting two surfaces, the surface facing the inner side in the axial direction and the surface facing the outer side in the axial direction of the steel pipe of the male side ridge, the male side engaging portion and the male side inclined surface can be formed. Processing cost can be reduced.

The steel pipe joint structure of the present invention is a steel pipe joint structure formed by joining steel pipes with a steel pipe joint,
The female side steel pipe joint according to claim 1 is provided at the joint end of one steel pipe to be joined, and the male side steel pipe joint according to claim 2 is provided at the joint end of the other steel pipe,
The male cylinder of the steel pipe joint on the male side is inserted into the female cylinder of the steel pipe joint on the female side, and the male cylinder and the male side inclined surface slide relative to each other. The steel pipes are joined by the steel pipe joint by relatively rotating the female cylinder and engaging the female side engaging part and the male side engaging part adjacent in the circumferential direction. It is characterized by that.

  Here, the male cylinder of the steel pipe joint on the male side is inserted into the female cylinder of the steel pipe joint on the female side so that the male inclined surface slides on the female inclined surface, thereby the male cylinder The steel pipes may be joined by a steel pipe joint, by rotating around the axis and engaging the male side engaging part with the female side engaging part adjacent in the circumferential direction, By inserting the female cylinder of the female pipe joint on the male side into the male cylinder of the male pipe joint on the male side so that the female inclined surface slides on the male inclined surface, the female cylinder is rotated around the axis. The steel pipes may be joined by a steel pipe joint by rotating the female side engaging part to engage with the male side engaging part adjacent in the circumferential direction.

In the present invention, the female side engaging portion and the female side inclined surface can be formed by cutting the two surfaces of the surface of the female-side protruding steel pipe facing the inner side in the axial direction and the surface facing the outer side in the axial direction. Since the male side engaging part and the male side inclined surface can be formed by cutting two surfaces, the surface facing the axially inner side and the surface facing the axially outer side of the steel pipe of the male side ridge, the processing cost is lower than before Can be reduced.
In addition, the female side inclined surface and the male side inclined surface relatively slide to relatively rotate the male cylinder and the female cylinder, and the female side engaging portion adjacent in the circumferential direction By engaging the male side engaging portion, the steel pipes are joined by the steel pipe joint. Therefore, when joining the steel pipes, the steel pipes can be rotated without applying a rotational force to the steel pipes from the outside. Can be made.

Further, in the above configuration of the present invention, the female side engaging portion and the male side engaging portion are respectively an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction. Formed in a staircase shape having
The orthogonal contact surface of the female engagement portion and the orthogonal contact surface of the male engagement portion abut, and the parallel contact surface of the female engagement portion and the male engagement portion It is preferable that the female side engaging part and the male side engaging part which are adjacent to each other in the circumferential direction are engaged with each other by contacting the parallel contact surface.

  According to such a configuration, since the orthogonal contact surface of the female engagement portion and the orthogonal contact surface of the male engagement portion are in contact, the tensile axial force of the steel pipe to be joined is reliably transmitted. In addition, since the parallel contact surface of the female side engaging portion and the parallel contact surface of the male side engaging portion are engaged with each other, positioning of the female side cylinder and the male side cylinder in the circumferential direction is ensured. Yes.

The steel pipe connection method of the present invention is a steel pipe joining method for joining steel pipes with a steel pipe joint,
The female side steel pipe joint according to claim 1 is provided at the joint end of one steel pipe to be joined, and the male side steel pipe joint according to claim 2 is provided at the joint end of the other steel pipe,
By inserting the male cylinder of the male pipe joint into the female cylinder of the female pipe joint on the female side and sliding the female inclined face and the male inclined face relatively, the male cylinder and The steel pipes are joined by a steel pipe joint by relatively rotating the female cylinder and engaging the female side engaging part and the male side engaging part adjacent in the circumferential direction. And

  Here, the male cylinder of the steel pipe joint on the male side is inserted into the female cylinder of the steel pipe joint on the female side so that the male inclined surface slides on the female inclined surface, thereby the male cylinder The steel pipes may be joined by a steel pipe joint by rotating the shaft around the axis and engaging the male side engaging part with the female side engaging part adjacent in the circumferential direction. The female cylinder of the steel pipe joint on the female side is extrapolated to the male cylinder of the steel pipe joint on the side so as to slide the female side inclined surface on the male side inclined surface, so that the female cylinder is rotated around the axis. The steel pipes may be joined by a steel pipe joint by rotating and engaging the female side engaging part with the male side engaging part adjacent in the circumferential direction.

  In the present invention, the male cylinder of the steel pipe joint on the male side is inserted into the female cylinder of the steel pipe joint on the female side, and the female inclined surface and the male inclined surface are relatively slid. A steel pipe is joined by a steel pipe joint by relatively rotating the male cylinder and the female cylinder and engaging the female side engaging part and the male side engaging part adjacent in the circumferential direction. Therefore, when joining steel pipes, the steel pipes can be rotated without applying a rotational force to the steel pipes from the outside.

According to the present invention, by cutting two surfaces of the female-side protrusion and the male-side protrusion, the surface facing the inner side in the axial direction and the surface facing the outer side in the axial direction, Since the engaging portion and the female-side inclined surface and the male-side inclined surface can be formed, the processing cost can be reduced as compared with the conventional case.
Further, since the male cylinder and the female cylinder are relatively rotated by relatively sliding the female inclined surface and the male inclined surface, when the steel pipes are joined to each other, the steel pipe is externally connected. Therefore, the steel pipe can be rotated without applying a rotational force.

It is the schematic of the female side steel pipe joint which concerns on embodiment of this invention. It is the schematic of the female side steel pipe joint which concerns on embodiment of this invention. The principal part of the female side engaging part which concerns on embodiment of this invention is shown, (a) is a schematic front view of a female side engaging part, (b) is sectional drawing of the principal part of a female side engaging part. It is. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a steel pipe to be joined, for explaining a steel pipe joining method according to an embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is for demonstrating the steel pipe structure which concerns on embodiment of this invention, (a) is the schematic which shows the state which has engaged the male side steel pipe joint with the female side steel pipe joint, (b) is female It is the schematic which shows the state which the steel pipe joint of the male side engaged with the steel pipe joint of the side.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic view of a female steel pipe joint according to the present embodiment, and FIG. 2 is a schematic view of a male steel pipe joint according to the present embodiment.
As shown in FIG. 1, a female-side steel pipe joint 10 includes a female cylinder 11 provided at a joining end (upper end in FIG. 1) to which the steel pipe 1 is joined, and an inner peripheral surface of the female cylinder 11. A plurality of spiral female side ridges 12 extending along the inner peripheral surface so as to intersect the axial direction of the female cylinder 11 and provided at predetermined intervals in the circumferential direction are provided.

The female cylinder 11 is formed to have substantially the same diameter as the steel pipe 1 and is disposed coaxially with the steel pipe 1 and is welded to the joining end portion (upper end portion in FIG. 1) of the steel pipe 1 by circumferential welding. It is joined.
The female protrusion 12 is provided on the inner peripheral surface of the female cylinder 11 so as to be inclined at a predetermined angle with respect to the axial direction of the female cylinder 11. The female protrusion 12 may be provided on the inner peripheral surface of the female cylinder 11 by welding or the like, or may be provided by cutting the inner peripheral surface of the female cylinder 11.
The female ridges 12 are provided at predetermined intervals along the circumferential direction of the female cylinder 11, and the distance between the adjacent female ridges 12, 12 is determined by the male ridge 22 described later. It is set to a length (circumferential length) sufficient to be able to enter between the adjacent female protrusions 12 and 12. Furthermore, the female-side ridges 12 are provided such that their upper and lower ends respectively reach the upper and lower ends of the female cylinder 11 or the vicinity thereof. The female-side protrusion 12 is inclined with respect to the axial direction of the female cylinder 11 so that an angle formed with the lower end surface of the female cylinder 11 is 30 ° to 60 ° in a front view of the female cylinder 11. .
In addition, although the upper end of the female-side protrusion 12 substantially coincides with the upper end of the female cylinder 11, it may be provided below the upper end portion of the female cylinder 11.

A female-side engaging portion 13 is formed on the surface of the female-side protrusion 12 facing the inner side (downward in FIG. 1) of the steel pipe 1. The female side engaging portion 13 is formed in a step shape having a plurality of orthogonal contact surfaces 13a orthogonal to the axial direction of the steel pipe 1 and a plurality of parallel contact surfaces 13b parallel to the axial direction. Moreover, the female side engaging part 13 is formed by cutting the surface which faces the axial direction inner side of the steel pipe 1 of the female side protrusion 12 in a step shape.
As shown in FIG. 3, the width (gear width) in the circumferential direction (the circumferential direction of the female cylinder 11) of the orthogonal contact surface 13a of the female side engaging portion 13 is B, and the female cylinder of the orthogonal contact surface 13a. When the height H from the inner peripheral surface 11 and the number of orthogonal contact surfaces 13a (number of gears) are N, these are the long-term allowable tensile strength (F1 / 1.5) of the steel pipe 1 determined from the yield value of the steel material. From the long-term allowable bearing strength (F2 / 1.1) of the steel pipe joint 10 and the plate thickness t of the steel pipe 1 and the diameter D of the steel pipe 1, it is possible to set as follows and matched the required performance The steel pipe joint 10 can be provided (the thickness of the steel pipe joint 10 can be designed in the same way).
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
Further, when the minimum gear length is L1, the inclination angle of the female protrusion 12 is θ, and the thickness of the female cylinder 11 is T, the following relationship is established.
L1 ≧ H · (3) ^1/2 -Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the above arithmetic expression is premised on N · B ≧ πD.

  Further, as shown in FIG. 1, a female-side inclined surface 14 extending along the female-side protrusion 12 is formed on a surface of the female-side protrusion 12 facing the axially outer side (upward in FIG. 1) of the steel pipe 1. Has been. The female inclined surface 14 extends so as to reach the upper and lower ends of the female cylinder 11. The female-side inclined surface 14 is inclined with respect to the axial direction of the female cylinder 11 such that an angle formed with the lower end surface of the female cylinder 11 is 30 ° to 60 ° in a front view of the female cylinder 11. . The female-side inclined surface 14 is formed by cutting a surface of the female-side ridge 12 facing the outside in the axial direction of the steel pipe 1 in a straight line when viewed from the front of the female cylinder 11.

  As shown in FIG. 2, the male-side steel pipe joint 20 includes a male cylinder 21 provided at a joining end portion to be joined to the steel pipe 1, and an outer peripheral surface of the male cylinder 21 along the outer peripheral surface of the male cylinder 21. A plurality of male protrusions 22 are provided which extend so as to intersect the axial direction and are provided at predetermined intervals in the circumferential direction.

The male cylinder 21 is formed to have substantially the same diameter as the steel pipe 1 and is arranged coaxially with the steel pipe 1 and is welded to the joining end portion (lower end portion in FIG. 2) of the steel pipe 1 by circumferential welding. It is joined. The male cylinder 21 is formed to have a diameter that can be inserted into the inner diameter side of the female cylinder 11. Therefore, the male cylinder 21 can be inserted into and removed from the female cylinder 11.
The male ridge 22 is provided on the outer peripheral surface of the male cylinder 21 so as to be inclined at a predetermined angle with respect to the axial direction of the male cylinder 21 and is provided in parallel with the female ridge 12. The male protrusion 22 may be provided on the outer peripheral surface of the male cylinder 21 by welding or the like, or may be provided by cutting the outer peripheral surface of the male cylinder 21.

The male protrusions 22 are provided at predetermined intervals along the circumferential direction of the male cylinder 21. The distance between the adjacent male protrusions 22 and 22 is such that the female protrusion 12 is adjacent. The length (circumferential length) is set so as to be able to relatively enter between the mating male protrusions 22 and 22. The pitch in the circumferential direction of the male ridge 22 is equal to the pitch in the circumferential direction of the female ridge 12.
Further, the male-side protrusion 22 is provided so that the upper and lower ends thereof reach the upper and lower ends of the male cylinder 21 or the vicinity thereof. Further, the male protrusion 22 is inclined with respect to the axial direction of the male cylinder 21 so that an angle formed with the lower end surface of the male cylinder 21 is 30 ° to 60 ° in a front view of the male cylinder 21. .
In addition, although the lower end of the male side ridge 22 substantially coincides with the lower end of the male cylinder 21, it may be provided above the lower end portion of the male cylinder 21.

  A male side engaging portion 23 is formed on a surface of the male side ridge 22 facing the inner side in the axial direction of the steel pipe 1 (upward in FIG. 1). The male side engaging portion 23 is formed in a step shape having a plurality of orthogonal contact surfaces 23a orthogonal to the axial direction of the steel pipe 1 and a plurality of parallel contact surfaces 23b parallel to the axial direction. Moreover, the male side engaging part 23 is formed by cutting the surface which faces the axial direction inner side of the steel pipe 1 of the male side protrusion 22 in a step shape.

Moreover, the male side engaging part 23 is formed so that engagement with the female side engaging part 13 is possible. That is, the orthogonal contact surface 23a of the male side engaging portion 23 and the orthogonal contact surface 13a of the female side engaging portion 13 are formed in the same shape and the same size, and are adjacent to each other in the axial direction of the male cylinder 21. The distance between the orthogonal contact surfaces 23a and 23a is also equal to that of the orthogonal contact surface 13a. In addition, the parallel contact surface 23 b of the male side engaging portion 23 and the parallel contact surface 13 b of the female side engaging portion 13 are formed in the same shape and the same size, and are adjacent to each other in the number and the circumferential direction of the male cylinder 21. The distance between the parallel contact surfaces 23b and 23b is also equal to that of the parallel contact surface 13b.
Therefore, the male side engaging portion 23 and the female side engaging portion 13 engage with each other when the orthogonal contact surfaces 13a and 23a contact each other and the parallel contact surfaces 13b and 23b contact each other. It is like that. In this case, the orthogonal contact surface 13a of the female side engaging portion 13 and the orthogonal contact surface 23a of the male side engaging portion 23 are separated from each other when the female cylinder 11 and the male cylinder 21 are separated from each other. When an axial tensile force is received in the direction, the two abut against each other to resist the axial tensile force.

The width (gear width) in the circumferential direction (circumferential direction of the male cylinder 21) of the orthogonal contact surface 23a of the male side engaging portion 23 is set to B, and the orthogonal contact surface 23a extends from the inner peripheral surface of the male cylinder 21. If the height H and the number of orthogonal contact surfaces 23a (the number of gears) are N, these are the long-term allowable tensile strength (F1 / 1.5) of the steel pipe 1 determined from the yield value of the steel material, and the long-term of the steel pipe joint 20. From the allowable bearing strength (F2 / 1.1), the plate thickness t of the steel pipe 1 and the diameter D of the steel pipe 1, it is possible to set as follows, and it is possible to provide a steel pipe joint 20 that matches the required performance. Yes (the thickness of the steel pipe joint 20 can be designed in the same way).
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
Further, when the minimum gear length is L1, the inclination angle of the female protrusion 12 is θ, and the thickness of the female cylinder 11 is T, the following relationship is established.
L1 ≧ H · (3) ^1/2 −Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the above arithmetic expression is premised on N · B ≧ πD.

  In addition, a male-side inclined surface 24 extending along the male-side protrusion 22 is formed on a surface of the male-side protrusion 22 facing the axially outer side (downward in FIG. 2) of the steel pipe 1. The male inclined surface 24 extends so as to reach the upper and lower ends of the male cylinder 21. The male-side inclined surface 24 is inclined with respect to the axial direction of the male cylinder 21 so that an angle formed with the lower end surface of the male cylinder 21 is 30 ° to 60 ° in a front view of the male cylinder 21. . The male-side inclined surface 24 is formed by cutting a surface of the male-side protrusion 22 facing the axial direction outside of the steel pipe 1 in a straight line when the male cylinder 21 is viewed from the front.

Next, a steel pipe joining structure and method in which the steel pipes 1 and 1 are joined by the steel pipe joints 10 and 20 will be described.
First, as shown in FIG. 4, the female-side steel pipe joint 10 is provided at a joint end which is one end of one steel pipe 1 to be joined, and the joint end which is one end of the other steel pipe 1 is A male-side steel pipe joint 20 is provided. When a plurality of steel pipes 1 are continuously joined, a male steel pipe joint 20 is provided at the other end of the one steel pipe 1, and a female side is provided at the other end of the other steel pipe 1. The steel pipe joint 10 is provided.

Next, the steel pipe 1 (1A) provided with the female-side steel pipe joint 10 is vertically arranged so that the steel pipe joint 10 is located on the upper end side.
Next, the steel pipe 1 (1B) provided with the male-side steel pipe joint 20 is arranged coaxially with the steel pipe 1A above the steel pipe 1A so that the steel pipe joint 20 is located on the lower end side. In this case, for example, the steel pipe 1B is suspended by a crane or the like and arranged coaxially with the steel pipe 1A.
Moreover, the circumferential positioning of the steel pipe 1B with respect to the steel pipe 1A, that is, the circumferential positioning of the male steel pipe joint 20 with respect to the female steel pipe joint 10 is performed. In this case, the male side of the male side ridge 22 provided on the outer peripheral surface of the steel pipe joint 20 at the upper end portion of the female side inclined surface 14 of the female side ridge 12 provided on the inner peripheral surface of the steel pipe joint 10. Positioning of the steel pipe 1B in the circumferential direction is performed such that the lower end portion of the inclined surface 24 overlaps in the axial direction of the steel pipe 1.

Next, by lowering the steel pipe 1B, as shown in FIG. 5A, the male cylinder 21 of the male steel pipe joint 20 is placed in the female cylinder 11 of the steel pipe joint 10, and the male inclined surface 14 is male. The side inclined surface 24 is inserted by gravity so as to slide. Then, since the male side inclined surface 24 is pushed in the circumferential direction by the female side inclined surface 14, the male cylinder 21 rotates around its axis, and the male side engaging portion 23 rotates while the male side engaging portion 23 rotates. It approaches the female side engaging portion 13. Then, when the male cylinder 21 rotates by a predetermined angle around the axis, the male side engaging portion 23 engages with the adjacent female side engaging portion 13 as shown in FIG. 1B is joined.
When the male side engaging portion 23 engages with the adjacent female side engaging portion 13, the plurality of orthogonal contact surfaces 23 a of the male side engaging portion 23 is connected to the plurality of orthogonal contact surfaces 13 a of the male side engaging portion 23. Are brought into contact with each other, and the plurality of parallel contact surfaces 23b of the male side engagement portion 23 are in contact with the plurality of parallel contact surfaces 13b of the female side engagement portion 13, respectively. It is engaged with the female side engaging part 13 adjacent to the circumferential direction. Moreover, the male side engaging part 23 is engaged with the female side engaging part 13 adjacent in the circumferential direction, and at the same time, the lower end surface of the male cylinder 21 is brought into contact with the upper end surface of the steel pipe 1A.

  After the male side engaging part 23 is engaged with the female side engaging part 13, an anti-rotation fitting (not shown) is set at the joint between the female cylinder 11 and the male cylinder 21. In order to prevent the rotation of the male cylinder 21 relative to the female cylinder 11 with the anti-rotation fitting, for example, a notch is formed on the outer peripheral surface of the joint between the female cylinder 11 and the male cylinder 21, and a key is provided in the notch. This may be done by fitting and fixing an anti-rotation fitting such as the above.

  When the male cylinder 21 is removed from the female cylinder 11, the male engagement portion 23 is engaged with the female side in the direction opposite to that when the male cylinder 21, that is, the steel pipe 1B is engaged, after removing the anti-rotation fitting. After rotating around the axis until it is separated from the portion 13, the male cylinder 21, that is, the steel pipe 1B, is pulled upward by sliding the male inclined surface 24 on the female inclined surface 14.

  In the present embodiment, the case where the steel pipe 1B provided with the male steel pipe joint 20 is joined to the steel pipe 1A provided with the female steel pipe joint 10 has been described as an example. The steel pipe 1A provided with the female steel pipe joint 10 may be joined to the steel pipe 1B provided with the steel pipe joint 20 on the side.

  According to the present embodiment, by cutting two surfaces of the female-side protrusion 12 of the female-side steel pipe joint 10, the surface facing the inner side in the axial direction of the steel pipe 1 and the surface facing the outer side in the axial direction, The joint portion 13 and the female inclined surface 14 can be formed, and two surfaces of the male-side protrusion 22 of the male-side steel pipe joint 20 facing the inner side in the axial direction and the surface facing the outer side in the axial direction are cut. Thereby, since the male side engaging part 23 and the male side inclined surface 24 can be formed, processing cost can be reduced compared with the past.

Further, by inserting the male cylinder 21 into the female cylinder 11 so as to slide the male inclined surface 24 on the female inclined surface 14, the male cylinder 21 is rotated about its axis, so that the male engaging portion is rotated. Since the steel pipes 1, 1 are joined by the steel pipe joints 10, 20 by engaging the female joints 23 adjacent to each other in the circumferential direction, when joining the steel pipes 1, 1, Even if a rotational force is not applied to the steel pipe 1 from the outside, the steel pipe 1 can be rotated.
Furthermore, the male side engaging part 23 is engaged with the female side engaging part 13, and at this time, the orthogonal contact surface 23a of the male side engaging part 23 is brought into contact with the orthogonal contact surface 13a of the female side engaging part 13. Are in contact with each other, the tensile axial force of the steel pipes 1 and 1 to be joined can be reliably transmitted, and the parallel engagement surface 13b of the female side engagement portion 13 is parallel to the male side engagement portion 23. Since the contact surface 23b is in contact, positioning of the male cylinder 21 in the circumferential direction with respect to the female cylinder 11 can be performed reliably.

  Further, the number of steps of the stepped female side engaging portion 13 of the female side steel pipe joint 10 and the number of steps of the stepped male side engaging portion 23 of the male side steel pipe joint 20, the female side protrusion 12 and the male side, etc. By appropriately setting the number of the protrusions 22 and the inclination angle, the joining strength (axial tensile strength) between the steel pipes 1 and 1 can be easily adjusted.

1, 1A, 1B Steel pipe 10 Female-side steel pipe joint 11 Female cylinder 12 Female-side protrusion 13 Female-side engagement portion 13a Orthogonal contact surface 13b Parallel contact surface 20 Male-side steel pipe joint 21 Male cylinder 22 Male-side protrusion 23 Male side engaging part 23a Orthogonal contact surface 23b Parallel contact surface

Claims (5)

A female-side steel pipe joint for joining steel pipes,
A female cylinder provided at a joining end portion of the steel pipe to be joined, and extends to the inner circumferential surface of the female cylinder so as to intersect the axial direction of the female cylinder along the inner circumferential surface, and at a predetermined interval in the circumferential direction. It is provided with a plurality of spiral female side ridges,
A female side engaging portion is formed on a surface of the female side ridge facing the inner side in the axial direction of the steel pipe, and a surface of the female side ridge facing the outer side in the axial direction of the steel pipe is along the female side ridge. female side inclined surface extending Te is formed,
The female engagement portion is formed in a step shape having an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction,
The width of the orthogonal contact surface in the circumferential direction is B (mm), the height of the orthogonal contact surface from the inner peripheral surface of the female cylinder is H (mm), the number of the orthogonal contact surfaces is N,
The plate thickness of the steel pipe is t (mm), the diameter of the steel pipe is D (mm),
When the shortest length between the orthogonal contact surface and the female inclined surface is L1 (mm), the inclination angle of the female protrusion is θ (°), and the thickness of the female cylinder is T (mm). A steel pipe joint characterized by satisfying the following formula:
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
L1 ≧ H · (3) ^1/2 -Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the long-term allowable tensile strength of the steel pipe determined from the yield value of the steel material is F1 / 1.5,
The long-term allowable bearing strength of the steel pipe joint (F2 / 1.1)
N · B ≧ πD. A male pipe joint for joining steel pipes,
A male cylinder provided at a joining end portion of the steel pipe to be joined, and a plurality of outer cylinders extending along the outer circumferential surface of the male cylinder so as to intersect the axial direction of the male cylinder and provided at predetermined intervals in the circumferential direction. Provided with a spiral male side ridge,
A male side engaging portion is formed on a surface of the male side ridge facing the inner side in the axial direction of the steel pipe, and a surface of the male side ridge facing the outer side in the axial direction of the steel pipe is along the male side ridge. male-side inclined surface extending Te is formed,
The male engagement portion is formed in a step shape having an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction,
The width of the orthogonal contact surface in the circumferential direction is B (mm), the height of the orthogonal contact surface from the outer peripheral surface of the male cylinder is H (mm), the number of the orthogonal contact surfaces is N,
The plate thickness of the steel pipe is t (mm), the diameter of the steel pipe is D (mm),
When the shortest length between the orthogonal contact surface and the male inclined surface is L1 (mm), the inclination angle of the male protrusion is θ (°), and the thickness of the male cylinder is T (mm). A steel pipe joint characterized by satisfying the following formula:
N · B · H = πD · t · F1 / F2 · 1.1 / 1.5
L1 ≧ H · (3) ^1/2 -Btanθ / 2
T ≧ F1 / F2 · t · 1.4 ≧ t
However, the long-term allowable tensile strength of the steel pipe determined from the yield value of the steel material is F1 / 1.5,
The long-term allowable bearing strength of the steel pipe joint (F2 / 1.1)
N · B ≧ πD. A steel pipe joint structure in which steel pipes are joined together by a steel pipe joint,
The female side steel pipe joint according to claim 1 is provided at the joint end of one steel pipe to be joined, and the male side steel pipe joint according to claim 2 is provided at the joint end of the other steel pipe,
The male cylinder of the steel pipe joint on the male side is inserted into the female cylinder of the steel pipe joint on the female side, and the male cylinder and the male side inclined surface slide relative to each other. The steel pipes are joined by the steel pipe joint by relatively rotating the female cylinder and engaging the female side engaging part and the male side engaging part adjacent in the circumferential direction. A steel pipe joint structure characterized by that. The female side engaging part and the male side engaging part are each formed in a step shape having an orthogonal contact surface orthogonal to the axial direction of the steel pipe and a parallel contact surface parallel to the axial direction. ,
The orthogonal contact surface of the female engagement portion and the orthogonal contact surface of the male engagement portion abut, and the parallel contact surface of the female engagement portion and the male engagement portion 4. The steel pipe joint according to claim 3, wherein the female side engaging portion and the male side engaging portion that are adjacent to each other in the circumferential direction are engaged with each other by contacting the parallel contact surface. Construction. A steel pipe joining method for joining steel pipes with a steel pipe joint,
The female side steel pipe joint according to claim 1 is provided at the joint end of one steel pipe to be joined, and the male side steel pipe joint according to claim 2 is provided at the joint end of the other steel pipe,
By inserting the male cylinder of the male pipe joint into the female cylinder of the female pipe joint on the female side and sliding the female inclined face and the male inclined face relatively, the male cylinder and The steel pipes are joined by a steel pipe joint by relatively rotating the female cylinder and engaging the female side engaging part and the male side engaging part adjacent in the circumferential direction. Steel pipe joining method.

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