JP7163937B2 - Steel pipe joining joint, method for joining steel pipes using said steel pipe joining joint, and steel pipe sheet pile - Google Patents

Description

The present invention comprises a male joint having a male thread and a female joint having a female thread, and is attached to the ends of steel pipes to join the steel pipes. The present invention relates to a method for joining steel pipes and a steel pipe sheet pile using steel pipes joined by steel pipe joining joints.

Conventionally, welding has been mainly used to connect steel pipe piles and steel pipe sheet piles. mechanical joints are increasingly being used instead of welding.

Although there are various types of mechanical joints, a screw type joint as shown in Patent Document 1 is a commonly used structure.
Threaded joints have sufficient strength in the tightening direction against the rotational force around the pipe axis, but cannot resist in the disengaging direction. Mounting, the shear of this bolt allows it to resist torsion.

In addition, as an improved version of the reverse rotation prevention mechanism for mechanical joints, as disclosed in Patent Document 2, the inner pipe is provided with a rough surface or an irregularly shaped surface portion, and by tightening the bolt, the outer pipe and the There is one that can prevent rotation regardless of the position of the inner tube in the circumferential direction.

Patent documents 3 and 4 disclose examples in which the bolt side is improved. The one disclosed in Patent Document 3 is to process the tip of the bolt to increase the frictional force, and the one disclosed in Patent Document 4 has the tip of the bolt made into a truncated cone shape to abut on the bolt. It is designed to be in line contact with the groove.

JP-A-10-311028 Japanese Patent Application Laid-Open No. 2007-63806 JP 2013-245480 A JP 2016-141976 A

The method disclosed in Patent Document 1 does not cause any particular problem when the steel pipes are connected singly, such as piles. Instead, if a connecting joint 17 is attached to the outer peripheral portion of the steel pipe 15 to connect with the adjacent steel pipe 15, the following problems arise.

In the steel pipe sheet pile 13, when connecting the upper and lower steel pipes 15, it is important to align the positions of the connection joints 17 vertically. When the upper and lower steel pipes 15 are welded, they are connected while finely adjusting the relative position of the steel pipes in the circumferential direction. A slight mismatch can occur. This is because, of course, the directions are aligned during manufacturing, but a maximum deviation of about 10 mm occurs due to the effects of the roundness of the members and welding deformation when attaching the members.
Therefore, it is common to align the positions of the connecting joints 17 and then weld the connecting joints 17 to prevent rotation. I often couldn't live.

Further, in the device disclosed in Patent Document 2, rotation can be prevented by adjusting the circumferential positions of the male and female joints. Also, it is difficult to manage the construction because it is greatly affected by the torque etc. when tightening the bolt. In addition, in the case of the type in which the deformed surface portion is formed, the contact state between the bolt and the deformed surface portion is substantially a point contact with respect to the resistance force of the deformed surface portion, so the reverse rotation prevention effect cannot be expected much.

In addition, the bolt side disclosed in Patent Document 3 is considered to have the effect of increasing the resistance, but it depends on the manufacturing accuracy and construction accuracy of the product, so a large effect cannot be expected.
In addition, the tip of the bolt disclosed in Patent Document 4 is improved to have a truncated cone shape, in which the inner joint pipe having a male thread is displaced from the outer joint pipe having a female thread in the axial direction of the steel pipe. Although it is thought that there is an effect of restraint, no effect can be expected from completely preventing rotation in the circumferential direction.

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and has a circumferential adjustment margin for an inner joint tube having a male thread and an outer joint tube having a female thread, and sufficiently exhibits the function of preventing reverse rotation. It is an object of the present invention to provide a joint of steel pipes, a method of joining steel pipes using the joint of steel pipes, and a steel pipe sheet pile using the steel pipes joined by the joint of steel pipes.

(1) A joint for steel pipes according to the present invention includes an inner joint pipe having a male thread, an outer joint pipe having a female thread and a tap hole for preventing rotation, and a rotation preventing bolt inserted into the tap hole. and attached to the end of a steel pipe and used for connecting the steel pipe,
The tapped hole for preventing rotation of the outer joint pipe penetrates in the radial direction of the pipe in a direction perpendicular to the pipe axis,
The inner joint pipe is a slanted surface portion that, when the outer joint pipe is fitted, is inclined to a position corresponding to the tap hole so that the depth becomes deeper in the direction of reverse rotation of the screwing. has an inclined surface portion whose length is set longer than the diameter of the anti-rotation bolt,
The anti-rotation bolt has a cone-shaped portion at its tip, and the angle of inclination of the cone-shaped portion is the same as the angle of inclination of the inclined surface portion of the inner joint pipe,
With the outer joint pipe and the inner joint pipe fitted together, a rotation prevention bolt is inserted into the tapped hole, and the conical portion of the rotation prevention bolt is brought into contact with the inclined surface portion to prevent reverse rotation. It is characterized by

(2) In addition, in the device described in (1) above, a plurality of the tap holes, the inclined surface portions, and the anti-rotation bolts are provided,
The inclined surface portion corresponding to at least one tapped hole is characterized by being inclined so that the depth increases in the positive rotation direction of screwing.

(3) A method for joining steel pipes according to the present invention is a method for joining steel pipes using the joint for joining steel pipes according to (2) above,
In a state where the outer joint pipe and the inner joint pipe are screwed together to a predetermined position before screwing is completed, a rotation prevention bolt is inserted into the tapped hole, and the tip of the rotation prevention bolt is inserted into the inclined surface portion. It is characterized in that both forward and reverse rotation of the outer joint pipe and the inner joint pipe are prevented by bringing them into contact with each other.

(4) A steel pipe sheet pile according to the present invention is characterized by using steel pipes joined by the steel pipe joining joint described in (1) or (2) above.

In the present invention, the inner joint pipe is an inclined surface portion which is inclined so that the depth becomes deeper in the opposite direction of screwing at a position corresponding to the tap hole of the outer joint pipe, and the length in the circumferential direction is rotated. It has an inclined surface portion set longer than the diameter of the anti-rotation bolt, and has a conical portion at the tip of the anti-rotation bolt, the inclination angle of the conical portion being equal to the inclination angle of the inclined surface portion of the inner joint pipe. In a state in which the outer joint pipe and the inner joint pipe are fitted, a rotation prevention bolt is inserted into the tapped hole, and the conical portion of the rotation prevention bolt is brought into contact with the inclined surface portion. Since the inner joint pipe and the outer joint pipe have an adjustment margin in the circumferential direction, accurate positioning in the rotational fitting direction is possible, and the reverse rotation prevention function is sufficient. can be demonstrated in

1 is a vertical cross-sectional view of a joining joint of this embodiment; FIG. 2 is a cross-sectional view taken along line AA of FIG. 1; FIG. FIG. 4 is an explanatory diagram of a state in which a rotation prevention bolt is inserted in the joining joint of the present embodiment; FIG. 4 is an explanatory diagram of another aspect of the present embodiment, and is an explanatory diagram when the present invention is applied to a steel pipe sheet pile. It is a side view of a steel pipe sheet pile. It is a top view of a steel pipe sheet pile.

As shown in FIGS. 1 and 2, a steel pipe joining joint 1 according to the present embodiment is attached to the end of a steel pipe 3 and includes an inner joint pipe 5 having a male thread and a tap for preventing rotation having a female thread. It has an outer joint pipe 7 having holes 7a and 7b and a rotation prevention bolt 9 inserted into the tap holes 7a and 7b. With the surface portion 5b provided and the outer joint pipe 7 and the inner joint pipe 5 fitted together, the anti-rotation bolt 9 is inserted into the tapped holes 7a and 7b, and the tip of the anti-rotation bolt 9 is placed on the inclined surface portions 5a and 5b. By abutting against the outer joint pipe 7 and the inner joint pipe 5, the reverse rotation and the forward rotation are prevented at a predetermined rotational engagement position.
A detailed description will be given below.
In the present application, the direction of rotation during screwing is defined by the direction of rotation of the inner joint tube 5 having a male thread, and is the direction of screwing (the direction of the arrow in FIG. 2). is forward rotation, and the anti-screw fitting direction (opposite direction to the arrow in FIG. 2) in which fitting is disengaged is reverse rotation.

<Steel pipe>
The steel pipes 3 support the structure, and examples thereof include steel pipes constituting steel pipe piles, steel pipe sheet piles, steel pipe columns, and the like.

<Outer joint pipe>
The outer joint pipe 7 has a female thread and is arranged on the outside when fitted. there is
Note that the tapped holes 7a and 7b are provided at a portion where no thread is formed, specifically at the proximal end portion of the outer joint pipe 7, as shown in FIG.

<Inner joint pipe>
The inner joint pipe 5 has a male thread and is disposed inside when screwed together. 5a and an inclined surface portion 5b for preventing normal rotation are provided.

As shown in FIGS. 2 and 3, the sloped surface portion 5b for preventing forward rotation has a rectangular shape that becomes deeper in the fitting rotation direction (forward rotation direction) on the outer peripheral surface of the inner joint pipe 5. For example, a groove is formed and the bottom of the groove is an inclined surface.
The inclined surface portion 5b is inclined by an angle θb with respect to a straight line X perpendicular to the straight line connecting the center P of the inclined surface portion 5b (the center of the tap holes 7a and 7b in the mated state) and the center O of the tube. This angle θb is set to be equal to the inclination angle α (see FIG. 2) of the conical portion 9a at the tip of the anti-rotation bolt 9. As shown in FIG.
The inclination angle θb of the inclined surface portion 5b is preferably 5 degrees to 15 degrees.

As a form of the inclined surface portion 5a, as shown in FIG. 2, a rectangular groove is formed on the outer peripheral surface of the inner joint pipe 5 so that the depth increases in the reverse rotation direction, and the bottom of the groove is the inclined surface portion. things are mentioned.
The inclination angle θa of the inclined surface portion 5a is the same as the inclination angle θb, and is set to be equal to the inclination angle α (see FIG. 2) of the conical portion 9a at the tip of the anti-rotation bolt 9.
Note that the inclined surface portions 5a and 5b are provided at a portion where no thread is formed, specifically at the tip portion of the inner joint pipe 5, as shown in FIG.

Here, the circumferential length of the inclined surface portions 5a and 5b of the inner joint pipe 5 will be described. First, as shown in FIG. 3, the length of the inclined surface portions 5a and 5b in the circumferential direction in the present invention means that the inclined surface portion 55b (5a) is perpendicular to the central axis (chain line) of the tap hole 7b (7a). means the length L when projected onto .
The circumferential length of the inclined surface portions 5a and 5b of the inner joint pipe 5 is set longer than the diameter of the anti-rotation bolt 9, as shown in FIGS. In this way, even when it is necessary to align the positions in the circumferential direction in units of several millimeters, such as the joints of steel pipe sheet piles, the anti-rotation bolts 9 can be tightened while the positions of the joints are accurately aligned when the steel pipes are connected. The conical portion 9a at the tip can be reliably brought into contact with the inclined surface portions 5a and 5b of the rectangular groove portion of the inner joint pipe 5 within the range of the groove portion.
The circumferential length of the inclined surfaces 5a and 5b of the inner joint pipe 5 is preferably about 1.5 to 3 times the diameter of the anti-rotation bolt 9, for example.

In the joint 1 for steel pipes according to the present embodiment configured as described above, as shown in FIGS. The anti-rotation bolt 9 is inserted into 7a and 7b, and the conical portion 9a at the tip of the anti-rotation bolt 9 is brought into contact with the inclined surface portions 5a and 5b.
In this state, for example, when the inner joint pipe 5 rotates in the opposite direction of fitting, that is, when it tries to rotate in the reverse direction, the inclined surface portion 5a for preventing reverse rotation comes into contact with the conical portion 9a at the tip of the rotation preventing bolt 9, causing a strong force. It will receive resistance, and reverse rotation can be reliably prevented.
In addition, when the inner joint pipe 5 rotates in the screwing engagement direction, that is, when it tries to rotate forward, the inclined surface portion 5b for forward rotation prevention hits the conical portion 9a at the tip of the rotation prevention bolt 9 and receives strong resistance. It is possible to reliably prevent forward rotation.

As described above, in this embodiment, if the tap holes 7a and 7b are positioned corresponding to the inclined surface portions 5a and 5b during rotational fitting, the anti-rotation bolt 9 prevents both forward and reverse rotation. Rotation can be prevented.
Therefore, when it is used as a joint for connecting the upper and lower sides of steel pipe sheet piles having a connecting joint for connecting adjacent steel pipes, construction can be performed as follows.
The positions of the inner joint pipe 5 and the outer joint pipe 7 in the circumferential direction are adjusted so that the positions of the connecting joints of the upper and lower steel pipe sheet piles match just before the completion of the rotary fitting. This position may be just prior to fully tightening the joint. By inserting the anti-rotation bolt 9 at that position, the upper and lower steel pipes can be joined while the positions of the upper and lower connecting joints are accurately aligned.

As described above, according to the present invention, even when the direction of the connecting joint of steel pipe sheet piles needs to be aligned in units of several millimeters, the joint can be easily joined while the direction of the connecting joint is accurately aligned when connecting the steel pipes. The rotation of the joint 1 can be fixed, and the construction time can be greatly shortened.
In the above-described embodiment, the tap holes 7a and 7b for both reverse rotation prevention and forward rotation prevention and the corresponding inclined surface portions 5a and 5b are provided. The invention is not limited to this, and even if only the tapped hole 7a for preventing reverse rotation and the inclined surface portion 5a corresponding to the tapped hole 7a are provided, an effect not found in the prior art can be obtained, and is therefore included in the scope of the invention.
Also, an example in which two tapped holes and two inclined surface portions corresponding thereto are provided has been shown, but even when three or more of these are provided, a more reliable effect can be obtained, and is therefore included in the scope of the invention.

It should be noted that even if the screwing completion position of the joint deviates slightly, it is possible to prevent rotation by inserting the rotation prevention bolt 9, which is the same as in Patent Document 2. Since the contact between the bolt 9 and the inner joint pipe 5 having a male thread is point contact, the resistance to rotation prevention is small. Since it is in line contact with the inclined surface portions 5a and 5b of the tube 5, the resistance is increased, and the anti-rotation effect can be reliably exhibited.

In the above embodiment, a steel pipe pile having no joints was taken as an example, but the joint 1 of steel pipes according to the present invention has a steel pipe sheet pile 13 as shown in FIG. It is also effective as a joining joint for steel pipes having a connecting joint 17 as shown.
When applied to the steel pipe sheet pile 13, the positions of the inner joint pipe 5 and the outer joint pipe 7 are adjusted in the circumferential direction so that the positions of the connecting joints 17 of the upper and lower steel pipe sheet piles 13 match just before the completion of the rotary joint. By inserting the anti-rotation bolt 9 at that position, the upper and lower steel pipe sheet piles 13 can be joined while the positions of the upper and lower connection joints 17 are accurately aligned.

REFERENCE SIGNS LIST 1 joining joint 3 steel pipe 5 inner joint pipe 5a, 5b inclined surface portion 7 outer joint pipe 7a, 7b tap hole 9 anti-rotation bolt 9a conical portion 11 pipe shaft 13 steel pipe sheet pile 15 steel pipe 17 connecting joint

Claims (3)

It has an inner joint pipe having a male thread, an outer joint pipe having a female thread and a plurality of anti-rotation tap holes, and an anti-rotation bolt inserted into the tap hole, and is attached to the end of the steel pipe. A steel pipe joint used for connecting steel pipes,
The tapped hole for preventing rotation of the outer joint pipe penetrates in the radial direction of the pipe in a direction perpendicular to the pipe axis,
The inner joint pipe is a slanted surface portion that, when the outer joint pipe is fitted, is inclined to a position corresponding to the tap hole so that the depth becomes deeper in the direction of reverse rotation of the screwing. An inclined surface portion for reverse rotation prevention, the length of which is set to be longer than the diameter of the anti-rotation bolt, and an inclined surface portion that is inclined so that the depth increases in the positive rotation direction of the screwing, and the length in the circumferential direction and an inclined surface portion for forward rotation prevention set longer than the diameter of the rotation prevention bolt ,
The anti-rotation bolt has a cone-shaped portion at its tip, and the angle of inclination of the cone-shaped portion is the same as the angle of inclination of the inclined surface portion of the inner joint pipe,
With the outer joint pipe and the inner joint pipe fitted together, a rotation-preventing bolt is inserted into the tapped hole, and the conical portion of the rotation-preventing bolt is brought into contact with the inclined surface portion to rotate in reverse and forward directions. A joining joint for steel pipes characterized in that it prevents rotation . A method for joining steel pipe sheet piles using the joining joint for steel pipes according to claim 1,
The outer joint pipe and the inner joint pipe are screwed together to a predetermined position before the completion of screwing , and the positions of the connecting joints of the upper and lower steel pipe sheet piles are aligned. With the directional position adjusted, a rotation-preventing bolt is inserted into the tapped hole, and the tip of the rotation-preventing bolt is brought into contact with the slanted surface portion to rotate the outer joint pipe and the inner joint pipe forward and backward. A method for joining steel pipe sheet piles , characterized in that the rotation of both is prevented. A steel pipe sheet pile joined by the steel pipe joining joint according to claim 1 .

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