JP7655347B2 - Mechanical joint, joining method of mechanical joint, steel pipe, structure, construction method of structure, design method of mechanical joint, manufacturing method of mechanical joint - Google Patents

Description

The present invention relates to a mechanical joint applied to steel pipe piles and steel pipe sheet piles, a joining method for the mechanical joint, a steel pipe fitted with the mechanical joint, a structure including the steel pipe as a component, a construction method for the structure, a design method for the mechanical joint, and a manufacturing method for the mechanical joint.

Traditionally, steel pipe piles and steel pipe sheet piles have been joined mainly by on-site welding, but in recent years, due to a decrease in skilled workers, shortening construction periods, and quality control, the use of mechanical joints for joining has been increasing.
In the case of steel pipe piles and steel pipe sheet piles, the common method is to manufacture tubular joint members separately from the steel pipes, and then weld the joint members to the ends of the steel pipes to be joined, and then join the joint members together.

The joint must be constructed in such a way that it can transmit the compressive, tensile, shear, and torsional loads that act during the construction and operation of the piles. In this regard, compression can be easily transmitted by bringing the end faces of the joint members into surface contact, and shear can be easily transmitted by inserting a male pipe into a female pipe to create a double-pipe structure. However, tensile and torsional loads cannot be transmitted by simple insertion and surface contact, and so the structure must be designed in a way that allows it to be transmitted easily.

Various methods have been devised and put into practical use in the past. For example, Patent Document 1 (JP Patent Publication No. 10-311028) discloses a structure in which the joint member is made into a multi-threaded screw shape, and the threads of the male and female joints mesh with each other through a rotary joint, allowing the transmission of tensile loads. Note that while forward torsional loads can be transmitted by fully tightening the screws, reverse torsional loads cannot be transmitted. Therefore, by arranging a bolt on the outer periphery that straddles the male and female joints, the reverse torsional load can be transmitted by the shear of the bolt.

Also, Patent Document 2 (JP 2004-36329 A) discloses a joint structure in which a plurality of slits in the axial direction are provided in the circumferential direction on either the male joint or the female joint, and the joint members separated by the slits are processed so as to be elastically deformable in the radial direction, and the separated joint members are provided with convex portions, while the other member is provided with concave portions that engage with the convex portions when fitting is complete. The structure disclosed here allows the divided joint members to bend in the radial direction when a compressive load is applied due to their own weight or the like when inserting the joint, and when they return to their original state upon completion of insertion, the convex portions and concave portions engage with each other, thereby transmitting a tensile load.
In addition, in this structure, similar to Patent Document 1, bolts are arranged on the outer peripheral surface, making it possible to transmit torsional loads.

As another method, Patent Document 3 (JP Patent Publication No. 11-36285) discloses a structure in which a groove is provided in each of the male joint and the female joint so that their axial positions match when mating is complete, and a ring-shaped member with a changeable diameter that fits into the groove is stored in either the male joint or the female joint, and when mating is complete, the ring-shaped member is moved in the radial direction and positioned so as to straddle the male joint and female joint, thereby transmitting a tensile load.
Since this structure also cannot transmit torsional loads, it is necessary to either place a bolt as in Patent Documents 1 and 2, or to place a separate anti-rotation mechanism as in Patent Document 4 (JP 2000-319874 A).

Japanese Patent Application Laid-Open No. 10-311028 JP 2004-36329 A Japanese Patent Application Laid-Open No. 11-36285 JP 2000-319874 A

With threaded joints like the one in Patent Document 1, even if the threads are multi-threaded, it is unavoidable to rotate the steel pipe when joining, so joining can be difficult when the pipe is very large in diameter or when there is insufficient space to work on the rotation.

In addition, in joints that undergo elastic deformation as in Patent Document 2, if the joint is thick, the load required to cause elastic deformation increases, and there are cases in which the joint cannot be fitted together by its own weight alone. It is possible to reduce the load by increasing the number of slits or lengthening them, but this increases processing costs and reduces the shear load transmission capacity.

On the other hand, the joint disclosed in Patent Document 3 differs from Patent Documents 1 and 2 in that although a ring-shaped member is required to form the joint, no rotation is required during joining and no load is required for elastic deformation.

However, as described above, the device in Patent Document 3 that uses a ring-shaped member cannot transmit torsional loads, and therefore requires either the placement of a bolt as in Patent Documents 1 and 2, or the placement of a separate anti-rotation mechanism as in Patent Document 4.
However, in the case of Patent Document 3, even if bolts are placed as in Patent Documents 1 and 2, or a separate anti-rotation mechanism is provided as in Patent Document 4, the ring-shaped member itself is in a state where it can rotate and deform, so there is a concern that the ring-shaped member may behave in an unexpected manner during construction or use, causing the joint to come loose or reducing the strength.

The present invention has been made to solve these problems, and has an object to provide a mechanical joint that does not require rotation or application of a large load to the joint, can transmit torsional loads without incurring excessive additional costs, and does not come loose or lose its strength.
Another object of the present invention is to provide a method for joining the mechanical joint, a steel pipe equipped with the mechanical joint, a structure having the steel pipe as a component, a construction method for the structure, a design method for the mechanical joint, and a manufacturing method for the mechanical joint.

(1) A mechanical joint according to the present invention comprises a tubular male joint and a female joint into which the male joint is inserted and fitted, and is attached to the end of a steel pipe to join the steel pipes together,
a step portion is formed on the base end side of the male joint, and when the male joint is inserted into the female joint, the tip portion of the female joint abuts on the step portion to reach an insertion complete state, the male joint comprises one or more steps of annular grooves formed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion complete state, a C-shaped ring member that can be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint and that can be arranged to straddle the male joint side and the female joint side within the annular groove in the insertion complete state, anti-rotation pin insertion holes provided in the male joint and the female joint at positions that coincide with the C-shaped cutout portion of the C-shaped ring member, and an anti-rotation pin that passes through the anti-rotation pin insertion hole and the C-shaped cutout portion of the female joint in the insertion complete state to reach the anti-rotation pin insertion hole of the male joint.

(2) Moreover, a method for joining a mechanical joint according to the present invention is a method for joining a mechanical joint according to the above (1), comprising the steps of:
a step of reducing a diameter of the C-shaped ring member and accommodating it in the annular groove of the male joint while aligning the position of the C-shaped cutout portion with the position of the anti-rotation pin insertion hole of the male joint;
a step of completing insertion of the male joint and the female joint in a state in which the positions of the rotation prevention pin insertion holes of the male joint and the female joint are aligned;
releasing the C-ring member from its reduced diameter state;
and disposing the anti-rotation pin in a state in which the anti-rotation pin passes through the anti-rotation pin insertion hole and the C-shaped notch portion and reaches the anti-rotation pin insertion hole of the male joint.

(3) Furthermore, the steel pipe according to the present invention has the male and female joints described in (1) attached to one end and the other end.

(4) The structure according to the present invention also includes a plurality of steel pipes connected by the mechanical joint described in (1) above.

(5) The construction method of the structure according to the present invention is the construction method of the structure described in (4) above, in which, while restraining the axial position of one of the jointed steel pipes to be connected, the other jointed steel pipe is aligned with the one jointed steel pipe and inserted into it.

(6) A design method for a mechanical joint according to the present invention is a design method for a mechanical joint that includes a tubular male joint and a female joint into which the male joint is inserted and fitted, and is attached to an end of a steel pipe to join the steel pipes, the design method comprising the steps of:
A step portion is provided on the base end side of the male joint,
a tip end of the female joint is set to abut against the step portion when the male joint is completely inserted into the female joint;
one or more stages of annular grooves are disposed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is set so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove in the insertion completion state;
a rotation prevention pin insertion hole provided in the male joint and the female joint is set at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
In the completed insertion state, an anti-rotation pin is set to pass through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reach the anti-rotation pin insertion hole of the male joint.

(7) A method for manufacturing a mechanical joint according to the present invention is a method for manufacturing a mechanical joint that includes a tubular male joint and a female joint into which the male joint is inserted and fitted, and is attached to an end of a steel pipe to join the steel pipes, the method comprising the steps of:
A step portion is formed on the base end side of the male joint,
The male joint is formed so that a tip portion of the female joint abuts on the step portion when the male joint is completely inserted into the female joint,
one or more stages of annular grooves are formed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is formed so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove when the insertion is completed;
a rotation prevention pin insertion hole is formed in the male joint and the female joint at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
In the completed insertion state, an anti-rotation pin is formed which passes through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reaches the anti-rotation pin insertion hole of the male joint.

In the present invention, annular grooves are provided in the male joint and the female joint, and when the male joint is fully inserted into the female joint, a C-shaped ring member is positioned so as to straddle both the male joint and the female joint, and an anti-rotation pin is provided which passes through the anti-rotation pin insertion hole and C-shaped notch of the female joint when the insertion is complete, and reaches the anti-rotation pin insertion hole of the male joint.This eliminates the need to apply rotation or large loads to the joint, and allows torsional loads to be transmitted without incurring excessive additional costs.
Furthermore, since the C-shaped notch does not close, the joint will not come off or its strength will not decrease.
Furthermore, since the anti-rotation pin serves both to prevent rotation of the male and female joints and to prevent the C-ring member from shrinking or moving, reliable load transmission is possible with a simple structure.

1(a) is an explanatory diagram of a mechanical joint according to embodiment 1, in which FIG. 1(a) is a vertical cross-sectional view (upper view in the figure (same below)) and a cross-sectional view taken along line A-A in the vertical cross-sectional view (lower view in the figure (same below)); FIG. 1(b) is a vertical cross-sectional view and a cross-sectional view taken along line B-B in the vertical cross-sectional view (however, cutting tool 22 is omitted); FIG. 1(c) is a vertical cross-sectional view and a cross-sectional view taken along line C-C in the vertical cross-sectional view (however, anti-rotation pin 11 is omitted); and FIG. 1(d) is a vertical cross-sectional view and a cross-sectional view taken along line D-D in the vertical cross-sectional view (however, anti-rotation pin 11 is omitted). 10A to 10C are explanatory diagrams of another aspect of the method for reducing the diameter of the C-shaped ring member in the first embodiment.

The mechanical joint according to this embodiment will be described with reference to Figure 1. Figure 1(a) shows the state before the joint is inserted, Figure 1(b) shows the state after the joint is inserted and before the C-shaped ring member is contracted and released, Figure 1(c) shows the state after the C-shaped ring member is contracted and released and before the anti-rotation pin is inserted, and Figure 1(d) shows the state after the anti-rotation pin 11 is inserted.

As shown in FIG. 1(a), the mechanical joint 1 according to this embodiment is made up of a tubular male joint 3 and a female joint 5 into which the male joint 3 is inserted and fitted, and is attached to the ends of steel pipes 7 to join the steel pipes 7 together. A step portion 9 is formed on the base end side of the male joint 3, and as shown in FIG. 1(b), when the male joint 3 is inserted into the female joint 5, the tip portion 10 of the female joint 5 abuts against the step portion 9, completing the insertion.

Further, the male joint 3 and the female joint 5 are provided with anti-rotation pin insertion holes 13M, 13F for inserting an anti-rotation pin 11 therein.
The anti-rotation pin insertion holes 13M, 13F may be tapped holes on both the male joint 3 and the female joint 5, or may be threaded holes on only one of the male joint 3 or the female joint 5. However, if either one is a threaded hole, it is preferable to have the female joint 5 side be a threaded hole because this makes it easier to install the anti-rotation pin 11.

Further, annular grooves 15 are formed on the outer peripheral surface of the male joint 3 and the inner peripheral surface of the female joint 5 so as to face each other when the insertion is complete.
The annular grooves 15M, 15F formed in the male joint 3 and the female joint 5 respectively form an annular groove 15 consisting of a circular closed space when the joints are in a fully inserted state.
Furthermore, it has a C-shaped ring member 17 that is stored in a reduced diameter state in the annular groove 15M of the male joint 3 so as not to hinder insertion of the male joint 3 into the female joint 5, and that can be positioned within the annular groove 15 so as to straddle the annular groove 15M of the male joint 3 and the annular groove 15F of the female joint 5 when the reduced diameter state is released.

As shown in Fig. 1, the C-shaped ring member 17 has a notch 19 at one location in the circumferential direction, and has a spring structure that expands and contracts in the radial direction. The C-shaped ring member 17 has a diameter larger than the outer diameter of the annular groove 15M in a free state without being restrained. Therefore, in order to completely fit into the annular groove 15M, a diameter reduction holding means is required to hold the C-shaped ring member 17 in a reduced diameter state. One example of the diameter reduction holding means is a fixing tape 21 that is attached so as to straddle the notch 19 in the reduced diameter state of the C-shaped ring member 17. By attaching the fixing tape 21 to hold the reduced diameter state, the C-shaped ring member 17 is disposed in the annular groove 15M in a state that is aligned with the outer circumferential surface of the annular groove 15M of the male joint 3.
It is preferable that the diameter of the rotation prevention pin insertion hole 13M is larger than the width of the annular groove 15M for the following reasons.
If the diameter of the anti-rotation pin insertion hole 13M is larger than the width of the annular groove 15M, when the C-shaped ring member 17 is contracted and stored in the annular groove 15M, the anti-rotation pin insertion hole 13M will not be completely covered, and part of the anti-rotation pin insertion hole 13M will be visible above and below the C-shaped ring member 17. In this state, the fixing tape 21 can reach not only the front surface of the C-shaped ring member 17, but also the side and rear surfaces, so that the fixing tape 21 can be wrapped around the entire circumference of the C-shaped ring member 17 near the cutout portion 19 and secured firmly in place.

The fixing tape 21 is preferably made of, for example, an adhesive tape, is thin, can be easily fastened with fingers, and is made of a material that is resistant to water and oil.
Furthermore, since the fixing tape 21 will be later cut or removed to release the diameter-reduced state of the C-ring member 17, it needs to be cuttable, such as made of resin, or it needs to be removable even if it cannot be cut.

The fixing tape 21 attached to the C-shaped ring member 17 must be cut by inserting a tool through the anti-rotation pin insertion hole 13F once the male joint 3 has been completely inserted into the female joint 5. For this reason, the C-shaped ring member 17 is placed in the annular groove 15M of the male joint 3 so that the cutout 19 is at the position of the anti-rotation pin insertion hole 13M.

The fitting operation of the mechanical joint 1 configured as above will now be described.
1(a), before the male joint 3 is inserted into the female joint 5, the C-shaped ring member 17 is stored in a contracted diameter state in the annular groove 15M of the male joint 3, and the fixing tape 21 prevents the C-shaped ring member 17 from expanding in diameter. Then, the male joint 3 and the female joint 5 are aligned, and the male joint 3 is inserted into the female joint 5.
Incidentally, aligning the directions of the male joint 3 and the female joint 5 means that the positions of the anti-rotation pin insertion holes 13M, 13F of the male joint 3 and the female joint 5 are aligned.

As shown in FIG. 1(b), the insertion of the male joint 3 into the female joint 5 is completed when the step portion 9 of the male joint 3 and the tip of the female joint 5 are in contact. In this state, the annular grooves 15 formed in the male joint 3 and the female joint 5 respectively form an annular groove 15 consisting of an elliptical closed space, and the C-shaped ring member 17 stored in the annular groove 15M of the male joint 3 is positioned opposite the annular groove 15F of the female joint 5.

Next, a cutting tool 22 such as a cutter is inserted through the anti-rotation pin insertion hole 13F of the female joint 5 to cut the fixing tape 21 (Fig. 1(b)). As a result, as shown in Fig. 1(c), the C-shaped ring member 17 is expanded in diameter by its own spring force, and the C-shaped ring member 17 is positioned so as to straddle both the annular groove 15M and the annular groove 15F.

Next, the anti-rotation pin 11 is disposed so as to pass through the anti-rotation pin insertion hole 13F and the notch 19 of the female joint 5 and reach the anti-rotation pin insertion hole 13M of the male joint 3 (FIG. 1(d)).
As a result, the female joint 5 and the male joint 3 are connected by the anti-rotation pin 11 , and the C-ring member 17 is prevented from moving and expanding/contracting within the annular groove 15 by the anti-rotation pin 11 .

In this state, the compressive force is transmitted mainly by the contact pressure between the step portion 9 of the male joint 3 and the tip portion 10 of the female joint 5, the tensile force is transmitted mainly by the support pressure of the C-ring member 17, the torsional force is transmitted by the anti-rotation pin 11, and the shear force is transmitted mainly by the double pipe portion formed by the male joint 3 and the female joint 5.

As described above, in this embodiment, annular grooves 15M, 15F are provided in the male joint 3 and the female joint 5, and when the male joint 3 is completely inserted into the female joint 5, the C-shaped ring member 17 is arranged to straddle the annular grooves 15 of both the male joint 3 and the female joint 5. Furthermore, by providing an anti-rotation pin 11, there is no need to apply rotation or large loads to the joint, and tensile loads, torsional loads, and shear loads can be transmitted without incurring excessive additional costs.
As described above, the C-shaped ring member 17 is prevented from moving or expanding/contracting by the anti-rotation pin 11, so that the C-shaped ring member 17 will not move unexpectedly, and the joint will not come loose or its strength will not be reduced.
Furthermore, since the anti-rotation pin 11 serves both to prevent rotation of the male joint 3 and the female joint 5 and to prevent movement of the C-ring member 17, reliable load transmission is possible with a simple structure.

In the above embodiment, the C-shaped ring member 17 is disposed horizontally, i.e., disposed perpendicular to the axis of the male joint 3 and the female joint 5, but the present invention is not limited to this, and the C-shaped ring member 17 may be disposed at an incline. In this case, the annular grooves 15M, 15F provided in the male joint 3 and the female joint 5 may be inclined.
When the annular groove 15 is inclined, the shape and size of the C-shaped ring member 17 may be set so that it can be stored in the inclined annular groove 15 .
It is preferable to arrange the C-shaped ring member 17 horizontally. If arranged horizontally, it is easy to process the C-shaped ring member 17 and the annular groove 15, and the lengths of the male joint 3 and the female joint 5 can be shortened, so that the manufacturing cost can be reduced.

In the above embodiment, the fixing tape 21 is exemplified as the diameter reduction holding means for holding the C-shaped ring member 17 in a diameter reduced state, but instead of this, for example, a fixing band 23 made of polypropylene (PP band) or the like may be used.
FIG. 2 shows a state in which the C-shaped ring member 17 is accommodated in the inclined annular groove 15 with its diameter reduced by the fixing band 23 .
The fixing band 23 is preferably made of a material that is thin, can be easily fastened by fingers, and is resistant to water and oil. The fixing band 23 fixes (fastens) the entire circumference of the C-shaped ring member 17, thereby preventing the C-shaped ring member 17 from expanding in diameter.

The method of storing the C-ring member 17 in a reduced diameter state in the annular groove 15M of the male joint 3 by the fixing band 23 is as follows.
The C-shaped ring member 17 is stored in the annular groove 15M, the entire circumference of the stored C-shaped ring member 17 is covered with a fixing band 23, and the fixing band 23 is tightened to reduce the diameter of the C-shaped ring member 17, and the fixing band 23 is fixed in this state.
In addition, like the fixing tape 21, the fixing band 23 is cut or removed after the insertion of the male joint 3 is completed.

In addition, in the above embodiment, an example was given in which the annular groove 15 is formed with one stage, but the present invention is not limited to this, and the number of stages of the annular groove 15 may be multiple stages in the central axial direction of the joint.
By using multiple stages, greater load transmission is possible.

Furthermore, the above embodiment is directed to a mechanical joint 1 that is fixed to the end of a steel pipe 7 by welding or the like, but by attaching such a mechanical joint 1 to one end and the other end of a steel pipe 7, a steel pipe 7 that can be easily joined can be formed.
Furthermore, by connecting steel pipes 7 to which mechanical joints 1 are attached, a structure joined by mechanical joints 1 can be formed.
Furthermore, to construct such a structure, while restraining the position in the axial direction of one of the jointed steel pipes 7 to be connected, the other jointed steel pipe 7 is aligned with the one jointed steel pipe 7 and inserted and fitted into it.

In addition, the above embodiment relates to the mechanical joint 1 as an invention of an object, but it can also be reconstructed as an invention of a design method or a manufacturing method, in which case it would look like this:

<Design method invention>
A design method for a mechanical joint that includes a tubular male joint and a female joint into which the male joint is inserted and fitted, the mechanical joint being attached to an end of a steel pipe to join the steel pipes together, comprising:
A step portion is provided on the base end side of the male joint,
a tip end of the female joint is set to abut against the step portion when the male joint is completely inserted into the female joint;
one or more stages of annular grooves are disposed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is set so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove in the insertion completion state;
a rotation prevention pin insertion hole provided in the male joint and the female joint is set at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
A method for designing a mechanical joint that sets an anti-rotation pin that passes through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reaches the anti-rotation pin insertion hole of the male joint in the inserted state.

<Production method invention>
A manufacturing method for a mechanical joint comprising a tubular male joint and a female joint into which the male joint is inserted and fitted, the female joint being attached to an end of a steel pipe to join the steel pipes, the manufacturing method comprising the steps of:
A step portion is formed on the base end side of the male joint,
The male joint is formed so that a tip portion of the female joint abuts on the step portion when the male joint is completely inserted into the female joint,
one or more stages of annular grooves are formed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is formed so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove when the insertion is completed;
a rotation prevention pin insertion hole is formed in the male joint and the female joint at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
A manufacturing method for a mechanical joint, in which an anti-rotation pin is formed that passes through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reaches the anti-rotation pin insertion hole of the male joint in the inserted state.

1 Mechanical joint 3 Male joint 5 Female joint 7 Steel pipe 9 Step portion 10 Tip portion 11 Anti-rotation pin 13M Anti-rotation pin insertion hole (male joint)
13F Anti-rotation pin insertion hole (female joint)
15 Annular groove 15M Annular groove (male joint)
15F Annular groove (female joint)
17 C-ring member 19 Notch portion 21 Fixing tape 22 Cutting tool 23 Fixing band

Claims (7)

A mechanical joint comprising a tubular male joint and a female joint into which the male joint is inserted and fitted, the mechanical joint being attached to the end of a steel pipe to join the steel pipes together,
a step portion is formed on a base end side of the male joint, and when the male joint is inserted into the female joint, a tip portion of the female joint abuts on the step portion to reach an insertion complete state, the mechanical joint comprising: one or more steps of annular grooves formed on an outer circumferential surface of the male joint and an inner circumferential surface of the female joint so as to face each other in the insertion complete state; a C-shaped ring member that can be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint and that can be arranged to straddle the male joint side and the female joint side within the annular groove in the insertion complete state; anti-rotation pin insertion holes provided in the male joint and the female joint at positions that coincide with C-shaped cutout portions of the C-shaped ring member; and an anti-rotation pin that passes through the anti-rotation pin insertion hole and the C-shaped cutout portion of the female joint in the insertion complete state to reach the anti-rotation pin insertion hole of the male joint. A method for joining a mechanical joint according to claim 1, comprising the steps of:
a step of reducing a diameter of the C-shaped ring member and accommodating it in the annular groove of the male joint while aligning the position of the C-shaped notch with the position of the anti-rotation pin insertion hole of the male joint;
a step of completing insertion of the male joint and the female joint in a state in which the positions of the rotation prevention pin insertion holes of the male joint and the female joint are aligned;
releasing the C-ring member from its reduced diameter state;
and arranging the anti-rotation pin in a state in which the anti-rotation pin passes through the anti-rotation pin insertion hole and the C-shaped notch portion and reaches the anti-rotation pin insertion hole of the male joint. A steel pipe having the male and female joints described in claim 1 attached to one end and the other end. A structure comprising multiple steel pipes connected by the mechanical joint described in claim 1. A method for constructing a structure as described in claim 4, in which, while restraining the axial position of one of the jointed steel pipes to be connected, the other jointed steel pipe is aligned with the one jointed steel pipe and inserted into it. A method for designing a mechanical joint that includes a tubular male joint and a female joint into which the male joint is inserted and fitted, and that is attached to an end of a steel pipe to join the steel pipes, comprising:
A step portion is provided on the base end side of the male joint,
a tip end of the female joint is set to abut against the step portion when the male joint is completely inserted into the female joint;
one or more stages of annular grooves are disposed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is set so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove in the insertion completion state;
a rotation prevention pin insertion hole provided in the male joint and the female joint is set at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
A method for designing a mechanical joint that sets an anti-rotation pin that passes through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reaches the anti-rotation pin insertion hole of the male joint in the inserted state. A manufacturing method for a mechanical joint comprising a tubular male joint and a female joint into which the male joint is inserted and fitted, the female joint being attached to an end of a steel pipe to join the steel pipes,
A step portion is formed on the base end side of the male joint,
The male joint is formed so that a tip portion of the female joint abuts on the step portion when the male joint is completely inserted into the female joint,
one or more stages of annular grooves are formed on the outer peripheral surface of the male joint and the inner peripheral surface of the female joint so as to face each other in the insertion completion state,
a C-shaped ring member is formed so as to be able to be stored in the annular groove of the male joint so as not to hinder the insertion of the male joint into the female joint, and so as to be able to be arranged so as to straddle the male joint side and the female joint side within the annular groove when the insertion is completed;
a rotation prevention pin insertion hole is formed in the male joint and the female joint at a position that coincides with a C-shaped notch portion of the C-shaped ring member;
A manufacturing method for a mechanical joint, in which an anti-rotation pin is formed that passes through the anti-rotation pin insertion hole and the C-shaped notch of the female joint and reaches the anti-rotation pin insertion hole of the male joint in the inserted state.