TW202300806A - Mechanical joint, steel pipe with joint, method of manufacturing steel pipe with joint, structure, method of constructing structure, and method of designing mechanical joint - Google Patents

Abstract

The purpose of the present invention is to reduce the push-in load required for fitting without causing an increase in machining cost and a reduction in strength. A mechanical joint 1 according to the present invention comprises an inner joint pipe 5 and an outer joint pipe 7, and comprises split pieces 11 capable of flexing in a radial direction, a projecting part 13, an engagement part 17, and a guide part 19. The split pieces 11 are grouped into a plurality of groups that satisfy the following conditions (1) and (2), and are configured to reach a maximum flexure in a fitting process at different timings between the split pieces 11 in the same group. (1) The split pieces that belong to the same group have the same axial position at which the maximum flexure is generated at the guide part, and the axial position varies between different groups, and (2) the split pieces that belong to the same group form, when the circumferential centers of adjacent ones are connected with a straight line, a straight line passing through the center of the pipe or a polygonal shape the center of gravity of which coincides with the center of the pipe.

Description

Mechanical joint, steel pipe with joint, method of manufacturing steel pipe with joint, structure, construction method of structure, and design method of mechanical joint

The present invention relates to a mechanical joint for joining steel pipes, a steel pipe with a joint including a mechanical joint, a method for manufacturing a steel pipe with a joint, a mechanical joint, and a plurality of joints including a mechanical joint. The structure of the steel pipe, the construction method of the structure, and the design method of the mechanical joint.

In the past, welding was mainly used to join steel pipes, but in recent years, due to the shortening of construction period and problems in quality control, mechanical joining has gradually been used. Regarding this mechanical joining, Patent Document 1 discloses a joint excellent in workability that can be joined only by insertion.

In the "joint structure of steel pipes" described in Patent Document 1, an outer joint pipe and an inner joint pipe are respectively provided at the ends of steel pipes to be joined. fitting, thereby joining the steel pipes. The tip of any one of the outer joint pipe and the inner joint pipe is divided in the circumferential direction and can be flexed in the radial direction. A press-fitting load is applied in the axial direction, and the tip of either the outer joint pipe or the inner joint pipe is bent and inserted. At this time, the deflection is restored at the end position of insertion, and the protrusion formed on the outer peripheral surface of the inner joint tube engages and fits with the engaging part formed on the inner peripheral surface of the outer joint tube, or the protrusion formed on the outer joint tube The convex portion on the inner peripheral surface of the inner joint tube engages and fits with the engaging portion formed on the outer peripheral surface of the inner joint pipe. [Prior art literature] [Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 2004-36329

[Problem to be Solved by the Invention] In the joint described in Patent Document 1, since the portion at the tip that is divided in the circumferential direction has an arc-shaped cross section, the bending rigidity is higher than that of a rectangular cross-section, and a large press-fitting load is required to fit the joints together. . In addition, the joint generally requires the same compressive and tensile strength as the steel pipe, so increasing the thickness of the joint according to the specification of the steel pipe requires a larger press-fitting load. The increase of the press-fit load required for insertion-based fitting deteriorates the workability, so methods for reducing the press-fit load are being studied.

Therefore, in order to reduce the necessary press-fitting load, it is conceivable to increase the number of divisions of the flexure portion, but when this portion is cut for fabrication, the number of cutting parts increases and processing costs are consumed. Furthermore, as the number of divisions increases, the strength of the portion may decrease, and irreversible deformation such as torsion may occur due to an unexpected load during transportation or work, and there is a possibility that the fitting may not be possible during construction. Therefore, there is a demand for a mechanical joint that can reduce the press-fitting load without increasing the number of divisions.

The present invention is made in view of the above problems, and its purpose is to provide a mechanical joint, a steel pipe with a joint, a method for manufacturing a steel pipe with a joint, a structure, a construction method for a structure, and a design method for a mechanical joint without causing The increase in processing cost and the decrease in strength reduce the press-fit load required for fitting and improve workability. [Means to solve the problem]

A mechanical joint according to one aspect of the present invention includes: an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, and either one of the inner joint pipe and the outer joint pipe is contained in The divided pieces are divided at equal intervals in the circumferential direction and can be flexed in the radial direction, and the mechanical joint includes: a convex part formed on the outer peripheral surface of the inner joint pipe; an engaging part formed on the outer joint pipe The inner peripheral surface of the inner joint pipe engages with the convex part in the state where the inner joint pipe and the outer joint pipe are fitted, and resists the tensile load together with the convex part; and the guide part is provided on The front end side of the outer joint pipe is closer to the engagement portion than the engaging portion, and abuts against the convex part during fitting of the inner joint pipe and the outer joint pipe, and cooperates with the convex part to The split pieces are flexed and the bent state is maintained until the engaging portion, and the split pieces are grouped into a plurality of groups satisfying the following conditions (1) and (2) so as to be embedded in In the combination process, the timing of reaching the maximum deflection is staggered in units of the same group of split slices. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

A mechanical joint according to one aspect of the present invention includes: an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, and either one of the inner joint pipe and the outer joint pipe is contained in The divided piece is divided at equal intervals in the circumferential direction and can be flexed in the radial direction, and the mechanical joint includes: a convex part formed on the inner peripheral surface of the outer joint pipe; an engaging part formed on the inner joint The outer peripheral surface of the pipe engages with the convex portion in a state where the outer joint pipe and the inner joint pipe are fitted together, and resists a tensile load together with the convex portion; and the guide portion is provided on The end side of the inner joint pipe is closer to the engaging portion than the engaging portion, and abuts against the convex portion during the fitting of the outer joint pipe and the inner joint pipe, and cooperates with the convex portion to The split pieces are flexed and the bent state is maintained until the engaging portion, and the split pieces are grouped into a plurality of groups satisfying the following conditions (1) and (2) so as to be embedded in In the combination process, the timing of reaching the maximum deflection is staggered in units of the same group of split slices. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

In the mechanical joint according to one aspect of the present invention, in the above-mentioned invention, the split pieces of the other set do not start radial deflection until the split pieces of one set reach the maximum deflection.

A steel pipe with a joint according to one aspect of the present invention includes the inner joint pipe and/or the outer joint pipe in the mechanical joint of the above-mentioned invention at both ends or at one end.

A method of manufacturing a steel pipe with a joint according to an aspect of the present invention is a method of manufacturing the steel pipe with a joint of the above-mentioned invention, and the outer sides of the mechanical joints of the above-mentioned invention are respectively attached to the ends of the steel pipes to be joined. Connector tube and/or inner connector tube.

A structure according to one aspect of the present invention includes the mechanical joint of the invention described above, and a plurality of steel pipes joined via the mechanical joint.

A method of constructing a structure according to an aspect of the present invention is a method of constructing the structure of the above invention, in which a steel pipe with the outer joint pipe attached to its end and a steel pipe with the inner joint attached to its end are constructed. Any one of the steel pipes of the pipe is erected in the ground, and the other steel pipe is placed on one of the steel pipes in this state, and the inner joint pipe and the outer joint pipe are fitted and joined. .

A method for designing a mechanical joint according to an aspect of the present invention designs a mechanical joint including: an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, and the inner joint pipe and any one of the outer joint pipes includes split pieces that are divided at equal intervals in the circumferential direction and are radially deflectable, and the mechanical joint includes: a convex portion formed on the outer periphery of the inner joint pipe surface; an engaging portion formed on the inner peripheral surface of the outer joint pipe, and engages with the convex portion in the state where the inner joint pipe and the outer joint pipe are fitted together, and is aligned with the convex portion and resists a tensile load; and a guide part provided on the distal end side of the outer joint pipe than the engaging part, and abuts against the inner joint pipe in the middle of fitting the inner joint pipe with the outer joint pipe. The convex part cooperates with the convex part to deflect the divided piece and maintain the deflected state until the engaging part, and in the design method of the mechanical joint, the The split pieces are grouped into multiple groups that satisfy the following conditions (1) and (2). The stress in the horizontal direction produced by the curvature is offset. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the center of the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

A method for designing a mechanical joint according to an aspect of the present invention designs a mechanical joint including: an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, and the inner joint pipe and any one of the outer joint pipes includes split pieces that are equally spaced in the circumferential direction and can be flexibly radially divided, and the mechanical joint includes: a convex portion formed in the inner portion of the outer joint pipe Peripheral surface; an engaging portion formed on the outer peripheral surface of the inner joint pipe, and engages with the convex portion in the state where the outer joint pipe and the inner joint pipe are fitted together, and is aligned with the convex portion and resist a tensile load; and a guide part provided on the front end side of the inner joint pipe than the engaging part, and abuts against the inner joint pipe in the middle of fitting the outer joint pipe with the inner joint pipe. The convex part cooperates with the convex part to deflect the divided piece and maintain the deflected state until the engaging part, and in the design method of the mechanical joint, the The split pieces are grouped into multiple groups that satisfy the following conditions (1) and (2). The stress in the horizontal direction produced by the curvature is offset. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed [Effect of the invention]

According to the present invention, the split pieces are grouped into a plurality of groups in such a way that the predetermined conditions are met, and the timing of reaching the maximum deflection is staggered in units of the same group of split pieces during the fitting process, thereby reducing the pressure required for fitting. The input load improves the constructability. Furthermore, according to the present invention, the press-fitting load can be reduced without increasing the number of divided pieces, so that the processing cost does not increase or the strength does not decrease.

Before describing the mechanical joint according to one embodiment of the present invention, the structure of a conventional mechanical joint will be described based on FIGS. 11 , 12 , 13 , 14A, 14B, 14C, and 14D.

As shown in FIG. 11 , an example of a conventional mechanical joint 23 includes an inner joint pipe 5 and an outer joint pipe 25 , which are respectively provided at the ends of the steel pipes 3 to be joined. The inner joint pipe 5 and the outer joint pipe 25 are disposed vertically facing each other. In the state of FIG. 11 , an axial load is applied to the inner joint pipe 5 disposed above, and the inner joint pipe 5 is inserted into the outer joint pipe 25 to fit the inner joint pipe 5 and the outer joint pipe 25 , as shown in FIG. 12 . The upper and lower steel pipes 3 are joined as shown.

The inner joint pipe 5 has a base end portion 9 welded to the steel pipe 3, and on the top end side of the base end portion 9, a cylindrical member having a smaller outer diameter than the base end portion 9 forms a narrow shaft extending in the axial direction. The split sheet 11 formed by splitting. FIG. 13 is a view taken along the line A-A of FIG. 11 , showing only the tip of the split piece 11 . As shown in FIG. 11 and FIG. 13 , in the mechanical joint 23 , the top end of the inner joint pipe 5 is divided into eight, for example, and eight divided pieces 11 having an arc-shaped cross section are arranged at equal intervals in the circumferential direction. The split piece 11 is deflectable in the radial direction, and a convex portion 13 protruding outward is formed on the outer peripheral surface of the tip portion.

The inner diameter of the outer joint pipe 25 is smaller than the outer diameter of the portion of the inner joint pipe 5 where the convex portion 13 is formed, and the concave portion 15 is formed on the proximal end side of the inner peripheral surface of the outer joint pipe 25 . In the middle of inserting and fitting the inner joint pipe 5 into the outer joint pipe 25, the inner peripheral surface of the outer joint pipe 25 presses into contact with the convex portion 13 of the inner joint pipe 5, whereby the split piece 11 of the inner joint pipe 5 faces toward the inner joint pipe 5. Radial inward deflection. In the inserted state, the deflection of the split piece 11 is restored, and the convex portion 13 of the inner joint tube 5 enters the concave portion 15 of the outer joint tube 25 to complete the fitting.

The process of joining the inner joint pipe 5 and the outer joint pipe 25 will be described in more detail based on FIGS. 14A , 14B, 14C, and 14D. 14A to 14D schematically show cross-sections in the axial direction of part B in FIG. 11 . As shown in FIG. 14A , an engaging portion 17 and a guide portion 19 are provided on the inner peripheral surface of the outer joint pipe 25 . The engaging portion 17 constitutes a side wall of the concave portion 15 and is engaged with the convex portion 13 of the inner joint tube 5 . During the insertion and fitting of the inner joint tube 5 into the outer joint tube 25 , the guide part 19 cooperates with the convex part 13 to bend the split piece 11 and maintains the bent state until the engagement part 17 . The guide part 19 has the inclined surface part 19a which starts the deflection of the split piece 11 and guides it to the maximum deflection, and the flat surface part 19b which maintains the maximum deflection to the engagement part 17. Furthermore, an inclined surface portion 13 a having a shape corresponding to the inclined surface portion 19 a of the guide portion 19 is formed on the distal end outer peripheral side of the convex portion 13 of the inner joint tube 5 .

FIG. 14A shows a state before the inner joint pipe 5 and the outer joint pipe 25 are pressed into contact, that is, before the split piece 11 starts to bend. In addition, let the axial position of the convex part 13 at this time be _X0 . When the split piece 11 is moved downward by applying an axial load to the inner joint tube 5, as shown in FIG. The inclined surface 19a of 19 is in contact with each other, and the convex part 13 is pressed, so that the split piece 11 is bent radially inwardly. By providing the correspondingly shaped inclined surface 19a and inclined surface 13a on the guide portion 19 and the convex portion 13 in this way, the axial force of the pipe can be converted into a radial force, and fitting by insertion can be smoothly performed. . In addition, FIG. 14B has shown the state in which the outer peripheral surface of the convex part 13 reached the apex of the inclined surface part 19a, ie, the split piece 11 was bent most. In addition, let the axial position of the convex part 13 at this time be _X1 .

Then, as shown in FIG. 14C , the split piece 11 is inserted while maintaining the state of maximum deflection. Let the axial position of the convex part 13 shown in FIG. 14C here be _X2 . When the distal end portion of the outer joint tube 25 abuts against the base end portion 9 of the inner joint tube 5, as shown in FIG. Splicing is complete. Let the axial position of the convex part 13 at this time be _X3 .

In the mechanical joint 23 joined as described above, the base end 9 of the inner joint pipe 5 and the distal end portion of the outer joint pipe 25 react to the axial compressive load acting on the inner joint pipe 5 and the outer joint pipe 25 . to fight. In addition, in the mechanical joint 23 , the convex portion 13 of the inner joint tube 5 and the engaging portion 17 of the outer joint tube 25 counteract the axial tensile load acting on the inner joint tube 5 and the outer joint tube 25 .

During the joining process, the load required to insert the inner joint pipe 5 differs depending on the deflection state of the split piece 11 . This aspect will be described using FIG. 15 . FIG. 15 is a graph showing the relationship between the displacement in the axial direction and the magnitude of the load required to bend and insert one split piece 11 .

As shown in FIG. 15 , when the inclined surface 19 a of the guide part 19 abuts against the inclined surface 13 a of the convex part 13 , the split piece 11 is flexed while being inserted and fitted (X ₀ to X ₁ ). , the insertion requires a large load. In particular, when the split piece 11 reaches the maximum deflection (X ₁ ), the maximum load is required. On the other hand, the flat surface 19b of the guide part 19 or the inner peripheral surface of the engaging part 17 abuts against the outer peripheral surface of the convex part 13, while maintaining the maximum deflection while inserting and fitting the process (X1 _～ In X ₃ ), it is only necessary to have a load exceeding the frictional resistance between the inner joint pipe 5 and the outer joint pipe 25 , so fitting can be performed with a small load.

FIG. 15 is a graph showing the load required for insertion and fitting while bending one split piece 11 . The load shown in FIG. 15 is also required for the other seven split pieces 11 in the same way. That is, in the case of the mechanical joint 23 shown in FIGS. 11 to 13 , since the eight split pieces 11 are uniformly bent, the load required to insert the inner joint tube 5 for fitting becomes approximately the load shown in FIG. 15 . 8 times.

As described above, in the conventional mechanical joint 23 , all the split pieces 11 are bent and inserted in unison. Therefore, when the eight split pieces 11 simultaneously achieve the maximum deflection (X1), a particularly large load is required. From this point of view, the present inventors conceived a method of staggering the timing at which each segmented piece 11 reaches the maximum deflection. Thereby, the maximum value of the load required to insert the mechanical joint 23 as a whole can be reduced.

In addition, when the steel pipes 3 are joined using the mechanical joint 23, either the steel pipe 3 with the outer joint pipe 25 or the steel pipe 3 with the inner joint pipe 5 is erected in the ground, and is used The other one is hoisted by a crane and placed above the steel pipe 3 erected in the ground for insertion. At this time, since it is difficult to restrict the horizontal movement of the upper steel pipe 3 lifted by the crane, it is preferable to completely cancel the horizontal stress generated when the split pieces 11 bend during the joining process. In this regard, in the conventional mechanical joint 23, the center of gravity of the polygon (two-dot chain line in FIG. 13 ) connecting the centers of the arcs of the divided pieces 11 (marked by x in FIG. 13 ) and the center of the tube Center 21 is consistent. Thereby, the stress in the horizontal direction generated by the deflection of the split pieces 11 is canceled out. The cancellation of the stress in the horizontal direction at the time of insertion should also be taken into account when the timing at which the split piece 11 reaches the maximum deflection is shifted as described above. This invention is made based on this knowledge. In one embodiment described below, a case where the inner joint pipe is divided into eight, for example, will be described as an example. In addition, in the following description, the same code|symbol is attached|subjected to the same part as FIG. 11-FIG. 14A-FIG. 14D which showed the previous example.

A mechanical joint 1 according to an embodiment of the present invention includes an inner joint pipe 5 and an outer joint pipe 7 provided at the ends of steel pipes 3 to be joined, respectively. The inner joint pipe 5 includes split pieces 11 that are divided into eight at equal intervals in the circumferential direction and that are flexible in the radial direction. Protrusions 13 are formed on the outer peripheral surface of the split piece 11 . On the inner peripheral surface of the outer joint pipe 7, an engaging portion 17 is provided, and the engaging portion 17 engages with the convex portion 13 in a state where the inner joint pipe 5 and the outer joint pipe 7 have been fitted together, and together with the convex portion 13, and resist tensile loads. On the distal end side of the outer joint pipe 7 than the engaging portion 17, a guide portion 19 is provided, and the guide portion 19 abuts against the convex portion 13 during the fitting of the inner joint pipe 5 and the outer joint pipe 7, The divided piece 11 is flexed in cooperation with the convex portion 13 , and the flexed state is maintained until the engaging portion 17 . The guide part 19 has the inclined surface part 19a which starts the deflection of the split piece 11 and guides it to the maximum deflection, and the flat surface part 19b which maintains the maximum deflection to the engaging part 17 . Furthermore, an inclined surface portion 13 a having a shape corresponding to the inclined surface portion 19 a of the guide portion 19 is formed on the distal end outer peripheral side of the convex portion 13 of the inner joint tube 5 . These structures are the same as those of the conventional mechanical joint 23 described with reference to FIGS. 11 to 14D , and thus description thereof will be omitted. Hereinafter, the characteristic part of this embodiment is demonstrated concretely.

The inner joint tube 5 of this embodiment has the same shape as the previous example except for the split piece 11 . The eight divided pieces 11 of the present embodiment are divided into a plurality of groups satisfying the following conditions (1) and (2). The eight split pieces 11 are configured such that the timings at which the maximum deflection is achieved are shifted in units of the same set of split pieces during the fitting process.

<Conditions> (1) The split pieces belonging to the same group have the same axial position where the maximum deflection occurs in the guide part, and the axial positions are different in each group The condition of (1) is to stagger the timing (period) at which the maximum deflection is achieved in units of divided slices of the same group during the fitting process. (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed The condition of (2) is a condition for completely canceling the stress in the horizontal direction generated by the deflection of the split pieces 11 during the fitting process of the mechanical joint.

As a prerequisite for satisfying these conditions (1) and (2), the number of divisions is four or more. When the number of divisions is 3 or less, one division piece may belong to one group, and in this case, the straight line or polygon of the condition (2) cannot be formed.

In this embodiment, the eight divided pieces 11 of the inner joint tube 5 are divided into two groups of A ₁ to A ₄ and B ₁ to B ₄ as shown in FIG. 2 . According to the condition (1), the axial position of the inclined surface portion 19 a that bends the divided pieces 11 of each group differs among the groups. FIG. 1A is a cross-sectional view of the divided pieces 11 of A ₁ to A ₄ and the guide portion 19 of the portion abutting on the divided pieces 11 of A ₁ to A ₄ . FIG. 1B is a cross-sectional view of the divided pieces 11 of B ₁ to B ₄ and the guide portion 19 of the portion abutting on the divided pieces 11 of B ₁ to B ₄ . 1A and 1B show the initial state of inserting the inner joint tube 5 into the outer joint tube 7 .

As shown in FIG. 1A, the inclined surface 19a on which the divided pieces 11 of _A1 to _A4 contact is formed between _X0 to _X1 , and the position on the top of the inclined surface 19a, which is the position where the deflection reaches the maximum, is X1 _. . Furthermore, as shown in FIG. 1B, the inclined surface 19a on which the segmented pieces 11 of _B1 to _B4 contact is formed between _X1 to _X2 , and the position on the top of the inclined surface 19a as the position where the deflection reaches the maximum is _x2 .

Thereby, in the initial stage of insertion shown in FIG. 1A and FIG. 1B , the split pieces 11 of A ₁ to A ₄ are in the middle of being bent against the inclined surface 19 a, while B ₁ to B . The split piece 11 of ₄ does not abut against the inclined surface 19a, and does not bend.

Next, the states where the inner joint tube 5 is further inserted from the positions shown in FIGS. 1A and 1B are shown in FIGS. 1C and 1D , respectively. As shown in FIG. 1C and FIG. 1D , when the split pieces 11 of A ₁ to A ₄ are in contact with the flat surface 19 b to maintain the maximum deflection state, the split pieces 11 of B ₁ to B ₄ are in contact with the inclined surface. 19a and the halfway state of the deflection.

Thus, in the present embodiment, the axial positions at which the respective split pieces 11 achieve maximum deflection are the same position in the same group, and are different positions in each group. In other words, during the fitting process, the timing at which the maximum deflection is achieved in units of the divided pieces 11 of the same group is shifted.

Moreover, in the present embodiment, as shown in FIG. 2 , among the divided pieces 11 of the same group, if the adjacent divided pieces are connected with the centers in the circumferential direction by a straight line, a quadrangular shape whose center of gravity coincides with the center 21 of the pipe is formed. (In Figure 2, two-dot chain line) (Condition (2)). In addition, in FIG. 2 , the group of divided slices 11 of A ₁ to A ₄ is indicated by a x mark, and the group of divided slices 11 of B ₁ to B ₄ is indicated by a square mark. In addition, the "circumferential center" is assumed to be at the same position in the axial direction in each of the split pieces 11 . When the split pieces 11 of A ₁ to A ₄ are bent, the split pieces 11 of A ₁ and A ₃ and the split pieces 11 of A ₂ and A ₄ arranged at positions facing each other cancel out the stress in the horizontal direction , so there is no overall stress in the horizontal direction. Similarly, when the divided pieces 11 of _B1 to _B4 are bent, the divided pieces 11 of _B1 and _B3 and the divided pieces 11 of _B2 and _B4 arranged at positions facing each other will be horizontally aligned. The stresses are offset, so the overall stress in the horizontal direction is not generated.

Next, the effect of reducing the load of the mechanical joint 1 of the present embodiment configured as above will be described below. First, as a comparative example, a case where the inner joint pipe 5 divided into eight as shown in FIG. 2 is inserted and fitted into the previous outer joint pipe 25 (see FIGS. 14A to 14D ) will be described. As described above, in the conventional outer joint pipe 25 , all the inclined surface portions 19 a against which the eight split pieces 11 abut are formed at the same position in the axial direction (positions X ₀ to X ₁ shown in FIGS. 14A to 14D ). The relationship between the axial displacement and the load required for insertion when the conventional outer joint pipe 25 is inserted and fitted into the inner joint pipe 5 as described above is shown in FIGS. 3A , 3B and 3C .

FIG. 3A shows the load required to deflect the four split pieces 11 corresponding to the positions _A1 to _A4 shown in FIG. 2 in the conventional outer joint pipe 25 and the timing of the deflection. As shown in FIG. 3A , when the split pieces 11 of A ₁ to A ₄ reach the maximum deflection (X ₁ ), the maximum load is required. FIG. 3B shows the load required to deflect the four split pieces 11 corresponding to positions B ₁ to B ₄ shown in FIG. 2 in the conventional outer joint pipe 25 and the sequence of occurrence of deflection. As shown in FIG. 3B , the split pieces 11 of B ₁ to B ₄ reach the maximum deflection at the same timing (X ₁ ) as the split pieces 11 of A ₁ to A ₄ , and require the largest load at this time.

FIG. 3C is a combination of FIG. 3A and FIG. 3B . FIG. 3C shows loads and timings required for bending the eight split pieces 11 when the inner joint pipe 5 is inserted into the outer joint pipe 25 for fitting. As shown in FIG. 3C , when the eight split pieces 11 of A ₁ to A ₄ and B ₁ to B ₄ all reach the maximum deflection (X ₁ ), the necessary load reaches the maximum value. The maximum value of the required load is the sum of the maximum value of the load in FIG. 3A and the maximum value of the load in FIG. 3B .

Next, a case where the inner joint pipe 5 shown in FIG. 2 is inserted and fitted into the outer joint pipe 7 of the present embodiment will be described. In the outer joint pipe 7 of the present embodiment, the inclined surface portions 19a on which the four divided pieces 11 of A1 _{to A4} abut are formed at positions X0 to _X1 shown in FIGS. _1A to 1D , respectively. Furthermore, in the outer joint pipe 7, the inclined surface portions 19a on which the four divided pieces 11 of B ₁ to B ₄ abut are formed at positions X ₁ to X ₂ shown in FIGS. 1A to 1D , respectively. 4A, 4B, and 4C respectively show the relationship between the axial displacement and the load required for insertion when the outer joint tube 7 of this embodiment is inserted into the inner joint tube 5 for fitting.

FIG. 4A shows the load required to deflect the four divided pieces 11 A ₁ to A ₄ and the timing of deflection. As shown in FIG. 4A , the load required to deflect the four split pieces 11 reaches the maximum when the split pieces 11 of A ₁ to A ₄ reach the maximum deflection (X ₁ ). FIG. 4B shows the load required to deflect the four divided pieces 11 of B ₁ to B ₄ and the sequence of occurrence of deflection. As shown in FIG. 4B , the load required to deflect the four split pieces 11 reaches the maximum when the split pieces 11 of B ₁ to B ₄ have the maximum deflection (X ₂ ).

FIG. 4C is a combination of FIG. 4A and FIG. 4B. FIG. 4C shows the loads and timings required to deflect the eight split pieces 11 when the inner joint tube 5 is inserted into the outer joint tube 7 . As shown in FIG. 4C , by staggering the timing of reaching the maximum deflection in units of the segmented pieces 11 of the same group of A ₁ to A ₄ and B ₁ to B ₄ , the timing requiring a large load is distributed to two places. . It can be seen that, thereby, the maximum value of the load required for the insertion of the mechanical connector 1 is approximately half of that in FIG. 3C .

Furthermore, the above-described example is an example in which the eight split pieces 11 are divided into two groups, and the timing of reaching the maximum deflection is staggered between the two groups, but for example, if two facing split pieces 11 By staggering the timing of reaching the maximum deflection in units, the maximum load can be further reduced. That is, four sets of A ₁ and A ₃ , A ₂ and A ₄ , B ₁ and B ₃ , and B ₂ and B ₄ shown in FIG. 2 are set. Furthermore, the position of the inclined surface portion 19a of the outer joint pipe 7 is different in the axial direction so that the timing at which the maximum deflection is achieved is shifted between these four groups. Thereby, it can insert with about 1/4 load compared with FIG. 3C.

In this way, even if the number of divided pieces 11 is the same, the effect of reducing the load varies depending on the number of groups. In terms of construction, it is ideal that the steel pipe 3 arranged above can be inserted and fitted only by its own weight, so it is preferable to set the load in consideration of the number of divisions, the plate thickness of the division piece 11, the weight of the steel pipe 3, etc. Lower the target to determine the number of sets.

Also, in the example described above, the top end of the inner joint pipe 5 is divided into eight, but the number of divisions is not limited thereto. For example, it is generally desirable to set the number of divisions to 4 or more for a small steel pipe with a steel pipe diameter of 400 mm or less, and to set it to 8 or more for a steel pipe with a diameter of more than 400 mm. Therefore, an example in which the tip of the inner joint pipe 5 is divided into four as the minimum number of divisions is shown in FIG. 5 . When there are four divided pieces 11 , as shown in FIG. 5 , A ₁ and A ₂ , and B ₁ and B ₂ facing each other can be respectively set as the same group. In the example of FIG. 5 , the straight line (chain line of two dots in FIG. 5 ) connecting the circumferential centers of the divided pieces 11 of the same group also passes through the center 21 of the tube, thus satisfying the condition (2) of the present invention.

Furthermore, as long as the condition (2) of the present invention is satisfied, the number of divided pieces 11 is not limited to a multiple of 2, but may also be a multiple of 3. For example, the top end of the inner joint pipe 5 may be divided into nine, and three figures formed by connecting the centers of the divided pieces 11 in the circumferential direction with straight lines may be set to form a set of regular triangles. In this case, the centers of gravity of the three equilateral triangles also coincide with the center 21 of the pipe respectively, and thus fall within the applicability of the present invention (not shown).

Furthermore, as described above, the condition (2) of the present invention is that when the inner joint pipe 5 is inserted into the outer joint pipe 7 for fitting, the stress in the horizontal direction accompanying the deflection of the split piece 11 is determined by It is a condition that the stress in the horizontal direction of the other split pieces 11 deflected at the same timing cancels out. When each group satisfies the condition (2) of the present invention, the stress in the horizontal direction is canceled within the group, and the workability during construction is not deteriorated.

On the other hand, an example that does not satisfy the condition (2) is shown in FIG. 6 . In FIG. 6 , eight divided slices 11 are divided into three groups of A ₁ to A ₂ , B ₁ to B ₃ , and C ₁ to C ₃ . In the example shown in FIG. 6 , the straight line connecting the circumferential centers of the divided pieces 11 of _A1 to _A2 (refer to the X mark in FIG. 6 ) does not pass through the center 21 of the tube, so only the centers of _A1 to _A2 The stresses in the horizontal direction do not cancel each other out when the split pieces 11 flex. Similarly, the triangles connecting the centers of the divided pieces 11 of B ₁ to B ₃ (see the □ mark in FIG. 6 ) and the circumferential centers of the divided pieces 11 of C ₁ to C ₃ (see the △ mark in FIG. 6 ) are respectively connected. The center of gravity of the pipe is not consistent with the center 21 of the pipe, so the stress in the horizontal direction is not offset in the same group. In the above-mentioned example, although the load required for insertion and fitting is reduced during construction, it is not preferable because the upper steel pipe 3 hoisted by a crane or the like generates movement in the horizontal direction and deteriorates workability.

As described above, according to the mechanical joint 1 of the present embodiment, all the split pieces 11 are grouped into a plurality of groups, and the position where the split pieces 11 abut to generate the maximum deflection is different in each group, thereby ensuring the maximum flexibility during the fitting process. Since the timing of reaching the maximum deflection is staggered in units of the divided pieces 11 of the same group, the press-fitting load required for fitting can be reduced, and workability can be improved. Furthermore, since the press-fitting load can be reduced without increasing the number of split pieces 11, the processing cost will not increase or the strength will not decrease.

Furthermore, the above-mentioned embodiment is configured such that the split pieces 11 of one group do not start to deflect in the radial direction until the split pieces 11 of one group reach the maximum deflection, but the present invention is not limited thereto. As mentioned above, since the maximum load is required for the maximum deflection of the segmented piece 11, the effect of the present invention can be obtained as long as there is at least a time difference in the timing of maximum deflection. Therefore, what is necessary is just to form so that the position on the top of at least the inclined surface part 19a differs in each group in the axial direction.

(first modified example) In addition, the above-mentioned embodiment has shown an example in which the side to be inserted inside (the inner joint pipe) is divided, but the present invention is not limited thereto, and as a first modification example of the mechanical joint, the side to be placed on the outer side may also be adopted. (outer joint pipe) to divide the structure. In this case, split pieces capable of bending in the radial direction are formed at equal intervals in the circumferential direction on the outer joint pipe, and guide portions are formed on the inner peripheral surface of the split pieces. Furthermore, in the inner joint tube, a convex portion is formed on the outer peripheral surface of a cylindrical member having a smaller diameter than the proximal portion, which is provided on the distal side of the proximal portion. In the above case, it is only necessary to group the split pieces into a plurality of groups satisfying the following conditions (1) and (2), and make the guide portion formed on the inner peripheral surface of the split pieces that produces the largest deflection The axial positions are different in each group, so that the timing of reaching the maximum deflection can be staggered in the unit of the same group of divided pieces during the mating process, and the same effect as the above-mentioned embodiment can be obtained. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

(Second modified example) Hereinafter, a second modified example of the mechanical joint will be described based on FIGS. 7 , 8 , 9A, 9B, 9C, and 9D. As shown in FIG. 7 , the mechanical joint 2 according to the second modification includes an inner joint pipe 5A and an outer joint pipe 7A, which are respectively provided at the ends of the steel pipes 3 to be joined. The inner joint pipe 5A and the outer joint pipe 7A are disposed vertically facing each other. In the state shown in FIG. 7 , an axial load is applied to the outer joint pipe 7A arranged above, and the outer joint pipe 7A is externally fitted into the inner joint pipe 5A. Thereby, as shown in FIG. 8 , the outer joint pipe 7A and the inner joint pipe 5A are fitted to join the upper and lower steel pipes 3 .

The outer joint pipe 7A has a base end portion 9A joined to the steel pipe 3 by welding, and on the distal end side of the base end portion 9A, a split piece 11A formed by forming a slit extending in the axial direction in a cylindrical member is provided. In the mechanical joint 2 shown in FIG. 7 , the top end of the outer joint pipe 7A is divided into eight, for example, and eight divided pieces 11A having an arc-shaped cross section are arranged at equal intervals in the circumferential direction. The split piece 11A is deflectable in the radial direction, and a convex portion 13A protruding inward is formed on the inner peripheral surface of the tip portion.

The outer diameter of the inner joint tube 5A is larger than the inner diameter of the portion of the outer joint tube 7A where the convex portion 13A is formed, and a concave portion 15A is formed on the proximal end side of the outer peripheral surface of the inner joint tube 5A. In the middle of fitting the outer joint pipe 7A with the inner joint pipe 5A, the outer peripheral surface of the inner joint pipe 5A presses into contact with the convex portion 13 of the outer joint pipe 7A, whereby the split piece 11A of the outer joint pipe 7A moves outward in the radial direction. flex. In the insertion-completed state, the deflection of the split piece 11A is restored, and the convex portion 13A of the outer joint tube 7A enters the concave portion 15A of the inner joint tube 5A to complete the fitting.

Each divided piece 11A in the second modified example is divided into a plurality of groups satisfying the condition (1) and the condition (2) as in the first embodiment. The eight divided pieces 11A are configured so that the timing at which the maximum deflection is achieved in units of the same group of divided pieces is shifted during the fitting process. Also in the second modified example, the number of divisions is 4 or more as a prerequisite for satisfying conditions (1) and (2). Moreover, the method of dividing each divided piece 11A into a plurality of groups is also the same as in the first embodiment.

That is, in the second modified example, the eight divided pieces 11A of the inner joint tube 5A are divided into two groups of A ₁ to A ₄ and B ₁ to B ₄ as in FIG. 2 . According to the condition (1), the axial position of the inclined surface portion 19 a that bends the divided pieces 11A of each group differs among the groups. FIG. 9A is a cross-sectional view of the divided pieces 11A of A ₁ to A ₄ and the guide portion 19A of the portion abutting on the divided pieces 11A of A ₁ to A ₄ . On the outer peripheral surface of the inner joint pipe 5A, an engaging portion 17A is provided. The engaging portion 17A engages with the convex portion 13A in a state where the outer joint pipe 7A and the inner joint pipe 5A are fitted together, and together with the convex portion 13A. against tensile loads. FIG. 9B is a cross-sectional view of the divided pieces 11A of B ₁ to B ₄ and the guide portion 19A of the portion abutting on the divided pieces 11A of B ₁ to B ₄ . 9A and 9B show an initial state in which the outer joint tube 7A is fitted to the inner joint tube 5A. FIG. 9A and FIG. 9B are diagrams corresponding to the above-mentioned FIG. 1A and FIG. 1B , respectively.

As shown in FIG. 9A , the inclined surface 19a on which the divided pieces 11A of _A1 to _A4 contact is formed between _X0 to _X1 , and the position on the top of the inclined surface 19a, which is the position where the deflection reaches the maximum, is _X1. . Furthermore, as shown in FIG. 9B , the inclined surface 19a on which the divided pieces 11A of _B1 to _B4 contact is formed between _X1 to _X2 , and the position on the top of the inclined surface 19a as the position where the deflection reaches the maximum is _x2 .

Thereby, in the initial stage of the fitting shown in FIG. 9A and FIG. 9B , the divided pieces 11A of A ₁ to A ₄ are in the middle of being bent against the inclined surface portion 19 a, while B ₁ to A 4 are in the middle of being bent. The split piece 11A of _B4 does not abut against the inclined surface 19a and does not bend.

Next, the states where the outer joint pipe 7A is further pushed in from the positions shown in FIGS. 9A and 9B are shown in FIGS. 9C and 9D , respectively. FIG. 9C shows a state where the outer joint pipe 7A is pushed in from the position shown in FIG. 9A . FIG. 9D shows a state where the outer joint pipe 7A is pushed in from the position shown in FIG. 9B . That is, FIG. 9C and FIG. 9D are diagrams corresponding to the aforementioned FIG. 1C and FIG. 1D , respectively. 9A to 9D are the same as those of the mechanical joint of the present invention described above with respect to FIGS. 1A to 1D .

As shown in FIG. 9C and FIG. 9D , when the split pieces 11A of A ₁ to A ₄ are in contact with the flat surface 19 b to maintain the maximum deflection state, the split pieces 11A of B ₁ to B ₄ are in contact with the inclined surface. 19a and the halfway state of the deflection. In this way, also in the second modified example, the axial positions at which the respective split pieces 11A reach the maximum deflection are the same position in the same group, and are different positions in each group. In other words, during the fitting process, the timing at which the maximum deflection is achieved in units of the same group of divided pieces 11A is staggered. When the outer joint tube 7A is further pushed in, the convex portion 13A engages with the concave portion 15A to complete the joining (the axial position of the convex portion 13A at this time is defined as X ₃ ). Other structures are the same as in the first embodiment.

(third modified example) Next, a third modified example will be described. That is, in the example shown in FIGS. 1A to 1D , both the convex portion 13 of the inner joint tube 5 and the guide portion 19 of the outer joint tube 7 have the inclined surface 13a and the inclined surface 19a, but they may be formed only on the convex portion. One of 13 and the guide portion 19 is formed with an inclined surface. If an inclined surface is formed on any one of the convex portion 13 and the guide portion 19 , the split piece 11 can be bent by a press-fitting load inserted into the inner joint tube 5 . Therefore, as another aspect of the mechanical joint 1 shown in FIGS. 1A to 1D , an example in which the inclined surface 13 a is formed on the convex portion 13 and the inclined surface 19 a is not formed on the guide portion 19 is shown in FIGS. 10A to 10D . .

Fig. 10A is a cross-sectional view of the split pieces 11 of _A1 to _A4 and the guide part 19 of the portion abutted with the split pieces 11 of _A1 to _A4 , and Fig. 10B is a cross-sectional view of the split pieces 11 of _B1 to _B4 and their contact with the split pieces 11 of A1 to A4. B ₁ to B ₄ are cross-sectional views of the guide portion 19 at the portion where the split pieces 11 abut. 10A and 10B show the initial state of inserting the inner joint tube 5 into the outer joint tube 7 . 10C and 10D respectively show the state where the inner joint tube 5 is further inserted from the positions in FIGS. 10A and 10B .

As shown in FIGS. 10A to 10D , when the guide portion 19 is not formed with an inclined surface portion 19 a, the inclined surface portion 13 a of the convex portion 13 and the tip-side corner portion of the guide portion 19 (the tip-side end of the flat surface portion 19 b ) part) press contact, whereby the split piece 11 flexes toward the inner side of the radius.

In the case of this example, the position where the split pieces 11 of A ₁ to A ₄ contact the guide portion 19 and the positions where the split pieces 11 of B ₁ to B ₄ contact the guide portion 19 are different in the axial direction. , so that the timing of reaching the maximum deflection can be staggered in units of the same group of split pieces. The above example is an example in which the inclined surface 13 a is formed on the convex part 13 and the inclined surface 19 a is not formed on the guide part 19 , but the inclined surface 19 a is formed on the guide part 19 and the inclined surface 13 a is not formed on the convex part 13 The situation is the same.

Originally, the fitting load differs depending on the axial length of the inclined surface (specifically, when the axial length of the inclined surface is long, the fitting load becomes smaller), so only the convex portion 13 and the guide portion 19 When one of them forms an inclined surface, if the inclined surface is provided on the side of the guide part 19, the axial length of the inclined surface can be ensured to be reasonable.

Moreover, the guide part 19 of the outer joint pipe 7 (the gray part in FIGS. 1A to 1D ) can be integrated with the outer joint pipe 7 , or can be manufactured in the form of other components and installed on the inner peripheral surface of the outer joint pipe 7 . For example, the engaging portion 17 of the outer joint pipe 7 is a part that resists a tensile load together with the convex portion 13 of the inner joint pipe 5 during fitting, and thus requires high durability, but the guide portion 19 is only used when inserted. Squeeze load acts, but load does not act during fitting, so strong durability is not required. Therefore, the guide part 19 can also be manufactured in the form of another member with the strength of an ordinary steel material, and can be attached to the inner peripheral surface of the outer joint pipe 7 by screws or welding, etc., and the screws or welding can also be minimal at this time .

Moreover, when installing the guide part 19 in the form of other components, the guide part 19 can also be brought into contact with the engaging part 17 as shown in FIGS. There may also be gaps as shown in FIGS. 1A to 1D until the joining portion 17 is reached.

In the above-mentioned embodiment, the mechanical joint attached to the end of the steel pipe has been described, but the outer joint pipe and/or the inner joint pipe in the mechanical joint can also be welded in advance in a factory or the like. Installed on the end of steel pipes to manufacture steel pipes with joints. That is, the jointed steel pipe includes the inner joint pipe and/or the outer joint pipe in the mechanical joint described in the embodiment at both ends or one end.

In addition, by connecting a plurality of jointed steel pipes at a construction site or the like, structures such as steel pipe piles, steel pipe sheet piles, steel pipe sheet pile walls, steel pipe columns, and steel pipe beams formed by connecting steel pipe sheet piles can be formed. That is, these structures include the mechanical joint described in the above embodiment, and a plurality of steel pipes joined via the mechanical joint.

When constructing these structures, it is only necessary to connect the mechanical joint of the other jointed steel pipe to the one of the jointed steel pipes while restricting one of the jointed steel pipes to be joined. The mechanical connector is aligned, inserted and mated. For example, when the structural body is a steel pipe pile or the like, any one of the steel pipe with the outer joint pipe attached to the end and the steel pipe with the inner joint pipe attached to the end is erected in the ground. In this state, the other steel pipe is placed on one of the steel pipes by hoisting by a crane or the like, the inner joint pipe is inserted into the outer joint pipe, and the inner joint pipe and the outer joint pipe are fitted and joined.

In addition, the mechanical joint of the present invention reduces the load required for insertion and offsets the horizontal stress during insertion, so there is no need to restrict the horizontal movement of the upper steel pipe suspended by the crane during construction.

Furthermore, in the description above, a mechanical joint as an article has been described, but this mechanical joint is designed by the following design method. That is, the mechanical joint design method designs a mechanical joint including an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, the inner joint pipe and the outer joint pipe Any one of them includes divided pieces that are equally spaced in the circumferential direction and can be flexibly radially divided, and the mechanical joint includes: a convex portion formed on the outer peripheral surface of the inner joint pipe; an engaging portion, formed on the inner peripheral surface of the outer joint pipe, engages with the convex portion in a state where the inner joint pipe and the outer joint pipe are fitted together, and resists a tensile load together with the convex portion; and a guide part provided on the distal end side of the outer joint tube than the engaging part, abutting against the convex part in the middle of fitting the inner joint tube and the outer joint tube, and The protrusions cooperate to deflect the split pieces and maintain the deflected state until the engaging portion, and in the design method of the mechanical joint, the split pieces are grouped to satisfy the following Multiple groups of conditions (1) and (2) mentioned above, during the fitting process, the timing of reaching the maximum deflection is staggered in units of the same group of split pieces, and the horizontal direction caused by the deflection of the split pieces is staggered. stress offset. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

Furthermore, another mechanical joint is designed by the following design method. That is, the mechanical joint design method designs a mechanical joint including an inner joint pipe and an outer joint pipe respectively provided at ends of steel pipes to be joined, the inner joint pipe and the outer joint pipe Any one of them includes divided pieces that are equally spaced in the circumferential direction and can be flexibly radially divided, and the mechanical joint includes: a convex portion formed on the inner peripheral surface of the outer joint pipe; an engaging portion , formed on the outer peripheral surface of the inner joint pipe, engaged with the convex portion in the state where the outer joint pipe and the inner joint pipe are fitted together, resisting a tensile load together with the convex portion; and a guide part provided on the distal end side of the inner joint tube than the engaging part, abutting against the convex part in the middle of fitting the outer joint tube and the inner joint tube, and The protrusions cooperate to deflect the split pieces and maintain the deflected state until the engaging portion, and in the design method of the mechanical joint, the split pieces are grouped to satisfy the following Multiple groups of conditions (1) and (2) mentioned above, during the fitting process, the timing of reaching the maximum deflection is staggered in units of the same group of split pieces, and the horizontal direction caused by the deflection of the split pieces is staggered. stress offset. (1) The split pieces belonging to the same group have the same axial position at which the maximum deflection occurs in the guide portion, and the axial positions are different in each group (2) For the divided pieces belonging to the same group, if the adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed

The embodiments of the present invention have been specifically described above, but the present invention is not limited to the above-described embodiments, and various modifications based on the technical idea of the present invention, or combinations of mutual embodiments or modified examples can be employed. For example, in the second modified example, the guide portion 19A or the concave portion 15A may be provided on the inner peripheral surface of the outer joint pipe 7A, and the convex portion 13A may be provided on the outer peripheral surface of the inner joint pipe 5A. [industrial availability]

The present invention is suitable for joining steel pipes, and is preferable.

1, 2, 23: Mechanical joint 3: Steel pipe 5, 5A: Inner joint tube 7, 7A, 25: Outer joint tube 9, 9A: Base end 11, 11A, A ₁ to A ₄ , B ₁ to B ₄ , C ₁ to C ₃ : split piece 13, 13A: convex portion 13a, 19a: inclined surface 15, 15A: concave portion 17, 17A: engagement portion 19, 19A: guide portion 19b: flat surface 21: center X of tube ₀ ~ X ₃ : Axial position

FIG. 1A is a diagram showing a mechanical joint according to an embodiment of the present invention, and is a diagram schematically showing how the split pieces are bent during joining. FIG. 1B is a diagram showing a mechanical joint according to an embodiment of the present invention, and is a diagram schematically showing how the split pieces are bent during joining. FIG. 1C is a diagram showing a mechanical joint according to an embodiment of the present invention, and is a diagram schematically showing how the split pieces are bent during joining. FIG. 1D is a diagram showing a mechanical joint according to an embodiment of the present invention, and is a diagram schematically showing how the split pieces are bent during joining. FIG. 2 is a diagram showing an example of grouping eight divided slices so as to satisfy the conditions of the present invention. FIG. 3A is a diagram for explaining a press-fitting load when a conventional mechanical joint is used as a comparative example. FIG. 3B is a diagram for explaining a press-fitting load when a conventional mechanical joint is used as a comparative example. FIG. 3C is a diagram for explaining a press-fitting load when a conventional mechanical joint is used as a comparative example. Fig. 4A is a diagram for explaining the press-fitting load of the mechanical joint according to the embodiment of the present invention. Fig. 4B is a diagram for explaining the press-fitting load of the mechanical joint according to the embodiment of the present invention. FIG. 4C is a diagram for explaining the press-fitting load of the mechanical joint according to the embodiment of the present invention. FIG. 5 is a diagram showing an example of grouping four divided slices so as to satisfy the conditions of the present invention. FIG. 6 is a diagram showing an example of grouping eight divided slices so as not to satisfy the conditions of the present invention. Fig. 7 is a schematic view showing a state before fitting of a mechanical joint according to a modified example of the embodiment of the present invention. Fig. 8 is a schematic view showing a state after fitting of a mechanical joint according to a modified example of the embodiment of the present invention. FIG. 9A is a diagram for explaining a joining process of a mechanical joint according to another aspect. FIG. 9B is a diagram for explaining a joining process of a mechanical joint according to another aspect. FIG. 9C is a diagram for explaining a joining process of a mechanical joint according to another aspect. FIG. 9D is a diagram for explaining a joining process of a mechanical joint according to another aspect. FIG. 10A is a view showing another aspect of the mechanical joint of FIG. 1A , and is a view schematically showing how the split pieces are bent during joining. FIG. 10B is a view showing another aspect of the mechanical joint of FIG. 1B , and is a view schematically showing how the split pieces are bent during joining. FIG. 10C is a view showing another aspect of the mechanical joint of FIG. 1C , and is a view schematically showing how the split pieces are bent during joining. FIG. 10D is a view showing another aspect of the mechanical joint of FIG. 1D , and is a view schematically showing how the split pieces bend during joining. Fig. 11 is a schematic view showing a conventional mechanical joint, and is a view showing a state before fitting. Fig. 12 is a view showing a state of the mechanical joint of Fig. 11 after fitting. Fig. 13 is a view of arrow A-A of Fig. 11 . Fig. 14A is a diagram for explaining a joining process of a conventional mechanical joint. FIG. 14B is a diagram for explaining a joining process of a conventional mechanical joint. FIG. 14C is a diagram for explaining a joining process of a conventional mechanical joint. FIG. 14D is a diagram for explaining a joining process of a conventional mechanical joint. Fig. 15 is a graph showing the relationship between axial displacement and load of one split piece during the joining process shown in Figs. 14A to 14D.

1: Mechanical connector

5: Inner joint pipe

7: Outer joint pipe

9: base end

11. A ₁ ~A ₄ , B ₁ ~B ₄ : split slice

13: convex part

13a, 19b: inclined face

15: Concave

17:Catching part

19: Guide Department

19a: Tilt the face

X ₀ ~X ₃ : Axial position

Claims (9)

A mechanical joint comprising: The inner joint pipe and the outer joint pipe are respectively provided at the ends of the steel pipes to be joined, Either one of the inner joint pipe and the outer joint pipe includes divided pieces that are divided at equal intervals in the circumferential direction and that are radially deflectable, and The mechanical joints include: a convex portion formed on an outer peripheral surface of the inner joint pipe; The engaging part is formed on the inner peripheral surface of the outer joint pipe, and engages with the convex part in a state where the inner joint pipe and the outer joint pipe are fitted together, and opposes the convex part together. tensile load; and The guide part is provided on the distal end side of the outer joint tube than the engaging part, and abuts against the convex part during the fitting of the inner joint tube and the outer joint tube, and is in contact with the outer joint tube. cooperate with the convex part to bend the split piece, and maintain the bent state until the engaging part, and The split pieces are grouped into a plurality of groups satisfying the following conditions (1) and (2), and are configured to stagger the timing of reaching the maximum deflection in units of the same group of split pieces during the fitting process; (1) The split pieces belonging to the same group have the same axial position where the maximum deflection occurs in the guide part, and the axial positions are different in each group; (2) As for the divided pieces belonging to the same group, if adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed. A mechanical joint comprising: The inner joint pipe and the outer joint pipe are respectively provided at the ends of the steel pipes to be joined, Either one of the inner joint pipe and the outer joint pipe includes divided pieces that are divided at equal intervals in the circumferential direction and that are radially deflectable, and The mechanical joints include: a convex portion formed on the inner peripheral surface of the outer joint pipe; The engaging portion is formed on the outer peripheral surface of the inner joint pipe, engages with the convex portion in a state where the outer joint pipe and the inner joint pipe are fitted together, and resists tension together with the convex portion. tensile load; and The guide part is provided on the distal end side of the inner joint tube than the engaging part, and abuts on the convex part during the fitting of the outer joint tube and the inner joint tube, and is in contact with the inner joint tube. cooperate with the convex part to bend the split piece, and maintain the bent state until the engaging part, and The split pieces are grouped into a plurality of groups satisfying the following conditions (1) and (2), and are configured to stagger the timing of reaching the maximum deflection in units of the same group of split pieces during the fitting process; (1) The split pieces belonging to the same group have the same axial position where the maximum deflection occurs in the guide part, and the axial positions are different in each group; (2) As for the divided pieces belonging to the same group, if adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed. The mechanical joint according to claim 1 or claim 2, wherein the split pieces of one set do not start radial deflection until the split pieces of one set reach a maximum deflection. A steel pipe with joints, comprising the inner joint pipe and/or the outer joint pipe in the mechanical joint described in any one of claim 1 to claim 3 at both ends or at one end. A method for manufacturing a steel pipe with a joint, manufacturing the steel pipe with a joint as described in claim 4, and The outer joint pipe and/or the inner joint pipe in the mechanical joint according to any one of claim 1 to claim 3 are respectively attached to the ends of the steel pipes to be joined. A structure comprising: The mechanical joint according to any one of claim 1 to claim 3; and A plurality of steel pipes are joined by the mechanical joint. A method for constructing a structure, comprising constructing the structure described in Claim 6, and Either one of the steel pipe to which the outer joint pipe is attached at the end and the steel pipe to which the inner joint pipe is attached to the end is erected in the ground, and the other steel pipe is disposed therein in this state. The inner joint pipe and the outer joint pipe are fitted and joined to one of the steel pipes. A method for designing a mechanical joint, designing a mechanical joint, the mechanical joint comprising: The inner joint pipe and the outer joint pipe are respectively provided at the ends of the steel pipes to be joined, Either one of the inner joint pipe and the outer joint pipe includes division pieces that are divided at equal intervals in the circumferential direction and are capable of radial deflection, and The mechanical joints include: a convex portion formed on an outer peripheral surface of the inner joint pipe; The engaging part is formed on the inner peripheral surface of the outer joint pipe, and engages with the convex part in a state where the inner joint pipe and the outer joint pipe are fitted together, and opposes the convex part together. tensile load; and The guide part is provided on the distal end side of the outer joint tube than the engaging part, and abuts against the convex part during the fitting of the inner joint tube and the outer joint tube, and is in contact with the outer joint tube. The convex part cooperates to deflect the split piece and maintain the deflected state until the engaging part, and in the design method of the mechanical joint, Group the segmented pieces into multiple groups that meet the following conditions (1) and (2), and in the fitting process, use the same group of segmented pieces as a unit to stagger the timing of reaching the maximum deflection, and the The stress offset in the horizontal direction caused by the deflection of the sheet; (1) The split pieces belonging to the same group have the same axial position where the maximum deflection occurs in the guide part, and the axial positions are different in each group; (2) As for the divided pieces belonging to the same group, if adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed. A method for designing a mechanical joint, designing a mechanical joint, the mechanical joint comprising: The inner joint pipe and the outer joint pipe are respectively provided at the ends of the steel pipes to be joined, Either one of the inner joint pipe and the outer joint pipe includes divided pieces that are divided at equal intervals in the circumferential direction and that are radially deflectable, and The mechanical joints include: a convex portion formed on the inner peripheral surface of the outer joint pipe; The engaging portion is formed on the outer peripheral surface of the inner joint pipe, engages with the convex portion in a state where the outer joint pipe and the inner joint pipe are fitted together, and resists tension together with the convex portion. tensile load; and The guide part is provided on the distal end side of the inner joint tube than the engaging part, and abuts on the convex part during the fitting of the outer joint tube and the inner joint tube, and is in contact with the inner joint tube. The convex part cooperates to deflect the split piece and maintain the deflected state until the engaging part, and in the design method of the mechanical joint, Group the segmented pieces into multiple groups that meet the following conditions (1) and (2), and in the fitting process, use the same group of segmented pieces as a unit to stagger the timing of reaching the maximum deflection, and the The stress offset in the horizontal direction caused by the deflection of the sheet; (1) The split pieces belonging to the same group have the same axial position where the maximum deflection occurs in the guide part, and the axial positions are different in each group; (2) As for the divided pieces belonging to the same group, if adjacent divided pieces are connected to the centers in the circumferential direction by a straight line, a straight line passing through the center of the tube or a polygon whose center of gravity coincides with the center of the tube is formed.

Images