coupler

Abstract

This invention provides a coupler that enables the construction of pavement surfaces with varying gradients in a two-way continuous reinforced concrete pavement. [Solution] A coupler (10) having a main body having a first surface (10a) and a second surface (10b), a first screw hole (12a) formed in the first axial direction (AX1) from the first surface (10a), and a second screw hole (12b) formed in the second axial direction (AX2) from the second surface (10b), wherein the first axial direction (AX1) and the second axial direction (AX2) intersect at a predetermined angle.

Description

Technical Field

[0001] The present invention relates to a coupler.

Background Art

[0002] In the technical field of heat-resistant concrete pavement for airports, a two-way continuously reinforced concrete pavement (CRCP: Continuously Reinforced Concrete Pavement) in which concrete slabs are provided with longitudinal reinforcing bars and transverse reinforcing bars is known. In two-way CRCP, by using PC steel bar reinforcements in a helix shape to suppress the sudden expansion of the concrete slab due to the high-temperature exhaust of aircraft, the occurrence of damage to the concrete slab is suppressed.

[0003] In two-way CRCP, it is necessary to connect PC steel bars in a helix shape using a coupler when connecting them. (See, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in two-way CRCP, as described above, since a plurality of PC steel bars in a helix shape are connected with a coupler and used as a substantially single PC steel bar, it is possible to construct a pavement surface with a constant gradient in the transverse direction. However, in the case of a pavement surface with a gradient that changes in both directions or two-dimensionally in the transverse direction, there is a problem that PC steel bars cannot be constructed with ordinary couplers.

[0006] Therefore, the present invention has been made in view of the above-mentioned conventional problems, and aims to provide a coupler that can connect PC steel bars in accordance with the road surface gradient when constructing a pavement surface with a changing gradient in a two-way continuous reinforced concrete structure. [Means for solving the problem]

[0007] To solve the above problems, the coupler of the present invention has a main body having a first surface and a second surface, a first screw hole formed in the first axial direction from the first surface, and a second screw hole formed in the second axial direction from the second surface, wherein the first axial direction and the second axial direction intersect at a predetermined angle.

[0008] In this type of coupler according to the present invention, the first axial direction and the second axial direction intersect at a predetermined angle in the first and second screw holes formed in the main body. This allows the PC steel bars connected to the first and second surfaces to be tilted, making it possible to construct a pavement surface with a changing gradient in a two-way continuous reinforced concrete pavement.

[0009] Furthermore, in one aspect of the present invention, the main body has a symmetrical shape on the first surface and the second surface, and the first screw hole and the second screw hole are symmetrically provided within the main body.

[0010] Furthermore, in one aspect of the present invention, the main body is cylindrical in shape with respect to the central axis of the main body, and the first axial direction and the second axial direction intersect with respect to the central axis of the main body at the same angle of inclination.

[0011] Furthermore, in one aspect of the present invention, the main body has a first cylindrical portion on the first surface side and a second cylindrical portion on the second surface side, the first axial direction coincides with the central axis of the first cylindrical portion, and the second axial direction coincides with the central axis of the second cylindrical portion.

[0012] Furthermore, in one aspect of the present invention, a communicating cavity is provided between the first screw hole and the second screw hole, and the first screw hole and the second screw hole are formed to communicate with each other.

[0013] Also, in one aspect of the present invention, a grout injection port that reaches the communication cavity from the outer periphery is formed in the main body portion.

[0014] Also, in one aspect of the present invention, a central partition wall portion is provided between the first screw hole and the second screw hole, and the first screw hole and the second screw hole are separately formed.

[0015] Also, in one aspect of the present invention, the predetermined angle ranges from 0.5 degrees to 6 degrees.

Advantages of the Invention

[0016] In the present invention, it is possible to provide a coupler capable of constructing a pavement surface with a changing gradient in two-way continuous reinforced concrete.

Brief Description of the Drawings

[0017] [Figure 1] It is a schematic diagram for explaining an example of a construction method of continuous reinforced concrete pavement using the coupler 10. [Figure 2] It is a schematic diagram showing the structure of the coupler 10 according to the first embodiment. [Figure 3] It is a schematic perspective view showing a state where the PC steel bars 20a and 20b are connected using the coupler 10. [Figure 4] It is a schematic diagram showing the structure of the coupler 10 according to the second embodiment. [Figure 5] It is a schematic diagram showing the structure of the coupler 10 according to the third embodiment. [Figure 6] It is a schematic diagram showing the structure of the coupler 10 according to the fourth embodiment. [Figure 7] It is a schematic diagram showing the structure of the coupler 10 according to the fifth embodiment.

Modes for Carrying Out the Invention

[0018] (First Embodiment) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant explanations will be omitted as appropriate. FIG. 1 is a schematic diagram for explaining an example of a construction method of a continuously reinforced concrete pavement using a coupler 10. In the construction method of the continuously reinforced concrete pavement of the present invention, PC steel bars 20a, 20b, 20c, 20d are connected by a plurality of couplers 10, 30, and a concrete layer 100 is placed on a roadbed 200. In FIG. 1, the structure for holding the PC steel bars 20a, 20b, 20c, 20d at a predetermined value by the couplers 10, 30 is not shown.

[0019] The coupler 10 is a member that is arranged at the ridge line position or valley line position of a pavement surface where the gradient changes, and connects the PC steel bars 20a, 20b at an inclination angle corresponding to the gradients on both sides. In FIG. 1, an example in which the coupler 10 itself is bent at an angle corresponding to the gradient is shown, but the shape is not limited and may be a straight pipe shape, or may have other polyhedrons or curved surfaces. Details of the specific structure of the coupler 10 and the connection of the PC steel bars 20a, 20b will be described later.

[0020] The PC steel bars 20a, 20b, 20c, 20d are metal rod-shaped members that are inserted into the couplers 10, 30 and arranged along the gradients on the pavement surfaces of both gradients. Further, the PC steel bars 20a, 20b, 20c, 20d are PC steel bars of a general threaded shape, and screw grooves for connecting to the couplers 10, 30 are formed at both ends. The materials and dimensions constituting the PC steel bars 20a, 20b are not limited, and conventionally known PC steel bars for two-way CRCP can be used.

[0021] The coupler 30 is a member that is arranged on the gradient surface of the pavement surface and linearly connects the PC steel bar 20a and the PC steel bar 20c, and the PC steel bar 20b and the PC steel bar 20d, respectively. The specific structure and size of the coupler 30 are not limited, and conventionally known ones for two-way CRCP can be used. In FIG. 1, an example in which one coupler 30 is provided on one side is shown, but it is also possible to connect and extend the PC steel bars 20c, 20d using a larger number of couplers 30.

[0022] The concrete layer 100 is a layer made of concrete material poured onto the roadbed 200. The surface of the concrete layer 100 has a double slope, sloping from the ridge line toward both sides. As described above, PC steel bars 20a, 20b, 20c, and 20d are connected to the concrete layer 100 with couplers 10 and 30, and after construction, the concrete layer 100 is restrained by the PC steel bars 20a, 20b, 20c, and 20d.

[0023] The roadbed 200 is a layer located above the subgrade (not shown) and below the concrete layer 100. The upper surface of the roadbed 200 has a double slope, sloping in both directions from the ridge line. In Figure 1, the roadbed 200 is shown as a single layer, but a conventionally known laminated structure of a lower roadbed and an upper roadbed can be used.

[0024] Figure 2 is a schematic diagram showing the structure of the coupler 10 according to this embodiment. The left side of Figure 2 shows a cross-sectional view along the longitudinal direction, and the right side of Figure 2 shows a side view from the end. As shown in Figure 2, the coupler 10 has a main body 11, a first surface 10a, a second surface 10b, a first screw hole 12a, a second screw hole 12b, screw grooves 13a, 13b, and a communication cavity 14.

[0025] The main body 11 constitutes the outer shape of the coupler 10 and is the part on which the various components are provided. One side of the main body 11 is provided with a first surface 10a, and the other side is provided with a second surface 10b. Figure 2 shows an example of a hexagonal prism-shaped cylindrical body 11 with length L and width W, extending along the central axis AX of the main body. For example, the length L can range from 100 mm to 150 mm, and the width W can range from 40 mm to 60 mm. In addition, a first screw hole 12a and a second screw hole 12b are provided extending from the first surface 10a and the second surface 10b toward the center of the main body 11, respectively. In the center of the main body 11, a communication cavity 14 is formed between the first screw hole 12a and the second screw hole 12b.

[0026] Figure 2 shows an example of a hexagonal prism-shaped straight tube as the main body 11, but the shape of the main body 11 is not limited and may be cylindrical, dodecagonal prism, etc. However, since the PC steel bars 20a and 20b are screwed into the first screw hole 12a and the second screw hole 12b and tensile force is applied, it is preferable that the main body 11 has a symmetrical shape on the first surface 10a side (left in the figure) and the second surface 10b side (right in the figure) so that the force is applied symmetrically to each part. Furthermore, in order to achieve miniaturization and weight reduction while realizing the function of connecting the PC steel bars 20a and 20b with the first screw hole 12a and the second screw hole 12b, it is preferable that it has a tube shape along the longitudinal direction. The material constituting the main body 11 is not limited, but it is preferable to use the same material as the PC steel bars 20a, 20b, 20c, and 20d.

[0027] The first surface 10a is a surface provided at one end of the main body 11, and a first screw hole 12a is formed facing inward towards the main body 11. The second surface 10b is a surface provided at the other end of the main body 11, and a second screw hole 12b is formed facing inward towards the main body 11. In Figure 1, the first surface 10a and the second surface 10b are shown as flat surfaces, but they may also be curved surfaces as long as the first screw hole 12a and the second screw hole 12b are provided. Also, in Figure 1, the first surface 10a and the second surface 10b are shown as examples of mutually parallel surfaces provided perpendicular to the main body central axis AX of the main body 11, but they may also be inclined with respect to the main body central axis AX.

[0028] The first screw hole 12a is a hole with a diameter D formed from the first surface 10a along the direction of the first axis AX1. The second screw hole 12b is a hole with a diameter D formed from the second surface 10b along the direction of the second axis AX2. The diameter D corresponds to the diameter of the PC steel bars 20a and 20b, and as an example, the diameter D is in the range of 9 mm to 40 mm.

[0029] Screw grooves 13a and 13b are formed on the inner circumference of the first screw hole 12a and the second screw hole 12b, respectively, extending from the first surface 10a and the second surface 10b in lengths L1 and L2, respectively. For example, lengths L1 and L2 can range from 60 mm to 65 mm. A connecting cavity 14 is provided between the first screw hole 12a and the second screw hole 12b, and the first screw hole 12a, the connecting cavity 14, and the second screw hole 12b are in communication from the first surface 10a to the second surface 10b. Figure 2 shows an example in which the first screw hole 12a and the second screw hole 12b are symmetrically arranged inside the main body 11, but they may also be arranged asymmetrically.

[0030] As shown in Figure 2, the first axis AX1 and the second axis AX2, which are the central axes of the first screw hole 12a and the second screw hole 12b, are inclined at angles θ1 and θ2, respectively, with respect to the main body central axis AX. Therefore, the direction of the first axis AX1 and the direction of the second axis AX2 intersect at a predetermined angle (θ1 + θ2). Figure 2 shows an example in which the first axis AX and the second axis AX2 intersect the main body central axis AX at the positions of the first surface 10a and the second surface 10b, respectively, but the position of intersection is not limited. For example, they may intersect at the center in the longitudinal direction of the main body central axis AX, or they may intersect midway along the lengths L1 and L2 of the first axis AX1 and the second axis AX2.

[0031] Figure 2 shows an example where the first axis AX1 and the second axis AX2 intersect at the same angle with respect to the main body's central axis AX, but the angles θ1 and θ2 may be different. Since one of the gradients in the two-directional CRCP with both gradients is between 0.5% and 5%, it is preferable that the angles θ1 and θ2 are in the range of 0.25 degrees to 3 degrees, corresponding to the gradients. Therefore, it is preferable that the range of the predetermined angle (θ1 + θ2) is between 0.5 degrees and 6 degrees.

[0032] The screw grooves 13a and 13b are helical grooves of lengths L1 and L2 provided on the inner circumference of the first screw hole 12a and the second screw hole 12b. The screw grooves 13a and 13b have groove depths and pitches corresponding to the screw grooves provided in the PC steel bars 20a and 20b, and one end of the PC steel bars 20a and 20b is inserted and screwed into them. The lengths L1 and L2 that form the screw grooves 13a and 13b are not limited, but it is preferable to have L1 and L2 be the same length and to provide the first screw hole 12a and the second screw hole 12b in a symmetrical shape.

[0033] The communicating cavity 14 is a space of length L3 provided between the first screw hole 12a and the second screw hole 12b. In this embodiment, the communicating cavity 14 makes the first screw hole 12a and the second screw hole 12b a single continuous space. No screw grooves 13a and 13b are formed on the inner circumference of the communicating cavity 14, and when the PC steel bars 20a and 20b are screwed to the deepest parts of the first screw hole 12a and the second screw hole 12b, respectively, the ends of the PC steel bars 20a and 20b stop at the deepest parts of the screw grooves 13a and 13b. This prevents the ends of the PC steel bars 20a and 20b from colliding with each other internally, even if the first axis AX1 and the second axis AX2 of the first screw hole 12a and the second screw hole 12b intersect at an angle to each other.

[0034] In Figure 2, the connecting cavity 14 is shown as a cavity extending along the first axis AX1 and the second axis AX2 of the first screw hole 12a and the second screw hole 12b, but the structure and shape of the connecting cavity 14 are not limited. For example, the inclination angle of the connecting cavity 14 may be different from that of the first screw hole 12a and the second screw hole 12b. Also, the diameter of the connecting cavity 14 may be different from that of the first screw hole 12a and the second screw hole 12b.

[0035] Figure 3 is a schematic perspective view showing the PC steel bars 20a and 20b connected using the coupler 10. The PC steel bars 20a and 20b are PC steel bars with uneven surfaces 21a and 21b formed on them, which increases friction with the concrete layer 100. In addition, screw grooves corresponding to screw grooves 13a and 13b are formed at the ends of the PC steel bars 20a and 20b (not shown). As shown in Figures 2 and 3, one end of the PC steel bars 20a and 20b is inserted into the first screw hole 12a and the second screw hole 12b of the coupler 10 and screwed in. As a result, the PC steel bars 20a and 20b are connected in a state where they intersect at a predetermined angle (θ1 + θ2) along the first axis AX1 and the second axis AX2 of the first screw hole 12a and the second screw hole 12b.

[0036] As described above, in the coupler 10 of this embodiment, the first axis AX1 direction and the second axis AX2 direction intersect at a predetermined angle (θ1 + θ2) in the first screw hole 12a and the second screw hole 12b formed in the main body 11. Therefore, the PC steel bars 20a and 20b connected to the first surface 10a side and the second surface 10b side are inclined, making it possible to construct a pavement surface with a changing gradient in two directions of CRCP.

[0037] (Second Embodiment) Next, a second embodiment of the present invention will be described with reference to Figure 4. Details that overlap with the first embodiment will be omitted. Figure 4 is a schematic diagram showing the structure of the coupler 10 according to this embodiment. The left side of Figure 4 shows a cross-sectional view along the longitudinal direction, and the right side of Figure 4 shows a side view from the end. This embodiment differs from the first embodiment in that the main body 11 is bent.

[0038] As shown in Figure 4, the coupler 10 of this embodiment has a main body 11, a first surface 10a, a second surface 10b, a first screw hole 12a, a second screw hole 12b, screw grooves 13a and 13b, and a communication cavity 14. The main body 11 is composed of a first cylindrical portion 11a on the first surface 10a side and a second cylindrical portion 11b on the second surface 10b side.

[0039] The axis AX shown in Figure 4 represents a direction parallel to the horizontal direction of the concrete layer 100, and the first axis AX1 and the second axis AX2 represent the central axes of the first screw hole 12a and the second screw hole 12b, respectively. Furthermore, the first axis AX1 and the second axis AX2 are inclined by angles θ1 and θ2, respectively, with respect to the axis AX which is parallel to the horizontal direction. Therefore, the direction of the first axis AX1 and the direction of the second axis AX2 intersect at a predetermined angle (θ1 + θ2). In addition, the first cylindrical part 11a and the second cylindrical part 11b are constructed in the shape of a hexagonal prism, and their respective central axes coincide with the first axis AX1 and the second axis AX2.

[0040] In the coupler 10 of this embodiment, the first axis AX1 direction and the second axis AX2 direction intersect at a predetermined angle (θ1 + θ2) in the first screw holes 12a and second screw holes 12b formed in the first cylindrical portion 11a and the second cylindrical portion 11b. Therefore, the PC steel bars 20a and 20b connected to the first surface 10a side and the second surface 10b side are inclined, making it possible to construct a pavement surface with a changing gradient in two directions of CRCP.

[0041] (Third embodiment) Next, a third embodiment of the present invention will be described with reference to Figure 5. Details that overlap with the first embodiment will be omitted. Figure 5 is a schematic diagram showing the structure of the coupler 10 according to this embodiment. The left side of Figure 5 shows a cross-sectional view along the longitudinal direction, and the right side of Figure 5 shows a side view from the end. This embodiment differs from the first embodiment in that the main body 11 is provided with a grout injection port 15 that reaches the communication cavity 14.

[0042] As shown in Figure 5, the coupler 10 of this embodiment has a main body 11, a first surface 10a, a second surface 10b, a first screw hole 12a, a second screw hole 12b, screw grooves 13a and 13b, a communicating cavity 14, and a grout inlet 15.

[0043] The grout injection port 15 is a hole that extends from the side of the main body 11 to the connecting cavity 14. Having the grout injection port 15 allows the connecting cavity 14 to communicate with the outside of the main body 11 even when the PC steel bars 20a and 20b are inserted and screwed into the first and second screw holes 12a and 12b. Therefore, by injecting grout material (not shown) into the connecting cavity 14 from the grout injection port 15 and allowing it to harden, the adhesion and bonding between the main body 11 and the PC steel bars 20a and 20b can be improved.

[0044] The type of grout material injected is not limited, but epoxy resin is one example. Furthermore, the specific configuration of the grout inlet 15 is not limited, but a hole with a diameter of several millimeters can be used. Also, while Figure 5 shows an example where the grout inlet 15 is provided in one location, multiple inlets may be provided to facilitate the injection of the grout material.

[0045] In the coupler 10 of this embodiment, the first axis AX1 direction and the second axis AX2 direction intersect at a predetermined angle (θ1 + θ2) in the first screw holes 12a and second screw holes 12b formed in the main body 11. This allows the PC steel bars 20a and 20b connected to the first surface 10a and the second surface 10b to be inclined, making it possible to construct a pavement surface with a changing gradient in two directions of CRCP. Furthermore, since the main body 11 is provided with a grout injection port 15, grout material can be injected into the connecting cavity 14 to improve the adhesion and bonding between the main body 11 and the PC steel bars 20a and 20b.

[0046] (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to Figure 6. Details that overlap with the first embodiment will be omitted. Figure 6 is a schematic diagram showing the structure of the coupler 10 according to this embodiment. The left side of Figure 6 shows a cross-sectional view along the longitudinal direction, and the right side of Figure 6 shows a side view from the end. This embodiment differs from the first embodiment in that a central partition wall 16 is provided between the first screw hole 12a and the second screw hole 12b.

[0047] As shown in Figure 6, the coupler 10 of this embodiment has a main body 11, a first surface 10a, a second surface 10b, a first screw hole 12a, a second screw hole 12b, screw grooves 13a, 13b, cavities 14a, 14b, and a central partition wall 16.

[0048] The cavities 14a and 14b are spaces provided between the first screw hole 12a and the second screw hole 12b and the central partition wall 16, respectively. No screw grooves 13a and 13b are provided on the inner circumference of the cavities 14a and 14b. When the PC steel bars 20a and 20b are screwed to the deepest parts of the first screw hole 12a and the second screw hole 12b, respectively, the ends of the PC steel bars 20a and 20b stop at the deepest part of the screw grooves 13a and 13b. This prevents the ends of the PC steel bars 20a and 20b from colliding with the central partition wall 16.

[0049] The central partition wall 16 is a wall-like portion provided between the first screw hole 12a and the second screw hole 12b. The central partition wall 16 separates the space of the first screw hole 12a and the cavity 14a from the space of the second screw hole 12b and the cavity 14b. In addition, the central partition wall 16 can increase the strength of the main body 11.

[0050] In Figure 6, the central partition wall 16 is shown as a flat, plate-like wall, but its shape is not limited and may be composed of inclined or curved surfaces. Furthermore, the thickness of the central partition wall 16 is not limited; for example, a thickness of approximately 2 mm to 5 mm can be used.

[0051] In the coupler 10 of this embodiment, the first axis AX1 direction and the second axis AX2 direction intersect at a predetermined angle (θ1 + θ2) in the first screw hole 12a and second screw hole 12b formed in the main body 11. This allows the PC steel bars 20a and 20b connected to the first surface 10a and the second surface 10b to be inclined, making it possible to construct a pavement surface with a changing gradient in two directions of CRCP. Furthermore, by providing a central partition wall 16 between the first screw hole 12a and the second screw hole 12b, the strength of the main body 11 can be increased.

[0052] (Fifth embodiment) Next, a fifth embodiment of the present invention will be described with reference to Figure 7. Details that overlap with the first embodiment will be omitted. Figure 7 is a schematic diagram showing the structure of the coupler 10 according to this embodiment. The left side of Figure 7 shows a cross-sectional view along the longitudinal direction, and the right side of Figure 7 shows a side view from the end. This embodiment differs from the first embodiment in that only the first axis AX1, which is the central axis of the first screw hole 12a, is inclined at an angle θ1 with respect to the main body central axis AX.

[0053] As shown in Figure 7, the first axis AX1, which is the central axis of the first screw hole 12a, is inclined at an angle θ1 with respect to the main body central axis AX. The second axis AX2, which is the central axis of the second screw hole 12b, is parallel to the main body central axis AX (θ2=0). Therefore, the direction of the first axis AX1 and the direction of the second axis AX2 intersect at a predetermined angle θ1. In this embodiment, since one of the gradients in the two directions of the CRCP is between 0.5% and 5%, it is preferable that the angle θ1 is in the range of 0.5 degrees to 6 degrees, which corresponds to the gradient.

[0054] In the coupler 10 of this embodiment, the first axis AX1 direction and the second axis AX2 direction intersect at a predetermined angle θ1 in the first screw hole 12a and second screw hole 12b formed in the main body 11. Therefore, the PC steel bars 20a and 20b connected to the first surface 10a side and the second surface 10b side are inclined, making it possible to construct a pavement surface with a changing gradient in two directions of CRCP.

[0055] (Sixth Embodiment) Next, a sixth embodiment of the present invention will be described. Details that overlap with the first embodiment will be omitted. In the first embodiment, a paved surface with a double slope, where the concrete layer 100 is inclined on both sides, was described. However, the coupler 10 of the present invention can also be used for paved surfaces where paved surfaces with different slopes are arranged two-dimensionally. In this case, the coupler 10 is used to connect the PC steel bars 20a, 20b, 20c, and 20d on paved surfaces with the same slope.

[0056] Furthermore, the first axis AX1 and the second axis AX2, which are the central axes of the first screw hole 12a and the second screw hole 12b of the coupler 10, intersect with the main body's central axis AX or an axis AX parallel to the horizontal direction at angles θ1 and θ2 corresponding to the gradient of the concrete layer 100.

[0057] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Explanation of Symbols]

[0058] 10,30... Coupler 20a~20d…PC steel bar 100... Concrete layer 200... Roadbed 10a...Side 1 10b…Second side 11...Main body 11a...First cylindrical part 11b...Second cylindrical part 12a...First screw hole 12b...Second screw hole 13a, 13b... Screw grooves 14...Communication cavity 14a, 14b…Cavity part 15…Grout inlet 16...Central bulkhead part 21a, 21b…Uneven shape

Claims

1. A main body having a first surface and a second surface, A first screw hole formed in the first axial direction from the first surface, It has a second screw hole formed in the second axial direction from the second surface, A coupler characterized in that the first axial direction and the second axial direction intersect at a predetermined angle.

2. A coupler according to claim 1, The main body portion has a symmetrical shape on the first surface side and the second surface side. A coupler characterized in that the first screw hole and the second screw hole are provided symmetrically within the main body.

3. The coupler according to claim 2, The main body is cylindrical in shape with respect to the central axis of the main body. A coupler characterized in that the first axial direction and the second axial direction intersect at the same angle with respect to the central axis of the main body.

4. The coupler according to claim 2, The main body portion has a first cylindrical portion on the first side and a second cylindrical portion on the second side. The first axial direction coincides with the central axis of the first cylindrical portion. A coupler characterized in that the second axial direction coincides with the central axis of the second cylindrical portion.

5. A coupler according to claim 1, A coupler characterized in that a communication cavity is provided between the first screw hole and the second screw hole, and the first screw hole and the second screw hole are formed to communicate with each other.

6. The coupler according to claim 5, The coupler is characterized in that the main body portion has a grout injection port that reaches from the outer circumference to the communicating cavity portion.

7. A coupler according to claim 1, A coupler characterized in that a central partition is provided between the first screw hole and the second screw hole, and the first screw hole and the second screw hole are formed separately.

8. A coupler according to any one of claims 1 to 6, The coupler is characterized in that the predetermined angle is in the range of 0.5 degrees or more and 6 degrees or less.

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