Connection structure

Abstract

To provide a connection structure for connecting wooden shaft members with a shaft connecting member, which makes splitting fractures in wooden shaft members less likely to occur.SOLUTION: A shaft connecting member 13 has a shaft core material 16 to be inserted into a connecting hole 15, and a filling material 17 with an inclusive portion 27 that includes the shaft core material 16, and an expanded portion 28 that is wider than inner portion 27. The expanded portion 28 has an expanded surface 34 extending outward from the inner portion 27, and a reduced diameter surface 35 that extends from the outer peripheral end of the expanded surface 34 in an in-pushing direction along which the shaft core material 16 is pushed into the connecting hole 15 and forms an oblique line toward the inner portion 27 in an axial cross section in the axial direction, and is formed in plurality at intervals in the axial direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a connection structure for connecting a wooden shaft to another member. [Background technology]

[0002] A known connection structure for connecting a wooden shaft to another component involves inserting a steel core material into a connection hole formed in the wooden shaft and then filling the gap between the wooden shaft and the core material with a filler material. Patent Document 1 also discloses such a connection structure, in which a connection hole is formed by a core material insertion section into which a core material (rod-shaped material) is inserted and a connection hole widening section (expanding filling groove) provided in the core material insertion section. The connection hole widening sections are semicircular in the shaft cross section, which is a cross section along the axial direction of the wooden shaft, and are provided at predetermined intervals in the axial direction of the wooden shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-123628 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the structure described in Patent Document 1, when a pushing force is applied to push the shaft connecting material into the shaft core material insertion portion or a pulling force is applied to pull the shaft connecting material out of the shaft core material insertion portion, the force resisting the force tends to be concentrated in the wooden shaft material, making it prone to splitting fracture. [Means for solving the problem]

[0005] A connecting structure that solves the above problem comprises a wooden shaft having a connecting hole extending in the axial direction, a core material partially inserted into the connecting hole, and a filler material filled in the connecting hole and having an inner portion containing the core material and an expanded portion having a diameter larger than that of the inner portion. The expanded portion has a widening surface extending outward from the inner portion and a narrowing surface extending from the outer peripheral edge of the widening surface in the pushing direction of pushing the core material into the connecting hole and facing the inner portion in an axial cross section in the axial direction, and is formed in plurality at intervals in the axial direction. [Effects of the Invention]

[0006] According to the present invention, splitting fracture is less likely to occur in the wooden shaft material. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a perspective view showing the schematic configuration of a wooden shaft and a shaft connecting member that constitute one embodiment of a connecting structure, together with other members. [Figure 2] FIG. 2(a) is a view showing a state in which a shaft core member is inserted into a connection hole in a cross section along the axial direction, and FIG. 2(b) is an enlarged view of the part surrounded by line 2b. [Figure 3] FIG. 3(a) is a view showing a state in which the filler has been formed in an axial cross section along the axial direction, and FIG. 3(b) is an enlarged view of the part surrounded by line 3b. [Figure 4] FIG. 4 is a partial perspective view showing the shaft connecting member. [Figure 5] FIG. 5 is a cross-sectional view showing a process of connecting a first wooden shaft member and a second wooden shaft member. DETAILED DESCRIPTION OF THE INVENTION

[0008] An embodiment of the connection structure will be described with reference to FIGS. As shown in Figure 1, the connecting structure 10 connects a wooden shaft 11 and another member 12 in the axial direction with a shaft connecting member 13. The wooden shaft 11 is a part of a member that constitutes a building, such as a pillar or beam. The other member 12 is a part of a member that constitutes a building, such as a pillar, beam, or joint. The other member 12 may be made of wood or precast material.

[0009] A connection hole 15 is formed in the wooden shaft 11. The connection hole 15 is a blind hole that extends in the axial direction and has an opening at the connection surface 11a, which is one end face in the axial direction. A core material 16 that constitutes the shaft connection member 13 is inserted into the connection hole 15. The "axial direction" refers to the direction in which the core material 16 extends. The core material 16 protrudes in the axial direction from the connection surface 11a. The wooden shaft 11 is connected to another member 12 using the protruding portion of the core material 16. The core material 16 can be made of a material that is stronger than the wooden shaft 11, such as a deformed steel bar, a fully threaded bolt, or glass fiber bar.

[0010] Filler 17 is formed in connecting hole 15 of wooden shaft 11 to integrate wooden shaft 11 and core material 16. Filler 17 is a hardened fluid filler material. The filler material is, for example, a cement-based material such as non-shrink mortar. The wooden shaft 11 integrated with core material 16 by filler 17 is called wooden shaft 50 with shaft connector.

[0011] It is preferable that a communication hole 18 that communicates with the connection hole 15 is formed in the wooden shaft 11. The communication hole 18 has an opening in the side surface 11b of the wooden shaft 11. The communication hole 18 is formed so that its entire area overlaps with the connection hole 15 when viewed from the side surface 11b. The communication hole 18 communicates with the connection hole 15 at its deepest part. The communication hole 18 is a hole that is used when injecting the filler material that forms the filler 17 into the connection hole 15.

[0012] (Connection hole) 2(a), the connection hole 15 has a core material insertion portion 21 and a connection hole widening portion 22. The connection hole 15 is a hole whose outer shape in the width direction, which is a plane direction perpendicular to the axial direction, is a circular hole.

[0013] The core insertion portion 21 is a portion that opens into the connection surface 11a and extends linearly from the connection surface 11a along the axial direction. The core insertion portion 21 is formed using a tool such as a drill. The deepest portion of the core insertion portion 21 is connected to the above-mentioned communication hole 18.

[0014] The connection hole widened portions 22 are larger in the width direction than the core material insertion portions 21. The connection hole widened portions 22 are provided at predetermined intervals in the axial direction. The connection hole widened portions 22 are formed using a special drill after the core material insertion portions 21 are formed. In Figure 2, the formation interval of the connection hole widened portions 22 is shown to be larger than the length of the connection hole widened portions 22 in the axial direction. With this configuration, the filler 17 can be formed with a small amount of filler material. On the other hand, the formation interval of the connection hole widened portions 22 may be smaller than the length of the connection hole widened portions 22 in the axial direction. With this configuration, a larger number of connection hole widened portions 22 can be formed.

[0015] Incidentally, when the core material 16 is a deformed rebar with a nominal diameter of 29, the diameter of the core material insertion portion 21 is about 45 mm, and the maximum diameter of the connection hole widening portion 22 is about 60 mm (diameter of the core material insertion portion 21 + 15 mm). In addition, the spacing of the connection hole widening portions 22 in the axial direction is preferably about 15 mm.

[0016] As shown in FIG. 2(b), the connection hole widening portion 22 is wedge-shaped in an axial cross section, which is a cross section along the axial direction, gradually approaching the side of the core material insertion portion 21 toward the opposite side of the connection surface 11a.

[0017] The connection hole widening portion 22 has an inclined surface 25 and a pull-out side end surface 26. The inclined surface 25 is a surface that is further away from the side surface of the core material insertion portion 21 as it approaches the connection surface 11a. In an axial cross section, which is a cross section along the axial direction, the inclined surface 25 is formed at an acute angle θ1 with respect to the side surface of the core material insertion portion 21. The angle θ1 is preferably about 30°.

[0018] The extraction-side end surface 26 is a surface connecting the end of the inclined surface 25 on the connection surface 11a side and the side surface of the core material insertion portion 21. At the connection end of the extraction-side end surface 26 with the core material insertion portion 21 in the shaft cross section, the angle θ2 with respect to the side surface of the core material insertion portion 21 is an angle that is equal to or greater than the complement angle to angle θ1 (= 90° - angle θ1). The angle θ2 is preferably close to 90°, and is preferably equal to or greater than 80°. The angle θ2 may also be a slightly obtuse angle. The extraction-side end surface 26 may be formed so as to extend linearly outward from the side surface of the core material insertion portion 21 in the shaft cross section, or may be formed in an arc shape that juts out toward the connection surface 11a side.

[0019] (Method of manufacturing wooden shafts with shaft connectors) An example of a method for manufacturing the wooden shaft member 50 with a shaft connector will be described. First, the connecting hole 15 and the communication hole 18 are formed in the wooden shaft 11, and then the shaft core material 16 is inserted into the connecting hole 15 (see FIG. 2(a)).

[0020] Thereafter, as shown in FIG. 3(a), the filler material is injected through the communication hole 18. The filler material is injected until outflow of the filler material is confirmed from the opening of the connection hole 15 in the connection surface 11a. When the filler material hardens, a filler 17 having an encapsulated portion 27 and an expanded portion 28 is formed in the connection hole 15. The encapsulated portion 27 is a portion formed in the core material insertion portion 21 that encapsulates the core material 16. The expanded portion 28 is a portion formed in the connection hole expanded portion 22 that has a larger diameter than the encapsulated portion 27. In the axial direction, the direction in which the core material 16 is pulled out of the connection hole 15 is called the pulling direction (upward in FIG. 3(a)), and the direction in which the core material 16 is pushed into the connection hole 15 is called the pushing direction (downward in FIG. 3(a)). In an axial cross section, which is a cross section along the axial direction, the expanded portion 28 is formed in a wedge shape that narrows toward the back side of the connection hole 15, i.e., toward the pushing direction. In this way, the wooden shaft 11 and the core material 16 are integrated with the filler material 17, thereby producing a wooden shaft 50 with a shaft connector.

[0021] (widening section) As shown in FIG. 3(b), the widening portion 28 has a widening surface 34 and a narrowing surface 35. The widening surface 34 is attached to the pull-out side end surface 26 of the connection hole widening portion 22. The widening surface 34 has an end surface angle, which is the angle at the end of the connection end with the inner case portion 27 in the shaft cross section, at the pull-out direction side, of the angle θ2. The widening portion 28 resists the pulling force that pulls the shaft connecting member 13 out of the wooden shaft 11 with the widening surface 34. The narrowing surface 35 is attached to the inclined surface 25 of the connection hole widening portion 22. The narrowing surface 35 extends from the outer peripheral end of the widening surface 34 toward the pushing direction and is obliquely oriented toward the inner case portion 27 in the shaft cross section. The narrowing surface 35 has an inclination angle, which is the angle at the end of the pushing direction side, of the shaft cross section, of the narrowing surface 35, which is the angle at the end of the pushing direction side, of the shaft cross section, of the angle θ1. A partial perspective view of such a shaft connecting member 13 is shown in FIG. 4.

[0022] (Method of connecting wooden shafts) Referring to Fig. 5, an example of a connection method for connecting a first wooden shaft, which is a wooden shaft 11, to a second wooden shaft, which is another member 12, with a shaft connecting member 13 will be described. The second wooden shaft has the same configuration as the wooden shaft 11 at the connection portion. Therefore, the same reference numerals as those for the wooden shaft 11 are used for the second wooden shaft for the portions with the same configuration. In Fig. 5, the reference numerals on the right side relate to the first wooden shaft, and the reference numerals on the left side relate to the second wooden shaft.

[0023] First, the shaft connecting member 13 is formed in the first wooden shaft member 11A, and the connecting hole 15 is formed in the second wooden shaft member 11B. The connecting hole 15 of the second wooden shaft member 11B has a communication hole 18 on the connecting surface 11a side and a communication hole 37 (see FIG. 5) that communicates with the deepest part of the shaft core member insertion portion 21.

[0024] Next, as shown in Figure 5, the first wooden shaft material 11A and the second wooden shaft material 11B are aligned with the connecting surface 11a of the first wooden shaft material 11A facing the connecting surface 11a of the second wooden shaft material 11B, and the protruding portion of the core material 16 is inserted into the connecting hole 15 of the second wooden shaft material 11B.

[0025] Then, after the connecting surfaces 11a are brought into contact with each other, the filler material is filled through the communication holes 18 of the second wooden shaft 11B, as indicated by the dark dots. At this time, air inside the connection holes 15 of the second wooden shaft 11B is discharged through the communication holes 37. When the filler material hardens in the connection holes 15 of the second wooden shaft 11B, a filler material 17 is formed in the second wooden shaft 11B, and the first wooden shaft 11A and the second wooden shaft 11B are connected by the shaft connecting material 13.

[0026] The operation and effects of this embodiment will be described. (1) In the connection structure 10, the widened portion 28 of the filler 17 has a reduced diameter surface 35 that forms an acute angle with the inner casing portion 27. This increases the proportion of force transmitted from the other member 12 to the wooden shaft 11 via the connecting surface 11a of the wooden shaft 11 when a pushing force acts to push the shaft connecting member 13 into the wooden shaft 11. As a result, the shear force generated in the filler 17 at the boundary between the inner casing portion 27 and the widened portion 28 can be reduced.

[0027] (2) The degree of freedom in the shape of the connection hole widened portion 22 can be increased compared to a configuration in which the connection hole widened portion 22 is semicircular in axial cross section. (3) In the connection structure 10, the angle of inclination of the diameter-reducing surface 35 is an acute angle, and the end face angle of the widening surface 34 is equal to or greater than the complementary angle to the angle of inclination. This ensures resistance to pull-out force while more reliably reducing the shear force generated in the filler 17 at the boundary between the inner portion 27 and the widening portion 28 when a pushing force acts on the shaft connecting member 13. In addition, the bearing surface between the wooden shaft 11 and the widening portion 28 can be increased when a pushing force acts on the shaft connecting member 13. As a result, the resistance generated in the wooden shaft 11 near the bearing surface can be effectively dispersed.

[0028] (4) The angle θ2, which is the end face angle of the widened surface 34, is less than 90°, so that air can be smoothly removed from the widened portion 22 of the connection hole when the filling material is injected. (5) The filler material 17 has multiple widened portions 28 formed at intervals in the axial direction. This allows the wooden shaft 11 to resist the pull-out force at multiple pull-out end faces 26. That is, the wooden shaft 11 can resist the pull-out force by effectively distributing the force across the multiple pull-out end faces 26. As a result, splitting fracture caused by the pull-out force is less likely to occur in the wooden shaft 11. Furthermore, when a pushing force acts on the shaft connecting member 13, the widened portions 28 can deflect the pushing force. This allows the wooden shaft 11 to resist the pushing force not only near the innermost portion of the connecting hole 15, but also near the connecting surface 11a of the wooden shaft 11 when another component 12 is connected to the connecting surface 11a. As a result, splitting fracture caused by the pushing force is less likely to occur in the wooden shaft 11.

[0029] (6) Furthermore, by forming a plurality of widened portions 28, it is possible to reduce the diameter of the widened portions 28 while suppressing splitting fracture. As a result, for example, when a plurality of shaft connecting members 13 are provided on the wooden shaft 11, it is possible to reduce the edge clearance dimension of the wooden shaft 11.

[0030] This embodiment can be modified as follows: This embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. When connecting the first wooden shaft 11A and the second wooden shaft 11B, the filler material may be injected into the connection holes 15 of the wooden shafts 11A and 11B with the shaft core material 16 disposed therein.

[0031] The technical ideas that can be understood from the above-described embodiment and modified examples will be described. (Note 1) The intervals between the widened portions are greater than the lengths of the widened portions in the axial direction. With this configuration, a plurality of widened portions can be formed with a small amount of filler material.

[0032] (Note 2) The interval between the widened portions is smaller than the length of the widened portions in the axial direction. With this configuration, it is possible to form a larger number of widened portions. [Explanation of symbols]

[0033] 10...connection structure, 11...wooden shaft material, 11a...connection surface, 11b...side surface, 11A...first wooden shaft material, 11B...second wooden shaft material, 12...other parts, 13...shaft connecting material, 15...connection hole, 16...shaft core material, 17...filler material, 18...communicating hole, 21...shaft core material insertion section, 22...connection hole widening section, 25...inclined surface, 26...pull-out side end face, 27...internal section, 28...widening section, 29...diameter, 34...widening surface, 35...narrowing surface, 50...wooden shaft material with shaft connecting material.

Claims

1. a wooden shaft having a connecting hole extending in the axial direction; a core member partially inserted into the connection hole; a filler filled in the connecting hole, the filler having an inner portion containing the core material and an expanded portion having a diameter larger than that of the inner portion; The widening portion is The inner shell portion is formed with a plurality of widened surfaces spaced apart in the axial direction, the widened surfaces extending outward from the inner shell portion and the narrowed surfaces extending from the outer peripheral end of the widened surfaces in the pushing direction of pushing the core material into the connection hole and facing the inner shell portion in an axial cross section in the axial direction. Connection structure.

2. the reduced diameter surface is formed such that an inclination angle at an end portion on the pushing direction side is an acute angle in an axial cross section in the axial direction, In an axial cross section in the axial direction, the widened surface has an end face angle at an end portion on the side of the drawing direction, which is the opposite direction to the pushing direction, that is, an angle equal to or larger than the complementary angle to the inclination angle. The connection structure according to claim 1 .

3. a first wooden shaft member having a first connection hole extending in the axial direction; a second wooden shaft member having a second connection hole extending in the axial direction; a core member having a portion to be inserted into the first connection hole and a portion to be inserted into the second connection hole; a first filling material filled in the first connection hole; a second filling material filled in the second connection hole, Each of the first filler and the second filler is The container has an inner portion that contains the core material and an expanded portion that has a diameter larger than that of the inner portion, The widening portion is A plurality of widening surfaces are formed at intervals in the axial direction, each having a widening surface extending outward from the inner packet portion and a narrowing surface extending from the outer circumferential end of the widening surface in the pushing direction of the core material and facing the inner packet portion in an axial cross section in the axial direction. Connection structure.

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