Fixture and fixing structure

Abstract

To provide a fixture and a fixing structure that can suppress deterioration in fastening strength which is caused by various changes in use environments and fix a stranded line with high fastening strength.SOLUTION: A fixture 10 for fixing a stranded line 20 formed by twisting wires 20a to a bolt 30 includes a case 12 and a fitting member 14. The case 12 includes: an attachment part 12b to which the bolt 30 is attached; and a first tapered part 12c. The fitting member 14 includes a second tapered part 14a. An outer peripheral surface of the second tapered part 14a includes a plurality of outer surface grooves 14b. In the fixture 10, the stranded line 20 is fixed to the bolt 30 by fitting the second tapered part 14a into the first tapered part 12c such that a plurality of twisting wires 20a inserted into the case 12 is held between the first tapered part 12c and the plurality of outer surface grooves 14b of the second tapered part 14a.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a fastener and a fastening structure. [Background technology]

[0002] Carbon fiber composite materials are composite materials in which carbon fibers are solidified with resin, and are both strong and lightweight. When multiple linear carbon fiber composite materials are combined to form what is known as a stranded wire, they have even greater strength. For this reason, stranded wires of carbon fiber composite materials (hereinafter simply referred to as "stranded wires") are used as tensile materials for earthquake-resistant reinforcement of buildings and the like. When used as a tensile material for earthquake-resistant reinforcement, the stranded wires are installed under tension.

[0003] At this time, a metal pipe with threads is attached to both ends of the stranded wire, and a cut bolt is attached to the metal pipe. The bolts are used to fix both ends of the stranded wire to a building or the like. For example, Patent Document 1 discloses a method of fixing the stranded wire to the metal pipe with an adhesive to prevent the stranded wire from moving inside the metal pipe.

[0004] Patent Documents 2 to 9 and Non-Patent Document 1 disclose methods for fixing a stranded wire by heating, brazing, etc. Patent Document 10 discloses a method for fixing a stranded wire by applying an external force to a pipe to deform the pipe and crimping the stranded wire and the pipe. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-201090 A [Patent Document 2] JP 2021-116499 A [Patent Document 3] JP 2004-106045 A [Patent Document 4] International Publication No. 2016 / 159010 [Patent Document 5] Japanese Unexamined Patent Publication No. 63-147873 [Patent Document 6] International Publication No. 2012 / 074083 [Patent Document 7] International Publication No. 2014 / 007342 [Patent Document 8] Japanese Patent Application Publication No. 4-321570 [Patent Document 9] Japanese Patent Application Publication No. 4-6178 [Patent Document 10] JP 2004-244750 A [Non-patent literature]

[0006] [Non-Patent Document 1] Takaiwa et al., "Research and Development of End Fixing Structures for Expanding the Use of CFRP Strands," Architectural Institute of Japan Technical Report Collection, February 2022, Vol. 28, No. 68, pp. 36-41.

[0007] As in Patent Document 1, the method of fixing the stranded wire using an adhesive or mortar is widely used. However, this method may cause a decrease in fastening strength due to changes in the usage environment, such as temperature changes, moisture changes, and repeated stress loads. In addition, the adhesive or mortar requires time to dry and harden.

[0008] In the method of fixing the stranded wire by heating as in the above Patent Documents 2 to 9 and Non-Patent Document 1, the mechanical properties of the stranded wire may be deteriorated due to heating. In addition, in the method described in Patent Document 10, for example, when a large tensile force is applied due to an earthquake or the like, the stranded wire may fall off the metal sleeve. Therefore, there is a demand for a fastener and a fastening structure that can prevent a decrease in fastening strength caused by various changes in the usage environment and can fix the stranded wire with high fastening strength. Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above, an object of the present invention is to provide a fastener and a fastening structure that can prevent a decrease in fastening strength caused by various changes in the usage environment and can fasten a stranded wire with high fastening strength. [Means for solving the problem]

[0010] The present invention has been made to solve the above problems, and the gist of the present invention is the following fixing device and fixing structure.

[0011] (1) A fastener for fastening a stranded wire made of a plurality of wire rods made of a carbon fiber composite material to a bolt, a cylindrical case made of a metal material and having a hollow portion passing therethrough in an axial direction; a columnar fitting member made of a metal material and fitted into the hollow portion; The case is a mounting portion provided at one end in the axial direction and to which the bolt inserted from the one side is attached; a first tapered portion provided on the other side in the axial direction relative to the mounting portion and having an inner circumferential surface that becomes thinner toward the other side, The fitting member is a second tapered portion formed so as to become narrower toward the other side, an outer circumferential surface of the second tapered portion includes a plurality of outer surface grooves that are spaced apart from one another in a circumferential direction of the second tapered portion and extend along the axial direction; The second tapered portion is fitted into the first tapered portion from the one side so that the multiple wires of the stranded wire inserted from the other side of the case are sandwiched between the first tapered portion and the multiple outer surface grooves of the second tapered portion, thereby fixing the stranded wire to the bolt. Fixtures.

[0012] (2) A hole portion is formed in a central portion of the second tapered portion, the hole portion extending in the axial direction so as to open on the other side in the axial direction, and into which one of the plurality of wires of the stranded wire can be inserted. The fixing device described in (1) above.

[0013] (3) A plurality of slits are formed in the second tapered portion, the slits extending radially from the hole portion to bottoms of the plurality of outer surface grooves in a cross section perpendicular to the axial direction of the second tapered portion, The slit is formed to extend in the axial direction along the outer surface groove. The fixing device described in (2) above.

[0014] (4) The inner circumferential surface of the first tapered portion includes a plurality of inner surface grooves that are spaced apart from each other in the circumferential direction of the first tapered portion and extend along the axial direction, The stranded wire is fixed to the bolt by fitting the second tapered portion into the first tapered portion from the one side such that the plurality of wire rods of the stranded wire are sandwiched between the plurality of inner surface grooves of the first tapered portion and the plurality of outer surface grooves of the second tapered portion. The fixing device described in (1) above.

[0015] (5) A thread groove is formed on the inner circumferential surface of the mounting portion, The bolt is screwed into the mounting portion to mount the bolt to the mounting portion, and the fitting member is pushed into the other side to fix the stranded wire to the bolt. The fixing device described in (1) above.

[0016] (6) The vehicle further includes a cylindrical adjustment member provided in the mounting portion, a thread groove is formed on an inner peripheral surface of the mounting portion and on an outer peripheral surface and an inner peripheral surface of the adjustment member, the adjustment member is screwed into the mounting portion to mount the adjustment member to the mounting portion, while the fitting member is pushed into the other side, and the bolt is screwed into the adjustment member to fix the stranded wire to the bolt. The fixing device described in (1) above.

[0017] (7) The metal material is steel, stainless steel, or titanium material; The fixing device described in (1) above.

[0018] (8) A stranded wire made of a plurality of wire rods made of a carbon fiber composite material is fixed to a bolt by the fastener described in any one of (1) to (7) above. Fixed structure. Effect of the Invention

[0019] According to the present invention, it is possible to obtain a fastener and a fastening structure capable of fixing a stranded wire with high fastening strength while suppressing deterioration of fastening strength due to aging. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a schematic diagram showing a fixture according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic perspective view showing a stranded wire. [Diagram 3] FIG. 3 is a diagram for explaining an example of the structure of the case and the fitting member. [Figure 4] FIG. 4 is a schematic diagram for explaining a method for fixing a stranded wire to a bolt using a fastener according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a diagram illustrating an example of the structure of a fitting member included in a fixture according to another embodiment of the present invention. [Figure 6] FIG. 6 is a diagram illustrating an example of the structure of a case included in a fixture according to another embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram for explaining a method of fixing a stranded wire to a bolt using a fastener according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] BEST MODE FOR CARRYING OUT THE PRESENTLY PREFERRED EMBODIMENTS Hereinafter, a fixing device and a fixing structure according to an embodiment of the present invention will be described with reference to the drawings.

[0022] (Fixing device configuration) Fig. 1 is a schematic diagram showing a fastener according to one embodiment of the present invention. The fastener of this embodiment is for fastening a stranded wire to a bolt. As shown in Fig. 1, the fastener 10 includes a cylindrical case 12 and a columnar fitting member 14.

[0023] The case and the fitting member are made of a metal material. The metal materials constituting the case and the fitting member may be the same or different. The type of metal material is not particularly limited, but is preferably any of steel, stainless steel, and titanium. It is preferable to paint or plate steel to improve corrosion resistance. Although any of the materials can achieve high strength, stainless steel and titanium are more preferable in terms of corrosion resistance. Titanium material has a low thermal expansion coefficient, is lightweight, and has excellent specific strength. In addition, since the potential difference between carbon fiber and titanium is small, the resistance to galvanic corrosion, so-called bimetallic corrosion, which occurs when the two come into contact with each other, is extremely high. For this reason, the metal material is most preferably titanium material.

[0024] Here, the titanium material refers to commercially pure titanium or titanium alloy. The commercially pure titanium is a material that does not contain any intentionally added alloy elements other than titanium and is composed of impurities and Ti, and the Ti content is usually 98 mass% or more. The titanium alloy is a material in which alloy elements are added to titanium to improve its properties, such as Ti-6Al-4V alloy. Among titanium materials, it is preferable to use a Ti-Al-Fe titanium alloy from the viewpoint of strength and thermal expansion coefficient.

[0025] Fig. 2 is a schematic perspective view showing a stranded wire. As shown in Fig. 2(a), the stranded wire 20 is formed by twisting together a plurality of wires 20a made of a carbon fiber composite material. In the example shown in Fig. 2, the number of wires 20a is seven, but is not limited to this. Also, as shown in Fig. 2(b), the tip portions of the twisted wires 20a of the stranded wire 20 can be unwound.

[0026] The case 12 and the fitting member 14 will be described in more detail. Fig. 3 is a diagram for explaining an example of the structure of the case and the fitting member, where (a) is a cross-sectional view of the aa portion of Fig. 1, (b) is a cross-sectional view of the bb portion of Fig. 1, (c) is a cross-sectional view of the cc portion of Fig. 1, and (d) is a cross-sectional view of the dd portion of Fig. 1. As shown in Fig. 3, the axial direction of the fixing device 10 (the case 12 and the fitting member 14) is referred to as the axial direction X. In this specification, the side in the axial direction X where the bolt is attached is referred to as one side in the axial direction X, and the opposite side is referred to as the other side in the axial direction X.

[0027] 3(a) and 3(b), the case 12 is formed with a hollow portion 12a penetrating in the axial direction X. The case 12 also includes an attachment portion 12b provided at one end in the axial direction X and attached by inserting a bolt (not shown) from one side, and a first tapered portion 12c provided on the other side in the axial direction X of the attachment portion 12b and formed such that the inner circumferential surface becomes thinner toward the other side.

[0028] In this embodiment, a thread groove is formed on the inner peripheral surface of the mounting portion 12b, and the bolt can be screwed into the mounting portion 12b to mount the mounting portion 12b, but the mounting method is not limited thereto. In the example shown in Fig. 3, the thread groove is formed only on the inner peripheral surface of the mounting portion 12b, but it may also be formed on the inner peripheral surface of the first tapered portion 12c. By forming a thread groove on the inner peripheral surface of the first tapered portion 12c, the wire 20a can be easily clamped and firmly fixed.

[0029] The fitting member 14 is a columnar member that is fitted into the hollow portion 12a of the case 12, and includes a second tapered portion 14a that is formed so as to become thinner toward the other side in the axial direction X, as shown in Figures 3(c) and (d). In addition, the outer circumferential surface of the second tapered portion 14a includes a plurality of outer surface grooves 14b that are spaced apart from each other in the circumferential direction of the second tapered portion 14a and are formed so as to extend along the axial direction X.

[0030] In addition, the fact that the outer surface grooves 14b are "separated from each other in the circumferential direction" does not exclude the case where adjacent grooves are connected in some cross sections (cross sections perpendicular to the axial direction X). In other words, a groove that connects multiple grooves may be formed. In this embodiment, the outer surface grooves 14b are open toward one side and the other side in the axial direction X. In this embodiment, six outer surface grooves 14b are formed, but this is not limited to this.

[0031] In this embodiment, the fitting member 14 is formed with a hole 14c penetrating in the axial direction X. The formation of the hole 14c makes it possible to insert one of the multiple wire rods 20a. However, this is not limited thereto, and the hole 14c may not be formed. In addition, since the hole 14c only needs to have a shape that allows one wire rod 20a to be inserted, it does not need to penetrate in the axial direction X, and it only needs to have a shape that extends in the axial direction X so as to open on the other side in the axial direction X.

[0032] (How to use the fixture) 4 is a schematic diagram for explaining a method for fixing a stranded wire to a bolt using a fastener according to one embodiment of the present invention. First, as shown in Figs. 4(a) and (b), the stranded wire 20 with the tip portion of the wire 20a unwound is inserted from the other side of the case 12. In this embodiment, the stranded wire 20 is made up of seven wires 20a. A thread groove is formed on the inner peripheral surface of the mounting portion 12b.

[0033] 4(b) and (c), the fitting member 14 is prepared. In this embodiment, six outer surface grooves 14b are formed on the outer circumferential surface of the second tapered portion 14a of the fitting member 14, and one hole portion 14c is formed in the center of the second tapered portion 14a. Of the seven wires 20a, one is inserted into the hole portion 14c, and the remaining six are arranged so as to be aligned with the outer surface grooves 14b.

[0034] 4(d), the second tapered portion 14a is fitted into the first tapered portion 12c from one side so that the multiple wires 20a inserted from the other side of the case 12 are sandwiched between the first tapered portion 12c and the multiple outer surface grooves 14b of the second tapered portion 14a. Furthermore, as shown in FIGS. 4(d) and 4(e), the bolt 30 is screwed into the mounting portion 12b to mount it to the mounting portion 12b, while the fitting member 14 is pushed into the other side, thereby making it possible to fix the stranded wire 20 to the bolt 30.

[0035] (Other configurations of fixtures) FIG. 5 is a diagram for explaining an example of the structure of a fitting member provided in a fixing device according to another embodiment of the present invention, where (a) is a schematic diagram, (b) is a cross-sectional view of portion ee in (a), and (c) is a cross-sectional view of portion ff in (a).

[0036] 5, in this embodiment, the second tapered portion 14a is formed with a plurality of slits 14d extending radially from the hole 14c to the bottoms of the plurality of outer surface grooves 14b in a cross section perpendicular to the axial direction X, the slits 14d extending in the axial direction X along the outer surface grooves 14b. It is not necessary to form the slits 14d in all of the outer surface grooves 14b. In other words, the number of slits 14d may be less than the number of the outer surface grooves 14b.

[0037] By forming the slits 14d, when the fitting member 14 is pressed into the inside of the case 12, the gaps of the slits are closed, and accordingly, the width of the outer surface groove 14b in the circumferential direction and the diameter of the hole 14c are reduced. As a result, the wire 20a is more firmly fixed by the outer surface groove 14b and the hole 14c.

[0038] FIG. 6 is a diagram illustrating an example of the structure of a case included in a fastener according to another embodiment of the present invention, where (a) is a schematic diagram, (b) is a cross-sectional diagram of portion gg in (a), and (c) is a cross-sectional diagram of portion hh in (a).

[0039] 6, in this embodiment, the inner peripheral surface of the first tapered portion 12c includes a plurality of inner surface grooves 12d that are spaced apart from each other in the circumferential direction of the first tapered portion 12c and that extend along the axial direction X. In this configuration, the wire rod (not shown) is sandwiched between the plurality of inner surface grooves 12d of the first tapered portion 12c and the plurality of outer surface grooves of the above-mentioned second tapered portion (not shown), and is therefore fixed more firmly.

[0040] (Other uses for fixtures) 7 is a schematic diagram for explaining a method for fixing a stranded wire to a bolt using a fixture according to another embodiment of the present invention. In this embodiment, as shown in FIG. 7, the fixture 10 further includes a cylindrical adjustment member 16.

[0041] 7(a) and (b), the stranded wire 20 with the tip portion of the wire 20a unwound is inserted from the other side of the case 12. In this embodiment, the stranded wire 20 is made up of seven wires 20a. A screw groove is formed on the inner peripheral surface of the mounting portion 12b.

[0042] 7(b) and (c), the fitting member 14 is prepared. In this embodiment, six outer surface grooves 14b are formed on the outer circumferential surface of the second tapered portion 14a of the fitting member 14, and one hole 14c is formed in the center of the second tapered portion 14a. Of the seven wires 20a, one is inserted into the hole 14c, and the remaining six are arranged so as to be aligned with the outer surface grooves 14b.

[0043] Next, as shown in FIG. 7(d), the second tapered portion 14a is fitted into the first tapered portion 12c from one side so that the wires 20a inserted from the other side of the case 12 are sandwiched between the first tapered portion 12c and the outer grooves 14b of the second tapered portion 14a. Furthermore, as shown in FIG. 7(d) and (e), the adjustment member 16 is attached to the attachment portion 12b by screwing it into the attachment portion 12b. The adjustment member 16 has thread grooves formed on its outer and inner peripheral surfaces. As shown in FIG. 7(e) and (f), the adjustment member 16 pushes the fitting member 14 to the other side, and the bolt 30 is screwed into the adjustment member 16, thereby fixing the stranded wire 20 to the bolt 30.

[0044] By using the adjustment member 16, even if the inner diameter of the mounting portion 12b and the outer diameter of the bolt 30 do not match, the bolt 30 can be attached via the adjustment member 16.

[0045] (Fixed structure configuration) As shown in Figures 4(e) and 7(f), a fixing structure according to one embodiment of the present invention is configured such that a stranded wire 20, which is made of a plurality of wires 20a made of a carbon fiber composite material, is twisted together, and the stranded wire 20 is fixed to a bolt 30 by the above-mentioned fastener 10. [Industrial Applicability]

[0046] According to the present invention, it is possible to obtain a fastener and a fastening structure capable of fixing a stranded wire with high fastening strength by suppressing the decrease in fastening strength due to aging. Furthermore, even if the fastening strength decreases due to aging or some other cause, it is possible to restore high fastening strength by retightening the tapered portion. [Explanation of symbols]

[0047] 10 Fixtures 12 cases 12a Cavity 12b Mounting part 12c First taper section 12d Inner groove 14 Fitting member 14a Second tapered section 14b External groove 14c hole 14d slit 16 Adjustment parts 20 Stranded Wire 20a wire rod 30 Volts

Claims

1. A fastener for fastening a stranded wire made of a plurality of wire rods made of a carbon fiber composite material to a bolt, comprising: a cylindrical case made of a metal material and having a hollow portion passing therethrough in an axial direction; a columnar fitting member made of a metal material and fitted into the hollow portion; The case is a mounting portion provided at one end in the axial direction and to which the bolt inserted from the one side is attached; a first tapered portion provided on the other side in the axial direction relative to the attachment portion and having an inner circumferential surface that becomes thinner toward the other side, The fitting member is a second tapered portion formed so as to become narrower toward the other side, an outer circumferential surface of the second tapered portion includes a plurality of outer surface grooves that are spaced apart from one another in a circumferential direction of the second tapered portion and that extend along the axial direction; the second tapered portion is fitted into the first tapered portion from the one side so that the plurality of wires of the stranded wire inserted from the other side of the case are sandwiched between the first tapered portion and the plurality of outer surface grooves of the second tapered portion, thereby fixing the stranded wire to the bolt. Fixtures.

2. a hole portion is formed in a central portion of the second tapered portion, the hole portion extending in the axial direction so as to open on the other side in the axial direction, and into which one of the plurality of wires of the stranded wire can be inserted; The fixture of claim 1 .

3. A plurality of slits are formed in the second tapered portion, the slits extending radially from the hole portion to bottoms of the plurality of outer surface grooves in a cross section perpendicular to the axial direction of the second tapered portion, The slit is formed to extend in the axial direction along the outer surface groove. The fixture of claim 2.

4. the inner circumferential surface of the first tapered portion includes a plurality of inner surface grooves that are spaced apart from one another in a circumferential direction of the first tapered portion and that extend along the axial direction, The stranded wire is fixed to the bolt by fitting the second tapered portion into the first tapered portion from the one side such that the plurality of wire rods of the stranded wire are sandwiched between the plurality of inner surface grooves of the first tapered portion and the plurality of outer surface grooves of the second tapered portion. The fixture of claim 1 .

5. A thread groove is formed on an inner circumferential surface of the mounting portion, The bolt is screwed into the mounting portion to mount the bolt to the mounting portion, and the fitting member is pushed into the other side to fix the stranded wire to the bolt. The fixture of claim 1 .

6. The mounting portion further includes a cylindrical adjustment member provided in the mounting portion. a thread groove is formed on an inner peripheral surface of the mounting portion and on an outer peripheral surface and an inner peripheral surface of the adjustment member, the adjustment member is screwed into the mounting portion to mount the adjustment member to the mounting portion, while the fitting member is pushed into the other side, and the bolt is screwed into the adjustment member to fix the stranded wire to the bolt. The fixture of claim 1 .

7. The metal material is steel, stainless steel, or titanium material; The fixture of claim 1 .

8. A stranded wire made of a plurality of wire rods made of a carbon fiber composite material is fixed to a bolt by the fastener according to any one of claims 1 to 7. Fixed structure.

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