JP7337010B2 - Strand rod connection method and strand rod connection structure - Google Patents

Description

The present invention relates to a strand rod connection method and a strand rod connection structure.

Conventionally, a connection method described in Patent Document 1 below is known as a technique in such a field. In this connection method, the ends of two FRP rods are butted against each other, a tubular member is installed to surround the butted portions across both ends, and an adhesive material is filled inside the tubular member to It connects the rods.

JP-A-10-30304

When connecting this type of strand rod, a connection method that is stronger than the connection method disclosed in Patent Document 1 is desired. SUMMARY OF THE INVENTION An object of the present invention is to provide a strand rod connection method and a connection structure that enable a strong connection.

The strand rod connection method of the present invention is a strand rod connection method in which two strand rods formed by twisting a plurality of thermoplastic strands are connected at their longitudinal ends. In each, a first step of heating the ends to loosen the plurality of softened wires, and a state in which the arrangement of the wires at the ends in each of the two strand rods in the cross section is different from the normal arrangement. and a second step of entangling and joining the ends of the two strand rods.

In the second step, in each of the two strand rods, a plurality of strand bundle layers each composed of a plurality of strands arranged one-dimensionally in the cross section by dividing the end into a plurality of strands are formed, and the two strands are The ends of the rods may be joined together in a state in which the wire bundle layers of the rods are alternately laminated.

In the second step, in each of the two strand rods, some side wires of the strands of the end are displaced in the cross section to form an uneven shape in the cross section of the end, and the two strands are The ends of the rods may be joined together while the concave and convex portions of the rods are engaged with each other.

In the second step, in each of the two strand rods, each side wire of the strands at the ends is radially displaced to the outer peripheral side in the cross section, and the side wires of the two strand rods are displaced in the cross section. The ends may be joined while being alternately arranged in the circumferential direction.

In the second step, in each of the two strand rods, each side wire of the strands at the ends is radially displaced to the outer peripheral side in the cross section, and the side wires of the two strand rods are displaced in the cross section. The ends of two strand rods are arranged so that they are alternately arranged in the circumferential direction, and one strand rod is twisted relative to the other strand rod to join the ends. good too.

In the second step, in each of the two strand rods, each side wire of the strands at the ends is radially displaced to the outer peripheral side in the cross section, and the side wires of the two strand rods are displaced in the cross section. The ends of two strand rods are arranged so that they are alternately arranged in the circumferential direction, and in each of the two strand rods, the tip of the lateral wire is woven into the lateral wire of the other strand rod, The ends may be joined together.

The strand rod connection structure of the present invention is a strand rod connection structure in which two strand rods formed by twisting a plurality of thermoplastic strands are connected at their longitudinal ends. In each case, the end portions of the two strand rods are entwined and joined together in a state where the arrangement of the wires at the end portions within the cross section is different from the usual arrangement.

The strand rod connection structure of the present invention is a strand rod connection structure that connects two strand rods formed by twisting a plurality of thermoplastic strands at their longitudinal ends, wherein the two strand rods Each of the ends has a plurality of strand bundle layers composed of a plurality of strands that are divided into a plurality of ends and are arranged one-dimensionally in the cross section, and two strand rods A strand rod connection structure may be used in which the ends of the wire bundle layers are joined to each other in a state in which the wire bundle layers are alternately laminated.

The strand rod connection structure of the present invention is a strand rod connection structure in which two strand rods formed by twisting a plurality of thermoplastic strands are connected at their longitudinal ends. Each end has an uneven shape portion formed in the cross section of the end by displacing a part of the side wires of the strands in the cross section, and the uneven shape of the two strand rods It may be a strand rod connection structure in which the ends are joined with the parts being engaged with each other.

The strand rod connection structure of the present invention is a strand rod connection structure in which two strand rods formed by twisting a plurality of thermoplastic strands are connected at their longitudinal ends. A strand-rod connection structure may be employed in which the ends are joined to each other in a state in which the side wires of the strands are alternately arranged in the circumferential direction in the cross section.

The strand rod connection structure of the present invention is a strand rod connection structure in which two strand rods formed by twisting a plurality of thermoplastic strands are connected at their longitudinal ends. In a state in which mutual lateral wires of the strands are alternately arranged in the circumferential direction in the cross section, and the tip of the lateral wire in each of the two strand rods is woven into the lateral wire of the other strand rod, the ends are It may be a bonded, strand rod connecting structure.

ADVANTAGE OF THE INVENTION According to this invention, the strand rod connection method and connection structure which can be firmly connected can be provided.

FIG. 3 is a perspective view showing two strand rods that are objects of the connection method of the present embodiment; (a) is a diagram showing a state in which the wire at the tip of the strand rod is unraveled, and (b) is a diagram schematically showing the strand rod in a state in which the wire at the tip is unraveled. (a) is a cross-sectional view at position P0 in FIG. 2(b), (b) is a cross-sectional view at position P1, and (c) is a cross-sectional view at position P2. (a) is a diagram showing opposing rod ends before connection, (b) is a diagram showing a state in which the connection regions are superimposed, and (c) is a c-c cross-sectional view in (b). is. (a) is a cross-sectional view showing a modification, (b) is a cross-sectional view showing another modification, and (c) is a cross-sectional view showing still another modification. (a) shows a cross section of the connecting region of the strand rods in the second embodiment, and (b) to (d) show cross sections of overlapping portions of the strand rods. (a) shows a cross section of the connection region of the strand rods in the third embodiment, and (b) shows a cross section of the overlapping portion of the strand rods. It is a figure which shows one process of 4th Embodiment. It is a figure which expands and shows a part of overlapping part in 1 process of 5th Embodiment.

[First embodiment]
EMBODIMENT OF THE INVENTION Hereinafter, 1st Embodiment of the strand rod connection method and connection method which concern on this invention is described in detail, referring drawings. As shown in FIG. 1, the connection method of the present embodiment is a method of constructing a strand rod connection structure (joint structure) by connecting one longitudinal end portions of two strand rods 1 having the same configuration. . The strand rod 1 is used, for example, to be embedded in concrete to reinforce the concrete.

The strand rod 1 is formed by twisting together a plurality (seven in this embodiment) of strands 10 having a circular cross section and having the same diameter. The wire 10 is made of a thermoplastic material and is softened by heating. For example, the diameter of the strand rod 1 is approximately 8.2-8.4 mm, and the diameter of the wire is approximately 2.73-2.80 mm. For example, the twist pitch of the strand rod 1 is approximately 210 mm.

For example, the strand rod 1 is a fiber-reinforced plastic rod material (FRP rod material) containing thermoplastic FRP (Fiber-Reinforced Plastics). More specifically, the material of strand 10 includes a thermoplastic resin and a tensile resistance material. The tensile resistance material is, for example, a fiber for reinforcing plastic made of resin fiber, cloth fiber, metal fiber, etc., and has the function of integrating and cross-linking by dissolving the thermoplastic resin between them.

Examples of FRP rod materials include carbon fiber reinforced plastics (CFRP (Carbon-Fiber-Reinforced Plastics)) in which carbon fibers as a tensile resistance material are impregnated or coated with a thermoplastic resin, and glass fibers as a tensile resistance material that are thermoplastic. GFRP (Glass-Fiber-Reinforced Plastics) impregnated or coated with resin; -Reinforced Plastics)), and boron fiber-reinforced plastics (BFRP (Boron Fiber-Reinforced Plastics)) in which boron fibers are impregnated or coated with a thermoplastic resin as tensile resistance materials, etc. can be adopted. The FRP rod material may be basalt fiber impregnated or coated with a thermoplastic resin. Examples of thermoplastic resins used as the material of the wire 10 include polypropylene (PP), polycarbonate (PC), polyamide (PA), and the like.

Below, each of the two strand rods 1 connected by the connection method of this embodiment may be distinguished from each other as strand rods 1a and 1b. Also, the central axis of the strand rods 1a and 1b is called an axis W. As shown in FIG. Moreover, when distinguishing each of the seven strands 10 which comprise the strand rod 1a, each strand is called strand k1, k2,..., k7, respectively. Among the wires k1 to k7, the wire k1 is a core wire located in the center of the cross section and extending linearly on the axis W, and is sometimes called the core wire k1. Further, among the wires k1 to k7, the wires k2 to k7 are side wires extending spirally around the core wire k1, and are sometimes called side wires k2 to k7.

Similarly, when each of the seven strands 10 forming the strand rod 1b is to be distinguished from each other, the strands are called strands j1, j2, . . . , j7 in order. Among the wires j1 to j7, the wire j1 is a core wire located in the center of the cross section and extending linearly on the axis W, and is sometimes called the core wire j1. Among the wires j1 to j7, the wires j2 to j7 are side wires spirally extending around the core wire j1, and are sometimes called side wires j2 to j7.

In the cross section of the strand rod 1a, the cross sections of the six side wires k2 to k7 are arranged in order in a regular hexagonal shape in the circumferential direction at a pitch that substantially circumscribes each other, and the center is surrounded by the cross sections of the six side wires k2 to k7. A section of line k1 is placed (see FIG. 1). Such arrangement of the wires 10 in the cross section of the strand rod 1 is called "normal arrangement". Ideally, in the "normal arrangement", the cross sections of the six lateral lines k2 to k7 are circumscribed each other, the centers of the lateral lines k2 to k7 are arranged on the vertices of the regular hexagon, and the cross-sectional center of the core line k1 is located at the center of the regular hexagon, and the core line k1 circumscribes all the side lines k2 to k7. However, the actual strand rod 1 is not necessarily in the ideal state as described above, and there may be places where the wires 10 are not in contact with each other due to a small gap. Also, within the cross section of the strand rod 1b, the strands j1 to j7 are in the above-described normal arrangement state.

A connection method according to the present embodiment will be described.

(First step)
The following processing is performed for two strand rods 1 (strand rods 1a and 1b). FIG. 2(a) is a diagram showing a state in which the wire 10 at the tip of the strand rod 1 is loosened, and FIG. 2(b) shows the strand rod 1 in a state in which the wire 10 at the tip is loosened. It is a figure shown typically.

As shown in FIG. 2, the binding band 15 is wound around a position P0 at a predetermined distance from the tip 13 of the strand rod 1. As shown in FIG. A portion of the strand rod 1 from the position P0 to the tip 13 is hereinafter referred to as a "rod end portion 17". In the following description, the rod end portion 17 is divided into a connection region 33 on the distal end 13 side and a transition region 34 on the proximal end side. The connection region 33 is a region that overlaps and joins with the mating strand rod 1 . The transition region 34 is a region where each wire 10 of the strand rod 1 gradually transitions from the normal arrangement state to the connection region 33 state.

After the binding band 15 is attached, the rod ends 17 are heated to soften the wires 10 . Here, for example, when the thermoplastic resin that is the material of the wire 10 is a thermoplastic resin such as polypropylene, polyamide, or thermoplastic epoxy, it is preferable to heat the wire 10 to a temperature of 80 to 250°C. . Then, as shown in FIG. 2(a), the softened wire 10 at the rod end 17 is untwisted. At this time, the binding band 15 functions as an anti-dislodgement of the wire 10, and the twist of the wire 10 of the strand rod 1 does not come loose on the base end side of the binding band 15.例文帳に追加

(Second step)
The second step following the first step is performed as follows. Each strand 10 of the rod end portion 17, which is understood as described above, is allowed to extend substantially linearly in the longitudinal direction of the strand rod 1, and then cooled and hardened again. Next, as shown in FIG. 2B, the boundary position between the transition region 34 and the connection region 33 (hereinafter referred to as "position P1") and the position closest to the tip 13 (hereinafter referred to as "position P2") , respectively, the shape retaining spacers 21 are installed.

3(a) to 3(c) are cross-sectional views of each part of the strand rod 1 of FIG. 2(b), FIG. 3(a) is a cross-sectional view of the position P0, , a cross-sectional view at position P1, and FIG. 3(c) is a cross-sectional view at position P2. The shape retaining spacer 21 has guide grooves 27 for guiding the wire 10, as shown in FIGS. 3(b) and 3(c). 3B and 3C, the guide grooves 27 are arranged in two parallel rows within the cross section of the strand rod 1, and each row has three or four guide grooves. 27 are arranged in a straight line. Here, the shape-retaining spacer 21 is composed of two parts including guide grooves 27 arranged in rows.

Then, as shown in FIGS. 3(b) and 3(c), each wire 10 is guided by each guide groove 27 of the shape retaining spacer 21 at positions P1 and P2. At this time, each strand 10 extends so that the helical shape gradually loosens (the helical pitch gradually increases) in the transition region 34 (FIG. 2), and extends linearly in the connection region 33 (FIG. 2). ing.

Subsequently, a stretcher (e.g., spring, weight, etc.) is attached to each wire 10 at the tip 13 to pull each wire 10 approximately in the direction of the axis W, and the same tensile force is applied to each wire 10. do. Then, each strand 10 of the rod end portion 17 is reheated while the tensile force is applied, and then cooled to adjust the shape of each strand 10 and remove slack. In addition, the connection region 33 of each wire 10 extends linearly in the direction of the axis W in general. After that, the shape retaining spacers 21 at positions P1 and P2 are removed.

Guided by the shape-retaining spacers 21, the cross section 35 of the connection region 33 is deformed from the normal arrangement of the wires 10 to the arrangement shown in FIGS. 3(b) and 3(c). That is, the seven strands 10 of the connection region 33 are divided into a layer composed of three strands 10 linearly aligned in the cross section and a layer composed of four strands 10 linearly aligned parallel to this. , is divided into two. A layer composed of a plurality of wires 10 arranged one-dimensionally in the cross section 35 of the connection region 33 in this way is called a wire bundle layer 30 . One of the two wire bundle layers 30 formed at the rod end portion 17 of the strand rod 1a is called a wire bundle layer 31a, and the latter is called a wire bundle layer 32a. The wire bundle layer 31 a consists of three wires 10 , and the wire bundle layer 32 a consists of four wires 10 . Similarly, one of the two wire bundle layers 30 formed at the rod end portion 17 of the strand rod 1b is called a wire bundle layer 31b, and the latter is called a wire bundle layer 32b. The wire bundle layer 31 b consists of three wires 10 , and the wire bundle layer 32 b consists of four wires 10 .

Subsequently, as shown in FIGS. 4A and 4B, the connecting regions 33 of the coaxially opposed strand rods 1a and 1b are overlapped. When the connecting regions 33 facing each other are overlapped in this way, the wires 10 included in each connecting region 33 enter the gaps between the opposing wires 10 so as to be misplaced. In the case of this embodiment, in the overlapping portion 37, the wire bundle layers 30 of the strand rods 1a and 1b are alternately laminated. That is, in the overlapping portion 37, as shown in FIG. 4C, the four wire bundle layers 30 are laminated in the order of wire bundle layers 31b, 32a, 32b, and 31a. Here, a buffer sheet may be interposed between each of the wire bundle layers 30 as necessary. A polyurea sheet, for example, is used as the cushioning sheet.

After that, by impregnating the overlapping portion 37 with an adhesive and hardening it, the connection regions 33 of the strand rods 1a and 1b are joined together. After that, by removing the binding bands 15 of the strand rods 1a and 1b, the connection of the strand rods 1a and 1b is completed.

The strand rod connection structure 90 (FIG. 4) of the present embodiment completed in this way is constructed by connecting two strand rods 1a and 1b formed by twisting a plurality of thermoplastic strands 10 together as ends of the rods in the longitudinal direction. It is a strand rod connection structure in which end portions 17 are connected to each other. In this connection structure, the rod end portion 17 of each of the two strand rods 1 has a plurality of wire bundle layers 30 formed by dividing the rod end portion 17 into a plurality of pieces. The strand bundle layer 30 is composed of a plurality of strands 10 one-dimensionally arranged in a cross section. At the overlapping portion 37, the connection regions 33 of the rod end portions 17 are joined together in a state in which the wire bundle layers 30 of the two strand rods 1a and 1b are alternately laminated.

According to the connection method and connection structure of the present embodiment, the wires 10 of the rod end portions 17 of the strand rods 1a and 1b are divided into a plurality of simple-shaped wire bundle layers 30 and laminated alternately. , relatively good workability. The cross-sectional arrangement of the wire bundle layers 31b, 32a, 32b, and 31a in the overlapping portion 37 as shown in FIG. 4C is an example, and can be changed as appropriate. For example, in the example of FIG. 4(c), the wire bundle layers 31b, 32a, 32b, and 31a are arranged so that the wire strands 10 are arranged in a rectangular grid in the cross section, but FIG. Alternatively, as shown in FIG. 5B, the wire bundle layers 31b, 32a, 32b, 31a may be arranged such that the wires 10 are partially arranged in a triangular lattice. According to the arrangement of FIG. 5(a) or 5(b), compared with the arrangement of FIG. 4(c), the number of contact points between the strand rods 1a and 1b is increased and the connection strength is increased. It is preferable in that respect. In addition, according to the arrangement of FIG. 5(a), the cross section of the overlapping portion 37 (that is, the connection portion between the strand rods 1) is compact compared to the arrangement of FIG. 4(c) or FIG. 5(b). This is preferable in that the outer periphery of the overlapped portion 37 is close to a circle.

As can be understood geometrically, the wires 10 of the strand rods 1a and 1b are in contact with each other at 10 points according to the arrangement shown in FIG. Contact is made at 16 points, and contact is made at 17 points according to the arrangement of FIG. 5(b).

Further, the arrangement and arrangement order of the wires k1 to k7 and j1 to j7 in the wire bundle layer 30 are not limited to those shown in FIGS. It may be determined as appropriate from the viewpoint of making the bending radius and bending angle of the wire 10 as loose as possible. For example, instead of the arrangement of FIG. 3, the arrangement of the wires 10 as shown in FIG. 5(c) may be employed. Although FIG. 5(c) shows the wires k1 to k7 of the strand rod 1a, the same applies to the wires j1 to j7 of the strand rod 1b.

The length of the transition region 34 may be set appropriately in consideration of the allowable value of the bending inner radius and bending angle of the wire 10 so as not to locally bend the wire 10 . The length of the transition region 34 may be approximately the same as the twist pitch of the strand rod 1, for example. The length of the connecting region 33 may be 10 to 25 times the diameter of the strand rod 1 . Therefore, the length of the rod end portion 17 should be set appropriately in consideration of the transition region 34 and the connection region 33 .

[Second embodiment]
Next, a second embodiment of the method for connecting strand rods according to the present invention will be described with reference to FIG. As in the first embodiment, the connection method of the present embodiment is a method of constructing a strand rod connection structure (joint structure) by connecting one end portions in the longitudinal direction of two strand rods 1 (see FIG. 1). is. FIG. 6(a) shows a cross section 35 of the connection region 33 of the strand rod 1 in this embodiment, and FIGS. indicates In the connection method of the present embodiment, after the above-described first step is performed for the two strand rods 1 (strand rods 1a and 1b), the second step described below is performed.

(Second step)
Each strand 10 of the rod end portion 17 unwound in the first step is cooled and rehardened while being extended approximately linearly in the longitudinal direction of the strand rod 1 . Next, in the connecting region 33 of the rod end portion 17, as shown in FIG. 6A, one of the side wires k2 to k7 (here, side wire k6) is moved from the normal arrangement state of the wire 10. ) is displaced by the diameter of the wire 10 in the cross section so that the side wire k6 and the side wire k5 are in contact with each other. Note that "displaced within the cross section" means displaced in any direction orthogonal to the extending direction of the strand rod 1 (the direction of the axis W).

As a result of the above processing, the cross section 35 of the connection region 33 is formed with an uneven portion 36 due to the displacement of the side line k6. That is, in the cross section 35, a notch concave portion is generated at the original position of the lateral line k6, and a convex portion is generated at the displacement destination of the lateral line k6. Here, as in the first embodiment, shape-retaining spacers 21 that guide each strand 10 according to the shape of the cross section 35 may be attached at positions P1 and P2. Subsequently, as in the first embodiment, the slack of each wire 10 is removed using a stretcher so that the connection region 33 of each wire 10 extends linearly in the direction of the axis W. do.

Subsequently, the connection regions 33 of the strand rods 1a and 1b coaxially opposed to each other are superimposed (see FIGS. 4A and 4B), and the superimposed portion 37 is shown in FIG. , the uneven portions 36 of the cross sections 35 of the strand rods 1a and 1b are engaged with each other. That is, the wire j6 enters into the notch recess at the original position of the wire k6, and the wire k6 enters into the notch recess at the original position of the wire j6.

After that, as in the first embodiment, by impregnating the overlapping portion 37 with an adhesive and curing it, the connection regions 33 of the strand rods 1a and 1b are joined together, and the binding band 15 is removed. The connection of the strand rods 1a and 1b is completed.

The strand rod connection structure 90 (FIG. 4) of the present embodiment completed in this way is constructed by connecting two strand rods 1a and 1b formed by twisting a plurality of thermoplastic strands 10 together as ends of the rods in the longitudinal direction. It is a strand rod connection structure in which end portions 17 are connected to each other. In this connection structure, the rod end portion 17 of each of the two strand rods 1a and 1b is displaced in the section by a portion of the side wire (for example, the side wire k6) of the strand 10. The connection region 33 has an uneven shape portion 36 formed in a cross section 35, and the connection region 33 of the rod end portion 17 is in a state where the uneven shape portions 36 of the two strand rods 1a and 1b are engaged with each other. are joined together.

The shape of the cross section 35 at the overlapped portion 37 as shown in FIG. 6B is an example, and can be changed as appropriate. For example, the shape of the cross section 35 as shown in FIGS. 6(c) and 6(d) may be adopted. According to the arrangement of FIG. 6(b), in each of the strand rods 1a and 1b, it is only necessary to displace one strand 10 within the cross section by the diameter. ) arrangement. 6(b) and (c) are preferable to the arrangement shown in FIG. 6(d) in that the cross section of the overlapping portion 37 becomes compact.

As can be understood geometrically, the wires 10 of the strand rods 1a and 1b are in contact with each other at nine points according to the arrangement shown in FIG. There are 7 points of contact, and 6 points of contact according to the arrangement of FIG. 6(d).

[Third Embodiment]
Next, a third embodiment of the method for connecting strand rods according to the present invention will be described with reference to FIG. As in the first embodiment, the connection method of the present embodiment is a method of constructing a strand rod connection structure (joint structure) by connecting one end portions in the longitudinal direction of two strand rods 1 (see FIG. 1). is.
FIG. 7(a) shows a cross section 35 of the connecting region 33 of the strand rod 1 in this embodiment, and FIG. 7(b) shows a central cross section of the overlapping portion 37 between the strand rods 1a and 1b. In the connection method of the present embodiment, after the above-described first step is performed for the two strand rods 1 (strand rods 1a and 1b), the second step described below is performed.

(Second step)
For each of the strand rods 1a and 1b, after the wire 10 is unwound in the first step, slack in each wire 10 is removed using a stretcher in the same manner as in the first embodiment, and each wire 10 , the connection region 33 extends linearly in the direction of the axis W.

Subsequently, the connecting regions 33 of the coaxially opposed strand rods 1a and 1b are overlapped (see FIGS. 4A and 4B). At this time, in the connection region 33 of each strand rod 1a, 1b, as shown in FIG. Radial displacement to the outer peripheral side. Moreover, the core wires k1 and j1 are displaced from the central position by the radius of the wire 10 in the cross section. 7(b), the side lines k2 to k7 of the strand rod 1a and the side lines j2 to j7 of the strand rod 1b are alternately arranged in the cross section in the circumferential direction. and That is, the lateral lines are arranged in the circumferential direction in the order of lateral lines k2, j2, k3, j3, . Furthermore, near the center of the space surrounded by the lateral lines k2 to k7 and j2 to j7, the core wire k1 of the strand rod 1a and the core wire j1 of the strand rod 1b are arranged side by side so as to circumscribe each other.

After that, as in the first embodiment, by impregnating the overlapping portion 37 with an adhesive and curing it, the connection regions 33 of the strand rods 1a and 1b are joined together, and the binding band 15 is removed. The connection of the strand rods 1a and 1b is completed. In the overlapping portion 37, the space surrounded by the lateral lines k2 to k7 and j2 to j7 (the space in which the core wires k1 and j1 exist) may be filled with resin or the like.

The strand rod connection structure 90 (FIG. 4) of the present embodiment completed in this way is constructed by connecting two strand rods 1a and 1b formed by twisting a plurality of thermoplastic strands 10 together as ends of the rods in the longitudinal direction. It is a strand rod connection structure in which end portions 17 are connected to each other. In this connection structure, the side wires k1 to k7 and j1 to j7 of the wires 10 of the two strand rods 1a and 1b are arranged alternately in the circumferential direction in the cross section, and the rod ends 17 The connection regions 33 are joined together.

According to the connection method of the present embodiment, the side wires k2 to k7 and j2 to j7 at the rod ends 17 of the strand rods 1a and 1b are radially displaced to the outer peripheral side without changing the arrangement order. , the state of each wire 10 can be transitioned relatively easily. As can be understood geometrically, the wires 10 of the strand rods 1a and 1b are in contact with each other at 13 points.

[Fourth embodiment]
Next, a fourth embodiment of the strand rod connecting method according to the present invention will be described. As in the first embodiment, the connection method of the present embodiment is a method of constructing a strand rod connection structure (joint structure) by connecting one end portions in the longitudinal direction of two strand rods 1 (see FIG. 1). is. In the connection method of the present embodiment, after the above-described first step is performed for the two strand rods 1 (strand rods 1a and 1b), the second step described below is performed.

(Second step)
For each of the strand rods 1a and 1b, after the wire 10 is unwound in the first step, slack in each wire 10 is removed using a stretcher in the same manner as in the first embodiment, and each wire 10 , the connection region 33 extends linearly in the direction of the axis W. Subsequently, the connecting regions 33 of the coaxially opposed strand rods 1a and 1b are overlapped (see FIGS. 4A and 4B). At this time, the method of overlapping the connection regions 33 is the same as in the third embodiment. That is, the cross section of the overlapped portion 37 is in the state shown in FIG. 7(b).

After that, the overlapping portion 37 is heated to 80 to 250° C., and in a state in which the overlapping portion 37 of the strand rods is softened, one strand rod 1a is placed against the other strand rod 1b as shown in FIG. and twist relatively around the axis W. The twisting direction at this time is the direction in which the twist pitch of the connection region 33 of the strand rods 1a and 1b is reduced (the direction in which the strand rods 1a and 1b are twisted tightly). Also, the twist angle is such that the twist pitch of the connection region 33 matches the original twist pitch of the strand rod 1 . Alternatively, the twist angle may be such that the twist pitch of the connection region 33 is smaller than the original twist pitch of the strand rod 1 . Such a twisting operation may be performed with a predetermined connecting device for connecting the strand rods 1a, 1b.

By twisting the strand rods 1 relative to each other as described above, the arrangement of the strands 10 in the cross section of the overlapping portion 37 is not maintained in the state shown in FIG. will do. Then, the softened strands 10 of the strand rods 1a and 1b are crimped and welded to each other, thereby joining the connection regions 33 of the strand rods 1a and 1b. Thereafter, the overlapped portion 37 is cooled and the binding band 15 of the strand rods 1a, 1b is removed, thereby completing the connection of the strand rods 1a, 1b.

According to the connection method of the present embodiment, the strand rods 1a and 1b are connected to each other by the welding of the strands 10 and the twisting resistance of the strands 10, so that a strong connection between the strand rods 1a and 1b can be obtained. be done. Further, since the twisting force acts to tighten the overlapped portion 37 radially inward, it is not necessary to cover the overlapped portion 37 with a separate member such as a heat-shrinkable tube.

As described above, instead of joining the connection regions 33 of the strand rods 1a and 1b by welding the wires 10 together by heating, the overlapped portion 37 may be impregnated with an adhesive and hardened. good. Alternatively, after the wire strands 10 are welded to each other by heating, the overlapping portion 37 may be impregnated with an adhesive and hardened.

[Fifth embodiment]
Next, a description will be given of a fifth embodiment of the strand rod connecting method according to the present invention. As in the first embodiment, the connection method of the present embodiment is a method of constructing a strand rod connection structure (joint structure) by connecting one end portions in the longitudinal direction of two strand rods 1 (see FIG. 1). is. In the connection method of the present embodiment, after the above-described first step is performed for the two strand rods 1 (strand rods 1a and 1b), the second step described below is performed.

(Second step)
As in the fourth embodiment, after the wires 10 are unwound in the first step, slack in each wire 10 is removed using a stretcher so that the connection region 33 of each wire 10 extends substantially in the direction of the axis W. so that it extends in a straight line toward the After that, in the same manner as in the fourth embodiment, the connection regions 33 of the coaxially opposed strand rods 1a and 1b are overlapped (see FIGS. 4A and 4B). At this time, the cross section of the overlapped portion 37 is in the state shown in FIG. 7(b).

After that, while heating the overlapping portion 37 to 80 to 250° C., as shown in FIG. do. Specifically, for example, the tip of the side wire k2 extending radially outward from between the side wire j2 and the side wire j3 at the central portion of the overlapped portion 37 is attached to the side wire on the side of the strand rod 1b near the binding band 15. It is sufficient to insert it into the gap between j3 and the lateral line j4 and let it slip inside. Note that the tip of the side wire k2 that has slipped inside through the gap between the side wires j3 and j4 may be pulled out further outside through the gap between the side wires j4 and j5, and the pulled-out ends are further connected to the side wires j5 and j6. You may make it slip inside from the clearance gap of. Such an operation is performed for the lateral lines k2 to k7. Similarly, the side wires j2 to j7 of the strand rod 1b are also woven into the overlapping portion 37 with the other side wires k2 to k7.

Next, while continuing to heat the overlapped portion 37 , a radial compressive force is applied to the overlapped portion 37 . Here, for example, the overlapped portion 37 may be covered with a heat-shrinkable tube, and a compressive force may be applied to the overlapped portion 37 by the shrinkage force of the heat-shrinkable tube. Due to the above compressive force, the arrangement of the wires 10 in the cross section of the overlapped portion 37 is not maintained as shown in FIG. Then, the softened strands 10 of the strand rods 1a and 1b are crimped and welded to each other, thereby joining the connection regions 33 of the strand rods 1a and 1b. Thereafter, the overlapped portion 37 is cooled and the binding band 15 of the strand rods 1a, 1b is removed, thereby completing the connection of the strand rods 1a, 1b.

The strand rod connection structure 90 (FIG. 4) of the present embodiment completed in this way is constructed by connecting two strand rods 1a and 1b formed by twisting a plurality of thermoplastic strands 10 together as ends of the rods in the longitudinal direction. It is a strand rod connection structure in which end portions 17 are connected to each other. In this connection structure, the side wires k1 to k7 and j1 to j7 of the wires 10 of the two strand rods 1a and 1b are arranged alternately in the circumferential direction in the cross section, and the two strand rods 1a and 1b The connecting regions 33 of the rod ends 17 are joined together in a state where the tip of the side wire is woven into the side wire of the other strand rod in each of the strand rods 1b.

Note that the heat-shrinkable tube may be left in the overlapping portion 37 even after the connection of the strand rods 1a and 1b is completed. In the heat-shrinkable tube to be left in this way, the outer peripheral surface of the heat-shrinkable tube may be processed to have unevenness or the like. According to this configuration, when the connecting portion of the strand rod 1 including the heat-shrinkable tube is embedded in concrete, the adhesion between the strand rod 1 and concrete is improved.

According to the connection method of the present embodiment, by weaving the wires 10 of the strand rods 1a and 1b, the number of points of contact between the wires 10 increases, thereby obtaining a stronger connection between the strand rods 1a and 1b. In addition, the braided wire 10 is mechanically engaged with the wire 10 of the mating strand rod 1 (for example, hooked like a hook), thereby increasing the connection strength.

Note that one step of the fourth embodiment may be combined with the connection method of the present embodiment. That is, after the side lines k2 to k7 and j2 to j7 of the strand rods 1a and 1b are woven into the other side lines j2 to j7 and k2 to k7 in the overlapping portion 37, the strand rods are You may add the process which twists 1a relatively with respect to the strand rod 1b. After that, the overlapped portion 37 is covered with a heat-shrinkable tube, and a compressive force is applied to the overlapped portion 37 by the shrinkage force of the heat-shrinkable tube.

Next, functions and effects of the first to fifth embodiments described above will be described. The connection method according to the first to fifth embodiments described above is a strand rod connection method in which two strand rods 1 formed by twisting a plurality of thermoplastic strands 10 are connected at their longitudinal ends. , the following first step and second step. In the first step, the rod ends 17 of each of the two strand rods 1 are heated to loosen the softened wires 10 . In the second step, in each of the two strand rods 1, the connection regions 33 of the two strand rods 1 are connected to each other in a state where the arrangement of the rod ends 17 in the cross section 35 of the wire 10 is different from the normal arrangement. The rod ends 17 are joined together by entangling them.

In addition, the strand rod connection structure 90 according to the above-described first to fifth embodiments connects two strand rods 1 formed by twisting a plurality of thermoplastic strands 10 at their longitudinal ends. It is a rod connection structure. In this connection structure, in each of the two strand rods 1, the rod end portions of the two strand rods 1 are arranged in a state different from the normal arrangement in the cross section of the wire 10 of the rod end portion 17. 17 are entwined and joined together.

According to such a connection method and connection structure, the wires 10 are in contact with each other in a state where the arrangement of the wires 10 in the cross section is different from the normal arrangement, so that a strong connection between the strand rods 1 can be achieved. be possible. That is, for example, when the ends of the strand rod 1 on which the wire 10 is normally arranged are adjacent to each other in the radial direction and joined, or when the end face of the strand rod 1 on which the wire 10 is normally arranged is axially The number of contact points between the strands 10 increases compared to the case where the strands are butted and covered with a sleeve for joining, and as a result, a strong connection can be achieved.

The present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art, including the embodiment described above. Moreover, it is also possible to configure a modified example using the technical matters described in the above-described embodiments. You may use it, combining the structure of each embodiment suitably.

For example, in the embodiment, the connection method and connection structure of the 7-twisted strand rod 1 have been described. The present invention can be applied to Further, when the wires 10 of the strand rods 1a and 1b are welded to each other, the welding is not limited to welding by heating the overlapped portion 37, and welding using a laser, welding using electric heat, or the like may be performed. .

In addition, in the first to third embodiments, the method of joining the connecting regions 33 of the strand rods 1a and 1b is not limited to the method using the adhesive as described above. That is, instead of impregnating the overlapping portion 37 with an adhesive and curing it, the connection regions 33 of the strand rods 1a and 1b may be joined together by welding the wires 10 together by heating the overlapping portion 37. good. In addition, in the fourth and fifth embodiments, instead of joining the connection regions 33 of the strand rods 1a and 1b by welding the strands 10 by heating, the overlapped portion 37 is impregnated with an adhesive and cured. You can let it run. Alternatively, in the first to fifth embodiments, after the wire strands 10 are welded together by heating the overlapped portion 37, the overlapped portion 37 may be impregnated with an adhesive and hardened.

In the case of joining the connection regions 33 of the strand rods 1a and 1b by welding the wires 10 to each other by heating the overlapping portion 37, the process of impregnating the overlapping portion 37 with an adhesive may be omitted. Thus, the construction period can be shortened, the quality can be improved by reducing the risk of defective filling of the adhesive, and the construction error of the strand rod 1 can be absorbed.

Reference Signs List 1 Strand rod 10, k1 to k7, j1 to j7 Element wire, k2 to k7, j2 to j7 Side line 17 Rod end 35 Cross section 36 Concavo-convex portion 30, 31a, 32a, 31b, 32b... Wire bundle layer, 90... Connection structure.

Claims (8)

A strand rod connection method for connecting two strand rods formed by twisting a plurality of thermoplastic strands at their longitudinal ends,
A first step of heating the ends of each of the two strand rods to loosen the softened strands;
In each of the two strand rods, the end portions of the two strand rods are entangled and joined in a state where the end portions are arranged in a cross section different from a normal arrangement. and a second step. In the second step,
In each of the two strand rods, forming a plurality of strand bundle layers composed of a plurality of strands arranged one-dimensionally in a cross section by dividing the end into a plurality of strands,
2. The method of connecting a strand rod according to claim 1, wherein the ends of the two strand rods are joined while the bundle layers of the two strand rods are alternately laminated. In the second step,
In each of the two strand rods, some side wires of the strands of the end are displaced in the cross section to form an uneven shape in the cross section of the end,
2. The method of connecting a strand rod according to claim 1, wherein the ends of the two strand rods are joined while the uneven portions of the two strand rods are engaged with each other. In the second step,
In each of the two strand rods, each side wire of the strands of the end portion is radially displaced to the outer peripheral side in the cross section,
The strand rod connection method according to claim 1, wherein the ends of the two strand rods are joined while the lateral lines of the two strand rods are arranged alternately in the circumferential direction in the cross section. In the second step,
In each of the two strand rods, each side wire of the strands of the end portion is radially displaced to the outer peripheral side in the cross section,
Arranging the ends of the two strand rods so that the lateral lines of the two strand rods are alternately arranged in the circumferential direction in the cross section,
2. The method of connecting strand rods according to claim 1, wherein one of the strand rods is twisted relative to the other strand rod to join the ends. In the second step,
In each of the two strand rods, each side wire of the strands of the end portion is radially displaced to the outer peripheral side in the cross section,
Arranging the ends of the two strand rods so that the lateral lines of the two strand rods are alternately arranged in the circumferential direction in the cross section,
2. The method of connecting strand rods according to claim 1, wherein in each of the two strand rods, the ends of the lateral wires are woven into the lateral wires of the other strand rod, and the ends are joined together. A strand rod connection structure that connects two strand rods formed by twisting a plurality of thermoplastic strands at their longitudinal ends,
In each of the two strand rods, the end portions of the two strand rods are intertwined and joined in a state where the end portions are arranged in a cross section different from a normal arrangement. and
Each of the ends of the two strand rods has a plurality of wire bundle layers, each of which is divided into a plurality of ends and composed of a plurality of the wires arranged one-dimensionally in a cross section. ,
The strand rod connection structure, wherein the end portions of the two strand rods are joined to each other in a state in which the wire bundle layers of the two strand rods are alternately laminated. A strand rod connection structure that connects two strand rods formed by twisting a plurality of thermoplastic strands at their longitudinal ends,
In each of the two strand rods, the end portions of the two strand rods are intertwined and joined in a state where the end portions are arranged in a cross section different from a normal arrangement. and
The strand rod connection structure, wherein the ends of the two strand rods are joined to each other in a state in which side wires of the strands of the two strand rods are alternately arranged in a circumferential direction in a cross section.

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