JP3816665B2 - Cable terminal fixing structure using fiber reinforced plastic strand and manufacturing method thereof - Google Patents

Description

【００６５】
この表から明らかなように、本発明の実施例にかかる構造によれば、比較例にかかる構造（被覆体を省略した構造）に比して定着効率を飛躍的に向上させることが可能になる。これは、被覆体のない比較例構造では、特にソケットの入口近辺での素線の応力集中が厳しく、この部分で破断しやすいのに対し、本発明の実施例にかかる構造では、素線と高剛性体との間に被覆体が介在することによって高剛性体から素線に加えられる圧力が軸方向に分散され、その結果、応力集中が効果的に緩和されるためである。
【００６６】
【発明の効果】
以上のように本発明は、ＦＲＰ製素線の端末が挿入されるソケット内に端末側から離れるに従って小径となる方向のテーパー状内周面を形成し、少なくとも端末側領域に充填される定着体をバインダ中に当該バインダよりも剛性の高い複数の高剛性体を含有する複合定着体で構成するとともに、少なくともこの複合定着体が充填される領域において、各素線の表面に当該表面を個別に被覆する被覆体を固着したものであるので、定着体内の高剛性体によって充分な定着力を確保しながら、各高剛性体から素線に加えられる局部的な押付力が素線表面に分散されると同時に、この定着体がＦＲＰ素線に対してその軸方向と直交する方向に押圧する力を軸方向に分散し、この２つの作用により、素線に直交する方向の押圧力の最大値を有効に下げることができる。
【００６７】
また本発明は、上記端末定着構造の製造方法であって、ソケット内に各素線及びその被覆体を挿入する素線挿入工程と、ソケットの端末側端部と反対側の端部を上に向けた状態で当該反対側の端部からソケット内に流動状態のバインダと複数の高剛性体との複合定着体を注入する定着体注入工程と、上記ソケット内のソケット内の高剛性体に外力を加えてその充填密度を端末側端部に近いほど高くする高密度化工程と、上記バインダを硬化させる硬化工程とを順に行うものであるので、ソケット内の高剛性体の充填密度を高め、ひいては定着体全体の剛性を有効に高めるとともに、端末側に向かうに従って高くなるような充填密度勾配（すなわち剛性勾配）を自動的に形成し、応力集中を緩和できる構造を容易に製造することができる効果がある。
【図面の簡単な説明】
【図１】本発明にかかるＦＲＰ製素線を用いたケーブル端末定着構造の断面正面図である。
【図２】（ａ）は（ｂ）のＡ−Ａ線断面図、（ｂ）は上記端末定着構造の側面図である。
【図３】図２（ａ）のＢ部拡大図である。
【図４】（ａ）は素線に直接高剛性体が押付けられる場合の応力分布を示した図、（ｂ）は素線表面に配された被覆体に高剛性体が押付けられる場合の応力分布を示した図である。
【図５】（ａ）は本発明構造のモデル図、（ｂ）は（ａ）のモデル図に対応する素線応力分布を示すグラフである。
【図６】（ａ）は被覆体の厚みと定着効率との関係を示すグラフ、（ｂ）はソケット内テーパー角度と定着効率との関係を示すグラフである。
【図７】（ａ）（ｂ）（ｃ）は本発明にかかるケーブル端末定着構造の製造工程図である。
【図８】（ａ）（ｂ）（ｃ）は本発明にかかるケーブル端末定着構造の製造工程図である。
【図９】（ａ）（ｂ）（ｃ）（ｄ）（ｅ）は本発明にかかるケーブル端末定着構造の製造工程図である。
【図１０】（ａ）は従来のケーブル端末構造の一例を示す断面正面図、（ｂ）は断面側面図である。
【符号の説明】
１０ 素線
１２ 筒状被覆体
１２ａ テーパー部
１４ コイルばね状被覆体
１６ 被覆層
２０ ソケット
２２ ソケット本体部
２４ テーパー状内周面
２８ フラット部
３０ バックプレート（背圧付与部材）
３２ 貫通孔
５０ バインダ
５２ 高剛性体
６０ バイブレータ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cable used for a tension member of a civil engineering building structure and the like, and relates to a cable terminal fixing structure using a fiber reinforced plastic (hereinafter referred to as “FRP”) strand and a manufacturing method thereof. is there.
[0002]
[Prior art]
In recent years, FRP strands have attracted attention as strands of cables used for tendons for civil engineering structures. This FRP is a composite material composed of a non-metallic fiber such as carbon fiber and an epoxy resin, and has a very high tensile strength while being lightweight, and has characteristics particularly suitable as a tension material for a structure.
[0003]
Conventionally, as shown in FIGS. 10A and 10B, a cable terminal fixing structure using such an FRP strand is known. In the figure, the terminal portions of a plurality of cable strands 90 are inserted into a cylindrical socket 92, and the inlet side (right side in FIG. 10A) opening of the socket 92 is closed by a spacer plate 94. . The gaps in the socket 92 (the gaps between the strands 90 and the gap between the strands 90 and the inner peripheral surface of the socket 92) are filled with a fixing body 96 made of epoxy resin or the like. The wire 90 is fixed by bonding. Further, the inner peripheral surface of the inlet side of the socket 92 is a tapered surface 93 whose diameter is reduced toward the inlet, and in this region, the tensile force applied to the wire 90 and the fixing member 96 bonded thereto (see FIG. 10 (a) is converted into a compressive force inward in the radial direction of the socket), and the fixing force of the strand 90 is enhanced by this compressive force.
[0004]
However, in this structure, fixing is basically performed only by the adhesive force between the strand 90 and the fixing body 96. Therefore, in order to perform sufficient fixing, the socket 90 must be very long. Inexpensive and compact are difficult. In addition, since the elastic modulus of the fixing member 96 is low and the shape of the fixing member itself cannot be maintained particularly under a high load, there is a disadvantage that it cannot be applied to a large-capacity FRP cable.
[0005]
Therefore, Japanese Patent Publication No. 9-501748 discloses a structure in which a large number of high-rigid bodies such as steel balls and glass balls are contained in an epoxy resin as a fixing body. According to this configuration, the rigidity of the entire fixing body can be increased and its deformation can be suppressed, and the high-rigidity body in the fixing body can receive the compressive force inward in the radial direction caused by the presence of the tapered surface in the socket. By pressing with a strong force, the wire terminal is fixed by the frictional force. Therefore, it is possible to ensure a sufficient fixing force without particularly increasing the socket length.
[0006]
[Problems to be solved by the invention]
As described above, FRP strands have the excellent characteristics of being lightweight and having high tensile strength, but have the disadvantage that they are weak and brittle with respect to the force (including shearing force) in the direction perpendicular to the axial direction. Here, in the above-mentioned JP-T-9-501748, a large number of high-rigid bodies having high rigidity are pressed against the surface of the strand with a small contact area (substantially point contact). There is a possibility that the pressure maximum value in a disadvantageous direction (that is, a direction orthogonal to the axial direction) becomes very high.
[0007]
In view of such circumstances, the present invention is a cable using an FRP strand that can effectively reduce stress generated in a direction perpendicular to the axial direction of the FRP strand while securing a sufficient fixing force. It is an object of the present invention to provide a terminal fixing structure and a manufacturing method thereof.
[0008]
[Means for Solving the Problems]
As means for solving the above-described problems, the present invention provides a fixing body for fixing a plurality of fiber-reinforced plastic strand terminals into a socket and fixing the strand ends in a gap in the socket. In a cable terminal fixing structure using a fiber reinforced plastic element wire filled with a taper-shaped inner peripheral surface in a direction in which the diameter becomes smaller as the distance from the terminal side increases in the socket But Formation Is , Fixing body filled in at least terminal side region But , Binder When, More rigid than the binder But high Large enough to enter the gap between the above strands Number of high-rigid bodies And composed of Composite fixing body And In addition, at least in the region where the composite fixing body is filled, a covering body that individually covers the surface of each strand. But Fixation Has been Is.
[0009]
According to this structure, since the high-rigidity body is included in the binder of the fixing body filled in at least the terminal side region, the fixing body is less likely to be deformed and can withstand the use of a large-capacity cable. can do. Also, the high rigidity body is pressed against the surface of the cover by the taper action on the inner surface of the socket, and the strands are held by the frictional force generated by this pressing. Compared to the structure that fixes only by the adhesive force between the strands and the fixing body. It is possible to secure a sufficient fixing force while reducing the socket length. In addition, since a covering is interposed between each high-rigid body and the strand, the local pressing force applied to the strand from each high-rigid body is dispersed on the surface of the strand, and at the same time from the fixing body. The pressing force acting on the strands is dispersed in the axial direction, the maximum value of stress generated in the strands in the direction perpendicular to the axial direction is lowered, and damage to the fibers in the strands is prevented.
[0010]
In this fixing structure, stress tends to concentrate near the inlet side end of the socket due to the bending load acting on the strands. This stress concentration can also be mitigated by the presence of the covering body, The overall stress maximum can be greatly reduced.
[0011]
Further, by adhering the covering to the surface of the strand through the resin layer, the stress is dispersed not only by the covering but also by the adhesive resin layer, and the stress maximum value is further reduced.
[0012]
Here, if at least a part of the covering body is a cylindrical covering body, the strands can be more reliably protected from the highly rigid body. On the other hand, if at least a part of the covering body is made of a flexible member that can be bent and deformed more easily than the cylindrical covering body, it is possible to bend the wire into a shape corresponding to the socket at the arrangement site. become. As the flexible member, a soft tube or a thin film wrapping may be used, but if it is a coil spring-like covering, it can follow the strands more than the soft tube, and it is more durable than the thin film wrapping. can do.
[0013]
The specific shape of the high-rigid body is not limited, but if it is spherical, the packing density can be made uniform, there is no risk of damaging the covering, and the direction of the high-rigid body is not affected. Therefore, the contact state between the highly rigid body and the covering body can be made constant.
[0014]
The material of the high-rigid body is not particularly limited as long as it is relatively high in rigidity. However, this high-rigid body is made of a material having a specific gravity greater than that of the binder (more preferably, a steel material that has a relatively large specific gravity and is easily available. Etc.), a terminal fixing structure with a high degree of filling of the high-rigid body can be obtained by the manufacturing method described later, and the packing density of the high-rigid body can be increased toward the terminal side. Thus, by giving a gradient to the packing density of the high-rigidity body, that is, by giving a gradient to the rigidity of the fixing body, it becomes possible to further disperse the wire stress that tends to concentrate on the socket inlet side in the axial direction.
[0015]
The material of the element wire is not particularly limited as long as it is FRP. However, when the element wire is composed of FRP having conductivity such as carbon fiber reinforced plastic (CFRP), the above covering is used. It is possible to prevent electrocorrosion by constituting the material with an insulating material.
[0016]
The region where the taper surface is formed in the socket may be set as appropriate, but when the taper surface reaches the socket inlet end, the direction perpendicular to the axial direction of the strand is caused by the taper action. The position where the load acting on the cable becomes the maximum and the position where the load acting on the element wire in the direction perpendicular to the axial direction due to the bending load of the cable overlaps the socket inlet end, and the stress The degree of concentration increases. On the other hand, the end of the socket opposite to the terminal side is a flat portion whose inner diameter is constant in the axial direction, and the socket inlet end is not subjected to a taper load so that the stress concentration described above is achieved. Can be avoided.
[0017]
Furthermore, if the thickness of the flat part is made smaller than the thickness of the other parts to make the flat part easy to bend, the bending load acting on the cable can be dispersed by the bending of the flat part. Stress can be further relaxed.
[0018]
The terminal of each strand may be embedded in the fixing body, but the back of the fixing body that is in contact with the fixing body from the rear in a state where the terminal of each strand is fixed at a position behind the fixing body filled in the socket. If a pressure applying member is provided, it is possible to apply a back pressure (pressure from the terminal side) to the fixing body by using a tensile load acting on each strand, and this back pressure further increases the fixing force due to the taper action. It becomes possible to increase.
[0019]
And by fixing the terminal of each strand to the back pressure applying member in a state where the terminals are separated from each other, an appropriate gap can be reliably maintained between the strand ends, and a high-rigidity body is provided between the gaps. Can be invaded. Thereby, it is possible to increase the isotropic property of the pressing force applied from the high-rigidity body to the covering body, and to prevent the occurrence of local bending stress of the strands due to the deviation of the direction of the pressing force.
[0020]
The means for fixing each strand end to the back pressure applying member is not particularly limited, but the end portion of the covering covering each strand is a tapered portion that expands toward the end, and this tapered portion is fitted. If a possible taper-shaped through hole is provided in the back pressure application member, it is possible to reliably prevent the strands and the covering from coming out from the back pressure application member.
[0021]
The present invention also relates to a method for manufacturing the terminal fixing structure, wherein a strand insertion step of inserting each strand and its covering into the socket, and an end opposite to the end on the end of the socket on the upper side. A fixing body injection step of injecting a composite fixing body of a fluidized binder and a plurality of high rigidity bodies into the socket from the opposite end, and applying an external force to the high rigidity body in the socket in the socket In addition, a densification process for increasing the packing density closer to the end on the terminal side and a curing process for curing the binder are performed.
[0022]
Here, as the densification step, for example, a high-rigid body in the socket may be sucked by air or magnetically from the end of the socket on the terminal side. It is possible to increase the density by a simple method that simply performs a vibration process for vibrating the plate.
[0023]
According to this method, the packing density of the high-rigid body in the socket can be increased with a simple configuration by vibrating the socket in the vibration step, and as a result, the rigidity of the entire fixing body can be effectively increased. Moreover, it is possible to automatically form a filling density gradient (that is, a stiffness gradient) that increases toward the terminal side.
[0024]
Here, when the above-described back pressure application member is introduced, each strand is inserted into the socket and a covering is attached to each strand, and the end of each strand is shared as the insertion step. The step of fixing to the back pressure applying member and the step of inserting the back pressure applying member into the socket may be performed.
[0025]
Further, as the fixing body injecting step, a binder injecting step of injecting a fluidized binder into the socket and a highly rigid body immersing step of immersing the highly rigid body in the injected binder are performed. Good. In this case, the order of the binder injection process and the high-rigidity body immersion process may be first.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described with reference to the drawings.
[0027]
In the fixing terminal structure shown in FIG. 1, a large number of FRP strands 10 (only one is shown for convenience in the figure) constituting the cable are inserted into the socket 20, and the end of each strand 10 is connected to the back plate (back pressure). (Giving member) 30.
[0028]
In the present invention, regardless of the type of reinforcing fiber and synthetic resin used for the FRP strand 10, the former is preferably glass, boron, silicon carbide, alumina, carbon, aramid, steel, etc. As the latter, epoxy, nylon, polyester and the like are suitable.
[0029]
As a feature of this structure, a cylindrical covering body 12 and a coil spring-like covering body 14 are attached to the terminal portion of each element wire 10, that is, a portion inserted into the socket 20. The cylindrical covering 12 is disposed in the region from the wire end to the length L1, and the coil spring-shaped covering 14 is disposed in the region from the end of the tubular covering 12 to the length L2. Yes. These coverings 12 and 14 are bonded to the surface of the strand 10 with a resin (for example, epoxy resin) as shown in FIG.
[0030]
In the present invention, any material such as steel, non-ferrous metal, glass, rubber, ceramic, plastic, synthetic resin, paper, etc. can be applied regardless of the specific material of each of the coverings 12 and 14. However, when the strand 10 is made of conductive FRP (for example, carbon fiber reinforced plastic), the coatings 12 and 14 are made of an insulating material such as resin, so that the electrical corrosion caused by the strand 10 is achieved. The advantage that can be avoided is obtained.
[0031]
The main body portion 22 of the socket 20 has a cylindrical shape that opens forward and backward, and most of the main body portion 22 has a tapered inner peripheral surface 24 having a taper angle θ in a direction of decreasing in diameter as it is farther from the terminal side (right side in FIG. 1). is doing. On the other hand, the end on the terminal side (right end in FIG. 1) and the end on the inlet side (left end in FIG. 1) each have a flat inner peripheral surface (inner diameter in the axial direction) continuous with the tapered inner peripheral surface 24. The flat portions 26 and 28 have a uniform inner peripheral surface), and the flat portion 28 on the inlet side has a thinner shape (that is, a shape having a smaller outer diameter) than the other main body portion 22.
[0032]
The terminal of each strand 10 is fixed to a back plate 30 as shown in FIGS. 2A and 2B, and the back plate 30 is inserted into the flat portion 26 on the terminal side. The terminal fixing position of each strand 10 is set to a position where the strand terminals are separated from each other. That is, the clearance between the terminals is secured by fixing the terminal to the back plate 30. Specifically, as shown in FIG. 3, the end portion of the cylindrical covering 12 bonded to the element wire 10 is a tapered portion 12 a that expands in diameter toward the terminal side, while the back plate 30 includes Tapered through holes 32 matching the tapered portions 12a are scattered in a honeycomb shape when viewed from the front, and the tapered portions 12a are fitted into the respective through holes 32, so that the back plate 30 is moved to the socket entrance side. The strand 10 and the cylindrical covering 12 are prevented from coming off.
[0033]
In the gap in the socket 20 (that is, the gap between the inner peripheral surface of the socket 20 and the strand 10 and the gap between the strands 10), a fixing body containing a large number of high-rigid bodies 52 is filled in the binder 50. Yes. The high-rigid body 52 is filled only in the area A1 from the back plate 30 to the middle part of the socket, and the binder 50 is also added to the area A2 leading to the socket inlet (that is, all areas A1 and A2 in the socket) in addition to the area A1. Filled.
[0034]
As a material of the binder 50, a material having a property of being cured by an appropriate treatment such as heating from a fluid state is preferable, and an inorganic material such as rubber or silicon is applicable in addition to a thermosetting resin such as an epoxy resin. .
[0035]
The material of the high-rigid body 52 is preferably as high as possible. Non-ferrous metals, glass, rubber, ceramics, sand, plastics, minerals, and the like can be applied in addition to steel materials. In particular, by using a material having a specific gravity greater than that of the binder, a better effect described later can be obtained, and this effect becomes more prominent as the specific gravity increases.
[0036]
The diameter of the high-rigid body 52 may be set within a range in which the gap between the strands 10 can enter. For example, when the gap between the strands is 4 mm, the diameter is about 0.7 to 1.5 mm. It is preferable to use the highly rigid body 52. In addition, the high-rigid body 52 does not necessarily have to be spherical, and may have a capsule shape, a fragment shape, or the like, but if it is spherical, there is almost no risk of damaging the covering 12 or the wire 10, The contact state and filling density of the highly rigid body 52 with respect to the covering body 12 can be made constant regardless of the orientation of the highly rigid body 52.
[0037]
The strands 10 are converged by a clamp at a position away from the entrance of the socket 20.
[0038]
According to this fixing terminal structure, the following effects can be obtained.
[0039]
(a) Since a fixing body containing a high-rigid body 52 in a binder 50 made of an epoxy resin or the like is used as a fixing body, the fixing body is less likely to be deformed than a fixing body that is composed only of an epoxy resin or the like. Thus, a structure capable of withstanding the use of a large-capacity cable can be obtained. Further, since the element wire 10 is fixed by the frictional force generated when the high-rigid body 52 is pressed against the covering bodies 12 and 14, unlike the structure in which the fixing is performed only by bonding the element wire and the fixing body, the socket 20 is lengthened. Even if it is not, sufficient fixing power can be secured.
[0040]
Here, as shown in FIG. 4A, if the high-rigid body 52 is in direct contact with the strand 10, the contact area is very small, and the high-rigid body 52 is on the surface of the strand. Since the pressing pressure is large, the maximum value of the stress σb generated in the direction perpendicular to the axial direction of the strand 10 becomes very high, and the strand 10 may be damaged. On the other hand, in this structure, as shown in FIG. 4B, the covering 12 (14) is bonded to the surface of the element wire 10 via the resin 16, and the high-rigidity body 52 is attached to the surface of the covering 12. Since the pressing force is set, the pressing force can be distributed on the surface of the element wire 10. Therefore, the maximum value of the local stress σb generated in the strand 10 in the direction orthogonal to the axial direction can be greatly reduced.
[0041]
Further, the stress concentration relaxation due to the presence of the coverings 12 and 14 exerts a remarkable effect in the entire terminal fixing structure. For example, in the structure shown in FIG. 5A, when the covering 12 is omitted, as shown by the broken line in FIG. 5B, the stress is remarkably concentrated near the inlet side end of the socket 20, By providing the covering 12, the stress can be dispersed in the axial direction as shown by the solid line in FIG. 5B, and the maximum stress value in the entire terminal fixing structure can be greatly reduced.
[0042]
(b) Since the tubular covering body 12 is arranged in the terminal side region in the socket 20, the strand 10 can be reliably protected from the high-rigid body 52 filled in this region. On the other hand, since the coil spring-like covering body 14 that is easier to bend and deform than the cylindrical covering body 12 is disposed in the region closer to the socket entrance than the cylindrical covering body 12, the strands are formed in this region. 10 can be satisfactorily adapted to the shape in the socket 20.
[0043]
(c) As shown in FIG. 5A, in the structure in which the tapered surface 24 in the socket 20 is formed up to the socket inlet end, the compressive force due to the taper effect up to the inlet end (the direction perpendicular to the axial direction of the strand 10). Is applied to the wire 10. In addition, since the bending stress generated in the strand 10 becomes maximum at the socket entrance end, the stress is concentrated on the socket entrance end. On the other hand, in the structure shown in FIG. 1, the flat portion 28 is provided at the inlet side end portion of the socket 20 so that the compressive force due to the taper action does not act on the element wire 10 at this portion. It is possible to avoid the overlap of stress concentration at. In particular, in this embodiment, since a relatively flexible resin is filled as a fixing material in the flat portion 28, the stress concentration can be further alleviated by elastically supporting the strands with the flat portion 28. ing.
[0044]
The flat portion 28 may have the same thickness as the other portions. However, if the flat portion 28 is thin and easily deformed as shown in the figure, the bending load acting on the cable is distributed by the bending deformation. The bending stress of the segment wire 10 can be further reduced.
[0045]
(d) Since a back plate (back pressure applying member) 30 is arranged behind the fixing body composed of the binder 50 and the high-rigid body 52 and the terminal of each element wire 10 is fixed thereto, it acts on the element wire 10. The back pressure can be applied to the fixing body by using the tensile force to increase the taper action, and the fixing force can be further increased. In particular, in the illustrated structure, the tapered portion 12 a formed at the end of the cylindrical covering 12 is fitted into the tapered through hole 32 of the back plate 30, so that the end of each strand 10 is attached to the back plate 30. It can be fixed securely.
[0046]
In addition, by fixing to the back plate 30, it is possible to reliably maintain a gap having a sufficient dimension between the ends of each of the strands 10, and by reliably intruding the high-rigidity body 52 into the gap, The direction in which the high-rigid body 50 is pressed against each strand 10 can be made uniform. By this uniformization, it is possible to avoid the occurrence of wire bending stress due to the bias in the pressing direction, and it is possible to improve the rigidity of the entire fixing body.
[0047]
In addition, what is necessary is just to set the thickness of the coverings 12 and 14 suitably. However, as shown in FIG. 6A, the fixing efficiency is drastically reduced when the thickness exceeds 1.0 mm. Therefore, it is preferable to set the thickness to 1.0 mm or less.
[0048]
The structure of the covering body 12 is preferably a structure that can transmit the pressing force from the fixing body to the wire. Specifically, the structure etc. with which the slit was formed in the both sides of the covering 12 are mentioned.
[0049]
The taper angle θ of the socket taper surface 24 may be set as appropriate. However, as shown in FIG. 6B, when the taper angle θ is less than 2 ° and more than 5 °, the fixing efficiency is significantly reduced. Therefore, it is more preferable to set the angle θ in the range of 2 ° to 5 °.
[0050]
Next, an example of a method for manufacturing the terminal fixing structure will be described with reference to FIGS.
[0051]
1) A plurality of FRP strands 10 are linearly bundled (FIG. 7A).
[0052]
2) Insert the wire bundle into the socket 20 ((b) in the figure).
[0053]
3) The terminal side portion of each element wire 10 is expanded and inserted into each through hole 32 of the back plate 30 ((c) in the figure).
[0054]
4) The coverings 12 and 14 are attached to the terminal-side portions of the respective strands 10 and led to the rear of the back plate 30 (FIG. 8A).
[0055]
5) The back plate 30 is retracted, and the terminal taper portion of each cylindrical covering 12 is fitted into the through hole 32 (FIG. 5B).
[0056]
6) Insert the back plate 30 into the rear end of the socket 20 and cover it with the cap 40 from the rear. Further, the strands 10 are converged by the clamps 42 at a position sufficiently spaced forward from the socket 20 ((c) in the figure). The convergence angle α (= tan) of the outermost strand between the convergence position and the back plate 30 ^-1 (b / d); b is the distance from the cable center line to the outermost strand, and d is the distance from the back plate 30 to the strand convergence position. It is good. By controlling the convergence angle α in this way, the curvature of the wire 10 in the socket 20 can be reduced and the bending stress can be reduced.
[0057]
7) The socket 20 is turned upright with the inlet of the socket 20 facing upward (FIG. 9A).
[0058]
8) The binder 50 in a fluidized state is poured into the entire area (area A1 + area A2) in the socket 20 ((b) in the figure).
[0059]
9) Fill the area A1 in the socket 20 with a large number of high-rigid bodies 52 ((c) in the figure). Note that the order of the process 9) and the process 8) may be reversed.
[0060]
10) The socket 20 is vibrated by the vibrator 60 (vibration process; FIG. 10 (d)). As a result, the high-rigid body 52 in the socket 20 approaches the closest packed state, thereby increasing the rigidity of the fixing body. This effect is obtained by using a material having a specific gravity greater than that of the binder for the high-rigid body 52, and becomes more prominent as the specific gravity increases. Further, an appropriate hole is formed in the back plate 30 and the high-rigid body 52 in the socket 20 is sucked together with air from the hole, or the high-rigid body 52 is sucked directly to the back plate 30 side with a magnet. Similarly, the density can be increased.
[0061]
11) The entire structure is heated to a predetermined temperature, and the binder 50 such as an epoxy resin is cured ((e) in the figure).
[0062]
In the cable terminal fixing structure manufactured as described above, the packing density of the high-rigid body 52 becomes higher as it approaches the lower side (that is, the terminal side) by the vibration process of 10), and the rigidity of the fixing body also increases toward the terminal side. The slope becomes larger as you go. On the other hand, the load acting in the direction orthogonal to the axial direction of the strand 10 tends to increase as it goes toward the socket entrance side. Therefore, by forming the rigidity gradient as described above, The acting load can be made uniform and more advantageous in terms of strength.
[0063]
【Example】
Table 1 below shows the tensile load capacity (sum of the breaking tensile loads of the individual wires) in the examples employing the fixing structure according to the present invention and the comparative examples in which the covering in the identification structure is omitted. It shows the load when the fixing actually starts to collapse (actual breaking load) and the fixing efficiency obtained by dividing the actual breaking load by the tensile load capacity.
[0064]
[Table 1]

[0065]
As is apparent from this table, according to the structure according to the example of the present invention, it becomes possible to dramatically improve the fixing efficiency as compared with the structure according to the comparative example (the structure in which the covering is omitted). . This is because the stress concentration of the wire is particularly severe in the vicinity of the socket entrance in the comparative example structure without the covering, and the portion according to the embodiment of the present invention is easily broken. This is because the pressure applied to the strands from the high-rigidity body is dispersed in the axial direction by interposing the covering body with the high-rigidity body, and as a result, stress concentration is effectively relieved.
[0066]
【The invention's effect】
As described above, the present invention forms a tapered inner peripheral surface in a direction in which the diameter decreases with increasing distance from the terminal side in the socket into which the terminal of the FRP strand is inserted, and at least the fixing body filled in the terminal side region. Is composed of a composite fixing body containing a plurality of high-rigid bodies having a higher rigidity than the binder in the binder, and at least in the region where the composite fixing body is filled, the surface is individually applied to the surface of each strand. Since the covering to be covered is fixed, the local pressing force applied to the strands from each of the high-rigid bodies is dispersed on the strand surface while ensuring a sufficient fixing force by the high-rigid bodies in the fixing body. At the same time, the force that the fixing body presses against the FRP strand in the direction perpendicular to the axial direction is dispersed in the axial direction, and by these two actions, the maximum value of the pressing force in the direction perpendicular to the strand Is effectively reduced It is possible.
[0067]
The present invention also relates to a method for manufacturing the terminal fixing structure, wherein a strand insertion step of inserting each strand and its covering into the socket, and an end opposite to the end on the end of the socket on the upper side. A fixing body injecting step of injecting a composite fixing body of a binder and a plurality of high rigidity bodies into the socket from the opposite end, and an external force applied to the high rigidity body in the socket in the socket Is added in order to increase the packing density closer to the end on the terminal side and the curing process to cure the binder, in order to increase the packing density of the high-rigid body in the socket, As a result, it is possible to effectively increase the rigidity of the entire fixing body and automatically form a filling density gradient (that is, a rigidity gradient) that increases toward the terminal side to easily manufacture a structure that can relieve stress concentration. Effect That.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view of a cable terminal fixing structure using FRP strands according to the present invention.
2A is a cross-sectional view taken along line AA of FIG. 2B, and FIG. 2B is a side view of the terminal fixing structure.
FIG. 3 is an enlarged view of a portion B in FIG.
4A is a diagram showing a stress distribution when a highly rigid body is directly pressed against a strand; FIG. 4B is a stress when the highly rigid body is pressed against a covering disposed on the surface of the strand; It is the figure which showed distribution.
5A is a model diagram of the structure of the present invention, and FIG. 5B is a graph showing a strand stress distribution corresponding to the model diagram of FIG.
6A is a graph showing the relationship between the thickness of the cover and the fixing efficiency, and FIG. 6B is a graph showing the relationship between the taper angle in the socket and the fixing efficiency.
7A, 7B, and 7C are manufacturing process diagrams of a cable terminal fixing structure according to the present invention.
FIGS. 8A, 8B, and 8C are manufacturing process diagrams of a cable terminal fixing structure according to the present invention. FIGS.
FIGS. 9A, 9B, 9C and 9E are manufacturing process diagrams of the cable terminal fixing structure according to the present invention. FIGS.
10A is a sectional front view showing an example of a conventional cable terminal structure, and FIG. 10B is a sectional side view.
[Explanation of symbols]
10 strands
12 Tubular covering
12a Taper part
14 Coil spring-shaped covering
16 Coating layer
20 sockets
22 Socket body
24 Tapered inner peripheral surface
28 Flat part
30 Back plate (back pressure application member)
32 Through hole
50 binder
52 High rigidity body
60 Vibrator

Claims (18)

A cable using a fiber reinforced plastic strand in which a plurality of fiber reinforced plastic strand ends are inserted into a socket, and a fixing body for fixing the strand ends in the socket is filled. in the terminal fixing structure, the tapered inner circumferential surface of the direction in which the diameter decreases away from the terminal in the socket is formed, the fixing member to be filled in at least the terminal side region, and a binder, rigidity than the binder high rather Rutotomoni is a composite fixing member composed of a large number of high-rigidity body clearance of intruding possible magnitude between the strands, in the region at least the composite fixing member is filled, each wire A cable terminal fixing structure using a fiber reinforced plastic strand, wherein a covering for individually covering the surface is fixed to the surface. 2. A cable terminal fixing structure using a fiber reinforced plastic strand according to claim 1, wherein the covering is bonded to the surface of the strand through a resin layer. The cable terminal fixing structure. The cable terminal fixing structure using the fiber reinforced plastic strand according to claim 1 or 2, wherein at least a part of the covering body is a cylindrical covering body. The cable terminal fixing structure. The cable terminal fixing structure using the fiber-reinforced plastic strand according to any one of claims 1 to 3, wherein at least a part of the covering is a flexible member. Cable terminal fixing structure using plastic strands. The cable terminal fixing structure using the fiber reinforced plastic strand according to claim 4, wherein at least a part of the covering is a coil spring-like covering. Cable terminal fixing structure. 6. A cable using a fiber-reinforced plastic strand, wherein the high-rigid body is spherical in the cable terminal fixing structure using the fiber-reinforced plastic strand according to any one of claims 1 to 5. Terminal fixing structure. The cable terminal fixing structure using the fiber-reinforced plastic strand according to any one of claims 1 to 6, wherein the high-rigidity body is made of a material having a specific gravity greater than that of the binder. Cable terminal fixing structure using wire. In the cable terminal fixing structure using the fiber reinforced plastic strand according to claim 7, the fiber reinforced plastic strand characterized by increasing the packing density of the high-rigid body toward the terminal side. Cable terminal fixing structure. The cable terminal fixing structure using the fiber reinforced plastic strand according to any one of claims 1 to 8, wherein the strand is made of conductive fiber reinforced plastic, and the covering is made of an insulating material. A cable terminal fixing structure using a fiber reinforced plastic strand characterized by comprising. The cable terminal fixing structure using the fiber reinforced plastic strand according to any one of claims 1 to 9, wherein an inner diameter of the end of the socket opposite to the terminal end is constant in the axial direction. A cable terminal fixing structure using a fiber reinforced plastic strand characterized by a flat part. The cable terminal fixing structure using the fiber reinforced plastic strand according to claim 10, wherein the thickness of the flat portion is smaller than the thickness of other portions. Used cable terminal fixing structure. The cable terminal fixing structure using the fiber reinforced plastic strand according to any one of claims 1 to 11, wherein the end of each strand is fixed at a position behind the fixing body filled in the socket. A cable terminal fixing structure using a fiber reinforced plastic element wire, wherein a back pressure applying member is provided in contact with the fixing body from the rear in a state where the fixing member is in contact. 13. A cable terminal fixing structure using a fiber reinforced plastic strand according to claim 12, wherein the end of each strand is fixed to a back pressure applying member in a state where the ends are separated from each other. Cable terminal fixing structure using wire. The cable terminal fixing structure using the fiber-reinforced plastic strand according to claim 12 or 13, wherein the end portion of the covering covering each strand is a tapered portion that expands toward the end, and the tapered portion is A cable terminal fixing structure using a fiber reinforced plastic strand, wherein a back pressure applying member is provided with a taper-shaped through hole that can be inserted. A method for manufacturing a cable terminal fixing structure using a fiber reinforced plastic strand according to claim 8, wherein the strand insertion step of inserting each strand and its covering into the socket, and the end side end of the socket A fixing body injecting step of injecting a composite fixing body of a binder and a plurality of high-rigid bodies in a fluid state into the socket from the end on the opposite side with the end on the opposite side facing upward; A fiber-reinforced plastic wire characterized by sequentially performing a densification step in which an external force is applied to the high-rigidity body to increase its packing density as it is closer to the end on the terminal side, and a curing step to cure the binder. For manufacturing a cable terminal fixing structure using a cable. 16. The manufacturing method of a cable terminal fixing structure using a fiber reinforced plastic strand according to claim 15, wherein the densification step is a vibration step for vibrating the socket containing the high-rigidity body. A method for manufacturing a cable terminal fixing structure using a fiber reinforced plastic strand. 17. The manufacturing method of a cable terminal fixing structure using a fiber reinforced plastic strand according to claim 15 or 16, wherein the inserting step inserts each strand into a socket and covers each strand with a covering. A fiber reinforced plastic strand characterized by comprising the steps of attaching and fixing the ends of each strand to a common back pressure application member and inserting the back pressure application member into the socket. Manufacturing method of cable terminal fixing structure. The method of manufacturing a cable terminal fixing structure using a fiber reinforced plastic strand according to any one of claims 15 to 17, wherein the fixing body injection step injects a fluidized binder into a socket. And a high-rigid body dipping step of immersing the high-rigid body in the injected binder, and a method for manufacturing a cable terminal fixing structure using a fiber reinforced plastic strand.

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