JPH07193953A - Bind wire and production thereof - Google Patents

Abstract

PURPOSE:To ensure sufficient grasping force or tensile strength by setting the pitch of a part to be coupled with the body part shorter than that of other part in a spiral part made of fiber reinforced synthetic resin. CONSTITUTION:The bind wire comprises a substantially semicircular flat body part 1 made of fiber reinforced synthetic resin having substantially rectangular cross-section and located in the center, and a pair of spiral parts 2 extending in the different directions from the opposite ends of the body part 1 while crossing each other. The pitch P1 of the part to be coupled with the body part 1 is set shorter than the pitch P. of other part in the spiral part 2. Consequently, the arrangement of fibers in the longitudinal direction of a tape-like FRP prepreg is not disturbed at the transition from the spiral part 2 to the body part 1 and the strength of fibers is exhibited sufficiently. Furthermore, when the spiral part 2 is wound around a cable, the short pitch part is pulled until the pitch is equalized to that of other part thus relaxing the stress concentrated between the body part 1 and the spiral par 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binding wire and a method for manufacturing the same, and more particularly to a fiber reinforced synthetic resin (hereinafter referred to as F
And a method for manufacturing the same.

[0002]

2. Description of the Related Art As a means for fixing an electric power cable or a communication cable installed outdoors to an insulator, a bind wire in which a steel wire is covered with plastic has been widely used. This kind of bind wire is provided on both ends of the substantially semicircular main body part wound around the outer periphery of the insulator supported by a power transmission tower and the like, and is installed in a direction substantially orthogonal to the insulator. And a pair of spiral parts wound around the cable. There are two types of bind wires, one is an Ω type that extends in different directions without intersecting a pair of spiral portions from both ends of the main body, and the other is a Q type that extends a pair of spiral portions from both ends of the main body. It is provided.

By the way, the bind wire in which such a steel wire is provided with a plastic coating is low in electrical insulation. In particular, when the bind wire is attached to an insulator or a cable, if the plastic coating layer is damaged, the reliability is significantly reduced. In addition, in a region near the coastline, when a scratch occurs on the coating layer, water containing salt invades from the end surface of the scratch, corrodes the steel wire inside, and decreases the strength of the bind wire.

Therefore, there is a demand for a bind wire made of only an insulating material that does not use any metal. However, such a method of manufacturing a bind wire that has been desired has the technical problems described below.

[0005]

That is, in the bind wire having the above-mentioned structure, it is necessary to firmly grasp the cable and exhibit sufficient tensile strength.
As an insulating material having such a performance, for example, it is conceivable to form a unidirectional fiber reinforced plastic into the main body portion and the spiral portion as described above. As a material that can be molded into such a three-dimensional shape, for example, unidirectionally reinforced uncured FRP (Ube Nitto Kasei Co., Ltd.) obtained by impregnating glass fiber with an uncured thermosetting resin and coating it with a thermoplastic resin. Made: There is an uncured compose).

When such an FRP is wound around a predetermined mold and then heated to cure the uncured thermosetting resin,
A bind line having the above-described structure can be obtained. However, if the cross-sectional shape of the bind wire formed in such a step is circular, the contact area between the cable and the insulator is small, and the expected gripping force cannot be obtained. Such problems can be solved by making the cross section of the bind wire a flat flat shape, but if the cross section is simply made flat, between the spiral portion wound around the cable and the main body portion wound around the insulator, Tensile stress and shearing stress are generated, which causes a problem of being twisted and broken.

The cause of this is that stress is first concentrated between the main body portion and the spiral portion, and during the process of winding around the mold, the arrangement of the fibers arranged in one direction is disturbed, and further twisting is added. This is because when it is hardened, the strength (all of bending, pulling, and shearing) of the part is significantly reduced. In addition, the work of fixing the cable to the insulator is a work at a high place where a worker climbs on a utility pole, etc., and is a dangerous work that may cause electric shock, and it is necessary to mechanize it to ensure safety. .

However, in the above-mentioned Q type bind wire, the main body is wound around the insulator almost once, so that when the cable is pulled, the main body is wound around the insulator and tightened, resulting in a gripping force. Increase,
The workability of winding is poor and mechanization becomes difficult. The present invention has been made in view of such problems,
It is an object of the present invention to provide a bind wire that can secure a sufficient gripping force or tensile strength and can easily cope with mechanization, and a manufacturing method thereof.

[0009]

To achieve the above object, the present invention has a substantially semicircular cross section having a flat and substantially rectangular cross section, which is provided in the central portion and wound around the outer periphery of an insulator. A binding wire made of a fiber-reinforced synthetic resin, which comprises a main body portion and a pair of spiral portions provided on both ends of the main body portion and wound around a cable installed in a direction substantially orthogonal to the insulator,
The spiral portions are extended from both ends of the main body portion in different directions without intersecting each other, and a pitch of a portion connected to the main body portion is set smaller than pitches of other portions.

Further, the main body has a flat and substantially rectangular cross section, is provided in the central portion and is wound around the outer periphery of the insulator, and has a substantially semicircular shape, and the insulator is provided at both ends of the main body. A method for manufacturing a bind wire, comprising: a pair of spiral parts wound around a cable extending in a direction substantially orthogonal to the above, wherein a central part of a thin tape-shaped fiber-reinforced synthetic resin prepreg is wound around an outer periphery of a cylindrical body. The first forming step of the body portion to be rotated and the spiral portion to be wound at a predetermined pitch on the outer periphery of the small diameter cylindrical body arranged so that both ends of the wound prepreg are orthogonal to the cylindrical body. It is characterized by comprising a second forming step and a step of repeating the first and second forming steps a plurality of times to form a multi-layered bind wire intermediate body, and then curing the prepreg.

[0011]

According to the bind wire of the above construction, the spiral portion made of the fiber-reinforced synthetic resin has the pitch of the portion connected to the main body portion set smaller than the pitch of the other portion, so that the spiral portion is connected to the main body portion. When shifting to, the arrangement of fibers in the longitudinal direction of the tape-shaped FRP prepreg becomes less likely to be disturbed, and the strength of the fibers can be fully utilized. Further, when the spiral portion is wound around the cable, the portion having the small pitch is pulled to be in the same state as the pitch of the other portion, whereby the stress concentration between the main body portion and the spiral portion is relaxed. .

Further, according to the method of manufacturing a bind wire having the above structure, a thin tape-shaped FRP prepreg is wound around a mold having a predetermined shape one by one to form a multi-layered bind wire intermediate, and then the prepreg is cured. Since the bind wire is manufactured by using the binding wire, the reinforcing fiber is less likely to be twisted when wound around the mold.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 shows an embodiment of the bind line according to the present invention. The bind wire shown in the figure has a flat, substantially rectangular cross section made of fiber reinforced synthetic resin, and has a substantially semicircular main body 1 provided in the center and different ends from the main body 1. And a pair of spiral portions 2 extending in the direction. The main body 1 is, as shown in FIG.
It is wound around the outer periphery of the insulator 3 along the groove provided on the head thereof. In addition, the pair of spiral portions 2 are wound around the cable 4 that is installed in a direction substantially orthogonal to the insulator 3.

In the spiral portion 2, the pitch P _{1 of} the portion connected to the main body portion 1 is set smaller than the pitch P ₂ of the other portion. The pitch of the spiral portion 2 is not limited to such a state. For example, the pitch may be gradually reduced from the end portion side of the spiral portion 2 toward the main body portion 1 side. According to the bind wire of the present embodiment configured as described above, since the spiral portions 2 do not intersect with each other, it is not difficult to mechanize like the Q type bind wire, and the insulator 3 is mechanically attached to the insulator 3. Easy to install.

Concrete Example An insulator 3 having a diameter of a winding portion of 60.8 mm has an outer diameter of 2
In order to fix the 2.5 mmφ cable 4, a bind wire having the shape shown in FIG. 1 was manufactured by the following method. First, as a raw material for the bind wire, a thin tape-like material obtained by impregnating glass fiber with epoxy resin, having a thickness of 0.33 mm, a width of 10 mm and a glass fiber content rate of 50 vol% in one direction. Prepreg sheet (manufactured by Nitto Boseki Co., Ltd., product name: Nitto Boseki register tape TR10150
A plurality of EC) were prepared.

One of the prepreg sheets was wound around the mold shown in FIG. The mold shown in the figure has a vertically standing cylindrical body 5 and a small-diameter cylindrical body 6 provided so as to be orthogonal to the outer circumference of the cylindrical body 5. A peripheral groove 7 is provided on the outer periphery of the cylindrical body 5, and a spiral groove 8 is formed on the small-diameter cylindrical body 6.
Is recessed. The central portion of the prepreg sheet is wound around the circumferential groove 7 of the cylindrical body 5, and this portion becomes the main body portion 1 of the bind wire. Then, both ends of the prepreg sheet are respectively wound around the spiral groove 8 of the small-diameter cylindrical body 6, and this portion becomes the spiral portion 2 of the bind wire. Circumferential groove 7 and spiral groove 8
Has a groove width of 13.3 to 13.4 mm and a groove depth of 2 mm.
Set to.

In this case, the pitch of the spiral portion 2 is 70 mm.
The pitch of the portion connecting the spiral portion 2 to the main body portion 1 was set to 60 mm. The portion having a pitch of 60 mm was 5 pitches. After the winding of one prepreg sheet was completed, another prepreg sheet was sequentially laminated on the upper side thereof to form a bind wire intermediate body composed of prepregs laminated in a total of 5 layers. Next, in this state, the intermediate was heated in an oven at 100 ° C. for 3 hours to cure the epoxy resin of the prepreg.

The hardened bind wire is removed from the mold and, according to the actual use condition, as shown in FIG.
Then, one end of the cable 4 was gripped and a tensile test was conducted. As a result, it was confirmed that the screw portion of the insulator 3 was bent at 140 kg, and was sufficiently practical.

Comparative Example The pitch of the portion connecting the spiral portion 2 to the main body portion 1 was 70 m.
A bind wire was manufactured using the same raw materials and molds as in the above specific example except that the binding wire was set to m. This bind wire was also subjected to a tensile test under the same conditions as in the above specific example.
With a load of 0 kg, a crack was formed in the intermediate portion of the main body portion 1 wound around the insulator 4, and the portion was broken from that portion.

Although the glass fiber is used as the FRP reinforcing fiber in the above specific examples, the present invention is not limited to this. For example, aromatic poamide fiber or aromatic polyester may be used. Fibers and the like can be used alone or in combination, and may be a non-conductive fiber having high strength and high elasticity. Further, the structure of the reinforcing fiber is not limited to one in which the fibers are aligned in one direction and impregnated with resin,
In order to maintain the parallel arrangement between the fibers, satin weave or pre-twisted fibers can be used.
Preferably, twisted fibers (satin weave) are applied so that uniform tension is applied between the fibers.

Further, the resin impregnated in the reinforcing fiber is not limited to the epoxy resin, but may be, for example, an unsaturated polyester resin or a phenol resin.

[0022]

As described above in detail in the embodiments,
According to the bind wire and the method for manufacturing the same according to the present invention, sufficient gripping force or tensile strength can be secured, and the repeated fatigue characteristics caused by the shaking of the cable are excellent, and it is possible to easily cope with mechanization.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a bind wire according to the present invention.

FIG. 2 is an explanatory view of a mold used in the method for manufacturing a bind wire according to the present invention.

FIG. 3 is a side view showing an example of use of such a bind wire according to the present invention.

[Explanation of symbols]

 1 body part 2 spiral part 3 insulator 4 cable 5 cylindrical body 6 small diameter cylindrical body

Claims (2)

[Claims] 1. A substantially semicircular main body having a flat, substantially rectangular cross section, which is provided in the center and is wound around the outer periphery of the insulator, and the insulator provided at both ends of the main body. A binding wire made of fiber-reinforced synthetic resin, comprising a pair of spiral parts wound around a cable installed in a direction substantially orthogonal to the spiral part, wherein the spiral parts of the main body part do not intersect each other. A bind wire extending from both ends in different directions, wherein a pitch of a portion connected to the main body portion is set smaller than pitches of other portions. 2. A substantially semicircular main body portion having a flat and substantially rectangular cross section, which is provided in the central portion and is wound around the outer periphery of the insulator, and the insulator provided at both ends of the main body portion. A method for manufacturing a bind wire, comprising: a pair of spiral parts wound around a cable extending in a direction substantially orthogonal to the above, wherein a central part of a thin tape-shaped fiber-reinforced synthetic resin prepreg is wound around an outer periphery of a cylindrical body. The first forming step of the body portion to be rotated, and the spiral portion to be wound at a predetermined pitch on the outer circumference of a small diameter cylindrical body arranged so that both ends of the wound prepreg are orthogonal to the cylindrical body. A method for manufacturing a bind wire, comprising: a second forming step; and a step of repeating the first and second forming steps a plurality of times to form a multi-layered bind wire intermediate body and then hardening the prepreg. .