JPH1196835A - Cable preventing damage from gnawing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the functions of keeping a cable which prevents damage from gnawing. SOLUTION: This cable preventive of damage from gnawing is equipped with a layer 1 preventive of damage by gnawing containing an agent preventive of damage by gnawing in a cable core 3, and a protection layer 2 protection of damage by gnawing constituting the outmost layer of its outside cable and containing no agent preventive of damage by gnawing. By making mutually different the respective layers of the layer 1 and the protection layer 2, damage by gnawing can be found out visually from the outside with case, when the cable is gnawed by rats.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anticorrosion cable such as an electric wire or a communication cable provided with an anticorrosion effect.

[0002]

2. Description of the Related Art Conventionally, when cables such as electric wires and communication cables are laid underground or laid inside buildings such as buildings, the outer periphery of the cables is protected from damage by rats. The erosion prevention layer containing the agent and the outermost layer of the outer cable also prevent the erosion inhibitor from diverging or decomposing to maintain the erosion prevention function for a long time, and prevent harm to the human body by the erosion inhibitor. An anti-corrosion cable provided with an anti-corrosion protection layer for the purpose of avoiding the like is known (Japanese Utility Model Laid-Open No. 1-1103120, Japanese Utility Model Application Laid-Open No. 3-4).
No. 4820).

[0003]

However, conventionally, in the case of a cable which is laid and recovered many times, such as a cable for transportation, and which is used repeatedly, the protective layer on the surface of the cable has been damaged during the use of the cable. When the erosion protection layer is exposed and the erosion protection layer is exposed, such as when a portion of the erosion protection layer is exposed, it is difficult to distinguish between the erosion protection layer and the erosion protection layer. The erosion control agent may be scattered from places where the prevention layer is exposed, etc., causing loss of the erosion prevention function, or by directly touching the erosion prevention layer without noticing the loss, or by spreading the erosion control agent into the air. Was sometimes harmed.

[0004]

According to the present invention, in order to solve the above-mentioned problems, in an anti-corrosion cable having an anti-corrosion layer and an anti-corrosion protection layer on the outside thereof, the cable is provided on the inner side of the outermost layer of the cable. It is characterized by having a damage identification layer. In the present invention, when the outermost layer of the cable is bitten by a mouse or the like and a defect occurs, the damage identification layer facilitates the visual identification of the outermost layer of the cable from the outermost layer of the cable to facilitate early damage. In general, the function of the erosion prevention layer is also given to the erosion prevention layer, and the erosion prevention protection layer is the outermost layer of the cable. Hereinafter, a description will be given mainly of a case where the damage prevention layer is also a damage identification layer.

In other words, when the erosion prevention layer is also an erosion prevention identification layer, the outermost layer of the cable is formed by changing the color, shape, etc. of each layer of the erosion prevention layer and the outer erosion prevention protection layer. When a defect occurs in a part of the erosion prevention protective layer forming a part, and when a part of the erosion prevention layer is exposed, etc., the respective layers are easily identified visually from the outside to find a defect part, and thereafter, It is easy to take measures such as repairing the cable, to maintain and secure the performance of preventing the cable from being damaged, and to ensure the prevention of chemical damage to the human body by the corrosion inhibitor. Note that the partial loss of the anti-corrosion protection layer does not necessarily have to be such that the anti-corrosion protection layer and the like inside thereof are exposed, and the anti-corrosion protection layer is made of a translucent material such as plastic. In such a case, it is sufficient that the respective layers can be identified from the outside without being exposed.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Note that the same elements are denoted by the same reference numerals, and redundant description will be omitted.

(Embodiment 1) As shown in FIG. 1, a cable for preventing erosion according to Embodiment 1 includes a cable core 3 at the center, an erosion prevention layer 1 outside the cable core 3, and the outermost cable outside the cable. And a protective layer 2 serving as an outer layer. The object of the present invention can be achieved by making the form of the erosion prevention layer 1 and the erosion prevention protection layer 2 different from each other in the form of the object, such as shape and color, which can be visually identified from the outside.

For example, the erosion prevention layer 1 and the erosion prevention protection layer 2
Each of these layers can also be identified by using various different materials, shapes, and the like. In addition, the erosion prevention layer 1
By changing the molding processing conditions at the time of coating the anti-corrosion protection layer 2, the roughness and gloss of each of these layers can also be distinguished by making them different. In addition, when the erosion protection layer 1 is red and the erosion protection layer 2 is black, the color of the erosion protection layer 2 is changed to a different color so that the erosion protection layer 1 is partially exposed and the erosion protection layer 1 is exposed. In addition, the fact that the damage prevention protective layer 2 is damaged can be easily detected visually from the outside.

[0009] The protective layer 2 protects the anti-corrosive agent from the anti-corrosive layer 1 from spreading and decomposing, thereby maintaining the anti-corrosive function for a long time, and directly touching the anti-corrosive layer without noticing any loss. The purpose of the present invention is to avoid harm to the human body due to the use of the anti-corrosion agent or the anti-corrosion agent diffused in the air, and may be the same material as the anti-corrosion layer 1 or a different material.

Therefore, the protective layer 2 must be always covered with the protective layer 1, but its thickness has an optimum value. In other words, rats have the habit of first biting a cable after confirming their safety by trial biting, and the thickness of the protective layer for the erosion protection is set at the early stage of trial biting. It is preferable that the thickness be such that the biting is stopped by sensing the damage and the damage to the erosion prevention protective layer is as small as possible and the erosion prevention layer is not exposed.
Therefore, from the viewpoint of the prevention of the damage, the protection layer 2 against the damage is not meaningful even if it is thicker than a certain thickness.

Further, since the corrosion protection layer 2 constitutes the outermost layer of the cable, at least during the life of the cable,
It is necessary to have a strength enough to withstand normal handling and a thickness enough to secure the service life, but this depends on the use of the cable, the installation environment, and the like. For example, in a moving cable in which laying and collecting are repeated and large wear is expected, a certain amount or more of thickness is required because the amount of wear is relatively large.

In consideration of the above, it is preferable that the thickness of the protection layer 2 is, for example, about 1 mm in the case of a plastic resin layer. Also, depending on the installation environment of the cable, in order to prevent the corrosion protection layer 2 from being damaged or missing due to the deterioration of plastic, carbur black or the like is mixed in to provide weather resistance, wear resistance, etc. It is necessary to maintain the soundness of the protection layer 2 over the entire period of the period.

The erosion prevention layer 1 is a layer having both an erosion prevention function and a cable sheath function. That is, usually, the rat stops biting at the stage of trial biting of the protection layer 2, but even if it does not stop, the drug exerts its medicinal effect at least while biting the protection layer 1 and stops biting. The function of the sheath needs to be maintained.

The corrosion protection layer 1 is made of a composition in which capsaicin, cycloheximide or the like as a corrosion protection agent is mixed with a plastic resin such as polyethylene or polyvinyl chloride, which can function as a carrier for a cable sheath and a corrosion protection agent. It is formed by extrusion coating on the cable core 3. In addition, it is desirable to use these corrosion inhibitors in a microencapsulated state so as to avoid decomposition by rainwater or air and to withstand high temperatures during molding.

The amount of the anti-corrosion agent mixed is such that while the rat is biting the anti-corrosion protection layer 2, the medicinal effect is exerted and the rat stops chewing, and even in the worst case, the harm remains in the anti-corrosion layer 1. Since it is necessary that the sheath function is maintained, the mechanical strength, thickness, etc. of the erosion prevention layer 1 are affected, but usually about 1 to 3% by weight is appropriate.

The cable core 3 is a portion inside a cable sheath layer of a normal electric wire or cable, such as an electric wire or a communication cable, which has a conductor at least at the center and is insulated by an insulator. This is because the erosion prevention layer 1 has a sheath function in addition to the erosion prevention function.

(Embodiment 2) As shown in FIG. 2, the embodiment 2 includes a tensile strength fiber layer 1a in which an erosion inhibitor is mixed as the erosion prevention layer 1, In this case, a similar plastic resin layer is formed, and these layers are identified by differences in the shapes of the constituent materials.

The anti-corrosion layer 1 comprises an anti-corrosion agent-containing tensile strength fiber layer 1a containing an anti-corrosion agent located on the surface side;
It is a laminate composed of the inner sheath layer 1b. The tensile strength fiber layer is made by twisting any fiber of aramid, polyester, ultra-high molecular weight polyethylene, carbon, and high-strength glass.

In this case, the thickness of the antifouling agent-containing tensile strength fiber layer 1a is set so that, even in the worst case, the medicinal effect is exerted before the rat bites and the rat damage does not reach the sheath layer. 0.5mm
About 2.0 mm is preferable. Even if the thickness is the same, the use of a laminate of a plurality of fiber layers in which the twisting directions are opposite to each other requires more time for the rat to bite, so that the corrosion prevention layer 1 can be formed relatively thin. .

The sheath layer 1b is a layer having the function of a cable sheath. In the case of the second embodiment, the tensile strength fiber layer cannot be provided with a sheath function such as waterproofing, and is necessary. The same material as that of the corrosion protection layer 2 may be used, or a different material is sufficient if it has a sheath function. This embodiment is particularly suitable for a cable having a relatively small outer diameter, such as an optical fiber cable, because the tensile strength fiber used for the corrosion protection layer 1 also shares the tension of the cable.

(Embodiment 3) In Embodiment 3, as shown in FIG. 3, a layer formed by twisting a rod 1c of reinforced plastic (FRP rod 1c) mixed with an anticorrosion agent is used as the anticorrosion layer 1. By using the same plastic resin layer as in Embodiment 1 as the corrosion protection layer 2,
Due to the difference in the shape of the material constituting each layer, the erosion prevention layer 1
In this case, the protection layer 2 is distinguished from the erosion protection layer 2.

Before the FRP rod 1c is cured as a rod, the FRP rod 1c is formed by molding and curing a mixture of glass fibers or a curing resin mixed with a corrosion inhibitor. The erosion prevention layer 1 and the erosion prevention protection layer 2 of the third embodiment are obtained by twisting the FRP rod 1c on the cable core 3 so as to impart flexibility to the cable. It is formed by coating a plastic resin to be No. 2. As can be seen from FIG.
The twisted FRP rod 1c is embedded in a plastic resin of the same material as the corrosion protection layer 2.

In the third embodiment, since the FRP rod 1c used for the erosion prevention layer 1 also shares the tension of the cable, similar to the second embodiment, in the case of a cable having a relatively small outer diameter such as an optical fiber cable. It is particularly suitable for

(Embodiment 4) Embodiment 4 is similar to FIG.
As shown in (a), by providing a gear-shaped cross section as the erosion prevention layer 1, each of these layers is distinguished by a difference in shape from the erosion prevention protection layer 2, and an expensive erosion inhibitor is saved. In this case, material costs can be reduced. In the case of the fourth embodiment, the effective anti-corrosion effect of the anti-corrosion layer 1 is, as shown in an enlarged view of FIG. 4 (b), on a circumference 1d connecting the tips of the convex portions of the gear-shaped cross section. As a result, the amount of the corrosion inhibitor corresponding to the concave portion can be saved, and the material cost can be saved accordingly.

The convex shape of the gear-like cross section of the erosion prevention layer 1 shown in FIG. 4 (a) is such that when the rattle bites the erosion prevention protection layer 2, the distance between the protrusions comes into contact with any of the protrusions. It is a necessary condition that the distance is short enough to exert a medicinal effect, and the other is not particularly limited. For example, FIG.
As shown in (c), if the bottom of the groove of the concave portion is deepened, the corrosion inhibitor can be further saved.

(Embodiment 5) In the above embodiment,
Although the present invention has been described with respect to the damage of rats, the present invention is not limited to this, and is also effective for small animals having habit of chewing, such as squirrel. However, in this case, it is necessary to select or dispense an appropriate edible inhibitor depending on the animal.

(Embodiment 6) In the above embodiment,
An anti-corrosion layer 1 in which an anti-corrosion protection layer 2 is formed on the outermost layer of a cable, and which also has a function as an anti-corrosion layer inside.
Although the present invention is not limited to this, the outermost layer of a cable such as a sheath may be formed with an edible identification layer containing no edible inhibitor inside the outermost layer. .

[0028]

As described above, in a cable for preventing damage to rats and the like, by changing the shape of each layer of the damage prevention layer and the damage prevention protection layer, the outermost layer of the cable can be used as a part of the protection layer. When the damage prevention layer is exposed due to a defect, the layers can be easily visually identified from the outside, and the defect location can be found at an early stage. Maintenance of
It is characterized by securing and avoiding phytotoxicity to the human body by the anti-corrosion agent.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a corrosion prevention cable according to the present invention.

FIG. 2 is a cross-sectional view showing another embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another embodiment of the present invention.

FIG. 4 is a cross-sectional view showing another embodiment of the present invention.

[Explanation of symbols]

 1 :: corrosion prevention layer 1a: tensile strength fiber layer containing a corrosion inhibitor 1b: sheath layer 1c :: FRP rod 1d: effective outer diameter of the corrosion protection layer 2: corrosion protection layer 3: cable core

Claims (6)

[Claims] 1. An anti-corrosion cable having an anti-corrosion layer and an anti-corrosion protection layer on the outside thereof, wherein the anti-corrosion cable has an anti-corrosion identification layer inside the outermost layer of the cable. 2. The anti-corrosion cable according to claim 1, wherein the anti-corrosion layer is an anti-corrosion layer containing an anti-corrosion agent. 3. The anticorrosion cable according to claim 1, wherein the anticorrosion layer is an anticorrosion layer including a tensile strength fiber layer in which an anticorrosion agent is mixed between fibers. 4. The anticorrosion cable according to claim 1, wherein the anticorrosion layer includes a twisted layer of an FRP rod containing an anticorrosion agent. 5. The corrosion-prevention cable according to claim 1, wherein the cross-section of the corrosion-prevention layer has a gear-like shape. 6. The anti-corrosion cable according to any one of claims 1 to 5, wherein the anti-corrosion agent is effective at least for small animals including rats and squirrels.