JP2022161492A - Fireproof wire and manufacturing method of fireproof wire - Google Patents

Abstract

To provide a fireproof wire capable of preventing insulation resistance deterioration of a folding part which is an overlapping part of a fireproof tape, and thereby improving fire resistance efficiency.SOLUTION: A fireproof wire 1 includes a conductor 10, a fireproof tape 20 attached vertically to the outer periphery of the conductor 10, and insulator layers 31, 32 applied to the outer periphery of the fireproof tape 20. The fireproof tape 20 is folded at both-side ends, and folding parts 23A, 24A are piled up so as to sandwich the end mutually by folding pieces thereof 23a, 24a.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a fire-resistant electric wire that can withstand long-term use even when exposed to high temperatures and flames due to a fire or the like, and a method for manufacturing the fire-resistant electric wire.

As this type of fire-resistant electric wire, there is one disclosed in Patent Document 1. The fire-resistant wire disclosed in Patent Document 1 includes a conductor, a fire-resistant tape that is wrapped around the outer periphery of the conductor in a longitudinal manner, one end is folded back and the other end is superimposed thereon, and a fire-resistant tape. It has a presser thread that presses the outer periphery and an insulating layer that covers the outer periphery of the fireproof tape.

JP 2020-57589 A

However, since the conventional fire-resistant wire has a structure in which one folded end of the fire-resistant tape is overlapped with the other end, the insulating layer burns in the event of a fire, and the presser thread comes off and the fire-resistant tape opens. Insulation resistance may be lost, conductors may be exposed, and current may be interrupted.

The present invention has been made in view of the problems of the prior art. An object of the present invention is to provide a fire-resistant electric wire capable of preventing a decrease in insulation resistance at folded portions, which are overlapping portions of fire-resistant tape, and improving fire-resistant performance.

A fire-resistant wire according to an aspect of the present invention comprises a conductor, a fire-resistant tape vertically attached to the outer periphery of the conductor, and an insulating layer applied to the outer periphery of the fire-resistant tape. It is folded back at the part, and the folded parts are overlapped so that the ends are sandwiched by the folded pieces.

It is preferable that a holding yarn is wound around the outer circumference of the fireproof tape.

The fireproof tape preferably has an adhesive within the folded portion.

The fireproof tape has a film-like base material made of resin or glass cloth, and a fire-resistant layer laminated on the film-like base material. It is preferable that the base material is laminated on the outer peripheral side, and the fireproof layer is laminated on the conductor side.

According to another aspect of the present invention, there is provided a method for manufacturing a fire-resistant electric wire, in which a fire-resistant tape is longitudinally attached to the outer periphery of a conductor using a tape longitudinally attaching jig having a tubular portion and a curved tubular portion having a folded portion on the outlet side. A method for manufacturing a fire-resistant electric wire, in which the conductor is inserted into the tubular portion, the fire-resistant tape is inserted into the curved tubular portion, and then the conductors are pulled out one after another from the tubular portion, and the fire-resistant In this method, the tapes are pulled out one after another from the folded portion on the exit side of the curved tubular portion, and both side ends of the fireproof tape are folded back at the folded portion of the curved tubular portion, and overlapped so as to sandwich the ends.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to prevent the insulation resistance fall of the folded part which is the overlapping part of a fireproof tape, and can provide the fireproof electric wire which can improve a fireproof performance.

BRIEF DESCRIPTION OF THE DRAWINGS It is a perspective view which shows an example of the fireproof electric wire which concerns on 1st Embodiment of this invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1; It is an expanded sectional view which shows the principal part of the fireproof tape in the said fireproof electric wire. (a) is a cross-sectional view of an intermediate portion of a tape vertical attachment jig for vertically attaching the fireproof tape to the outer circumference of a conductor, and (b) is a cross-sectional view of the outlet side of the same tape vertical attachment jig. (a) is a cross-sectional view of an intermediate portion of the tape vertical attachment jig when the fireproof tape is vertically attached, and (b) is a cross-sectional view of the exit side of the tape vertical attachment jig when the fireproof tape is vertically attached. 4(a) to 4(c) are enlarged cross-sectional views of essential parts showing how to open the folded portion of the fireproof tape. FIG. 6 is an enlarged cross-sectional view showing a main part of the fireproof tape in the fireproof electric wire of the second embodiment of the present invention;

Hereinafter, fire-resistant wires according to embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an example of a fireproof electric wire according to an embodiment of the invention. FIG. 2 is a cross-sectional view taken along line II--II in FIG. FIG. 3 is an enlarged cross-sectional view showing the main part of the fireproof tape in the fireproof electric wire. FIG. 4(a) is a cross-sectional view of an intermediate portion of a tape vertical attachment jig for vertically attaching a fireproof tape to the outer periphery of a conductor. FIG. 4(b) is a cross-sectional view of the exit side of the tape vertical attaching jig. FIG. 5(a) is a cross-sectional view of an intermediate portion of the tape vertical attaching jig when the fireproof tape is vertically attached. FIG. 5(b) is a cross-sectional view of the exit side of the tape vertical attaching jig when the fireproof tape is vertically attached. 6(a) to 6(c) are enlarged cross-sectional views of essential parts showing how to open the folded portion of the fireproof tape.

As shown in FIG. 1, the fire-resistant wire 1 includes a conductor 10, a fire-resistant tape 20 vertically attached to the outer circumference of the conductor 10, a holding yarn 30 wound around the outer circumference of the fire-resistant tape 20, and an outer circumference of the fire-resistant tape 20. and an insulating coating 31 and a sheath 32 as an insulating layer applied to the .

As shown in FIGS. 1 and 2, the conductor 10 is a single-core conductor with a circular cross section. The conductor 10 is made of a copper material, a copper alloy material, an aluminum material, or the like.

As shown in FIG. 3, the fireproof tape 20 vertically attached to the outer periphery of the conductor 10 includes, for example, a film-like base material 21 made of polyethylene (PE) or glass cloth, and a film-like base material 21 on the film-like base material 21. It consists of a laminated mica layer (refractory layer) 22 . As shown in FIGS. 2 and 3, the fireproof tape 20 is folded back at both side ends 23 and 24, and the folded portions 23A and 24A sandwich the ends 23 and 24 with the folded pieces 23a and 24a. are superimposed on each other. Further, as shown in FIG. 3, in the folded pieces 23a, 24a of the folded portions 23A, 24A, the film-like base material 21 is placed on the outer peripheral side, and the mica layer 22 is placed on the conductor 10 side.

As shown in FIG. 1, the pressing yarn 30 wound around the outer circumference of the fireproof tape 20 is, for example, glass yarn, silica yarn, alumina yarn, or the like. Then, both side ends 23 and 24 of the fireproof tape 20 are sandwiched between the folded pieces 23a and 24a of the folded portions 23A and 24A, and the holding yarn 30 is wound around the both sides 23 and 24 so that the two side ends 23 and 24 are in close contact with each other. It is superimposed on and fixed to. An insulating coating 31 made of, for example, polyethylene is extruded onto the fire-resistant tape 20 in this state, and the insulating coating 31 is further covered with a sheath 32 to form the fire-resistant wire 1 .

When manufacturing this refractory electric wire 1, a tape vertical attaching jig 40 shown in FIGS. 4(a) and 4(b) is used. The tape vertical attachment jig 40 includes a tubular portion 41 and a curved tubular portion 42 having a bent portion 43 in the middle and a folded portion 44 on the exit side.

Next, a method for manufacturing the fire-resistant electric wire 1, more specifically, a method for vertically attaching the fire-resistant tape 20 to the outer periphery of the conductor 10 using the tape vertical attachment jig 40 will be described in order along FIGS. explain.

First, as shown in FIG. 5( a ), the conductor 10 is inserted into the tubular portion 41 of the tape vertical attachment jig 40 , and the fireproof tape 20 is inserted into the curved tubular portion 42 of the tape vertical attachment jig 40 .

Next, as shown in FIG. 5(b), the conductors 10 are pulled out one after another from the tubular portion 41, and the fireproof tapes 20 are pulled out one after another from the bent portion 44 on the exit side of the curved tubular portion 42. Next, as shown in FIG. As a result of this pulling out, both side end portions 23 and 24 of the fireproof tape 20 are folded back at the folded portion 44 of the curved tubular portion 42 and overlapped closely so that the mutual end portions 23 and 24 are sandwiched between the folded pieces 23a and 24a. The refractory tape 20 is vertically attached to the outer periphery of the conductor 10 by overlapping the folded pieces 23a and 24a. Next, after winding the pressing yarn 30 around the outer circumference of the fireproof tape 20, the outer circumference is covered with an insulating coating 31 and a sheath 32, whereby the fireproof electric wire 1 is completed.

As described above, according to the fire-resistant wire 1 of the first embodiment, even if the holding yarn 30 comes off from the fire-resistant tape 20 due to the combustion of the insulating coating 31 and the sheath 32, the fire-resistant tape 20 is more difficult to open than the conventional product. Also, it becomes difficult to lose the insulation resistance. Thereby, the fire-resistant electric wire 1 with higher fire-resistant performance is obtained. In other words, it is possible to prevent the insulation resistance of the folded portions 23A and 24A, which are the overlapping portions of the fireproof tape 20, from decreasing, and the fireproof performance of the fireproof wire 1 can be further improved.

Specifically, as shown in FIGS. 6(a) to 6(c), even if the pressing yarn 30 is separated from the fireproof tape 20 and the fireproof tape 20 moves in the opening direction, both ends 23 and 24 are folded back 23A. , 24A hinder and make it difficult to open. As a result, the conductor 10 is less likely to be exposed in the direction of fire and is less likely to lose its insulation resistance. In addition, since the winding man angle of the pressing yarn 30 is widened, the gap between the ends 23 and 24 of the fireproof tape 20 is widened, and even if the melted insulating coating 31 flows into the gap, the melted insulating coating 31 is It is blocked by the folded portions 23A and 24A of the fireproof tape 20 and does not reach the conductor 10. - 特許庁This makes it difficult to lose insulation resistance. Since the insulation resistance is less likely to be lost, the possibility of power interruption is reduced.

FIG. 7 is an enlarged cross-sectional view showing the main part of the fireproof tape in the fireproof wire of the second embodiment of the present invention.

The fireproof tape 20 in the fireproof wire 1 of the second embodiment has an adhesive 25 in the folded portion 23A of the end portion 23 on one side (between the fireproof tape 20 and the folded piece 23a). different from that of form. Since the rest of the configuration is the same as that of the first embodiment, the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

The fireproof tape 20 of the fireproof wire 1 of the second embodiment has higher fireproof performance than that of the first embodiment because the adhesive 25 is applied to the folded portion 23A of the end portion 23. In addition, the possibility that the adhesive 25 adheres to the conductor 10, the pressing yarn 30, the insulating coating 31, etc. can be reduced, and the possibility of deterioration can be reduced.

Although the present embodiment has been described above, the present embodiment is not limited to these, and various modifications are possible within the scope of the gist of the present embodiment.

That is, according to the above embodiment, the insulating coating is made of polyethylene, but the insulating coating may be made of a resin material other than polyethylene.

REFERENCE SIGNS LIST 1 refractory electric wire 10 conductor 20 refractory tape 21 film-like substrate 22 mica layer (refractory layer)
23, 24 end portions 23A, 24A folded portions 23a, 24a folded pieces 25 adhesive 30 pressing yarn 31 insulating coating (insulating layer)
32 sheath (insulating layer)
40 tape vertical attachment jig 41 cylindrical portion 42 curved cylindrical portion 43 bending portion 44 folding portion

Claims (5)

a conductor;
a fireproof tape vertically attached to the outer periphery of the conductor;
An insulating layer applied to the outer periphery of the fireproof tape;
with
A fire-resistant wire, wherein the fire-resistant tape is folded back at both side ends thereof, and the folded-back portions are overlapped so that the ends are sandwiched between the folded-back pieces. 2. The fire-resistant wire according to claim 1, wherein a retaining yarn is wrapped around the circumference of said fire-resistant tape. The fire-resistant wire according to claim 1 or 2, wherein the fire-resistant tape has an adhesive in the folded portion. The fire-resistant tape has a film-like base material made of resin or glass cloth, and a fire-resistant layer laminated on the film-like base material,
4. The fire-resistant wire according to any one of claims 1 to 3, wherein the film-like base material is stacked on the outer peripheral side and the fire-resistant layer is stacked on the conductor side at one folded portion of the folded portions. . A method for manufacturing a fire-resistant electric wire in which a fire-resistant tape is vertically attached to the outer periphery of a conductor using a tape vertical attachment jig having a tubular portion and a curved tubular portion having a folded portion on the outlet side, the method comprising the steps of:
inserting the conductor into the cylindrical portion and inserting the fireproof tape into the curved cylindrical portion;
Next, while pulling out the conductors one after another from the tubular portion and pulling out the fireproof tape one after another from the folded portion on the exit side of the curved tubular portion, both side ends of the refractory tape are pulled out at the folded portions of the curved tubular portion. A method for manufacturing a fire-resistant electric wire by folding back portions and stacking the ends so as to sandwich each other.

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