JP2001093349A - Fire resistant cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent wrinkling and breakage of mica tapes, improve workability and reduce cost. SOLUTION: A plurality of mica tapes are wound on a conductor 2, in such a manner that one mica tape is overlapped at both ends with both ends of the other mica tape adjacent thereto, while dislocating one from the other at both side ends, and longitudinally moved therealong while wrapping the conductor 2, to form a fire resistant layer 10 on which a holddown winding 11 is wound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant cable made of a synthetic resin which can withstand use for a long time even when exposed to high heat or flame due to a fire or the like, and more particularly to a fire-resistant layer formed by vertically attaching mica tape. The present invention relates to a fireproof cable having a predetermined fireproof property without increasing the number of expensive glass yarns used as a holding roll of a vertically attached mica tape.

[0002]

2. Description of the Related Art Generally, in a place where a large number of people gather, in the event of a fire or the like, evacuation is completed by evacuation guide lights such as emergency exit guide lights in order to safely guide people in the hall to an emergency exit. It is required to keep the light on for a certain period of time. Therefore, regarding fire-resistant cables used for wiring fire-extinguishing equipment, alarm equipment, and evacuation equipment for fire-resistant objects, etc., the Japan Electric Wire & Cable Makers Association has voluntarily established its own certification standards for fire-resistant electric wires, etc. The quality of materials is being ensured.

A conventional fire-resistant cable has a configuration as shown in FIG. That is, the fire-resistant cable 1 is
As shown in FIG. 8, a mica tape 3 is vertically attached such that one end is overlapped with the other end, and a glass yarn 4 is wound on the mica tape 3 and the mica tape 3 is held down. It is attached. The reason why the mica tape 3 is attached vertically is that the mica tape 3 is excellent in workability as compared with wrapping the mica tape 3 and that the mica tape is less likely to be damaged or cracked during the work.

Then, the mica tape 5 is further changed on the mica tape 3 held by the glass yarn 4 to change the overlapping position.
With the glass yarn 6 on top of the mica tape 5.
And the mica tape 5 is pressed down. This mica tape is used in accordance with fire resistance (for example, 4 to 8).
Sheets) (two sheets in FIG. 7). The reason why the glass yarn is wound on the mica tape every time the mica tape is vertically attached is to leave the vertically attached mica tape as it is, and to further vertically attach the mica tape on it, There is a risk that the mica tape may fall apart, so wrap the glass yarn on the vertically attached mica tape and do not press down on the mica tape. This is to prevent wrinkles from being generated on the mica tape. And
An insulator 7 made of polyethylene is extruded and coated on the mica tape 5 to form an insulated wire core, and a sheath 8 is coated on the insulated wire core to form the fireproof cable 1.

[0005]

In such a conventional fire-resistant cable, every time a mica tape is vertically attached,
Since the glass yarn is wound on the mica tape, there is a problem that the working efficiency is low and the material cost is high because the expensive glass yarn is used. Therefore, stopping the winding of the glass yarn on the mica tape every time this mica tape is applied vertically improves work efficiency,
Since less expensive glass yarn is used, material costs can be reduced. However, if the winding of the glass yarn is simply stopped each time the mica tape is vertically attached with the conventional fire-resistant cable, it becomes difficult to vertically attach the mica tape and then further attach the mica tape. When the mica tape is further vertically attached, wrinkles are formed on the lower mica tape. Further, in the case of a conventional fire-resistant cable, even if the winding of the glass yarn is not stopped every time the mica tape is longitudinally applied, as the number of mica tapes to be vertically extended increases, the inner line becomes gradually rounder and wrinkles increase.

[0006] The wrinkles of the mica tape generated during and after the mica tape molding are a major factor in deteriorating the fire resistance performance. When the fire-resistant cable is exposed to a flame in a state in which such wrinkles are generated, the mica tape may be damaged. Cracks are formed, and carbon penetrates from the cracks, which lowers insulation performance.

An object of the present invention is to prevent wrinkles and breakage of a mica tape, improve workability, and reduce costs.

[0008]

According to a first aspect of the present invention, there is provided a fire-resistant cable according to the present invention, wherein a plurality of mica tapes are provided on a conductor, and both end portions of each mica tape are both end portions of each mica tape. The mica tape is overlapped with the mica tape adjacent to the mica tape so that the mica tape is overlapped so as to be different at both side ends thereof, and vertically attached so as to surround the conductor, thereby forming a refractory layer. It is configured by winding a holding roll. With this configuration, according to the first aspect of the invention, it is possible to reduce the number of presser windings wound on the fireproof layer, to prevent wrinkles and breakage of the mica tape, and to improve workability. And cost can be reduced.

In the fire-resistant cable according to the second aspect of the present invention, each of the plurality of mica tapes vertically attached on the conductor comes into contact with the conductor at one end of both ends in the longitudinal direction of the tape, and the other end. Is formed on the mica tape so as to surround the conductor and form a refractory layer while being brought into contact with another mica tape at the side end of the mica tape. With this configuration, according to the second aspect of the invention, it is possible to reduce the number of presser windings wound on the refractory layer, to prevent wrinkles and breakage of the mica tape, and to improve workability. And cost can be reduced.

The fireproof cable according to the third aspect of the present invention uses two mica tapes to form a fireproof layer formed by superimposing mica tapes on a conductor and vertically attaching them.
Each of the mica tapes is configured so as to be superimposed differently. With this configuration, according to the third aspect of the invention, it is possible to easily manufacture the fireproof cable, and to use a small number of mica tapes to reduce the number of presser turns wound on the fireproof layer. Can be reduced, wrinkles of the mica tape can be prevented from being generated and damaged, workability can be improved, and costs can be reduced.

The fire-resistant cable according to the fourth aspect of the present invention is a fire-resistant cable in which a plurality of fire-resistant layers are superposed. In other words, when the refractory layer is formed by laminating two mica tapes with different overlaps at both ends, a plurality of mica tapes are laminated with different mica tapes at adjacent ends at both ends of each mica tape. The refractory layer thus formed may be formed as a single layer, but may be formed as a plurality of layers. With this configuration, according to the invention described in claim 4, it is possible to easily manufacture a fire-resistant cable adapted to fire-resistant characteristics.

According to a fifth aspect of the present invention, in the fireproof cable, a plurality of mica tapes are overlapped at the end of each mica tape. When forming a fire-resistant layer, which is a structure of a fire-resistant cable, a large overlap (50% to 90%) of a plurality of mica tapes can provide sufficient fire resistance, but if the conductor is not exposed, the fire resistance is reduced. Since the characteristics are not affected, a sufficient fire resistance can be obtained even if the plurality of mica tapes are overlapped only at the end of each mica tape. With this configuration, according to the invention described in claim 5, the amount of mica tape used can be suppressed, and the cost can be reduced.

According to a sixth aspect of the present invention, there is provided a fire-resistant cable, wherein a presser winding is wound on an outermost layer of a fire-resistant layer. With this configuration, according to the invention described in claim 6, the number of presser windings wound on the refractory layer can be reduced.

The fire-resistant cable according to the invention of claim 7 is characterized in that the presser winding is made of glass yarn, textile fiber yarn,
It is composed of either a glass tape or a textile fiber tape.

According to the above construction, a seventh aspect is provided.
According to the invention described in the above, since it is possible to reduce the number of presser winding wound on the refractory layer, expensive glass yarn,
Even if a glass tape is used, the cost can be reduced. Further, by using a yarn made of textile fiber or a tape made of textile fiber, it is possible to selectively use a material that requires fire resistance and a material that does not require fire resistance, thereby giving a wide range of materials to be used.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a fire-resistant cable according to the present invention will be described below.

FIG. 1 shows a first embodiment of a fire-resistant cable according to the present invention. In the figure, reference numeral 1 denotes a fire-resistant cable, in which a fire-resistant layer 10 is vertically attached to the surface of a conductor 2 made of copper or a copper alloy, and the fire-resistant layer 10 is suppressed on the fire-resistant layer 10. For this purpose, a presser winding 11 is wound, the insulator 7 is coated on the refractory layer 10, and the sheath 8 is coated on the insulator 7. The refractory layer 10 formed on the surface of the conductor 2 is composed of a mica tape 10A and a mica tape 10B as shown in FIG. 2, and the refractory layer 10 has a mica tape 10A vertically attached to the surface of the conductor 2. Then, mica tape 1 is attached to one end of mica tape 10A.
The mica tape 10B is longitudinally attached so that one end of the mica tape 10A overlaps and the other end of the mica tape 10A overlaps the other end of the mica tape 10B.

The presser winding 11 wound on the refractory layer 10 to suppress the refractory layer 10 can be made of any of glass yarn, yarn made of textile fiber, glass tape, and tape made of textile fiber. When the fire-resistant layer 10 is a single layer, fire resistance is required, and glass yarn, silica yarn, alumina yarn or the like can be used.

FIG. 3 shows a second embodiment of the fireproof cable according to the present invention. This embodiment differs from the first embodiment shown in FIG. 1 in that the overlap of the end of the mica tape 10A and the end of the mica tape 10B of the refractory layer 10 is different. That is, the surface of the conductor 2 made of copper or a copper alloy is vertically covered with a refractory layer 12, and a presser winding 11 is wound on the refractory layer 12. The insulator 7 is covered, and the sheath 8 is covered on the insulator 7 to constitute the fireproof cable 1.

The refractory layer 12 formed vertically on the surface of the conductor 2 comprises a mica tape 12A and a mica tape 12A.
B, the mica tape 12A and the mica tape 12B have a width enough to cover substantially the entire surface of the conductor 2, and one end of the mica tape 12A is formed of the mica tape 12B. The mica tape 12B is overlapped so as to overlap one end, and the other end of the mica tape 12B is overlapped so as to overlap the other end of the mica tape 12A. Since the mica tape 12A and the mica tape 12B have a width enough to cover the entire surface of the conductor 2,
The overlap margin of the mica tape 12A and the mica tape 12B is large, and the refractory layer 12 is formed in two layers.

FIG. 4 shows a third embodiment of the fireproof cable according to the present invention. The difference between this embodiment and the first embodiment shown in FIG. 1 is that the first embodiment shown in FIG. 1 has a fire-resistant layer 10 composed of two mica tapes 10A and 10B. On the other hand, in this embodiment, a plurality of mica tapes (4
Is used to form the refractory layer. That is, the surface of the conductor 2 made of copper or a copper alloy is vertically covered with a refractory layer 13, and a presser winding 11 is wound on the refractory layer 13. The insulator 7 is covered, and the sheath 8 is covered on the insulator 7 to constitute the fireproof cable 1.

The refractory layer 13 formed vertically on the surface of the conductor 2 comprises a mica tape 13A and a mica tape 13
B, mica tape 13C and mica tape 13D. One end of this mica tape 13A is
The mica tape 13B is formed to overlap one end of the mica tape 13B, the other end of the mica tape 13B is formed to overlap one end of the mica tape 13C, and the other end of the mica tape 13C is formed of a mica tape. 13D is formed so as to overlap with one end of the mica tape 13D.
Is formed so as to overlap with the other end of the. With such a configuration, sufficient fire resistance can be obtained even when a narrow mica tape is used.

FIG. 5 shows a fourth embodiment of the fireproof cable according to the present invention. In the drawing, reference numeral 1 denotes a fire-resistant cable, which is formed by vertically attaching a first fire-resistant layer 14 on the surface of a conductor 2 made of copper or a copper alloy, and a second fire-resistant cable is formed on the first fire-resistant layer 14. Forming a refractory layer 15;
The refractory layer 14 and the second refractory layer 15 form a refractory layer 16. On the second refractory layer 15, a presser winding 17 for suppressing the refractory layer 16 is wound. The insulator 7 is coated on the refractory layer 16, and a sheath is placed on the insulator 7. 8, the fire-resistant cable 1 is formed.

The refractory layer 14 formed on the surface of the conductor 2
Is composed of a mica tape 14A and a mica tape 14B as shown in FIG.
A mica tape 14A is longitudinally attached to the surface of the conductor 2, one end of the mica tape 14B overlaps one end of the mica tape 14A, and the other end of the mica tape 14A is connected to the other end of the mica tape 14B. The mica tape 14B is vertically attached so as to overlap the ends.

As shown in FIG. 6, the refractory layer 15 vertically laid on the refractory layer 14 is composed of a mica tape 15A and a mica tape 15B.
The end of the mica tape 15A and the end of the mica tape 15B are arranged vertically out of phase with the end of the mica tape 14A and the end of the mica tape 14B of the refractory layer 14. The refractory layer 15 is
Vertically with mica tape 15A on top of
The mica tape 15B is longitudinally attached so that one end of the mica tape 15B overlaps one end of the mica tape 15B, and the other end of the mica tape 15A overlaps the other end of the mica tape 15B. It is formed.

The presser winding 17 wound on the refractory layer 16 is used to hold the mica tape so that it does not spread by pressing the mica tape to insulate the vertically attached wire core. Mica tapes 15A and 15B applied vertically when fire occurs (for example, in a fire)
May not be opened. In the case of the presser winding 17 which is used simply to hold down the mica tape so as not to spread by pressing the mica tape to insulate the vertically attached wire core, fire resistance is not required, and when heat is applied from the outside (for example, In order to prevent the mica tape attached vertically from opening during fire), fire resistance is required. In such a case, refractory fibers and non-refractory fibers can be mixed and used.For the refractory fibers, glass yarn, silica yarn, alumina yarn, etc., and as the non-refractory fibers, use fibers having a certain strength such as nylon yarn. Can be.

In such a case, the presser winding 17 can be made of any of glass yarn, textile fiber yarn, glass tape, and textile fiber tape. The presser winding 17 is formed of an outermost layer (refractory layer 1 in FIG. 5) of a plurality of refractory layers (refractory layers 14 and 15 in FIG. 5).
It is sufficient to provide only on 5).

Therefore, according to the present embodiment, since the presser winding is not wound around the outermost layer of the refractory layer, the mica tape does not wrinkle or damage the refractory layer when the outermost refractory layer is formed. It can fully exhibit the fire resistance characteristic of the. Therefore, stable fire resistance can be obtained even at a high temperature, and the work of winding the mica tape and the presser winding at the time of manufacturing the fire resistant layer becomes easy, so that the work efficiency can be improved.

[0029]

According to the first aspect of the present invention, it is possible to reduce the number of presser windings wound on the refractory layer, prevent wrinkles and breakage of the mica tape, and improve workability. And cost can be reduced.

According to the second aspect of the present invention, it is possible to reduce the number of presser windings wound on the refractory layer, prevent wrinkles and breakage of the mica tape, and improve workability. , Cost can be reduced.

According to the third aspect of the present invention, it is possible to easily manufacture a fire-resistant cable, and to reduce the number of presser windings wound on the fire-resistant layer even with a small number of mica tapes. Thus, wrinkles of the mica tape can be prevented from being generated and damaged, workability can be improved, and costs can be reduced.

According to the fourth aspect of the invention, it is possible to easily manufacture a fire-resistant cable adapted to fire-resistant characteristics.

According to the fifth aspect of the present invention, the amount of mica tape used can be suppressed and the cost can be reduced.

According to the sixth aspect of the present invention, it is possible to reduce the number of presser windings wound on the refractory layer.

According to the seventh aspect of the invention, the number of presser windings wound on the refractory layer can be reduced.
Even if expensive glass yarn or glass tape is used, the cost can be reduced. In addition, yarn made of textile fiber,
By using a textile fiber tape, those requiring fire resistance and those not requiring fire resistance can be selectively used, and a wide range of materials can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of a fireproof cable according to the present invention.

FIG. 2 is a sectional view of the fireproof cable shown in FIG.

FIG. 3 is a cross-sectional view showing a second embodiment of the fireproof cable according to the present invention.

FIG. 4 is a sectional view showing a third embodiment of the fireproof cable according to the present invention.

FIG. 5 is a perspective view showing a fourth embodiment of the fireproof cable according to the present invention.

FIG. 6 is a sectional view of the fireproof cable shown in FIG.

FIG. 7 is a sectional view showing a conventional fireproof cable.

FIG. 8 is a cross-sectional view of the conventional fireproof cable shown in FIG.

[Explanation of symbols]

 1 ………………………………………………………………………………………………………………… Conductor 7 …………… …………………………………………………………………………………………………… Sheath 10 ………………………………………………………………………… Refractory layer 10A, 10B ............ Mica tape 11 ............ ...... Holding tape 12 .................. ............ Fireproof layer 12A, 12B .................. Mica tape 13 .................. Fireproof layer 13A, 13B, 13C, 13D Mica tape 14, 15, 16 ... Fireproof layer 14A, 14B, 15A, 15B ... Mica tape 17 ... …………………

Claims (7)

[Claims] 1. A method in which a plurality of mica tapes are placed on a conductor, and both ends of each mica tape are overlapped with mica tapes adjacent to both side ends of each mica tape. A fire-resistant cable characterized in that a fire-resistant layer is formed by vertically overlapping the ends of the conductor so as to surround the conductor so as to surround the conductor, and a presser winding is wound on the fire-resistant layer. 2. Each of a plurality of mica tapes vertically attached on a conductor comes into contact with the conductor at one end of both ends in the longitudinal direction of the tape and at the other end on the other mica tape. A fire-resistant cable, wherein a fire-resistant layer is formed by surrounding the periphery of a conductor while being overlapped by being brought into contact with a conductor, and a holding roll is wound on the fire-resistant layer. 3. A refractory layer formed by superimposing mica tapes on the conductor and vertically applying the mica tapes to each other, using two mica tapes and superposing the mica tapes so that the mica tapes are superimposed differently. The fire-resistant cable according to claim 1 or 2, wherein 4. The fire-resistant cable according to claim 1, wherein the fire-resistant layer is formed by stacking a plurality of layers. 5. The method of superposing a plurality of mica tapes,
Claims 1 and 2, wherein each mica tape is provided at an end.
The fire-resistant cable according to 3 or 4. 6. The fire-resistant cable according to claim 1, wherein the presser winding is wound on the outermost layer of the fire-resistant layer. 7. The fire-resistant cable according to claim 1, wherein the presser winding is any one of glass yarn, textile fiber yarn, glass tape, and textile fiber tape.