JP3571970B2 - Fireproof cable - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fire-resistant cable made of synthetic resin that can withstand use for a long time even when exposed to high heat or flame due to a fire or the like, and particularly to a fire-resistant cable having 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 attached mica tape.
[0002]
[Prior art]
Generally, in places where many people gather, in the event of a fire or the like, in order to safely guide the people in the hall to the emergency exit, a certain amount of evacuation guidance light, such as an emergency exit guide light, is sufficient to complete the evacuation. It is required to keep it on for hours. Therefore, regarding the fire-resistant cables used for the wiring of 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 cables, etc. We are working to ensure the quality of materials.
[0003]
A conventional fire-resistant cable has a configuration as shown in FIG. That is, the fireproof cable 1 is vertically attached to the outer periphery of the conductor 2 such that one end of the mica tape 3 is overlapped with the other end as shown in FIG. 4, and the mica tape 3 is pressed down. The reason why the mica tape 3 is longitudinally attached is that workability is superior to wrapping the mica tape 3 by wrapping, and the mica tape is less likely to be damaged or cracked during work.
[0004]
Then, the mica tape 3 is further vertically attached to the mica tape 3 held by the glass yarn 4 while changing the overlapping position, and the glass yarn 6 is wound on the mica tape 5 to hold down the mica tape 5. The mica tape is wound according to the fire resistance (for example, 4 to 8) (two 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 if you try to further attach the mica tape further on this, the vertical attachment 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, and further apply the mica tape vertically, wrinkles on the mica tape in the lower layer This is to prevent wrinkles from being generated on the mica tape.
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]
[Problems to be solved by the invention]
In such a conventional fire-resistant cable, every time the mica tape is applied vertically, the glass yarn is wound on the mica tape, so that the work efficiency is low and the material cost is high because expensive glass yarn is used. There is a problem of sticking. Therefore, stopping the winding of the glass yarn on the mica tape every time the mica tape is applied vertically improves the working efficiency and reduces the use of expensive glass yarn, thereby reducing the material cost. it can.
However, if the conventional fire-resistant cable simply stops winding the glass yarn each time the mica tape is longitudinally attached, it becomes difficult to further vertically attach the mica tape on top of the mica tape, or it is difficult to attach the mica tape vertically. When the mica tape is further vertically attached, wrinkles are formed on the lower mica tape. Further, in the case of the conventional fireproof cable, even if the winding of the glass yarn is not stopped every time the mica tape is longitudinally applied, as the number of the 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 molding of the mica tape are a major factor that degrades the fire resistance performance. When the fire-resistant cable is exposed to a flame in a state where such wrinkles are generated, cracks enter from the portion. Then, carbon penetrates from the crack, and the insulation performance is reduced.
[0007]
An object of the present invention is to prevent the generation and breakage of wrinkles of a mica tape, improve workability, and reduce costs.
[0008]
[Means for Solving the Problems]
In the fire-resistant cable according to the first 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 side end of both ends in the tape longitudinal direction and the other side end. A portion is formed by forming a refractory layer surrounding the periphery of the conductor while contacting and superimposing the mica tape on another mica tape at a portion, and wrapping a holding roll over the refractory layer.
With this configuration, according to the first aspect of the present 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.
[0009]
The fire-resistant cable according to the second aspect of the invention is a fire-resistant cable in which a mica tape is formed on a conductor by superimposing the mica tapes on each other and vertically attaching the mica tapes, using two mica tapes .
With this configuration, according to the second aspect of the invention, it is possible to easily manufacture the fire-resistant cable, and to use a small number of mica tapes to reduce the number of presser turns wound on the fire-resistant 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.
[0010]
In the fire-resistant cable according to the third 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 side end. Surrounding the periphery of the conductor while overlapping it by contacting it with another mica tape at the portion, and on the plurality of mica tapes surrounding the periphery of the conductor, each of the plurality of mica tapes is an end portion on both sides in the tape longitudinal direction. One end of the mica tape contacts one mica tape and the other end contacts the other mica tape to form a refractory layer that surrounds and overlaps the mica tape. It is configured by winding a winding .
With this configuration, according to the third 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.
[0011]
In the fireproof cable according to the fourth aspect of the present invention, each of the plurality of mica tapes is overlapped at an end of each mica tape .
In forming the fire-resistant layer, which is the structure of the fire-resistant cable, if the superposition of a plurality of mica tapes is large (50% to 90%), sufficient fire resistance can be obtained. Since the characteristics are not affected, 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 fourth aspect of the invention, the amount of mica tape used can be reduced, and the cost can be reduced .
[0012]
According to a fifth aspect of the present invention, there is provided a fire-resistant cable, wherein the holding coil is wound on the outermost layer of the fire-resistant layer .
With this configuration, according to the fifth aspect of the invention, it is possible to reduce the number of presser windings wound on the refractory layer .
[0013]
In the fire-resistant cable according to the sixth aspect of the present invention, the presser winding is formed of any one of glass yarn, textile fiber yarn, glass tape, and textile fiber tape .
With this configuration, according to the invention described in claim 6, the number of presser windings wound on the refractory layer can be reduced, so that even if expensive glass yarn or glass tape is used, cost is reduced. Can be reduced. In addition, by using textile fiber yarns and textile fiber tapes, those requiring fire resistance and those not requiring fire resistance can be selectively used, and a wide range of materials can be used .
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the fireproof cable according to the present invention will be described.
[0017]
FIG. 1 shows a first embodiment of a fireproof 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, one end of the mica tape 10A overlaps one end of the mica tape 10B, and the other end of the mica tape 10A overlaps the other end of the mica tape 10B. Are formed vertically.
[0018]
The presser winding 11 wound on the refractory layer 10 to suppress the refractory layer 10 can be made of any of glass yarn, textile fiber yarn, glass tape, and textile fiber tape. 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.
[0019]
FIG. 3 shows a second embodiment of the fireproof cable according to the present invention. This embodiment is different 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, a refractory layer 12 is vertically coated on the surface of the conductor 2 made of copper or a copper alloy, 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.
[0020]
The refractory layer 12 formed vertically on the surface of the conductor 2 is composed of a mica tape 12A and a mica tape 12B, and the mica tape 12A and the mica tape 12B cover substantially the entire surface of the conductor 2. The mica tape 12A is overlapped so as to overlap one end of the mica tape 12B, and the other end of the mica tape 12B is connected to the other end of the mica tape 12A. Are overlapped so as to overlap with the ends of the. Since the mica tape 12A and the mica tape 12B have a width enough to cover the entire surface of the conductor 2, a large allowance is provided for the mica tape 12A and the mica tape 12B. It is formed in layers.
[0021]
FIG. 4 shows a fire-resistant cable according to a third embodiment of 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, the present embodiment is different from the first embodiment in that the fireproof layer is formed by using a plurality of mica tapes (four in FIG. 4).
That is, the surface of the conductor 2 made of copper or copper alloy is vertically covered with the fire-resistant layer 13, and the presser winding 11 is wound on the fire-resistant layer 13. The insulator 7 is covered, and the sheath 8 is covered on the insulator 7 to constitute the fireproof cable 1.
[0022]
The refractory layer 13 formed vertically on the surface of the conductor 2 is composed of a mica tape 13A, a mica tape 13B, a mica tape 13C, and a mica tape 13D. One end of the mica tape 13A is formed so as to overlap one end of the mica tape 13B, and the other end of the mica tape 13B is formed so as to overlap one end of the mica tape 13C. The other end of 13C is formed so as to overlap with one end of mica tape 13D, and the other end of mica tape 13D is formed so as to overlap with the other end of mica tape 13A.
With this configuration, sufficient fire resistance can be obtained even when a narrow mica tape is used.
[0023]
FIG. 5 shows a fourth embodiment of the fireproof cable according to the present invention. In the figure, reference numeral 1 denotes a fire-resistant cable, which is formed by vertically attaching a first fire-resistant layer 14 to the surface of a conductor 2 made of copper or a copper alloy, and a second fire-resistant layer is formed on the first fire-resistant layer 14. A refractory layer 15 is formed, and the first 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.
[0024]
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. 6, and the refractory layer 14 vertically attaches the mica tape 14A to the surface of the conductor 2. Then, one end of the mica tape 14A is overlapped with one end of the mica tape 14B, and the other end of the mica tape 14A is overlapped with the other end of the mica tape 14B. Are formed vertically.
[0025]
As shown in FIG. 6, the refractory layer 15 vertically attached on the refractory layer 14 is composed of a mica tape 15A and a mica tape 15B, and the end of the mica tape 15A of the refractory layer 15 and the mica tape 15B. Of the mica tape 14A of the refractory layer 14 and the end of the mica tape 14B are arranged at positions out of phase with each other and vertically attached. Then, the fireproof layer 15 vertically attaches the mica tape 15A on the fireproof layer 14, makes one end of the mica tape 15A overlap one end of the mica tape 15B, and the other end of the mica tape 15A. The mica tape 15B is formed so as to vertically overlap the other end of the mica tape 15B so as to overlap the other end.
[0026]
The presser winding 17 wound on the refractory layer 16 is used to prevent the mica tape from spreading by pressing the mica tape in order to insulate the vertically attached wire core and to apply heat from the outside. In some cases (for example, in the event of a fire), the vertically attached mica tapes 15A and 15B may not be opened. In the case of the presser winding 17 which is used merely to hold 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, Fireproofing is required to prevent the mica tape attached vertically from opening during fire). 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.
[0027]
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. It is sufficient that the presser winding 17 is provided only on the outermost layer (the fireproof layer 15 in FIG. 5) of the plurality of fireproof layers (the fireproof layers 14 and 15 in FIG. 5).
[0028]
Therefore, according to the present embodiment, since the presser winding is not wrapped around other than the outermost layer of the fireproof layer, the fireproof layer of the mica tape has no wrinkles or damages when the outermost fireproof layer is formed. Characteristics can be fully exhibited. 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]
【The invention's effect】
According to the first aspect of the present invention, it is possible to reduce the number of presser windings wound on the fire-resistant layer, prevent wrinkles and breakage of the mica tape, improve workability, and reduce costs. Can be reduced.
[0030]
According to the second 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. It is possible to prevent wrinkles and breakage of the tape, improve workability, and reduce costs.
[0031]
According to the invention described in claim 3, it is possible to reduce the number of pressing windings wound on the anti-fire layer, achieving improvement in workability as well as preventing the occurrence and breakage of wrinkles mica tape, the cost Can be reduced.
[0032]
According to the fourth aspect of the present invention, the amount of mica tape used can be suppressed, and the cost can be reduced .
[0033]
According to the fifth aspect of the invention, it is possible to reduce the number of presser windings wound on the refractory layer .
[0034]
According to the invention described in claim 6, the number of press windings wound on the refractory layer can be reduced, so that even if expensive glass yarn or 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 one that requires fire resistance and one that does not require fire resistance, and can have a wide range of materials to be used.
[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 fire-resistant 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 cross-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 cross-sectional view of the fire-resistant 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 ……………………… Fireproof cable 2 …………………………………… Conductor 7 ……… ………………… Insulator 8 ……………………………………… Sheath 10 …………………………………………………… Refractory layers 10A, 10B ............ Mica tape 11 ........................ Pressing roll 12 ............... ............ Fireproof layers 12A and 12B .................. Mica tape 13 .................. Fireproof layers 13A and 13B. 13C, 13D mica tape 14, 15, 16 ... fireproof layer 14A, 14B, 15A, 15B mica tape 17 ............... ………………… Retainer winding

Claims (6)

Each of the plurality of mica tapes vertically attached on the conductor is brought into contact with the conductor at one end of both ends in the longitudinal direction of the tape, and is brought into contact with another mica tape at the other end to overlap. A fire-resistant cable, wherein a fire- resistant layer is formed by surrounding the periphery of the conductor while being joined together, and a presser winding is wound on the fire-resistant layer . The fire-resistant cable according to claim 1, wherein the fire- resistant layer formed by superimposing mica tapes on the conductor and vertically applying the mica tapes is formed using two mica tapes . Each of the plurality of mica tapes vertically attached on the conductor is brought into contact with the conductor at one end of both ends in the longitudinal direction of the tape, and is brought into contact with another mica tape at the other end to overlap. Each of the plurality of mica tapes surrounds the periphery of the conductor while being fitted together, and surrounds the periphery of the conductor. In contact with another mica tape at the other side end to form a refractory layer surrounding the mica tape while superimposing it, and wrapping a holding roll over the refractory layer. Fireproof cable. 4. The fire-resistant cable according to claim 1, wherein the overlapping of the plurality of mica tapes is performed at an end of each mica tape . 5. 5. The fire-resistant cable according to claim 1, wherein the holding coil is wound on the outermost layer of the fire-resistant layer . The fire-resistant cable according to claim 1, 2, 3, 4, or 5, wherein the presser winding is any one of glass yarn, textile fiber yarn, glass tape, and textile fiber tape .

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