JP2002100247A - Fire-resistant electric wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire-resistant electric wire, in which a laminated mica foil will not fall in between conductive element wires. SOLUTION: A fire-resistant layer 13 is formed with a double-side coated plastic mica tape 15 located just over a twisted wire conductor 12, where the mica tape 15 has plastic tapes 18, 18 on both surfaces of a soft laminated mica foil 17. In short, this makes the plastic tape 18 located between the conductor 12 and the soft laminated mica foil 17.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fire-resistant electric wire in which a fire-resistant layer including a soft mica foil is formed on a stranded conductor.

[0002]

2. Description of the Related Art Generally, in a place where a large number of people gather, such as a theater or a department store, in case of a fire or the like, an evacuation guide light such as an emergency exit guide light is provided in order to safely guide people in the hall to an emergency exit. For example, it is required that the light source be turned on for a certain period of time such that the evacuation is completed. Therefore, the Japan Electric Wire & Cable Makers Association has voluntarily established its own certification standards for fire-resistant electric wires, etc. used for the wiring of fire-extinguishing equipment, alarm equipment, and evacuation equipment for fire-resistant objects, etc. The quality of materials is being ensured. In this specification, the term "fireproof electric wire" refers to a general term for cables having fireproof performance specified in Fire Service Agency Notification No. 10 of 1997.

[0003] In FIG. 2, a conventional fire-resistant electric wire is obtained by twisting a plurality of insulated cores 1 together with inclusions (not shown) and providing a plastic sheath (not shown) on the outside thereof. A conductor 2 and a refractory layer 3 composed of two types of refractory tape layers formed on the conductor 2;
And an insulator 4 coated on the outside of the refractory layer 3.

The layers of the above two types of fireproof tapes of the fireproof layer 3 include a layer of a plastic mica tape 5 disposed on the conductor 2 side and a layer of a glass mica tape (not shown) disposed on the insulator 4 side. 6, the layer of the plastic mica tape 5 is formed by using one or a plurality of plastic mica tapes 5 each having a plastic tape 7 and a laminated mica foil 8 attached to one surface of the plastic tape 7. . The plastic mica tape 5 is configured to wind the laminated mica foil 8 toward the conductor 2.

[0005]

In the above-mentioned conventional fire-resistant electric wire, the conductor 2 is twisted because the mica foil 8 of each insulated wire core 1 is wound so as to contact the conductor 2. In the case of a wire, the mica foil 8 constitutes the conductor 2 by a tape pressure for winding the glass mica tape when forming the glass mica tape layer 6 or a resin pressure when covering the insulator 4. There was a problem that it fell between the strands.

If the laminated mica foil 8 falls between the strands, the insulation performance of the refractory wire during combustion decreases, the terminal processing property decreases during the construction, or the remaining mica foil 8 is used for construction. There is a possibility that a defect such as poor contact later will be caused.

The present invention has been made in view of the above circumstances, and has as its object to provide a fire-resistant electric wire in which mica foil does not fall between conductor wires.

[0008]

According to a first aspect of the present invention, there is provided a refractory electric wire according to the present invention, wherein plastic tapes are disposed on both sides of a soft mica foil immediately above a stranded conductor. It is characterized by providing a double-sided plastic mica tape to form a fire-resistant layer.

According to the first aspect of the present invention,
There will be a plastic tape between the conductor and the soft mica foil. Thus, the mica foil does not fall between the conductor wires.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an embodiment of the fire-resistant wire of the present invention.

In FIG. 1, a refractory electric wire according to the present invention comprises a plurality of (only one is shown) insulated wires 11, an unillustrated inclusion twisted together with the plurality of insulated wires 11, (Not shown) (the plastic sheath may be provided outside one insulated wire core 11). The insulated wire core 11 includes a conductor 12, a fire-resistant layer 13, and an insulator 14.

The insulated wire core 11 will be described in more detail. The conductor 12 is a stranded wire formed by twisting a plurality of electrically conductive wires, and a refractory layer 13 formed on the conductor 12 is formed. Has a layer formed by winding a double-sided plastic mica tape 15 and a layer 16 formed by winding a glass mica tape (not shown). Further, an insulator 14 covering the refractory layer 13
Is formed by extruding a polyolefin resin.

The double-sided plastic mica tape 15 is
It is a fire-resistant tape, which is composed of a soft mica foil 17 and plastic tapes 18 provided on both sides of the soft mica foil 17, respectively. In addition, these soft laminated mica foil 17 and plastic tape 18,
Numeral 18 is attached and fixed by a suitable bonding means (not shown) formed on one surface of each of the plastic tapes 18.

The soft laminated mica (phlogopite) foil 17 is formed, for example, to have a thickness in the range of 0.09 to 0.15 mm, and a plastic tape 18.
Is composed of, for example, a film (backing material) made of polyethylene, polypropylene, or the like having a thickness in the range of 0.015 to 0.030 mm, and an appropriate bonding means (not shown).

The double-sided plastic mica tape 15
Means that the double-sided plastic mica tape 15 is wound around the conductor 12 while being wrapped or wound vertically (the same applies to the winding of the glass mica tape (not shown)). . Also, one or more double-sided plastic mica tapes 15 are used.

On the other hand, glass mica tape (not shown)
Is a glass tape having a glass cloth (backing material) formed by laminating glass fibers or the like into a cloth, and a soft laminated mica foil similar to the above is adhered to one surface of the glass tape.

The plastic sheath is formed by extruding a polyolefin resin or a vinyl chloride resin.

In the above construction, the fire-resistant electric wire of the present invention is obtained by twisting a plurality of insulated cores 11 together with inclusions (not shown), and then providing a plastic sheath (not shown) on the outside.
It is manufactured by applying. Insulated wire core 1
1 is to wind a double-sided plastic mica tape 15 directly above the conductor 12 and wind a glass mica tape (not shown) thereon to form a refractory layer 13 and cover the outside thereof with an insulator 14. It is manufactured by.

Since the refractory electric wire of the present invention uses the double-sided plastic mica tape 15 so as to be in contact with the conductor 12, the plastic tape 18 exists between the conductor 12 and the soft laminated mica foil 17. In order to prevent the mica foil 17 from falling between the strands of the conductor 12 even when receiving a tape pressure at the time of winding a glass mica tape (not shown) or a resin pressure at the time of coating the insulator 14. (The original shape of the mica tape can be maintained.)

Therefore, the refractory wire of the present invention prevents the occurrence of various problems such as a decrease in insulation performance during combustion, a decrease in terminal treatment during construction, or a poor contact after construction due to residual mica foil. Is what you can do. Also, as can be seen from the results in Table 1 below,
The thickness of the double-sided plastic mica tape 15 can be reduced, in other words, the thickness of the soft mica foil 17 can be reduced, which can contribute to cost reduction.

Example 1 in the following Table 1 is a fire-resistant electric wire in which a double-sided plastic mica tape having a thickness of 0.13 mm is provided directly above a conductor. Example 2 is assumed to be a fire-resistant electric wire in which a double-sided plastic mica tape having a thickness of 0.11 mm is provided directly above a conductor. On the other hand, Comparative Example 1 is a fire-resistant electric wire in which a single-sided plastic mica tape having a thickness of 0.13 mm (the same as the conventional plastic mica tape 6 (see FIG. 2)) is provided directly above the conductor. I do. Comparative Example 2
Is a fire-resistant electric wire in which a plastic mica tape having a thickness of 0.11 mm (same as a conventional plastic mica tape 5 (see FIG. 2)) is provided directly above a conductor.

The thickness of the film (backing material) of each of the mica tapes of Example 1, Example 2, Comparative Example 1, and Comparative Example 2 is the same. The evaluation of the fire resistance characteristics in Table 1 is based on the 1997 Fire Service Agency Notification No. 10, and “○” in Table 1 indicates that the fire resistance characteristics are good. Table 1
"X" in the inside indicates that the fire resistance was poor.

[0023]

[Table 1]

The results in Table 1 show that the thickness is 0.13 mm.
Example 1 using double-sided plastic mica tape
It was found that the fire resistance of the refractory wire was good. It was also found that the fire resistance of the fire-resistant electric wire of Example 2 using the double-sided plastic mica tape having a thickness of 0.11 mm was good. Furthermore, it was found that the fire-resistant property of the fire-resistant wire of Comparative Example 1 using a single-sided plastic mica tape having a thickness of 0.13 mm was also good. However, it was found in the evaluation that the fireproof electric wire of Comparative Example 2 using the single-sided plastic mica tape having a thickness of 0.11 mm causes dielectric breakdown at 1100 V after heating.

Further, from the results shown in Table 1, it was found that the fire-resistant electric wires of Examples 1 and 2 had good fire-resistance characteristics even when the thickness of the double-sided plastic mica tape was different. Thus, it was found that the fireproof wire using the double-sided plastic mica tape had stable fireproof characteristics. Therefore, it can be said that the cost can be reduced by reducing the thickness of the soft mica foil.

[0026]

As described above, according to the first aspect of the present invention, since the plastic tape exists between the conductor and the soft mica foil, the mica foil is made of a conductor element. It is possible to prevent a drop between the lines. In addition, this can prevent the insulation performance from deteriorating during combustion. Furthermore, since the mica foil does not fall between the conductor strands, peeling at the time of terminal treatment is facilitated, and a decrease in terminal treatment at the time of construction can be prevented. Furthermore, it is possible to prevent problems such as poor contact after construction due to residual mica foil. Further, cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a fire-resistant wire according to the present invention.

FIG. 2 is a cross-sectional view of a conventional fire-resistant wire.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Insulated wire core 12 Conductor 13 Fireproof layer 14 Insulator 15 Double-sided plastic mica tape 17 Soft laminated mica foil 18 Plastic tape

Claims (1)

[Claims] 1. A fire-resistant electric wire characterized in that a fire-resistant layer is formed by providing a double-sided plastic mica tape in which a plastic tape is provided on both sides of a soft mica foil, immediately above a conductor which is a stranded wire.