JPH0727021U - Fireproof cable - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose of the invention is to provide a fireproof cable that does not suffer deterioration of insulation resistance and withstand voltage characteristics through a fireproof test based on the fireproof certification standard stipulated by the Fire Department Notification. [Structure] A fire resistant cable in which a plurality of fire resistant tapes 13a, 13b, 13c in which laminated mica is attached to the inside of a lining material are applied on a conductor 12 to form a fire resistant layer 13, and an insulator 14 is applied on the fire resistant tape 13. In the above, the metal film is provided at least on the outer side of the outermost layer of the fireproof tape 13c among the plurality of layers of the fireproof tape 13a, 13b, 13c.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fire resistant cable having fire resistance and flame retardancy.

[0002]

[Prior art]

 Conventionally, as an insulating wire core 11 used for a fireproof cable, as shown in FIG. 3, three fireproof tapes 13a, 13b, 13c having a thickness of about 0.1 to 0.3 mm are sequentially arranged on a conductor 12. There is one in which a refractory layer 13 is formed by wrapping or wrapping it vertically, and an insulator 14 made of polyethylene is extruded on the fireproof layer 13.

As shown in FIG. 4, each of these fireproof tapes 13a, 13b, 13c is a base material (lining material) 13a ₂ (13b ₂ , 13c) made of an inorganic material such as a glass fiber cloth or a plastic material. _The integrated mica 13a ₁ (13b ₁ , 13c ₁ ) is attached to ₂ ) and integrated, and the integrated mica 13a ₁ side is the conductor 12 side and is wound or vertically attached. In FIG. 3, three fireproof tapes 13a, 13b, and 13c are used to form the fireproof layer 13, but in reality, the fireproof tapes 13a, 13b, and 13c are appropriately used within a range of 2 to 4.

The fireproof cable having a single-core structure has, as shown in FIG. 5, a presser-winding tape 15 applied on the insulating wire core 11 formed as described above, and then the outer circumference thereof. It is formed by covering a sheath 16 made of polyvinyl chloride resin or polyolefin resin by extrusion. In addition, as shown in FIG. 6, a fireproof cable having a multi-core structure is formed by twisting a plurality of insulated wire cores 11 together with an interposer 17, applying a holding tape 15, and then covering the sheath 16 by extruding. Is formed. The fire-resistant cable formed in this way can almost meet the fire-resistant standards stipulated by the Fire Department Notification.

[0005]

[Problems to be solved by the device]

 However, although the above-mentioned fire resistant cables meet the fire resistance standards set forth by the Fire Service Agency, they do not allow the mica to come off due to the entry of combustion products into the fire resistant layer during combustion or the disappearance of the lining material during the fire resistance test. As a result, it is possible to bite iron wires, etc., and the insulation resistance and the withstand voltage are remarkably low.

An object of the present invention is to provide a fireproof cable which does not suffer deterioration of insulation resistance and withstand voltage characteristics by a fireproof test according to the fireproof certification standard stipulated by the Fire Department Notification.

[0007]

[Means for Solving the Problems]

 The fire-resistant cable according to the present invention is a fire-resistant cable in which multiple layers of fire-resistant tape having laminated mica on the inside of a lining material are formed on a conductor to form a fire-resistant layer, and an insulator is applied on the fire-resistant tape. A metal film is provided at least on the outer side of the outermost layer of the fireproof tape among the plurality of layers of the fireproof tape.

[0008]

[Action]

 As a result of performing a fire resistance test on this fire resistant cable, since it has the above-mentioned structure, it is difficult for the backing material to disappear, so that the laminated mica does not easily peel off and even if the insulator or sheath on the outside of the fire resistant tape burns. The mechanical strength of the product is maintained and the products of combustion do not enter the fire resistant cable.

[0009]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. Note that the same or corresponding parts as those described in the section of the prior art are designated by the same reference numerals, and the description thereof will be omitted. FIG. 1 shows an embodiment of an insulated wire core 1 used in the fireproof cable of the present invention. The insulation wire core 1 of this embodiment is different from the insulation wire core 11 for a conventional fireproof cable shown in FIG. 3 in that the fireproof tape forming the outermost layer of the fireproof tapes 13a, 13b, 13c constituting the fireproof layer 13 is the same. Located on tape 13c.

That is, as shown in FIG. 2, the backing material 13c ₂ of the fire-resistant tape 13c provided immediately below the insulator 14 is stretched with a polyolefin-based plastic film such as polyethylene, polypropylene, or polyisobutylene. together to constitute in what was, at its surface, iron, copper, or a metal film 13c ₃ made of a metal tape or metal foil having a thickness of 0.010 to 0.0 50 mm of stainless steel that has been laminated or deposited.

As shown in FIG. 1, the insulated wire core 1 is formed by winding the same fire resistant tape 13a as the conventional one on the conductor 12 in a 1/5 wrap, and further applying a fire resistant tape 13b having the same structure to 1/5. A fireproof tape 13c laminated with a metal film 13c ₃ is wrapped around it with a lap to form a fireproof layer 13, and an insulator 14 made of polyethylene is extruded on the fireproof layer 13 by extrusion. It is configured by coating.

The fireproof cable using this insulated wire core 1 has the same dimensions as the conventional one shown in FIG. 5 or 6, and the holding tape 15, sheath 16 and interposition 17 used are also the same. . In order to compare this fire resistant cable with the conventional fire resistant cable, a fire resistance test was conducted according to the Fire Department Notification No. 7. The results are shown in Table 1.

[0013]

[Table 1]

As is clear from the above comparative test results of the fireproof cable, both the fireproof cable according to the example and the fireproof cable according to the conventional example satisfy the fireproof certification standard set by the Fire Agency, but are exposed to high temperatures. Insulation resistance and withstand voltage when applied are 1 to 10 MΩ and 1600 to 2200 V in the conventional example, whereas they are 20 to 30 MΩ and 2500 V in the case of the example, which is the same as the example in spite of the same size. It can be seen that such fire resistant cables are much better.

Since the metal film 13c ₃ is provided on the outer side of the fireproof tape 13c, the backing material 13c ₂ does not disappear, so that the laminated mica 13c ₁ can be prevented from peeling off, and the sheath 16 or the insulator 14 can be prevented in the event of a fire. This is because the mechanical strength from the outside can be maintained even when is burned, and the entry of combustion products into the refractory layer 13 can be prevented.

In this embodiment, only the outermost refractory tape 13c of the refractory layer 13 is provided with the metal film 13c ₃ , but the present invention is not limited to this and the same applies to the other refractory tapes 13a and 13b. You may use the thing of.

[0017]

[Effect of device]

 As described above, according to the present invention, a plurality of layers of fireproof tape having laminated mica on the inside of a backing material is applied on a conductor, and an insulating material is applied on the fireproof tape. Among the layers of fireproof tape, at least the outermost layer of fireproof tape was provided with a metal film, improving the insulation resistance and withstand voltage of the fireproof cable during a fire.

[Brief description of drawings]

FIG. 1 is a view showing an example of an insulated core used in a fireproof cable of the present invention.

FIG. 2 is a cross-sectional view of a fireproof tape used for the insulated core shown in FIG.

FIG. 3 is a diagram of an insulated wire core used in a conventional fireproof cable.

FIG. 4 is a cross-sectional view of a fireproof tape used for the insulated core shown in FIG.

FIG. 5 is a cross-sectional view of a fireproof cable having a single-core structure.

FIG. 6 is a cross-sectional view of a fireproof cable having a multi-core structure.

[Explanation of symbols]

1, 11 Insulated wire core 12 Conductor 13 Fireproof layer 13a Fireproof tape 13b Fireproof tape 13c Fireproof tape 13c ₁ Backing material 13c ₂ Integrated mica 13c ₃ Metal film 14 Insulator 16 Sheath 17 Interposition

Claims (1)

[Scope of utility model registration request] 1. A fire resistant cable comprising a conductor and a plurality of layers of fire resistant tape having laminated mica on the inside of a lining material to form a fire resistant layer, and an insulator thereon. Among fireproof tapes, a fireproof cable characterized in that a metal film is provided on at least the outermost layer of the fireproof tape.