JPH0590743U - Fireproof cable - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to easily stabilize the fire resistance. A fireproof cable having a metal braid 1 on its surface is characterized in that a part of the metal braid 1 is formed of combustible yarn 6. [Effect] When a fire occurs, combustion products inside the braid escape to the outside of the braid.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to a fireproof cable.

[0002]

[Prior Art]

 In general, there are many methods of wrapping a cable by braiding metal of the same material in a tubular shape. When the purpose of the braid was mainly to prevent trauma, it was always made more rigid with metal such as steel.

[0003]

[Problems to be solved by the device]

 The most important characteristic of fireproof cables is that they have stable electrical characteristics (withstand voltage, insulation resistance, etc.) during a fire. It is widely known that an inorganic refractory material is wound on a conductor as a means for stabilizing the electrical characteristics, but it is also necessary to take care not to contaminate the refractory material. A cable structure that maximizes the combustion effect and spreads the flame to the inside of the cable is extremely effective.

However, for example, in a marine-type fire-resistant cable or the like, since the outer braid is impeded by the robustness of the exterior braid, the flame does not spread well inside the cable at the time of a fire, resulting in a smoldering state. As a result, it causes contamination of the refractory layer (decrease in MEG), and in anticipation of this, excessive fire resistance treatment is required.

The present invention has been made in view of the above points, and it is an object of the present invention to provide a fireproof cable that can easily stabilize fireproof characteristics.

[0006]

[Means for Solving the Problems]

 The above object is achieved by forming part of the metal braid from a flammable material.

[0007]

[Action]

 Since the above-mentioned means is provided, the combustion products inside the braid can escape to the outside of the braid in case of fire.

[0008]

【Example】

 Next, the present invention will be specifically described by way of examples.

First Embodiment FIGS. 1 and 2 show an embodiment of the present invention. A fireproof cable having a metal braid 1 on its surface, and in this embodiment, a part of the metal braid 1 was formed of a flammable material. By doing this, the combustion products inside the braid escape to the outside of the braid in the event of a fire, and the contamination of the refractory layer is reduced, making it easier to stabilize the fire resistance characteristics. Fireproof cables can be obtained.

That is, the fireproof cable is composed of an insulator 3 provided on the conductor 2, a sheath 5 provided on the outer circumference of the insulator 3 with an intervening 4 interposed therebetween, and a metal braided coarse material provided on the sheath 5. It has a set 1 and. In the fireproof cable configured as described above, a part of the metal braid is formed of the combustible yarn 6. By doing so, as shown in Table 1 in which the results of the fire resistance test conducted by comparison with the conventional example in which the conventional metal braid is applied are shown, the fire resistance characteristics of the product of this example are excellent. . The test method was as follows: When JIS A 1304 was heated at 840 ° C./30 minutes, the applied voltage was (1) 2200 V continuously applied up to 840 ° C./30 minutes, and (2) 840 ° C./30 minutes afterward continuously applied 3800 V / 10 minutes.

[0011]

[Table 1]

As is clear from the table, in the product of this example in which the metal braid is sewn with the combustible thread, the combustion products inside the braid escape to the outside of the braid at the time of fire, and the stain resistance of the refractory layer is reduced. Fire resistance characteristics such as excellent characteristics and insulation resistance characteristics can be obtained.

As described above, according to this embodiment, the following effects can be obtained.

(1) Economical effect In the case of a fireproof cable, since the ratio of fireproof tape (mica tape, etc.) to the manufacturing cost is large, it is possible to reduce the number of tapes by one. Cost reduction of tape etc.

(B) Reduction of man-hours.

(C) Since the total construction period can be shortened due to the reduction in the number of processes, it is possible to deal with short delivery time.

(D) Since the outer diameter of the core can be reduced by reducing the number of tapes, a ripple effect such as a reduced outer diameter of the finished cable can be obtained.

Can be achieved.

(2) Fire resistance characteristics In comparison with the conventional product, the degree of decrease in insulation resistance up to 30 minutes of heating is small and stable, and it is possible to maintain the characteristics with a sufficient margin with respect to the standard value.

Instead of stitching with a combustible thread material, (1) a band-shaped metal braid may be hung on a cable and then pressed with a flammable thread or tape. Further, in the present embodiment, an example in which the combustible thread is sewn at one place in the longitudinal direction, it is also possible to provide a plurality of other places. It is also conceivable to use (2) joining with an adhesive and (3) connecting with a low-temperature molten metal or the like by a completely different means from stitching.

[0021]

[Effect of the device]

 As described above, in the present invention, since a part of the metal braid is formed of a flammable material, the combustion products inside the braid can escape to the outside of the braid in the event of a fire, thus reducing the pollution of the refractory layer. As a result, it is possible to obtain a fire resistant cable that can easily stabilize the fire resistant characteristics.

[Submission date] April 6, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

[Prior Art]

In general, there are many methods in which a metal of the same material is knitted in a tubular shape to wrap the cable. The purpose of the braid of metal, especially such as steel when mainly preventing trauma was always that are more firmly provided al.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

That is, the fireproof cable is composed of an insulator 3 provided on a conductor 2, a sheath 5 provided on an outer periphery of the insulator 3 with an interposition 4 interposed therebetween, and a metal braid 1 provided on the sheath 5. It is configured with. In the fireproof cable thus configured, a part of the metal braid is formed by the combustible yarn 6. By doing so, as shown in Table 1 as a result of the fire resistance test conducted in comparison with the conventional example in which the conventional metal braid is applied, the fire resistance property of the product of this example is excellent. The test method was as follows: JIS A 1304 was heated at 840 ° C./30 minutes, and continuously applied voltage was 2200 V until the applied voltage (1) 840 ° C./30 minutes and (2) 840 ° C./30 minutes and then 3800 V / 10 minutes.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view of an embodiment of the fireproof cable of the present invention.

FIG. 2 is a perspective view of the same embodiment.

[Explanation of symbols]

 1 Metal braid 6 Combustible yarn

Claims (1)

[Scope of utility model registration request] 1. A fire resistant cable having a metal braid on its surface, wherein a part of the metal braid is formed of a flammable material.