JPH0664328U - Fireproof cable - Google Patents

Abstract

(57) [Summary] [Purpose] It is possible to significantly improve fire resistance. [Construction] A fireproof cable comprising a conductor 4, a fireproof layer 1, an insulator layer, a tape winding layer, and a sheath layer, which are provided in this order. Using the sheath layer 3a, voids 6 and 7 (6) extending in the longitudinal direction of the cable are formed inside the respective layers 2a and 3a.
', 7') are provided, and a foaming agent-coated tape winding layer 5a in which a foaming agent is applied to the tape winding layer inside the sheath layer 3a is used. [Effect] At the time of combustion, the supply of air to combustible materials such as the insulator layer and the sheath layer is improved.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a fireproof cable.

[0002]

[Prior art]

 Fireproof cables shall meet the following conditions when heated at 840 ° C for 30 minutes in accordance with the fire curve specified in JIS A1304 (Fireproof test method for building structures).

(1) The insulation resistance after heating is 0.4 MΩ or more.

(2) Withstand a withstand voltage of 600 V during heating, and withstand 1500 V / 1 minute after heating.

(3) In the test method, there are two methods for simulating the installation: an exposure test for exposed wiring and an in-pipe test for in-pipe wiring.

Therefore, as shown in FIG. 3 in which a conventional example of a fireproof cable is shown in the related art, for example, the mica layer which is the fireproof layer 1 is thickened, or the insulation layer 2 and the sheath layer 3 are formed. The material properties were made to have good fluidity, or combustible materials were set to burn in a short time by using a material that burns easily to prevent the insulation resistance of the cable from decreasing during the fire resistance test. In the figure, 4 is a conductor and 5 is a tape winding layer.

[0007]

[Problems to be solved by the device]

 The above conventional technique has the following problems.

(1) Due to the structure of the fireproof cable, the insulator layer and the sheath layer are directly coated on the fireproof layer or the tape winding layer without any gap, so that the vinyl or rubber mixture is likely to be in a steaming state at the time of combustion, and the insulation Since the resistance decreases significantly, it was necessary to make the refractory layer thicker than necessary and to increase the width of the winding wrap.

(2) Since the insulator layer and the sheath layer of the combustible material continue to burn forever, the gas and carbon at the time of combustion enter the refractory layer, causing a decrease in the insulation resistance. It had to be burned and dropped.

(3) Depending on the place of use, the thick size may lack flexibility.

The present invention has been made in view of the above points, and an object of the present invention is to provide a fire resistant cable capable of significantly improving fire resistant characteristics.

[0012]

[Means for Solving the Problems]

 The above object is achieved by providing voids extending in the longitudinal direction of the cable inside the insulator layer and the sheath layer, respectively, and applying a foaming agent to the tape winding layer inside the sheath layer.

[0013]

[Action]

 Since the above means is provided, the supply of air to combustible materials such as the insulator layer and the sheath layer at the time of combustion is improved.

[0014]

【Example】

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

[Embodiment 1] FIGS. 1 and 2 show an embodiment of the present invention. Since the same parts as those of the prior art are designated by the same reference numerals, the description thereof will be omitted. In this embodiment, voids 6 and 7 (6 ', 7') extending in the longitudinal direction of the cable are provided inside the insulator layer and the sheath layer, respectively, and a foaming agent is applied to the tape winding layer inside the sheath layer. Applied. By doing so, the supply of air to the combustibles such as the insulating layer and the sheath layer at the time of combustion will be improved, the combustibles will burn faster, and it is possible to greatly improve the fire resistance characteristics. You can get a fireproof cable.

That is, the insulator layer 2a with an inner void portion is used as the insulator layer, the sheath layer 3a with an inner void portion is used as the sheath layer, and the foaming agent-coated tape winding layer 5a is used as the tape winding layer. I used it. By doing so, the following operational effects can be obtained.

(1) Since the air gap during combustion is entangled due to the presence of the voids 6, 7 (or 6 ′, 7 ′) on the inner surfaces of the insulator layer with inner void part 2a and the sheath layer with inner void part 3a, Combustibles such as the insulator layer 2a and the sheath layer 3a are burned quickly, and steaming can be prevented.

(2) Further, at the same time, the foaming agent-coated tape winding layer 5a coated with the foaming agent applied under the sheath layer 3a is foamed and expanded by the heat at the time of combustion, and the void portion 7 (7 ′) of the sheath layer 3a is formed. ), There is a hole in the sheath layer 3a to facilitate the supply of oxygen, which accelerates the burning of combustible substances throughout the cable.

(3) Since the void portions 6, 7 (6 ′, 7 ′) are provided on the inner surfaces of the insulator layer 2a and the sheath layer 3a, the flexibility of the cable itself is improved.

As described above, according to this embodiment, the following effects can be obtained. (1) Since the voids are provided in the inner surface of the insulator layer and the sheath layer in the longitudinal direction of the cable, the supply of air is improved, the combustion of combustible materials inside the cable is accelerated, and the combustion gas to the refractory layer is increased. Intrusion is reduced and the insulation resistance is improved.

(2) Since the combustible material burns quickly and the amount of combustion gas entering the refractory layer is reduced, it is possible to reduce the thickness of the mica layer, which is the refractory layer, and to reduce the wrap width. Is economical.

(3) By providing the voids on the inner surfaces of the insulating layer and the sheath layer, the flexibility of the cable itself is improved as compared with the conventional direct covering, and it is easy to handle depending on the place when laying.

[0023]

[Effect of device]

 As described above, according to the present invention, the insulating layer and the sheath layer each have a void portion extending in the longitudinal direction of the cable, and the tape winding layer inside the sheath layer is coated with the foaming agent, so that the insulating layer is provided during combustion. The supply of air to the combustibles such as the body layer and the sheath layer is improved, the combustibles burn faster, and it is possible to obtain a refractory cable capable of significantly improving the fire resistance.

[Brief description of drawings]

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

2A and 2B also show the shapes of voids in the insulating layer and the sheath layer of one embodiment, where FIG. 2A is a rectangular void, and FIG.
FIG. 6 is a front view showing a triangular void portion.

FIG. 3 is a vertical sectional side view of a conventional fireproof cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fire-resistant layer 2a Insulator layer with inner void part 3a Sheath layer with inner void part 4 Conductor 5a Foaming agent-coated tape winding layer 6, 6'Insulator layer void part 7, 7 'Sheath layer void part

Claims (1)

[Scope of utility model registration request] 1. A fireproof cable comprising a conductor, a fireproof layer, an insulator layer, a tape winding layer, and a sheath layer, which are provided in this order. A void extending in the longitudinal direction of the cable inside each of the insulator layer and the sheath layer. And a foaming agent applied to the tape winding layer inside the sheath layer.