JP2539777Y2 - Branch for fireproof cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a branch portion for a fire-resistant cable, and more particularly to a branch portion for a fire-resistant cable having greatly improved insulation performance.

[Conventional technology]

FIG. 2 shows a conventional branching portion for a fireproof cable, for example, in which three fireproof cables 10, 10a and 10b are branched by a T-shaped branch connection fitting 1. In this branch portion, the sheath 9 of the fire-resistant cable 10 is peeled to expose the insulator 5, and further, the insulator 5 is peeled and the fire-resistant layer 4 on the conductor is removed.
The conductor 3 is exposed and inserted into the sleeve 1a of the branch fitting 1 and crimped. In addition, branch connection fitting 1
A refractory tape 2 such as a mica tape is wound around the refractory layer 4 while surrounding the exposed portion of each conductor 1. Further, an insulating layer 6 is formed on the outer periphery of the branch connection portion, and a waterproof layer 7 is formed over the sheath 9 to waterproof the whole.

According to such a branch portion, even if a fire occurs, the waterproof layer 7 and the insulating layer 6 are flame-burned, but the layer of the fire-resistant tape 2 made of a refractory material escapes the flame-burning, so that the function as an insulating layer is maintained. After the fire, power can be supplied for a specified time.

[Problems to be solved by the invention]

However, according to the conventional fire-resistant cable branch, it is very difficult to wind the fire-resistant tape around the outer circumference of the branch connection fitting, so that high insulation performance cannot be obtained, and high-voltage (for example, 600 V or more) There is a disadvantage that it cannot be used as a branch. Further, since the tape winding operation is difficult, there is a disadvantage that workability and reliability are low.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a branch portion for a fire-resistant cable which can be used as a high-voltage branch portion by greatly improving insulation performance and further improve reliability and workability.

[Means for solving the problem]

The present invention provides a branch portion for a fire-resistant cable in which a heat-resistant ceramic is molded on a branch connection fitting in order to achieve the above-mentioned object.

That is, the branch portion for the fire-resistant cable of the present invention is, for example, a heat-resistant ceramic made of mica powder and special glass, etc., sintered and molded on the branch connection fitting. Fire resistant tape is wrapped. Therefore, reliable insulation without insulation loss can be performed, and insulation performance can be greatly improved. Therefore, it can be used as a branch for high pressure. Further, since the tape winding operation is reduced, workability and reliability are improved.

〔Example〕

Hereinafter, the branch portion for a fireproof cable of the present invention will be described in detail.

FIG. 1 shows an embodiment of the present invention, and shows a T-branch connection portion in which three refractory cables 10, 10a, 10b are branched by a branch connection fitting 1. FIG. This branch connection is fireproof cable 10,10
a, the sheath 9 of 10b is peeled off to expose the insulator 5;
The insulator 5 is peeled off to expose the refractory layer 4 on the conductor and the conductor 3, and are inserted into the sleeve 1 a of the branch fitting 1 and crimped. The branch connection fitting 1 is formed with a heat-resistant ceramics mold 8 in which mica powder and special glass are sintered on the outer periphery other than the sleeve 1a. After the conductors 3 are connected by crimping, the fire-resistant tape 2 such as a mica tape, which is conventionally used, is wound around the outer periphery of the sleeve 1a, that is, from the end of the mold 8 to the fire-resistant layer 4 respectively. Further, a connection insulating layer 6 is provided in the same thickness as the mold 8 from the end of the mold 8 to the insulator 5 so as to cover the winding layer of the refractory tape 2. For waterproofing, a connection waterproof layer 7 is provided so as to entirely cover the sheath 9. The heat-resistant ceramic mold 8 is not limited to this, and may be formed by dissolving mica powder in a solvent, for example.

Since the heat-resistant ceramic is molded on the connection fitting 1 as described above, high insulation performance can be obtained without lowering the original fire resistance performance, and it can be sufficiently applied to a high-pressure branch portion. . In addition, since cumbersome work such as tape winding is reduced, work efficiency can be improved and reliability can be improved.

In the above-described embodiment, the example of the T-type branch is described. However, the present invention is not limited to this. For example, a Y-type, H-type, or X-type branch may be used. it can.

[Effect of the invention]

As described above, according to the branch portion for the fire-resistant cable of the present invention, since the heat-resistant ceramic is molded on the branch connection fitting, the insulation performance is greatly improved and the branch portion can be used as a high-pressure branch portion. Performance and reliability can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of the present invention, and FIG. 2 is an explanatory view showing a conventional branch portion for a fireproof cable. DESCRIPTION OF SYMBOLS 1 ... Branch fittings 2 ... Fireproof tape 3 ... Cable conductor 4 ... Fireproof layer on conductor 5 ... Cable insulator 6 ... Insulating section insulating layer 7 ... Connecting section waterproof layer 8 ... Heat-resistant ceramic mold 10, 10a, 10b …… Fire-resistant cable

Claims (3)

(57) [Scope of request for utility model registration] 1. A branch portion for a fire-resistant cable in which a plurality of fire-resistant cables having a fire-resistant layer on a conductor are connected via a branch connection fitting, the cable-connection sleeve formed at each end of the branch connection fitting does not cover. In this way, a mold of heat-resistant ceramic is applied on the branch connection fitting, a fire-resistant tape is wound from the end of the mold to the fire-resistant layer, and the mold is formed so as to cover the winding layer of the fire-resistant tape. A connection portion insulating layer having a thickness substantially equal to that of the mold from the end of the cable to the cable insulator. 2. The branch for a fire-resistant cable according to claim 1, wherein said mold of heat-resistant ceramic is formed by sintering mica powder and special glass. 3. The branch for a fire-resistant cable according to claim 1, wherein said mold of heat-resistant ceramic is formed by dissolving mica powder in a solvent.