JPH09294321A - Structure of cable insertion port for fireproofing cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent firing or burning at a cable insertion port of a junction box, by forming the insertion port for a fireproofing cable which is applied with a pipe, a filler, and a pressing treatment, inside the junction box. SOLUTION: In every cable insertion port of a main body 4 of junction box, a pipe 5' for inserting a cable is formed so as to project inside the main body 4 of the junction box. By this, firing at the insertion ports can be prevented. An inner diameter D2 of a hole formed in the main body 4 of the junction box and an inner diameter of the pipe 5' are made large enough for fireproofing cables 1, 2, 3 and terminal processed sections to pass through. After the fireproofing cables 1, 2, 3 are passed through the pipe 5', a space between the fireproofing cables 1, 2, 3 and the pipe 5' is filled with a heat insulator 11 to prevent heat from being transmitted to the fireproofing cables 1, 2, 3. Then, a fire- resistance filler 12 is applied so as to cover the pipe 5', the inside ends of the heat insulator 11 and the fireproofing cables 1, 2, 3 which are extended from the insulator and the filler is covered with a heat contracting tube 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an insertion port of a fireproof cable used in a high voltage circuit into a connection box.

[0002]

2. Description of the Related Art In general, a connection part of a high-voltage fireproof cable is wrapped with a glass mica tape or an insulating tape on a conductor connection part so that it can withstand the working voltage even if the insulator melts due to high temperature and high heat during combustion. Is being processed. But,
In the glass mica tape winding structure, it is not easy to disconnect the cable or change the connection. Further, since connection in a narrow space in the connection box is not good in workability, work is likely to be overloaded, and a problem remains in reliability.

On the other hand, in order to make the junction box compact, as shown in FIG. 4, a pipe-shaped structure 5 protruding outside the junction box is provided at the cable insertion portion of the junction box main body 4, and a tape is wound. There are many cases where the cable is fixed. Further, if the pipe 5 of the cable insertion port is brought close to the outer diameter of the corresponding cable, the cable can be easily fixed. In addition, 1 is a load side trunk line fireproof cable, 2,
2 ', 2 ", 2'" are power line side fire resistant cables and 3 is a branch side fire resistant cable. Also, 10 is the junction box body 4
Is a door to cover.

FIG. 5 shows the structure of the cable insertion port of the above-mentioned junction box, in which a heat insulating material 6 is attached to the inner surface of the junction box main body 4, and a hole portion provided at a predetermined position is formed. A pipe 5 is erected on the outside. The cables 1, 2 (2 ', 2 ", 2'"), 3 are passed through the pipe 5, and the cable insertion port sealing material 7 is applied across the end portion of the pipe 5 and the cable, and then the cable insertion port. The holding tape 8 was wrapped around, so that the gap 9 was filled at the cable insertion port and the cable was fixed.

[0005]

In the prior art described above; in FIGS. 4 and 5, in order to prepare for a fire, heat insulation boards and fillers are used on the inner and outer surfaces of the junction box to increase the heat insulation effect. However, if it is compact as described above, the heat insulation effect is not sufficient. Moreover, since the gap between the cable and the insertion port is small, heat is easily transferred to the cable, and the sheath of the fire-resistant cable emits smoke from this part; it burns and produces a large amount of soot, which leads to deterioration of insulation and the worst case. In that case, it will cause a ground fault or a short circuit between phases, which will have a fatal effect on evacuation guidance and fire fighting activities during a fire. Therefore, it is necessary to maintain the power supply during a fire in any state.

Based on the above, the inventors have obtained the following knowledge as a result of various trial and error. That is, in the fireproof cable, it is important not to burn the fireproof cable main body as much as possible even if the terminal connection part of the cable or the insulation treatment material encounters a fire or the like. Is attached with a heat insulating plate, and a heat insulating material is inserted into the cable insertion port to suppress heat conduction and make it difficult for a space to be created in case of combustion, and to prevent the entry of flames. It is more effective to do this. In particular, by making the flammable cable insertion port inside the connection box by thickening the through hole, cable terminals such as connection terminals and stress cones can be easily operated in a large space outside the box. Moreover, after fixing the cable in the connection box, the heat insulating material can be easily filled. It is also possible to cover the gap generated around the cable with the shrinking force of the tube by covering the tube that presses the surface after filling the filler with the heat shrinking tube.

Therefore, the problem (objective) to be solved by the present invention
The first object is to provide a structure of a cable insertion opening for a fireproof cable, which can prevent ignition and combustion at the cable insertion opening in the connection box. Secondly, it is to provide a structure of a cable insertion port for a fireproof cable, which enables insertion of a terminal treatment portion of the fireproof cable. Thirdly, it is to provide a structure of a cable insertion port for a fireproof cable, which can prevent a flame from entering by filling a gap generated during the combustion accompanying the combustion.

[0008]

The first means provided to achieve the first object (object) of the present invention is to provide a fireproof cable which is added to a connection box with a pipe and a filling material and a pressing process. The insertion port is provided inside the junction box,
It consists of a cable insertion port for fireproof cables.

A second means provided to achieve the second object (object) of the present invention is that a cable and a terminal processing portion thereof can be inserted through a pipe at a fireproof cable insertion port added to a connection box. The structure has a structure of a cable insertion port for a fireproof cable in which a heat insulating material is interposed in a gap between the pipe and the fireproof cable inserted through the pipe.

A third means provided to achieve the third object (object) of the present invention is a cable insertion port added to a connection box, which is passed from the end of the pipe to the pipe. The fireproof cable has a structure in which a filler is applied over the fireproof cable, and the filler is covered with a heat-shrinkable tube or a heat-shrinkable tape.

[0011]

1 to 3 show the structure of a cable insertion port for a fireproof cable, which is an embodiment of the present invention and is embodied by including all the first to third means of the present invention. Indicates. FIG. 1 shows a connection state of a connection box and a fireproof cable, FIG. 2 shows a structure of a cable insertion port in the connection state, and FIG. 3 shows a series of structures of a connection box and a cable insertion port.

The junction box of this embodiment is for branch connection, and as shown in FIG. 1, on one side wall of the junction box body 4, the load side main line fireproof cable 1 and the branch side fireproof cable 3 are provided.
Is penetrated, and the power supply side main line fireproof cable 2 is penetrated through the other side wall of the junction box body 4, and the power supply side main line fireproof cable 2 is composed of 3 pieces of 2 ′, 2 ″, 2 ′ ″. There is. These cables 1, 2 (2 ', 2 ",
2 ′ ″) and 3 are branched and connected in the connection box body 4. A heat insulating plate 6 is lined inside the connection box body 4. Reference numeral 10 is an opening / closing door of the connection box body 4.

However, at any of the cable insertion ports of the connection box main body 4, as shown in FIG. Is suppressed, and the junction box body 4
The inner diameter D ₂ of the hole portion and the inner diameter of the pipe 5 ′ are made large so that the fireproof cables 1, 2, 3 and the end treatment portion thereof can be inserted, and the fireproof cables 1, 2, 3 are placed in the pipe 5 ′. After passing the wire to the fireproof cables 1, 2, 3 and the pipe 5 ', the heat transfer to the fireproof cables 1, 2, 3 is suppressed by interposing a heat insulating material 11 between the fireproof cables 1, 2, 3 (restriction). Then, the pipe 5 '
The flame-retardant filler 12 is provided between the inner extended end of the heat insulating material 11 and the fireproof cables 1, 2 and 3 extending therefrom, and the heat-shrinkable tube 13 is covered over the flame-retardant filler 12.

According to the structure as described above, the terminal treatment of the fireproof cable can be performed outside the junction box. That is,
As shown in FIG. 3, a connection terminal 17 to a cable conductor is provided.
Attaching the stress cone 16 to the cable insulator; coating the silicon-based tube 15 and the like, and inserting the terminal processing unit into the hole of the connection box body 4 and the pipe 5'to perform the terminal processing. It is sufficient to connect and fix the connection terminal 17 of the part to a terminal attached to a predetermined support member;

The pipe 5'thickened as described above
Since the gaps between the refractory cables 1, 2, and 3 passed through this are filled with the heat insulating material 11, the heat from the fire resistant cables 1, 2, 3 side is suppressed by the heat insulating material 11 (limited). ), The combustion from the fire resistant cables 1, 2 and 3 can be blocked by the heat insulating material 11 and the flame retardant filler 12. Even if the insulation on the cable side might flow out, the flame-retardant filler 12 and the heat-shrinkable tube 1
The contraction force due to the heat of 3 fills the gap, and the invasion of the flame can be suppressed.

Further, since the terminal treatment parts of the fireproof cables 1, 2, 3 are fixed by being connected to the supporting member of the conductor-attached connecting terminal 13; the insulator 14, the movement of the cable in case of fire is prevented. It is possible to prevent contact accidents inside the junction box.

As shown in FIG. 3, the heat-shrinkable tube 13 may be provided between the hole portion of the junction box body 4 and the fireproof cable extending from the hole portion to the outside.

In the above embodiment, the flame retardant filler 12
Instead of, a flame-retardant foaming agent or the like may be used. Further, in the above-mentioned embodiment, the junction box for branching is targeted, but the invention can be applied to a cable lead-in port of a general distribution box.

[0019]

As described above, according to the first means of the present invention, there is provided the structure of the cable insertion opening for the fireproof cable which can prevent the ignition and combustion at the cable insertion opening in the connection box. According to the second means, there is provided a structure of a cable insertion port for a fireproof cable, which enables insertion of a terminal treatment portion of the fireproof cable. The second object (objective) can be achieved, and further, according to the third means, it is possible to prevent the invasion of the flame by filling the gap generated during the combustion with the combustion and preventing the intrusion of the flame resistant cable. The third object (purpose) of providing a structure can be achieved.

[Brief description of drawings]

FIG. 1 is a front view showing a state of connection between a junction box and a fireproof cable according to an embodiment of the present invention, and FIG.

FIG. 2 is a cross-sectional view showing a specific structure of a cable insertion port formed by the connection box and the fireproof cable shown in FIG.

FIG. 3 is a cross-sectional view showing a series of specific structures of a connection box and a cable insertion port shown in FIG.

[FIG. 4] FIG. 4 is a front view showing, in a conventional example, a connection state between a junction box and a fireproof cable, and (B) is a side view of the connection state.

5 is a cross-sectional view showing a specific structure of a connection box and a cable insertion port shown in FIG.

[Explanation of symbols]

1 Load side main line fireproof cable 2, 2 ', 2 ", 2'" Power supply side main line fireproof cable 3 Branch side fireproof cable 4 Junction box body 5, 5 'Pipe 6 Insulation material (connection box lining) 10 Door 11 Insulation material ( Insertion side) 12 Flame-retardant filler 13 Heat-shrinkable tube 14 Support (insulator) 15 Silicon tube 16 Stress cone 17 Connection terminal D ₁ Thermal insulation material inner diameter D ₂ Connection box hole inner diameter

Claims (3)

[Claims] Claim: What is claimed is: 1. A structure of a cable insertion port for a fireproof cable, which is provided with a pipe, a filler, and a fireproof cable insertion port which is added to the connection box by a pressing process inside the connection box. 2. A pipe at a fireproof cable insertion port added to a connection box is made thick so that a cable and its terminal processing portion can be inserted therethrough, and heat insulation is provided in a gap between the pipe and the fireproof cable inserted therethrough. The structure of the cable insertion port for the fireproof cable, with the material interposed. 3. A cable insertion port added to a junction box, wherein a filler is applied from the end of the pipe to the fireproof cable passed through the pipe, and the filler is heat-shrinkable tube or heat-shrinkable. It will be covered with tape,
It consists of a cable insertion port for fireproof cables.