JP2001136650A - Joint of high voltage fire-resistant cables - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate gaps between a conductor splicing tube and a mica composite tape which is wound on the joint of high voltage fire-resistant cables. SOLUTION: A conductor splicing tube 17 is applied to a conductor splicing part composed of exposed end part conductors of two cables which are butted against each other. A mica composite tape is wound over the conductor splicing tube 17 from the fire-resistant layer 4 of one cable to the fire-resistant layer 11 of the other cable to form a joint fire-resistant layer 18. A joint insulating layer 19 is formed over the joint fire-resistant layer 18 from the insulating layer 5 of the one cable to the insulating layer 12 of the other cable. A joint metal shielding layer 21 is formed on the joint insulating layer 19 with a joint semiconducting layer 20 therebeteen. A fire-resistant protective layer 22 is formed on the joint metal shielding layer 21. A water-proof layer 23 is formed on the fire-resistant protective layer 22 to form the joint 24 of high voltage fire-resistant cables. Ceramic adaptors 27 and 28 whose inner walls are coated with clayey adhesive inorganic compound 29 are provided between the conductor splicing tube 17 and the joint fire-resistant layer 18 to fill gaps 25 and 26 between the conductor splicing tube 17 and the joint fire-resistant layer 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection portion of a fire-resistant cable which can withstand use for a long time even when exposed to high heat or flame due to a fire or the like.

[0002]

2. Description of the Related Art Generally, in a place where a large number of people gather, in the event of a fire or the like, evacuation is completed by evacuation guide lights such as emergency exit guide lights in order to safely guide people in the hall to an emergency exit. It is required to keep the light on for a certain period of time. Therefore, regarding fire-resistant cables used for wiring fire-extinguishing equipment, alarm equipment, and evacuation equipment for fire-resistant objects, etc., the Japan Electric Wire & Cable Makers Association has voluntarily established its own certification standards for fire-resistant electric wires, etc. The quality of materials is being ensured.

[0003] Such a high-pressure fire-resistant cable is not infinitely long, and it is not unusual to use two cables connected in the middle. Even when two cables are connected and used in the middle as described above, fire resistance similar to a fire-resistant cable is required at a connection portion of the cables. Therefore,
The connection part of the conventional high-pressure fireproof cable has a configuration as shown in FIGS. That is, in connecting the two high-pressure fire-resistant cables 1 and 2, first, the ends of one high-pressure fire-resistant cable 1 are stripped off, and the cable conductor 3, the cable fire-resistant layer 4, and the cable insulation layer 5 are removed. , The cable metal shielding layer 7, the cable fire protection layer 8, and the cable sheath 9 are exposed.

[0004] Further, the end of the other high-pressure fireproof cable 2 is stripped off, and the cable conductor 10, the cable fireproof layer 11,
The cable insulation layer 12, the cable metal shielding layer 14, the cable fire protection layer 15, and the cable sheath 16 are exposed. Then, the cable conductor 3 of the high-pressure fireproof cable 1 and the cable conductor 10 of the high-pressure fireproof cable 2 are inserted into the conductor connection pipe (sleeve) 17 so as to abut each other, and the crimp connection is performed by compressing the conductor connection pipe 17. I do. A mica tape is wound around the outer periphery of the conductor connection pipe 17 over the cable fireproof layer 4 of the high-pressure fireproof cable 1 and the cable fireproof layer 11 of the high-pressure fireproof cable 2 to form a connection portion fireproof layer 18. Then, a self-fusing tape or an adhesive polyethylene tape is wound around the outer periphery of the connection part fireproof layer 18 over the cable insulation layer 5 of the high-pressure fireproof cable 1 and the cable insulation layer 12 of the high-pressure fireproof cable 2 to form the connection part insulation layer 19. Form.

Further, a semiconductive tape is wound around the surface of the connecting portion insulating layer 19 to form a connecting portion semiconductive layer 20, and the cable metal shielding layer 7 of the high-pressure fireproof cable 1 is formed around the connecting portion semiconductive layer 20. Then, the connection part metal shielding layer 21 is formed over the cable metal shielding layer 14 of the high-pressure fireproof cable 2. A fireproof protective layer 22 is provided by winding a foamed fireproof tape or the like around the outer periphery of the connection metal shielding layer 21 over the cable fireproof protective layer 8 of the high-pressure fireproof cable 1 and the cable fireproof protective layer 15 of the high-pressure fireproof cable 2. A waterproof layer 23 is formed on the fire-resistant protective layer 22 to form a connection portion 24 for a high-pressure fire-resistant cable.

Incidentally, the high-pressure fire-resistant cable 1 and the high-pressure fire-resistant cable 2 include the Fire Service Agency Notification No. 7 (June 1978).
(Jan. 16) is required to use a material having fire resistance as specified in JIS-130.
It is required to perform heating for 30 minutes along the fire temperature curve defined in 4, and to perform a predetermined test before and after the heating to have predetermined characteristics. Therefore, also in the case of the connection part 23 of the high-pressure fire-resistant cable, the connection part fire-resistant layer 18 is formed on the conductor connection pipe 17 by the glass mica tape as in the case of the high-pressure fire-resistant cables 1 and 2. The connection portion 23 of the cable is exposed to the flame, and the connection portion protection layer 22 and the connection portion insulating layer 19 around the connection portion refractory layer 18.
Even after the components are burned down, the connection portion refractory layer 18 maintains the electrical insulation for a required time.

[0007]

In the connection portion of such a conventional high-pressure fire-resistant cable, the cable conductors 3 and 10 of the two high-pressure fire-resistant cables 1 and 2 are butted together.
The conductor connection tube 17 is compressed and connected, and the conductor connection tube 17 is compressed.
A mica composite tape of an inorganic insulator, in which a soft laminated mica and a film are bonded together and integrated, is wound around the cable fireproof layers 4 and 11 of the respective high-pressure fireproof cables 1 and 2 to form a connection portion fireproof layer 18. Is formed. However, since there is a gap between the diameter of the conductor connection pipe 17 and the diameter of the cable conductors 3, 10, a step is formed between the conductor connection pipe 17 and the cable conductors 3, 10, and when the mica composite tape is wound as it is. The conductor connection pipe 17 and the cable conductor 3,
The gaps 25 and 26 which are gaps are generated between the gaps 10 and 10. Therefore, after filling the gaps 25 and 26 with the composite tape, the mica composite tape is 5-1 to 1 on the conductor connection portion.
The connection part refractory layer 18 is formed by overlapping and winding zero sheets.

However, since the composite tape is difficult to wind around the gap formed between the conductor connection pipe 17 and the cable conductors 3 and 10, it cannot be wound neatly. 26 may occur. Further, in the undulating portion at the center of the conductor connection pipe 17, the mica composite tape cannot be adhered well, and a slight gap is generated. When the gaps 25 and 26 are generated as described above, such gaps 2 are generated in the high-voltage cable.
On the other hand, there is a problem that the corona discharge easily occurs at 5, 26, and the insulation performance of the connection part is remarkably deteriorated.

An object of the present invention is to prevent a gap from being formed between a conductor connecting pipe and a mica composite tape when the mica composite tape is wound around a connection portion of a high-pressure fire-resistant cable.

[0010]

According to the first aspect of the present invention, in the connecting portion of the high-pressure fireproof cable, a conductor connecting tube is formed on the conductor connecting portion where the exposed conductors at the ends of the two cables are joined. A mica composite tape is wound over the conductor connection pipe from one cable fire-resistant layer to the other cable fire-resistant layer to form a connection section fire-resistant layer, and one cable insulation layer is placed on the connection section fire-resistant layer. A connection part insulating layer is formed by hanging from the layer to the other cable insulation layer, a connection part metal shielding layer is formed on the connection part insulation layer via a connection part semiconductive layer, and the connection part metal shielding layer is formed. Form a fire protection layer on top,
At the connection part of the high-pressure fireproof cable having a waterproof layer formed on this fireproof protective layer, an inorganic compound having clay-like adhesive strength on the inner wall surface is provided between the conductor connection part and the connection part fireproof layer. The ceramic adapter provided is interposed to fill the gap between the conductor connection portion and the connection portion fireproof layer. With this configuration, according to the first aspect of the invention, when the mica composite tape is wound around the connection portion of the high-pressure fire-resistant cable, a gap is generated between the conductor connection pipe and the mica composite tape. Can be prevented.

The connecting part of the high-pressure fireproof cable according to the second aspect of the present invention is formed by dividing a ceramic adapter into a plurality of parts. With this configuration, according to the second aspect of the present invention, when the mica composite tape is wound around the connection portion of the high-pressure fire-resistant cable, the gap between the conductor connection pipe and the mica composite tape is finely filled. be able to.

According to the third aspect of the present invention, the connecting portion of the high-pressure fireproof cable is a clay-like inorganic compound having an adhesive force provided on the inner wall surface of a ceramic adapter.
It is provided with a thickness of 1 to 2 mm. With this configuration, according to the third aspect of the invention, when the mica composite tape is wound around the connection portion of the high-pressure fire-resistant cable, the gap between the conductor connection pipe and the mica composite tape is reliably formed. Can be filled.

[0013]

FIG. 1 shows an embodiment of a connecting portion of a high-pressure fire-resistant cable according to the present invention. In the figure, the end of one high-pressure fireproof cable 1 of the two high-pressure fireproof cables to be connected is stripped off to expose the cable conductor 3, the cable fireproof layer 4, and the cable insulator 5. The end of the high-pressure fireproof cable 2 connected to the high-pressure fireproof cable 1 is stripped off so that the cable conductor 10,
The cable fireproof layer 11 and the cable insulator 12 are exposed. The cable conductor 3 of the high-pressure fireproof cable 1 and the cable conductor 10 of the high-pressure fireproof cable 2 are inserted into the conductor connection pipe (sleeve) 17 so as to abut each other from the left and right, and when the cable conductor 3 and the cable conductor 10 abut. Then, the conductor connection pipe 17 is compressed to compressively connect the cable conductor 3 and the cable conductor 10.

On the cable conductor 3 of the high-pressure fireproof cable 1, a ceramic adapter 27 formed in a truncated cone shape from the cable fireproof layer 4 of the high-pressure fireproof cable 1 to the end of the conductor connection pipe 17. Is covered. Further, on the cable conductor 10 of the high-pressure fire-resistant cable 2, the conductor connection pipe 17 is provided from the cable fire-resistant layer 11 of the high-pressure fire-resistant cable 2.
Is covered with a ceramic adapter 28 formed in a truncated conical cylindrical shape.

The ceramic adapters 27 and 28
As shown in FIG. 2, for example, the cable conductor 3 of the high-pressure fireproof cable 1 is divided into two so that the two are combined.
It is overlaid on the cable conductor 10 of the high-pressure fireproof cable 2. The ceramic adapters 27 and 28
As shown in FIG. 3, the clay is divided into two, and an inorganic material compound 29 having a clay-like adhesive force is applied to each inner wall surface. This inorganic compound 29
Is formed by kneading inorganic additives and the like. The inorganic material compound 29 includes, for example, aluminum hydroxide (inorganic filler), halogen-containing condensed phosphoric acid ester (flame retardant), halogen Hydrocarbon (organic binder),
There is a cap seal (trade name) manufactured by Nippon Steel Chemical Co., Ltd., which is formed by blending glass fiber (inorganic fiber), stabilizer and the like.

The inorganic compound 29 is, as shown in FIG. 3, a ceramic adapter 2 divided into two parts.
7 and 28 are applied to the inner wall surfaces, respectively.
mm. The reason why the coating thickness of the inorganic compound 29 is set to 1 to 2 mm is that when the ceramic adapters 27 and 28 are put on the cable conductors 3 and 10 of the high-pressure fire-resistant cable 2, the conductor connection pipe 17 and the mica composite The thickness is such that the gaps 25 and 26 between the connection portion and the refractory layer 18 formed by the tape can be reliably filled.

On the ceramic adapters 27 and 28, the structure is the same as that of the connection portion 24 of the high-pressure fireproof cable shown in FIG. That is, on the ceramic adapters 27 and 28, the connecting portion fireproof layer 18 is formed by winding mica tape over the cable fireproof layer 4 of the high-pressure fireproof cable 1 and the cable fireproof layer 11 of the high-pressure fireproof cable 2. ing. A self-fusing tape or an adhesive polyethylene tape is wound around the outer periphery of the connection part fire-resistant layer 18 over the cable insulation layer 5 of the high-pressure fire-resistant cable 1 and the cable insulation layer 12 of the high-pressure fire-resistant cable 2 to form a connection part insulation layer. 19 are formed.

Furthermore, a semiconductive tape is wound around the surface of the connecting part insulating layer 19 to form a connecting part semiconductive layer 20,
On the outer periphery of the connection semiconductive layer 20, a connection metal shield layer 21 is formed over the cable metal shield layer 7 of the high-pressure fireproof cable 1 and the cable metal shield layer 14 of the high-pressure fireproof cable 2. Further, for example, a foamed fire-resistant tape is wound around the outer periphery of the connection metal shielding layer 21 over the cable fire-resistant protective layer 8 of the high-pressure fire-resistant cable 1 and the cable fire-resistant protective layer 15 of the high-pressure fire-resistant cable 2. 22 are provided. The foamed fireproof tape forming the fireproof protective layer 22 is formed by coating a base fabric with a foamable resin. Then, a waterproof tape is wound on the fire-resistant protective layer 22 to form a waterproof layer 23, thereby forming a connection portion 24 of the high-pressure fire-resistant cable. This waterproof tape is a tape in which a compound mainly composed of high-quality synthetic rubber and plastic is uniformly adhered to one surface of a chloroprene rubber film.

Therefore, according to the present embodiment, when the mica composite tape is wound around the connection portions of the high-pressure fire-resistant cables 1 and 2, the conductor connection pipe 17 and the connection-portion refractory layer 18 constituted by the mica composite tape are used. It is possible to prevent the generation of a gap between them.

[0020]

According to the first aspect of the present invention, when a mica composite tape is wound around a connection portion of a high-pressure fire-resistant cable, a gap is formed between the conductor connection pipe and the mica composite tape. Can be prevented.

According to the second aspect of the present invention, when the mica composite tape is wound around the connection portion of the high-pressure fire-resistant cable, the gap between the conductor connection pipe and the mica composite tape can be filled finely.

According to the third aspect of the present invention, when the mica composite tape is wound around the connection portion of the high-pressure fireproof cable, the gap between the conductor connection pipe and the mica composite tape can be reliably filled. .

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a connecting portion of a high-pressure fire-resistant cable according to the present invention.

FIG. 2 is a perspective view of a fire-resistant cable at a connection portion of the high-pressure fire-resistant cable shown in FIG.

FIG. 3 is an overall perspective view of the adapter shown in FIG. 2;

FIG. 4 is an enlarged cross-sectional view of a portion of a conductor connection pipe of a connection portion of a conventional high-pressure fire-resistant cable.

FIG. 5 is a sectional view of a connection portion of a conventional high-pressure fire-resistant cable.

[Explanation of symbols]

 1, 2… High-pressure fire-resistant cable 3, 10… Conductor 4, 11… Cable fire-resistant layer 5, 12… Cable insulation layer 17… … Conductor connecting pipe 18 …………………………… Fireproof layer 27, 28 ………… Adapter 29 ……………………………… Compound

Claims (3)

[Claims] 1. A conductor connecting tube is formed on a conductor connecting portion in which exposed conductors at ends of two cables are joined to each other, and one of the cable refractory layers and the other cable refractory layer are formed on the conductor connecting tube. A mica composite tape is wound to form a connection portion fireproof layer, and a connection portion insulation layer is formed by applying one cable insulation layer to the other cable insulation layer on the connection portion fireproof layer. Forming a connection metal shielding layer on the connection insulating layer via a connection semiconductive layer, forming a fire protection layer on the connection metal shielding layer, and forming a waterproof layer on the fire protection layer In the connecting portion of the high-pressure fireproof cable, a ceramic adapter having a clay-like adhesive inorganic material compound on the inner wall surface is interposed between the conductor connecting portion and the connecting portion fireproof layer. Between the conductor connection portion and the connection portion fireproof layer Connection of the high pressure fire-proof cable, characterized in that to fill the gap portion. 2. The connection part for a high-pressure fire-resistant cable according to claim 1, wherein the ceramic adapter is divided into a plurality of parts. 3. The clay-like inorganic compound having adhesive strength provided on the inner wall surface of the ceramic adapter,
The connection part for a high-pressure fireproof cable according to claim 1 or 2, wherein the connection part is provided with a thickness of 1 to 2 mm.