JPH052926A - Waterproof cable and injecting device for water permeation preventive material - Google Patents

Abstract

PURPOSE:To facilitate connection works and enhance the reliability upon connection. CONSTITUTION:Insulated electric wires are stranded and bundled, to which waterproofing admixture 50z, 51z, 52z is injected or fitted in by pressure, followed by provision thereover of an external covering, and thus waterproof cables 50, 51, 52 are fabricated. Those portions of these cables as specified previously, for example end parts 50a, 50b, 51a, 51b, 52a, 52b and middle part 51c, does not contain the waterproofing admixture 50z, 51z, 52z already at the time of being manufactured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof cable and a water permeation preventive material injection device. The waterproof cable of the present invention does not include a water permeation preventive material (waterproof admixture or water-absorptive material) in a limited portion along a predetermined length direction. In the device, the supply of the water permeation preventive material to a predetermined portion of the cable is stopped and the water permeation preventive material is supplied to the other portion.

[0002]

2. Description of the Related Art A conventional waterproof communication cable is formed by twisting a plurality of insulated electric wires, supplying a water permeation preventive material to a cable core, which is a bundle of electric wires, and applying an outer coating to the outer circumference. As the water permeation preventive material, a jelly-like waterproof mixture (petroleum-based jelly, etc.) or a water-absorptive material that expands in a jelly-like state by absorbing water is used. Conventionally, the water permeation preventive material is applied to the entire length of the cable. . This water permeation preventive material has a function of preventing the liquid from propagating in the length direction of the cable even if a liquid such as water enters the cable due to the damage of the cable.

When a waterproof communication cable containing a waterproof admixture is laid in the ground or in a pipeline for a long section to form a communication line, a large number of waterproof communication cables are cascaded. FIG. 5 shows a state in which the waterproof communication cables are connected to each other. As shown in FIG. 5, waterproof communication cables 01a, 01
In order to connect b, the waterproof mixture at the cable ends is completely removed, and in some cases the cable ends are washed with kerosene or the like, and the insulated wires 02a, 01b of both cables 01a, 01b are
02b Connect to each other. In the figure, the connection points are indicated by "x" marks. After connecting the insulated wires 02a and 02b, the connection closure 03 and the seals 04a and 04b are provided. 05a,
05b is the outer coating of the cable.

FIG. 6 shows a conventional example in which a waterproof communication cable containing a waterproof mixture is connected to a transmission device in a station building. As shown in FIG. 6, since the waterproof communication cable 08 drawn out from the underground conduit 06 and drawn inside the station building 07 has a waterproof mixture, the waterproof communication cable 08 is directly connected to the terminal board 09. I can't connect. Therefore, in the station building, the waterproof communication cable 08 is connected to the termination cable 010 which is an ordinary cable (a cable without a waterproof mixture or a water-absorptive expansion material), and the insulated wire 010a of the termination cable 010 is connected to the terminal board. It is connected to 09. The terminal board 09 is connected to the exchange 0 via the jumper wire 011.
12 and other transmission devices.

Here, two examples of a cable manufacturing apparatus for manufacturing a waterproof cable are shown in FIGS. 7 and 8.

The cable manufacturing apparatus 1 shown in FIG. 7 employs a method of injecting the waterproof mixture J in the step of twisting the insulated wires 2. That is, the plurality of insulated electric wires 2 delivered from the supply reel 3 are guided by the guide roller 4 and gathered at the twisting point P to be twisted. The twisting point P is provided with the water permeation preventive material injection device 5, and the waterproof mixture J stored in the tank 6 is sent to the injection device 5 via the press-fitting pump 7. Therefore, the waterproof mixture J is injected / press-fitted around the twisted insulated wires 2 and in the gaps between the wires, and the cable core 8 is obtained. The cable core 8 includes a plurality of insulated wires 2
The waterproof mixture J is applied to a bundle of electric wires twisted together.
The waterproof mixture J overflowing from the injection device 5 is sucked by a suction pump (not shown) and returned to the tank 6.

A tape 10 such as plastic is wound around the cable core 8 by a tape winding machine 9. By winding the tape 10 in this manner, the waterproof mixture J can be confined in the cable core 8 and the arrangement of each insulated wire of the cable core 8 can be held at the specified position. The cable core 8 a around which the tape 10 is wound is taken up by the take-up machine 11 and taken up on the drum 12. The outer coating is often applied to the cable core 8a in another subsequent step, but the outer coating may be applied before the cable core 8a is wound on the drum 12.

The cable manufacturing apparatus 15 shown in FIG. 8 employs a method of injecting the waterproof mixture J immediately before the outer coating material 16 is applied to the cable core 17. On the outer periphery of the cable core 17 fed from the drum 18, a narrow tape, a string, a thread, or the like is roughly wound with a gap provided intermittently.
That is, in order to apply the waterproof mixture J in the next step, the tape is not wound around the entire circumference of the cable core 17 but is wound with an interval between the tapes. On the outer periphery and inside of the cable core 17, the tank 19,
The waterproof mixture J sent through the press-fitting pump 20 and the water permeation preventive material injection device 21 is injected and press-fitted. An external coating material (plastic (PE, PV, PV
C or the like) or aluminum tape) 16 is applied to form a waterproof cable 23. The waterproof cable 23 is taken up by the take-up machine 24 and then wound around the drum 25.

An example of a waterproof cable manufactured by the manufacturing apparatus 1 shown in FIG. 7, the manufacturing apparatus 15 shown in FIG.
Shown in. In the waterproof cable 30 shown in FIG. 9, the copper wire 31
A plurality of insulated electric wires 31 in which an insulator 31b such as PE is coated on a is twisted and gathered, a tape 32 is wound around the outer periphery thereof, and an outer coating 33 is cylindrically applied on the tape 32. . Furthermore, a portion inside the outer coating 33 is filled with a waterproof admixture (or “water-absorption expanded material”) 34. Conventionally, the waterproof mixture 34 is filled over the entire length of the cable. As described above, since the waterproof mixture 34 is filled, even if the waterproof cable 30 is damaged and liquid such as water enters the cable, the water and the like are prevented from propagating in the cable length direction. Can be prevented.

[0010]

As shown in FIG. 5, when connecting waterproof communication cables 01a and 01b to each other,
No waterproof admixture at the end of the cable is required. Therefore, the waterproof mixture at the end of the cable is removed at the time of connection, but it is difficult to completely remove it, and therefore it was difficult to connect with high quality and high reliability. Also, it took a lot of time to remove the waterproof mixture. Furthermore, when washing with kerosene, etc., the remaining waterproof mixture reacts with kerosene, etc., and becomes sticky, the skin of the worker develops a disease, and the evaporated kerosene deteriorates the working environment. There was a problem of doing.

Further, as shown in FIG. 6, in order to draw the waterproof communication cable 08 into the station building, the length is several m to 100 m.
This requires a certain amount of termination cable 010, which is inconvenient and increases the cost. Further, since the waterproof communication cable 08 and the termination cable 010 are connected, the number of connection points is increased by that much, the connection work is increased, and the connection reliability is reduced.

In view of the above-mentioned prior art, the present invention provides a waterproof cable having a water permeation preventive material such as a waterproof admixture or a water absorbing expansive material, in which a predetermined portion is provided with a water permeation preventive material at the time of manufacture. It is an object of the present invention to provide a waterproof cable that is free from the above. It is another object of the present invention to provide a water permeation preventive material injection device used when manufacturing a waterproof cable that does not partially have the water permeation preventive material.

[0013]

The structure of the waterproof cable of the present invention which solves the above-mentioned problems is such that a plurality of electric wires are bundled together, an outer cover is provided on the outermost periphery, and a water permeation preventive material is provided inside the outer cover. The waterproof cable having the above is characterized in that the waterproof cable is not provided in a limited portion of the waterproof cable in a predetermined length direction. Further, the structure of the water permeation preventive material injection device of the present invention is such that a cable core formed by assembling and twisting a plurality of electric wires is sent while penetrating, and the water permeation preventive material is injected and pressed from the outer peripheral side of the cable core. In the water permeation preventive material injection device described above, a shutoff mechanism for temporarily shutting off the supply of the water permeation preventive material is provided in the middle of a route of sending the water permeation preventive material to the cable core.

[0014]

In the waterproof cable of the present invention, the water permeation preventive material is removed in advance at the portion where the connection or branch is performed. Therefore, the connection / branch operation can be performed without removing the water permeation preventive material in the connecting / branching work. You can Further, by passing the cable core through the water permeation preventive material injection device of the present invention,
The water permeation preventive material can be injected by removing the predetermined portion.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows waterproof cables 50, 51 and 52 according to an embodiment of the present invention. In FIG. 1A, the waterproof cable 50 is shown wound around the drum 60.
In FIG. 1B, the drum is omitted and the waterproof cable 50 is shown. In FIG. 1C, the waterproof cables 51 and 52 are shown.

In the waterproof cable 50, both ends 50 are
Water permeation preventive materials (water-proof mixture and water-absorption product) for a and 50b
Is not provided from the beginning, and the remaining portion is filled with the waterproof mixture 50z. The portion filled with the waterproof mixture 50z is shown by hatching in the figure.
When such waterproof cables 50 are connected to each other, since there is no waterproof mixture 50z at the ends of the cables, the waterproof cables 50 can be connected to each other without removing the waterproof mixture. For this reason, connection work can be saved and at the same time,
You can connect with high reliability. In addition, if the waterproof cable 50 is used, the cable 50 can be used for transmission equipment in the station building.
Can be directly connected.

In the waterproof cable 51, both ends 51 are
a, 51b and the intermediate portion 51c are not provided with a water permeation preventive material from the beginning, and the remaining portion has a waterproof mixture 51.
z is provided. In the waterproof cable 52, both of the end portions 52a and 52b are not provided with the water permeation preventive material from the beginning, and the remaining portion is provided with the waterproof mixture 52z. By connecting the intermediate portion 51c of the waterproof cable 51 and the end portion 52a of the waterproof cable 52, the T
It is possible to make a branch connection in a letter shape. Also in this connection work, it is not necessary to remove the waterproof admixture, and the work can be labor-saving and highly reliable connection can be made.

Next, a water permeation preventive material (waterproof mixture,
Two specific examples of a water permeation preventive material injection device suitable for use in manufacturing a waterproof cable that does not include a water absorption expansion material will be described.

The water permeation preventive material injection device 100 shown in FIG. 2 which is a vertical sectional view and FIGS. 3A and 3B which is a horizontal sectional view is preferably used as the injection device 21 of the cable manufacturing device 15 shown in FIG. Is. A cable core 17 in which a narrow tape or the like is roughly wound is pierced and sent to the injection device 100. The cylindrical filling chamber 101 is provided with a supply hole 101a in the upper part and a discharge hole 101b in the lower part, and the heated / melted waterproof mixture J is supplied to the supply hole 101a.
a is supplied under pressure into the filling chamber 101, and the excess waterproof mixture J in the filling chamber 101 is discharged into the discharge hole 101.
It is discharged from b.

In the filling chamber 101, an inner cylinder 102 and an outer cylinder 103 are provided in two layers in a state of concentrically surrounding the cable core 17. The inner cylinder 102 is mechanically fixed to the filling chamber 101, and the outer cylinder 1
03 is capable of rotating in the circumferential direction, and the outer cylinder 103
Two shield plates 106 are fixedly provided on the outer peripheral surface of the device at 180 ° apart in the circumferential direction. In the cylinders 102 and 103, openings 102a and 103a extending in the axial direction are formed intermittently along the circumferential direction. Then, when the outer cylinder 103 is rotated by a rotation mechanism (not shown) so that the shield plate 106 becomes vertical as shown in FIG.
02a is closed by the outer cylinder 103, and the opening 103a is closed by the inner cylinder 102. When the outer cylinder 103 is rotated so that the shielding plate 106 becomes horizontal as shown in FIG. 3B, the positions of the opening 102a and the opening 103a coincide with each other.

Rubber tube-shaped sealing portions 104 and 105 are provided on both end surfaces of the filling chamber 101. In the sealing portions 104 and 105, when the pressure gas is injected from the injection portions 104a and 105a, the central throttle portions 104b and 105b come into contact with the cable core 17 at an appropriate pressure and throttle. Therefore, the waterproof mixture J in the filling chamber 101 is prevented from flowing out from both end surfaces.

Next, the operation of the water permeation preventive material injection device 100 shown in FIGS. 2 and 3 will be described. When the injection device 100 operates, pressure gas is injected into the sealing parts 104 and 105, and the throttle parts 104a and 105b are connected to the cable core 17.
Contact with a suitable pressure. When injecting the waterproof mixture J into the cable core 17, the waterproof mixture J is supplied under pressure through the supply hole 101a of the filling chamber 101, and the outer cylinder 103 is rotated as shown in FIG. 3 (b). The positions of the openings 102a and 103a are matched with each other.
In this way, the waterproof mixture J flows into the inside of the inner cylinder 102 through the openings 102a, 103a located above the shield plate 106, and the cable mixture 17 is pressurized and injected. It At this time, since the shielding plate 106 is horizontal, the waterproof mixture J is entirely in the inner cylinder 10.
It flows into the inside of 2. Excessive waterproof mixture J inside the inner cylinder 102 is discharged from the discharge hole 101b through the openings 102a and 103a located below the shielding plate 106. The cable core 17 is sent to the right in FIG. 2, the waterproof mixture J is pressurized and injected when penetrating the injection device 100, and the cable core 17a in which the waterproof mixture J is injected is injected. It is delivered from the right end surface (FIG. 2) of the apparatus 100.

When the injection of the waterproof mixture J into the cable core 17 is stopped, the outer cylinder 103 is rotated to block the openings 102a and 103a as shown in FIG. 3 (a). Therefore, the waterproof mixture J supplied from the supply hole 101a cannot flow into the inner cylinder 102, and is discharged from the discharge hole 101b through the space between the outer cylinder 103 and the filling chamber 101. . At this time, since the shielding plate 106 is in the vertical position, it does not hinder the distribution of the waterproof mixture J. Thus, the inner cylinder 102
Since the waterproof mixture J is no longer supplied to the inside of the, the injection of the waterproof mixture J into the cable core 17 is stopped. However, the state of FIG. 3A, that is, the openings 102a and 103a
Even if the waterproof mixture J is closed, the injection of the waterproof mixture J into the cable core 17 does not immediately stop, but all the waterproof mixture J remaining in the inner cylinder 102 is injected into and attached to the cable core 17 and carried away. Until the mixture is added, the injection of waterproof mixture J continues. Therefore, the timing for closing the openings 102a and 103a is controlled in consideration of such a temporal operation delay.

In order to restart the injection of the waterproof mixture J into the cable core 17, the outer cylinder 103 is again shown in FIG. 3 (b).
Set to the state shown in. In this case as well, a time delay occurs until the waterproof mixture J is injected / press-fitted into the cable core 17, so the control timing is adjusted in consideration of this delay.

The water permeation preventive material injection device 10 shown in FIGS. 2 and 3.
By using 0, it is possible to easily manufacture a waterproof cable that does not have a water permeation preventive material (waterproof admixture, water-absorptive material) in a limited portion along a predetermined length direction.

FIG. 4 shows a water permeation preventive material injection device 200 according to another embodiment. As shown in the figure, the cylindrical filling chamber 201 has a supply hole 201a and a discharge hole 201b,
Sealing portions 202 are provided on both end surfaces of the filling chamber 201.
203 is provided. Inside the filling chamber 201, an inner cylinder 204 and a bellows 205 are provided. The inner cylinder 204 is formed with an opening 204a. The bellows 205 is composed of a flexible inner pipe 205a and a flexible outer pipe 205b.
Cylindrical ring 205c for keeping the distance of 5b constant
Is inserted between both pipes 205a and 205b at an appropriate interval, and a ring-shaped contact portion 205d is provided at the tip (right end).
Is provided. The length of the pipes 205a and 205b (the length when extended) is longer than the axial length inside the filling chamber 201.

The base end (left end) of the bellows 205 is fixed to the gas supply chamber 206, and the compressor 20
When the compressed gas from No. 7 is supplied to the bellows 205 through the switching valve 208 and the gas supply chamber 206, the bellows 205 extends and the ring-shaped contact portion 205d moves to the chamber 20.
It contacts the contact inner wall 201c of the right side wall of the No. 1 unit. Bellows 2
The stretched state of 05 is indicated by a dotted line in the figure. Bellows 205
As the bellows 2 expands, the opening 204a of the inner cylinder 204 is extended.
Blocked by 05. When the switching valve 208 is switched and the gas in the bellows 205 is sucked by the vacuum pump 209, the bellows 205 contracts and shortens to the state shown by the solid line in the figure. When the bellows 205 contracts, the opening 204a opens.

When the waterproof mixture J is injected into the cable core 17 by the injection device 200 shown in FIG. 4, the vacuum pump 209 is actuated to retract the bellows 205.
In this way, the waterproof mixture J supplied from the supply hole 201a passes through the opening 204a of the inner cylinder 204 and is supplied to the cable core 17. The cable core 17a in which the waterproof mixture J is injected comes out from the right end of the injection device 200. When the injection is stopped, the compressor 207 is operated to extend the bellows 205 and completely close the opening 204a. In this way, the supply of the waterproof mixture J into the inner cylinder 204 is stopped, and the injection of the waterproof mixture J into the cable core 17 can be stopped. The waterproof mixture J passes through between the extended bellows 205 and the filling chamber 201 and the discharge hole 2
It is discharged from 01b.

This injection device 200 is also the injection device 1 described above.
Similarly to 00, a delay occurs in the supply / stop of the waterproof mixture J, and therefore the expansion / contraction control of the bellows 205 is performed in consideration of this.

[0031]

According to the waterproof cable of the present invention as described in detail with reference to the above embodiments, the water-proof material is not provided in a predetermined portion, so that the connecting work is easy.
It will be easier and the connection reliability will be higher. Further, according to the water permeation preventive material injection device of the present invention, it is possible to easily manufacture a waterproof cable that does not include a water permeation preventive material in a predetermined portion.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a waterproof cable of the present invention.

FIG. 2 is a vertical sectional view showing an example of a water permeation preventive material injection device of the present invention.

FIG. 3 is a cross-sectional view showing an example of a water permeation preventive material injection device.

FIG. 4 is a cross-sectional view showing another example of the water permeation preventive material injection device of the present invention.

FIG. 5 is a configuration diagram showing a conventional connection state of a waterproof communication cable.

FIG. 6 is a configuration diagram showing a connection state of a waterproof communication cable in a station building.

FIG. 7 is a configuration diagram showing a cable manufacturing apparatus.

FIG. 8 is a configuration diagram showing a cable manufacturing apparatus.

FIG. 9 is a cross-sectional view showing a waterproof cable.

[Explanation of symbols]

50, 51, 52 Waterproof cable 50a, 50b, 51a, 51b, 52a, 52b End part 51c Intermediate part 50z, 51z, 52z Waterproof mixture 100, 200 Water permeation preventive material injection device 101, 201 Filling chamber 102, 204 Internal cylinder 102a, 103a, 204a Opening 103 External cylinder 104, 105, 202, 203 Sealing part 106 Shielding plate 205 Bellows J Waterproof mixture

Claims (2)

[Claims] 1. A waterproof type cable having a plurality of electric wires bundled together, an outer cover on the outermost periphery, and a water permeation preventive material on the inner side of the outer cover, in a predetermined length direction of the waterproof type cable. A waterproof cable characterized in that it does not have a water permeation preventive material in a limited portion extending over. 2. A water permeation preventive material injection device for injecting and press-fitting a water permeation preventive material from the outer peripheral side of the cable core, which is fed while a cable core formed by assembling and twisting a plurality of electric wires penetrates through the cable core. An apparatus for injecting a water permeation preventive material, comprising a shutoff mechanism for temporarily interrupting the supply of the water permeation preventive material in the middle of a route for sending the water permeation preventive material to a cable core.