JP6738694B2 - Power cable connection method, power cable connection auxiliary jig - Google Patents

Description

The present invention relates to a power cable connecting method in a power cable intermediate junction box and a power cable connection auxiliary jig used for the same.

At the connecting portion between the power cables, for example, a rubber block insulating type power cable intermediate junction box is used. The rubber block insulation type junction box expands the diameter of the rubber block on a hollow pipe or spiral core at the factory or assembly site, inserts the power cable into the conductor sleeve and compresses and connects the power cable, and shrinks the rubber block. It is installed by making a diameter.

After the rubber block is attached to the connection portion of the power cable, an electrical shielding layer treatment with a metal layer is performed on the outer periphery of the rubber block, and a protective tube assembly for guaranteeing mechanical strength and a ground wire withdrawal treatment are performed (for example, Patent Document 1). 1).

On the other hand, there is an intermediate junction box in which a rubber block is electrically shielded and a protection tube is assembled in advance and shipped. In such an intermediate junction box, the inner diameter is not greatly expanded by the spiral core, the inner diameter is shipped in a bare pipe state, and at the construction site, the power cable can be connected using the slip-on type conductor connection part. Done. The slip-on type conductor connection part is divided into a plug side and a socket side (hereinafter, referred to as a connection terminal and an internal electrode), and both are slidably inserted and fitted to be connected (for example, Patent Document 2).

JP, 2001-37065, A JP, 2016-46854, A

The power cable intermediate connection box of the slip-on type conductor connection part is composed of, for example, an internal electrode, an insulating tubular body accommodating the internal electrode, a protective tube provided on the outer peripheral side of the insulating tubular body, and the like. The power cables are connected to each other by inserting the power cables from both sides of the power cable intermediate junction box and inserting the respective ends into the internal electrodes.

However, when the power cable is inserted into such a power cable intermediate junction box from one side, the inner electrode may be pushed by the power cable, and the inner electrode may be displaced in the axial direction of the rubber block. Further, similarly, there is a possibility that the insulating cylinder is axially displaced with respect to the protective tube due to friction between the power cable and the insulating cylinder. If the internal electrodes and the like are displaced in this way, electric field distortion inside the rubber block will occur, and this will cause deterioration of electrical characteristics and dielectric breakdown.

The present invention has been made in view of the above problems, and provides a power cable connection method and a power cable connection auxiliary jig capable of reliably preventing deviation of each part in a slip-on type conductor connection part. The purpose is to provide.

In order to achieve the above-mentioned object, a first aspect of the present invention is to provide an internal electrode for connecting conductors of a power cable, an insulating tubular body accommodating the internal electrode, and a protective tube provided on the outer peripheral side of the insulating tubular body. A method for connecting a power cable in a power cable intermediate junction box, comprising: inserting a connection auxiliary jig from one opening end of the power cable intermediate junction box; A step of supporting the insulating tube and the protection tube from one side, and receiving a reaction force from the connection auxiliary jig, the first power cable from the other open end of the power cable intermediate junction box. Step b of inserting the tip of the first power cable to connect the tip of the first power cable to the internal electrode, and removing the connection auxiliary jig to expose from the other open end of the power cable intermediate junction box. Step c of mounting the connection auxiliary jig on the outer periphery of the first power cable, and supporting the protection tube from the other side by the connection auxiliary jig, and receiving a reaction force from the connection auxiliary jig. And d) inserting the tip of the second power cable from one open end of the power cable intermediate junction box to connect the tip of the second power cable to the internal electrode. It is a power cable connection method.

The connection auxiliary jig includes a shaft body, a first bush that can be mounted on the outer circumference of the shaft body, a second bush that can be mounted on the outer circumference of the first bush, and an outer circumference of the power cable. A third bush that can be mounted, and a grip portion that can be mounted on the outer periphery of the second bush and the third bush, and in the step a, one open end of the power cable intermediate junction box. From the above, the shaft portion is inserted, the tip of the shaft portion is brought into contact with the internal electrode, and the first bush is provided on the outer periphery of the shaft portion exposed from the end portion of the power cable intermediate junction box. Then, the tip of the first bush is brought into contact with the end of the insulating cylinder, the second bush is attached to the outer periphery of the first bush, and the tip of the second bush is attached to the protective tube. Of the second bush is attached to the outer periphery of the second bush in step b, and the first power cable is pulled toward the side of the grip by receiving a reaction force from the grip. In the step c, the third bush is attached to the outer circumference of the first power cable, and the tip of the third bush is brought into contact with the end of the protection tube. It is preferable that the grip is attached to the outer circumference of the bush of No. 3, and the grip receives a reaction force to pull the second power cable toward the grip.

The first bush is slidable with respect to the shaft body and can be fixed to the shaft body at an arbitrary position, and the second bush is slidable with respect to the first bush. It is possible, and it may be fixable to the first bush at any position.

According to the first invention, the connection auxiliary jig is inserted from one opening end of the power cable intermediate junction box, and the internal electrode, the insulating cylinder, and the protection tube are supported from one side by the connection auxiliary jig. In this state, since the tip of the power cable is inserted into the power cable intermediate junction box, it is possible to prevent misalignment of each part.

Further, since the members for pressing the respective parts of the power cable intermediate connection box are separated from each other in the connection auxiliary jig, the positions of the respective parts can be easily adjusted according to the size of the power cable intermediate connection box and the like.

In particular, the first bush is slidable with respect to the shaft body, can be fixed to the shaft body at any position, and the second bush is slidable with respect to the first bush. If it can be fixed to the first bush at any position, the positioning is easy.

2nd invention is a connection auxiliary jig used when connecting a power cable in a power cable intermediate connection box, Comprising: A 1st bush which can be fixed to a shaft part and the outer periphery of the said shaft part. A second bush attachable to the outer periphery of the first bush, a third bush attachable to the outer periphery of the power cable, and an attachable outer periphery of the second bush and the third bush. The first bush is slidably movable with respect to the shaft body portion and can be fixed to the shaft body portion at an arbitrary position, and the second bush is the first bush. A jig for connecting a power cable, which is slidable with respect to one bush and can be fixed to the first bush at an arbitrary position.

According to the second aspect of the invention, it is possible to reliably prevent the slip-on type conductor connecting portion from being displaced.

According to the present invention, it is possible to provide a power cable connection method and a connection auxiliary jig for a power cable capable of reliably preventing the slip-on type conductor connection part from being displaced.

Sectional drawing which shows the power cable intermediate connection box 1. FIG. 3 is an exploded perspective view showing the power cable connection auxiliary jig 10. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable. (A), (b) is a figure which shows the connection process of a power cable.

Hereinafter, a method for connecting a power cable according to an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing a power cable intermediate junction box 1. The power cable intermediate junction box 1 is mainly composed of internal electrodes 3, an insulating cylinder 5, a protective tube 7, and the like. It should be noted that the shielding layer provided on the outer periphery of the insulating tubular body 5, the terminals of the protective tube 7, and the like are not shown.

The internal electrode 3 is a member into which the tips (connection terminals) of the power cables are inserted from both sides to electrically connect the conductors of both power cables. The internal electrode 3 is provided with, for example, a pin that can be fitted into a groove provided at the tip of the power cable, and prevents the power cable from coming off. When the tip of the power cable is inserted into the internal electrode 3, the connection terminal at the tip of the power cable and the internal electrode 3 are electrically connected and electrically connected.

The internal electrode 3 is housed in the insulating cylindrical body 5. The insulating tubular body 5 is a substantially tubular member having elasticity as a whole. The inner semiconductive layer 5a is made of a semiconductive rubber material. The inner semiconductive layer 5a is formed on the inner surface side of the insulating cylindrical body 5.

The stress cones 5c are provided coaxially with the inner semiconductive layer 5a and spaced apart from the inner semiconductive layer 5a so as to be located at both ends of the insulating cylinder 5. The stress cone 5c is also made of a semiconductive rubber material. The stress cone 5c and the inner semiconductive layer 5a are integrated by the reinforcing insulating layer 5b. The reinforcing insulating layer 5b is formed so as to cover a part of the outer periphery of the inner semiconductive layer 5a and the stress cone 5c. An outer semiconductive layer 5d is formed on the outer peripheral surface of the reinforcing insulating layer 5b.

A shield layer (not shown) is provided on the outer circumference of the insulating cylinder 5, and the insulating cylinder 5 is housed inside the protective tube 7. That is, the protective tube 7 is provided on the outer peripheral side of the insulating cylindrical body 5. A compound (not shown) is filled inside the protective tube 7. Open ends 9a and 9b are provided at both ends of the protective tube 7. The open ends 9a and 9b are provided coaxially with the hollow portion of the insulating tubular body 5. The structure of the power cable intermediate junction box 1 is not limited to the illustrated example.

Next, the power cable connection auxiliary jig 10 will be described. FIG. 2 is an exploded perspective view showing the configuration of the power cable connection auxiliary jig 10. The power cable connection auxiliary jig 10 mainly includes a shaft portion 11, a first bush 13, a second bush 15, a third bush 17, a grip portion 19, and the like.

The shaft portion 11 is a rod-shaped member, and the tip portion thereof has the same shape as the connection terminal of the power cable. The outer diameter of the shaft portion 11 is slightly smaller than the outer circumference of the target power cable.

The first bush 13 is a tubular member having a hole 13a inside. The inner diameter of the hole 13a is slightly larger than the outer diameter of the shaft portion 11. Therefore, the shaft portion 11 can be inserted into the first bush 13. The first bush 13 is slidable with respect to the shaft body 11, and can be mounted by fixing the first bush 13 at an arbitrary position on the outer circumference of the shaft body 11 with, for example, a bolt (not shown). Is.

The second bush 15 is a tubular member that has a hole 15a inside and a flange 15b at the end. The inner diameter of the hole 15a is slightly larger than the outer diameter of the first bush 13. Therefore, the first bush 13 can be inserted into the second bush 15. The second bush 15 is slidable with respect to the first bush 13, and can be mounted by fixing the second bush 15 at an arbitrary position on the outer circumference of the first bush 13 with, for example, bolts (not shown). Is.

The third bush 17 is made of a half-divided member, and when the half-divided portions 17a facing each other are made to face each other and abutted against each other, the third bush 17 becomes a substantially circular hole shape, and becomes a tubular member having a flange at the end. The inner diameter of the third bush 17 formed in this manner substantially matches the outer diameter of the power cable. Therefore, the power cable can be sandwiched between the third bushes 17 and the third bush 17 can be attached to the outer periphery of the power cable.

The grip portion 19 is made of a half-divided member, and when the half-divided portions 19a facing each other are faced and abutted, a substantially circular hole shape is formed, and a rod-shaped member (handle portion) projects in the facing direction. .. The inner diameter of the grip portion 19 thus formed can be attached to the outer circumferences of the second bush 15 and the third bush 17. That is, the outer diameters of the second bush 15 and the third bush 17 are almost the same. The gripping portion 19 can be maintained in the closed state by facing and tightening the half split portions 19a.

As shown in the figure, in the power cable connection auxiliary jig 10, the shaft body portion 11, the first bush 13, the second bush 15, the third bush 17, and the grip portion 19 may all be separate bodies. Some members may be integrated with each other.

Next, a power cable connection method using the power cable connection auxiliary jig 10 will be described. 3 to 10 are diagrams showing a power cable connecting step.

First, as shown in FIG. 3A, the shaft body portion 11 is inserted from one open end 9a of the power cable intermediate junction box 1. FIG.3(b) is a figure which shows the state which inserted the shaft part 11 in the power cable intermediate connection box. In this state, the tip of the shaft 11 is brought into contact with the internal electrode 3.

As described above, the tip of the shaft portion 11 has the same shape as the connection terminal of the power cable that can be fitted to the internal electrode 3, so that the tip of the shaft portion 11 can be surely brought into contact with the internal electrode 3. You can Moreover, since the shaft body portion 11 has a diameter equal to or smaller than the inner diameter of the hollow portion of the insulating tubular body 5, the shaft body portion 11 can be easily inserted into the insulating tubular body 5. Since the shaft body portion 11 is sufficiently longer than (half the length of) the power cable intermediate junction box 1, the shaft body portion 11 is inserted into the power cable intermediate junction box 1 when the shaft body portion 11 is inserted. Protruding from the end of.

Next, as shown in FIG. 4A, the first bush 13 is inserted into the shaft body portion 11 exposed from the end portion of the power cable intermediate junction box 1. That is, the first bush 13 is attached to the outer circumference of the shaft body portion 11.

FIG. 4B is a diagram showing a state in which the first bush 13 is inserted into the power cable intermediate junction box 1. The tip of the first bush 13 is brought into contact with the insulating cylindrical body 5, and in this state, the first bush 13 is fixed to the outer periphery of the shaft body portion 11 with a bolt or the like not shown.

Since the first bush 13 is sufficiently long with respect to the length from the end portion of the insulating tubular body 5 to the open ends 9a and 9b of the protection tube 7, the first bush 13 is connected to the power cable intermediate junction box 1 (protection box). The first bush 13 projects from the end of the power cable intermediate junction box 1 when inserted into the pipe 7).

Next, as shown in FIG. 5A, the second bush 15 is inserted into the first bush 13 exposed from the end of the power cable intermediate junction box 1. That is, the second bush 15 is attached to the outer circumference of the first bush 13.

FIG. 5B is a diagram showing a state in which the first bush 13 is inserted into the power cable intermediate junction box 1. The end surface (flange 15b) of the second bush 15 is brought into contact with the end portion of the protective tube 7, and in this state, the second bush 15 is fixed to the outer periphery of the first bush 13 with a bolt or the like not shown.

As described above, the power cable connection auxiliary jig 10 is inserted from one opening end 9a of the power cable intermediate junction box 1, and the internal electrode 3, the insulating cylinder 5 and the protective tube 7 are inserted by the power cable connection auxiliary jig 10. It can be supported from the open end 9a side.

Next, as shown in FIG. 6A, the second bush 15 is sandwiched by the grips 19. That is, the grip portion 19 is attached to the outer circumference of the second bush 15. FIG. 6B is a diagram showing a state in which the grip portion 19 is arranged on the outer circumference of the second bush 15. In this state, the grip portion 19 contacts the flange 15b of the second bush 15.

Next, as shown in FIG. 7A, a lever hoist 21 (for example, a lever block (registered trademark)) is connected to the handle of the grip 19 and the other end is connected to the first power cable 23a. The illustrated example shows an example in which the lever hoists 21 are respectively connected to a pair of handle portions arranged at opposite positions.

In this state, the power cable 23a is pulled toward the grip portion 19 and the tip of the power cable 23a is inserted from the other open end 9b of the power cable intermediate junction box 1. FIG. 7B is a diagram showing a state in which the power cable 23 a is completely inserted into the insulating tubular body 5 and the power cable 23 a is connected to the internal electrode 3.

Here, when the power cable 23a is pulled toward the grip 19 (arrow A in the figure), the grip 19 receives the reaction force (arrow B in the figure). That is, since the power cable connection auxiliary jig 10 contacts and supports the internal electrode 3, the insulating cylindrical body 5, and the protection tube 7, the reaction force when pulling the power cable 23a is not affected by the power cable connection auxiliary jig 10. , The internal electrode 3, the insulating cylindrical body 5 and the protective tube 7 can receive them.

As described above, the power cable connection auxiliary jig 10 receives a reaction force, the power cable 23a is inserted into the open end 9b side of the power cable intermediate junction box 1, and the conductor of the power cable 23a is electrically connected to the internal electrode 3. can do. At this time, since each part of the power cable intermediate connection box 1 is supported by the power cable connection auxiliary jig 10, when the power cable 23a is inserted, the insulating cylinder body 5 and the protection tube 7 are relatively displaced due to the resistance thereof. Can be prevented. Further, it is possible to prevent the internal electrode 3 from being excessively pushed in and being displaced with respect to the axial direction of the insulating cylindrical body 5 in a state where the power cable 23a is connected to the internal electrode 3.

After the power cable 23a is connected, all the mounted power cable connection auxiliary jigs 10 are removed from the power cable intermediate junction box 1. Next, as shown in FIG. 8A, the power cable 23 a exposed from the open end 9 b of the power cable intermediate junction box 1 is sandwiched by the third bushes 17. That is, the third bush 17 is attached to the outer circumference of the power cable 23a. FIG.8(b) is a figure which shows the state which has arrange|positioned the 3rd bush 17 in the outer periphery of the power cable 23a. In this state, the third bush 17 comes into contact with the end of the protection tube 7.

Next, as shown in FIG. 9A, the attached third bush 17 is sandwiched by the grips 19. That is, the grip portion 19 is attached to the outer circumference of the third bush 17.

FIG. 9B is a diagram showing a state in which the grip portion 19 is arranged on the outer circumference of the third bush 17. In this state, the grip portion 19 is brought into contact with the flange of the third bush 17. By doing so, the protection tube 7 can be supported from the opening end 9b side by the power cable connection auxiliary jig 10. The third bush 17 can be fixed to the outer circumference of the power cable 23a by sandwiching and tightening the third bush 17 with the grip portion 19.

Next, as shown in FIG. 10A, a lever hoist 21 (for example, a lever block (registered trademark)) is connected to the handle of the grip 19 and the other end is connected to the second power cable 23b. Also in this case, the lever hoists 21 are connected to the pair of handle portions arranged at the opposite positions, respectively.

In this state, the power cable 23b is pulled toward the grip 19 and the tip of the power cable 23b is inserted from one open end 9a of the power cable intermediate junction box 1. FIG. 10B is a diagram showing a state in which the power cable 23b is completely inserted into the insulating tubular body 5 and the power cable 23b is connected to the internal electrode 3.

Here, like the power cable 23a, when the power cable 23b is pulled toward the grip portion 19 side (arrow C in the figure), the grip portion 19 receives the reaction force (arrow D in the figure). That is, since the power cable connection auxiliary jig 10 contacts and supports the protective tube 7, the reaction force when pulling the power cable 23a can be received by the protective tube 7 by the power cable connection auxiliary jig 10. ..

As described above, the power cable connection auxiliary jig 10 receives a reaction force, the power cable 23b is inserted into the open end 9a side of the power cable intermediate junction box 1, and the conductor of the power cable 23b is electrically connected to the internal electrode 3. can do.

The internal electrode 3 and the insulating cylinder 5 do not directly contact the power cable connection auxiliary jig 10, but by supporting the protective tube 7 and the power cable 23a by the power cable connection auxiliary jig 10, the power cable 23a and The friction between the inner electrode 3 and the insulating cylinder 5 prevents the inner electrode 3 and the insulating cylinder 5 from being displaced.

As described above, according to the present embodiment, by using the power cable connection auxiliary jig 10, when the power cables 23a and 23b are inserted into the power cable connection auxiliary jig 10, the internal electrodes in the power cable intermediate connection box 1 are inserted. 3 and the like can be prevented from shifting in the axial direction.

Moreover, since the shaft body portion 11, the first bush 13, the second bush 15, the third bush 17, and the grip portion 19 of the power cable connection auxiliary jig 10 are separate bodies, the size of the power cable intermediate junction box 1, etc. The position of each other can be adjusted and applied.

In particular, since the first bush 13 can be slidably moved with respect to the shaft body portion 11 and can be fixed to the shaft body portion 11 at an arbitrary position, the position adjustment of the first bushing 13 is easy. Similarly, the second bush 15 can be slidably moved with respect to the first bush 13 and can be fixed to the first bush 13 at an arbitrary position, so that the position adjustment of the second bush 15 is easy.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not affected by the above-described embodiments. It is obvious to those skilled in the art that various alterations or modifications can be conceived within the scope of the technical idea described in the claims, and those are naturally within the technical scope of the present invention. It is understood that it belongs.

1... Power cable intermediate junction box 3... Internal electrode 5... Insulating cylinder 5a... Internal semiconductive layer 5b... Reinforced insulating layer 5c... Stress cone 5d... External semiconductive Layer 7... Protective tubes 9a, 9b... Open end 10... Power cable connection auxiliary jig 11... Shaft part 13... First bush 13a... Hole 15... Second Bushing 15a... Hole 15b Flange 17 Third bush 17a Half-split part 19 Grip part 19a Half-split part 21 Lever hoists 23a, 23b.... Power cable

Claims (4)

An internal electrode that connects the conductors of the power cable,
An insulating cylindrical body in which the internal electrode is housed,
A protective tube provided on the outer peripheral side of the insulating cylinder,
A power cable connection method in a power cable intermediate junction box comprising:
Step a in which a connection auxiliary jig is inserted from one open end of the power cable intermediate junction box, and the internal electrode, the insulating cylinder, and the protection tube are supported from one side by the connection auxiliary jig When,
The tip of the first power cable is inserted from the other open end of the power cable intermediate junction box by receiving a reaction force by the connection auxiliary jig, and the tip of the first power cable is connected to the internal electrode. Step b
The connection auxiliary jig is removed, the connection auxiliary jig is attached to the outer periphery of the first power cable exposed from the other open end of the power cable intermediate connection box, and the connection auxiliary jig is used to Step c of supporting the protective tube from the other side,
The tip of the second power cable is inserted from one opening end of the power cable intermediate junction box by receiving a reaction force by the connection auxiliary jig, and the tip of the second power cable is connected to the internal electrode. Step d
A method of connecting a power cable, comprising: The connection auxiliary jig includes a shaft body, a first bush that can be mounted on the outer circumference of the shaft body, a second bush that can be mounted on the outer circumference of the first bush, and an outer circumference of the power cable. A mountable third bush, and a grip part mountable on the outer periphery of the second bush and the third bush,
In the step a, the shaft portion is inserted from one open end of the power cable intermediate junction box, the tip of the shaft portion is brought into contact with the internal electrode, and the end portion of the power cable intermediate junction box is changed. The first bush is attached to the exposed outer periphery of the shaft portion, the tip of the first bush is brought into contact with the end portion of the insulating cylinder, and the second bush is attached to the outer periphery of the first bush. A bush is attached, and the tip of the second bush is brought into contact with the end of the protection tube;
In the step b, the grip is attached to the outer circumference of the second bush, and the grip receives a reaction force to pull the first power cable toward the grip,
In the step c, the third bush is attached to the outer periphery of the first power cable, and the tip of the third bush is brought into contact with the end of the protection tube,
In the step d, the grip portion is attached to the outer periphery of the third bush, and the grip portion receives a reaction force to pull the second power cable toward the grip portion. The power cable connection method described in 1. The first bush is slidable with respect to the shaft body, and can be fixed to the shaft body at an arbitrary position,
The power cable connecting method according to claim 2, wherein the second bush is slidably movable with respect to the first bush and can be fixed to the first bush at an arbitrary position. A connection auxiliary jig used when connecting the power cable in the power cable intermediate junction box,
Shaft part,
A first bush that can be fixed to the outer periphery of the shaft portion;
A second bush attachable to the outer periphery of the first bush;
A third bush that can be attached to the outer periphery of the power cable,
A grip portion attachable to the outer circumferences of the second bush and the third bush,
The first bush is slidable with respect to the shaft body, and can be fixed to the shaft body at an arbitrary position,
The above-mentioned second bush is slidable with respect to the first bush, and can be fixed to the first bush at an arbitrary position.

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