JP2000166045A - Method for laying power cable and power cable having insulated connecting part used in the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce stresses applied to the insulation cylinder of an insulated connecting part, when laying power cables connected in advance with the insulated connecting part at a laying site, and to prevent the breakage of the insulation cylinder even if stresses are applied to it. SOLUTION: A protective pipe 28, connected to both sides of the insulation cylinder 26 of the insulated connecting part 12, has flexibility. Thus, even if stresses like bending or twisting is applied to the insulated connecting part 12, stress is hardly transmitted to the cylinder 26. Thus, the stresses applied to the cylinder 26 are reduced. Also, a reinforcing rigid metal pipe 31A is attached to the cylinder 26, so that the cylinder 26 reinforced by the metal pipe 31A will not break, even if stress is applied to the cylinder 26.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of laying a power cable such as an ultra-high-voltage power cable, and more particularly, to a method of laying a power cable by transporting the power cable to a laying site after forming an insulated connection. The present invention relates to a cable laying method and a power cable having an insulated connection used in the method.

[0002]

2. Description of the Related Art After a power cable of a predetermined length is transported to a laying site, the power cable is laid and extended at the laying site, and then a connection box is formed at the site. It will be expensive.

For this reason, recently, at a place other than the installation site such as a factory or a connection base, a power cable is previously connected to an insulated connection portion and lengthened, and then a long power cable having the insulated connection portion is connected to the installation site. A method of transporting and laying cables is being studied.

[0004] In order to carry out this method, several conditions are required. One of the conditions is that when laying a long power cable including an insulated connection, the insulated connection tends to be bent or twisted. Therefore, the insulated connecting portion has flexibility. The insulated connection part of a general power cable is formed by providing a protection tube so as to surround a core connection portion and connecting an insulation tube in which an end electrode is embedded in the middle of the protection tube corresponding to the core connection portion. .

However, when bending or twisting is applied to the insulated connection portion when the power cable is laid, a stress such as bending, pulling, or twisting is applied to the insulating tube through the protective tube, and this stress is applied to the material of the insulating tube. If the strength exceeds the strength, the insulating cylinder may be damaged. In order to avoid such damage, the bending diameter at the time of laying must be increased. There is a disadvantage that the properties are reduced.

[0006]

One of the problems to be solved by the present invention is to reduce the stress applied to the insulating cylinder at the insulated connecting portion and to prevent the insulating cylinder from being damaged even if stress is applied to the insulating cylinder. It is an object of the present invention to provide a method by which a power cable can be laid out in a manner that does not occur.

Another problem to be solved by the present invention is to reduce the stress applied to the insulating tube of the insulated connecting portion when the power cable is laid, and to prevent the insulating tube from being damaged even if stress is applied to the insulating tube. It is to provide a power cable having an insulated connection suitable for doing so.

[0008]

According to one aspect of the present invention, a power cable is connected in advance to a site other than a site where the power cable is laid, such as a factory or a connection base, and the power cable is transported together with the connecting portion to the site. In the laying method, an insulating cylinder having an end electrode in which an end electrode is buried is provided corresponding to a main body connecting portion of a power cable, and is arranged so as to surround the main body connecting portion, and flexible is provided on both sides of the insulating cylinder. And a rigid reinforcing member is attached to the outside of the insulating tube to form an insulated connecting portion, and a power cable is laid while protecting the insulated connecting portion with the flexible protective tube and the rigid reinforcing member. Another object of the present invention is to provide a power cable laying method.

A second object of the present invention is a method of laying an electric power cable according to the first object of the present invention, wherein the rigid reinforcing member is made of metal. An object of the present invention is to provide a power cable laying method characterized in that the power cable is detached from the insulating tube.

A third object of the present invention is to provide a method of laying an electric power cable according to the second object of the present invention, wherein a metal rigid reinforcing member is removed from an insulating cylinder and then the metal rigid reinforcing member is removed. Another object of the present invention is to provide a method of laying a power cable, wherein another insulating material is attached to an insulating cylinder instead of a member.

According to a fourth aspect of the present invention, there is provided a power cable laying method according to the first or second aspect, wherein the rigid reinforcing member is mechanically connected to an end electrode in the insulating cylinder. It is another object of the present invention to provide a method for laying a power cable.

A fifth object of the present invention is to provide a power cable having an insulated connecting portion which is connected in advance at a place other than a laying site such as a factory or a connection base. An insulating tube provided corresponding to the body connection portion and having an end electrode embedded therein, a flexible protection tube provided to surround the body connection portion and connected to both sides of the insulation tube, It is an object of the present invention to provide a power cable having an insulated connection part, which comprises an attached rigid reinforcing member.

According to a sixth aspect of the present invention, there is provided a power cable having an insulated connection according to the fifth aspect, wherein the rigid reinforcing member is mechanically connected to an end electrode in the insulating cylinder. A power cable having an insulated connection.

As described above, when the protective tubes connected to both sides of the insulating tube of the insulating connecting portion formed at a place other than the installation site have flexibility, stress such as bending and twisting is applied to the insulating connecting portion. However, it is difficult for this stress to be transmitted to the insulating cylinder, so that the stress applied to the insulating cylinder is reduced.

Further, since a rigid reinforcing member is attached to the insulating cylinder, even if stress is applied to the insulating cylinder, the insulating cylinder is not reinforced by the rigid reinforcing member and is not damaged. The power cable including the portion can be laid economically and efficiently with a small bending diameter.

Furthermore, when the rigid reinforcing member is mechanically connected to the end electrode in the insulating cylinder, the rigid reinforcing member is firmly connected to the insulating cylinder, so that the strength of the insulating cylinder is protected. Can be further improved

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, an embodiment of the present invention will be described in detail. FIG. 1 shows a power cable 10 having an insulated connection 12 used in the method of the present invention.
Although only one insulated connection portion 12 is shown in FIG. 1, a large number of power cables 10 are actually connected via a large number of insulated connection portions 12.

Each power cable 10 has a cable conductor 14
And an insulating layer 16 provided thereon, a metal jacket 18 further provided thereon, and an anticorrosion layer 20 provided on the metal jacket 18. These power cables 1
Numerals 0 are connected to each other by a main body connection portion 22 including a connection portion 14A of the cable core 14 and a connection portion 16A of the insulating layer 16.

The insulating connection portion 12 is provided in correspondence with the main body connection portion 22 of the power cable 10 and has an end electrode 24 embedded therein, and an insulation tube 26 provided so as to surround the main body connection portion 22. Flexible protective tube 2 connected on both sides
8 and a rigid reinforcing member 30 attached to the outside of the insulating tube 26. As shown in FIG. 1, the insulated connection portion 12 is formed so as to maintain a quasi-equivalent shape with respect to the power cable 10.

For example, the insulating tube 26 is made of epoxy resin, the end electrode 24 is made of brass, and the flexible protective tube 28 is made of a material of the same quality as the metal jacket 18 of the power cable 10. For example, it is made from a corrugated (bellows) metal tube made of stainless steel. As shown in FIG. 1, one end of the protection tube 28 is connected to the metal jacket 18 of the power cable 10 by welding or the like via a spacer 32, and the other end is connected to the end electrode 24 of the insulating tube 26 by welding or the like. It is connected.

The rigid reinforcing member 30 is made of, for example, a metal tube 31A made of stainless steel, for example, divided into two or split, and the metal tube 31A is covered with a screw over the entire length of the insulating tube 26 including the end electrode 24. It is connected to the end electrode 24 by 34 and attached to the insulating tube 26.

The main body connecting portion 22 includes a flexible protective tube 28.
Having an anticorrosion layer 36 provided thereon.
Are provided in portions other than the rigid body reinforcing member 30 to expose the rigid body reinforcing member 30. In addition, the rigid reinforcing member 3
On top of 0 is an anticorrosion layer 4 such as a tape winding and shrink tube.
1 is formed so as to straddle the anticorrosion layer 36.

Next, the method of laying a power cable according to the present invention will be described in detail with reference to FIGS. 1 and 2. First, as shown in FIG. . As described above, the rigid reinforcing member 30
Consists of a metal tube 31A.

A plurality of power cables 10 are
The power cable 10A that has been connected and lengthened is transported to the installation site by appropriate means, and the long power cable 10A is installed at the installation site and extended. The long power cable 10 is not only laid in a straight line, but also laid in a snake for the purpose of absorbing thermal expansion and contraction, or laid in a curved manner depending on the situation of the laying site.

In this case, it should be noted that the insulated connecting portion 12 is connected to the protective tubes 2 connected to both sides of the insulating tube 26.
8 is made of a corrugated metal tube and has flexibility, so that when the long power cable 10A is laid, even if stress such as bending or twisting is applied to the insulated connecting portion 12, this stress is possible. Since this is absorbed by the protective tube 28 having flexibility, this stress is not easily transmitted to the insulating cylinder 26, and therefore, the stress applied to the insulating cylinder 26 is reduced.

Another thing to note is that the metal tube 31A, which is the rigid reinforcing member 30, is attached to the insulating tube 26, so that even if stress is applied to the insulating tube 26, the insulating tube 26 will be rigidly reinforced. The insulation tube 26 is not damaged because it is reinforced by the member 30.

After laying the long power cable 10A, the anticorrosion layer 41 is removed, and a two-piece or split metal tube 31A which is a metal rigid reinforcing member 30 mounted on the insulating tube 26 is removed. After the screws 34 are removed and removed, and a ground wire for cross bonding is processed, as shown in FIG. 2, instead of the metal tube 31A, a two-piece insulating tube 38 is attached by appropriate means such as bonding. Then, the anticorrosion layer 40 is formed by tape winding over the tape anticorrosion layer 36 on both sides of the insulating tube 26 to which the insulating tube 38 is attached. Finally, the long power cable 10A is fixed on the laying surface by appropriate means, and the installation is completed.

The above-mentioned method of the present invention is summarized in the time chart of FIG. 3. As can be seen from this time chart, according to this method, the metal pipe 31A which is the rigid reinforcing member 30 is insulated at the installation site. It is only necessary to replace the pipe 38 and apply the anticorrosion layer 40, and it is not necessary to perform many complicated connection operations, and the installation work can be performed efficiently.

In the above embodiment, the rigid reinforcing member 30 is formed of the metal tube 31A. However, as shown in FIG. 4, the rigid reinforcing member 30 may be formed of a rigid split insulating tube 31B. Good. The rigid reinforcing member 30 is an insulating tube 31B.
After the long power cable 10A is laid and extended, there is no need to remove the insulating tube 31B, and the long power cable 1A remains attached with the rigid reinforcing member 30 attached.
0A can be installed. Therefore, in this case, the tape wound anticorrosion layer 40 is formed on the rigid reinforcing member 30 at a factory or a connection base in advance and transported to the installation site,
It may be laid. This is the insulated connection 12 at the installation site.
This eliminates the need for additional work and makes it possible to perform the installation work more efficiently.

[0030]

According to the present invention, as described above, a power cable having an insulated connection formed at a place other than the installation site is laid at the installation site. Since the protection tube to be connected has flexibility, even if stress such as bending or twisting is applied to the insulating connection portion, the stress is hardly transmitted to the insulating cylinder, and therefore, the stress applied to the insulating cylinder is reduced.

Further, since a rigid reinforcing member is attached to the insulating cylinder, even if stress is applied to the insulating cylinder, the insulating cylinder is not reinforced by the rigid reinforcing member and is not damaged. The power cable including the portion can be laid economically and efficiently with a small bending diameter.

Further, when the rigid reinforcing member is mechanically connected to the end electrode in the insulating cylinder, the rigid reinforcing member is firmly connected to the insulating cylinder, so that the strength of the insulating cylinder can be protected. It can be further improved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing only an upper half of a power cable having an insulated connection portion used in a method of laying a power cable according to one embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an upper half of an insulated connection portion of a long power cable laid by the method of the present invention.

FIG. 3 is a time chart showing the method of the present invention in the order of steps.

FIG. 4 is a longitudinal sectional view of an upper half portion of an insulated connecting portion of a power cable used in a method of laying a power cable according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Power cable 10A Long power cable 12 Insulated connection part 14 Cable core 14A Connection part of cable core 14 16 Insulation layer 16A Connection part of insulation layer 16 18 Flexible protective tube 20 Metal jacket 22 Body connection part 24 End Electrode 26 Insulating tube 28 Flexible protective tube 30 Rigid reinforcing member 31A Split or split metal tube 31B Split insulating tube 32 Spacer 34 Screw 36 Tape anticorrosion layer 38 Insulation tube 40 Tape anticorrosion layer

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hironobu Hirano 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Yoshimi Adachi 2-6-1 Marunouchi, Chiyoda-ku, Tokyo No. F-term in Furukawa Electric Co., Ltd. (reference) 5G355 AA01 BA04 BA12 CA22

Claims (6)

[Claims] 1. A method of connecting a power cable in advance at a place other than a site where the power cable is laid, such as a factory or a connection base, and transporting and laying the power cable to a site along with a connection portion, the power cable being connected to a main body connection portion of the power cable And an insulating tube in which the end electrodes are embedded, provided so as to surround the body connection portion, and connected to flexible protection tubes on both sides of the insulating tube, and a rigid reinforcing member is provided outside the insulating tube. A power cable laying method, wherein the power cable is laid while protecting the insulated connection with the flexible protective tube and the rigid reinforcing member. 2. The power cable laying method according to claim 1, wherein the rigid reinforcing member is made of metal, and the metal rigid reinforcing member is detached from the insulating cylinder after laying. Power cable laying method. 3. The method of laying a power cable according to claim 2, wherein after removing the metal rigid reinforcing member from an insulating cylinder, another insulator is replaced with the metal rigid reinforcing member. A power cable laying method, wherein the power cable is attached to an insulating tube. 4. The method of laying a power cable according to claim 1, wherein the rigid reinforcing member is mechanically connected to an end electrode in the insulating cylinder. How to lay. 5. A power cable having an insulated connection portion connected in advance at a place other than the installation site such as a factory or a connection base, wherein the insulated connection portion is provided corresponding to a main body connection portion of the power cable. An insulating tube in which the electrode is embedded, a flexible protective tube provided so as to surround the body connecting portion and connected to both sides of the insulating tube, and a rigid reinforcing member attached to the outside of the edge tube And a power cable having an insulated connection. 6. A power cable having an insulated connection according to claim 5, wherein the rigid reinforcing member is mechanically connected to an end electrode in the insulating cylinder. Power cable having a section.