JP5554168B2 - Submarine cable - Google Patents

Description

  The present invention relates to a submarine cable for electric power.

Since the cable laid on the seabed is long, it is composed of a plurality of connected power cables. In many cases, the power cable is placed on a submarine cable laying ship in a state where it is connected in advance at a factory, and is drawn out and laid along the facility route from the ship. The central conductors of the power cables constituting the submarine cable are connected by a method called a so-called flexible joint.
By the way, the size (conductor cross-sectional area) of the center conductor of the power cable is designed so that the conductor temperature does not exceed the allowable temperature (for example, 90 ° C. for a crosslinked polyethylene insulated power cable) with respect to the transmission current. A power cable having a conductor size suitable for the installation location is selected according to the surrounding environment and thermal conditions.
The submarine cable has a part that is laid on the seabed and a part that is laid on the land side and the landing part (see Fig. 1). Among these, thermal conditions are severe, such as dredging and landing. Therefore, the conductor cross-sectional area of the central conductor is determined so as not to cause a problem at this point, and the entire submarine cable is manufactured with the same conductor cross-sectional area.

As the aforementioned flexible joint, there is a technique described in Patent Document 1. This Patent Document 1 describes a technique of connecting the center conductors of the power cables by V-cut welding when connecting the power cables to manufacture a long power cable. In addition, a technique for connecting a segmented conductor, which is a central conductor of a power cable, by V-cut welding for each segment is also known (see, for example, Patent Document 2 and Patent Document 3).
Thus, the cable connection part which connected the center conductors of the power cable by welding has flexibility, and is called a flexible joint. The flexible joint is used to connect cables having the same structure. After connecting center conductors having the same diameter (same cross-sectional area) by a welding method, the center conductor portion is covered with a mold insulator made of the same kind of resin as the cable insulator.
In addition, the welding method is not employ | adopted for the connection of the center conductors from which a conductor cross-sectional area differs, Usually, it compression-connects using the sleeve for different diameter conductor connection. The cable connecting portion using the sleeve for connecting different diameter conductors has poor flexibility.

  The flexible joint is applied to the cable connection part of the submarine cable. In order to improve workability when laying the submarine cable on the seabed, flexibility (flexibility) is required for the submarine cable. by.

Japanese Patent Laid-Open No. 10-214523 Japanese Patent Laid-Open No. 10-162883 Japanese Patent No. 3305614

  Conventional submarine cables, as mentioned above, have a structure in which the conductor cross-sectional area of the central conductor is large over the entire length in accordance with the dredging and landing areas where the thermal conditions of the laying environment are more severe than those under the sea. Consists of cables. For this reason, submarine cables have become expensive products.

  An object of the present invention is to reduce the cost of submarine cables.

In order to solve the above problems, one aspect of the present invention is a submarine cable,
A submarine cable in which a plurality of conductor wires each having a central conductor having a different conductor cross-sectional area are welded by dividing the plurality of conductor wires constituting the central conductor into several parts and connected to each other. Because
Both connected cables have a central conductor formed by concentrically twisting conductor strands having different strand diameters with the same number of layers,
The conductor wires are concentrically welded for each layer corresponding to the central conductors.

When connecting cables with different conductor cross-sectional areas of the center conductor, repeat the process of welding the conductor wires that make up the center conductor in several groups to form multiple small welds. For example, since the dimensional difference of the central conductors can be dispersed, the central conductors having different cross-sectional areas can be easily welded together, and a submarine cable having the connection portion as a flexible joint can be manufactured.
On the other hand, for example, when the central conductors are welded together to form a large weld location, welding is difficult due to the dimensional difference between the central conductors, and the rigidity of the cable connection portion is increased. There is a risk that flexibility will be reduced. And when (mechanical) stress is added to a cable, there exists a possibility that the cable connection part may fracture | rupture because stress concentrates on the one welding part. In particular, when a load is applied to the welded portion where the central conductors having different conductor cross-sectional areas of the central conductor are connected together, the welded portion tends to be distorted and tends to break.
That is, according to the present invention, the conductor strands which are the minimum units constituting the central conductor are grouped, and the central conductors are welded and connected to each other in a plurality of small welding locations. Since the portion can be a flexible joint, cables having different conductor cross-sectional areas can be connected well to obtain a flexible submarine cable.
In particular, when connecting cables having different conductor cross-sectional areas of the central conductor, and connecting the central conductors formed by concentrically twisting multiple conductor strands having different strand diameters, By repeatedly welding and connecting the conductor wire constituting the central conductor and the conductor wire constituting the other central conductor for each layer of concentric strands (each group), the conductor wires are welded. The submarine cable in which the central conductor is connected by a welding method can be obtained. And the submarine cable which connected the cable from which a conductor cross-sectional area differs flexibly can be obtained.
With such a submarine cable, the cost can be reduced by connecting a cable having an appropriate conductor cross-sectional area selected according to the thermal conditions of the installation environment.

Another aspect of the present invention is a submarine cable,
A submarine cable in which a plurality of conductor wires each having a central conductor having a different conductor cross-sectional area are welded by dividing the plurality of conductor wires constituting the central conductor into several parts and connected to each other. Because
Both connected cables have a central conductor formed by concentrically twisting conductor wires having the same wire diameter with different numbers of layers,
The conductor wires are welded concentrically for each corresponding layer between the center conductors, and the outer conductor wire remaining in the center conductor with a large number of layers is welded to the outer peripheral surface of the center conductor with a small number of layers. It is characterized by that.

When connecting cables with different conductor cross-sectional areas of the center conductor, repeat the process of welding the conductor wires that make up the center conductor in several groups to form multiple small welds. For example, since the dimensional difference of the central conductors can be dispersed, the central conductors having different cross-sectional areas can be easily welded together, and a submarine cable having the connection portion as a flexible joint can be manufactured.
On the other hand, for example, when the central conductors are welded together to form a large weld location, welding is difficult due to the dimensional difference between the central conductors, and the rigidity of the cable connection portion is increased. There is a risk that flexibility will be reduced. And when (mechanical) stress is added to a cable, there exists a possibility that the cable connection part may fracture | rupture because stress concentrates on the one welding part. In particular, when a load is applied to the welded portion where the central conductors having different conductor cross-sectional areas of the central conductor are connected together, the welded portion tends to be distorted and tends to break.
That is, according to the present invention, the conductor strands which are the minimum units constituting the central conductor are grouped, and the central conductors are welded and connected to each other in a plurality of small welding locations. Since the portion can be a flexible joint, cables having different conductor cross-sectional areas can be connected well to obtain a flexible submarine cable.
In particular, when connecting cables having different conductor cross-sectional areas of the central conductor, and connecting the central conductors formed by concentrically twisting multiple conductor strands having the same strand diameter with one another, After repeatedly connecting the conductor wire constituting the central conductor and the conductor wire constituting the other central conductor by welding for each concentric layer (each group), the central conductor having a large number of layers If the conductor wires on the outer layer surplus on the side are welded to the outer peripheral surface of the central conductor having a small number of layers, a submarine cable in which all conductor wires are connected by a welding method can be obtained. And the submarine cable which connected the cable from which a conductor cross-sectional area differs flexibly can be obtained.
With such a submarine cable, the cost can be reduced by connecting a cable having an appropriate conductor cross-sectional area selected according to the thermal conditions of the installation environment.

Moreover , it is preferable that the welding part which welded the said conductor strand for every layer of the said center conductors takes the arrangement | positioning mutually shifted in the longitudinal direction of the said cable.

If the arrangement of the plurality of welds is shifted and dispersed in the longitudinal direction of the cable, the heat generated in the welds during energization can be dissipated without being partially concentrated.
Moreover, it is possible to prevent the rigidity from increasing due to the partial concentration of the plurality of welds, and to further improve the flexibility and flexibility of the cable.

Moreover, it is preferable that the submarine cable connecting three or more cables is a cable having a smaller conductor cross-sectional area of the central conductor as the cable is closer to the center side than the cable on the end side .

With such a submarine cable, a power cable having a small conductor cross-sectional area of the center conductor can be laid on the seabed side where the thermal conditions of the laying environment are loose. And if it is a submarine cable in which the cable is connected so as to have a conductor cross-sectional area according to the thermal conditions of the laying environment, the conductor cross-sectional area of the central conductor is large over the entire length as in the case of a conventional submarine cable. Cost can be reduced compared to the structure .

  According to the present invention, by selecting and connecting a cable having an appropriate conductor cross-sectional area according to the thermal conditions of the laying environment, it is possible to reduce the cost compared to a conventional submarine cable.

It is explanatory drawing which shows the state which laid the submarine cable. They are the side view (a) which shows the cable connection part of the submarine cable which concerns on Embodiment 1 of this invention in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is a side view which shows the cable connection part which welded the central conductor collectively as a comparative example in partial cross section. It is the side view (a) which shows the cable connection part of the submarine cable in the modification 1 of Embodiment 1 in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is the side view (a) which shows the cable connection part of the submarine cable in the modification 2 of Embodiment 1 in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is the side view (a) which shows the cable connection part of the submarine cable in the modification 3 of Embodiment 1 in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is the side view (a) which shows the cable connection part of the submarine cable which concerns on Embodiment 2 of this invention in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is a side view which shows the cable connection part which welded the central conductor collectively as a comparative example in partial cross section. It is the side view (a) which shows the cable connection part of the submarine cable in the modification 1 of Embodiment 2 in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is the side view (a) which shows the cable connection part of the submarine cable in the modification 2 of Embodiment 2 in partial cross section, and explanatory drawing (b) regarding the welding part in the cable connection part of the submarine cable. It is a side view which shows the cable connection part of the submarine cable which concerns on Embodiment 3 of this invention. It is explanatory drawing regarding the welding part of the cable connection part of the submarine cable which concerns on Embodiment 3 of this invention. It is a side view which shows the cable connection part which welded the center conductor collectively as a comparative example. FIG. 10 is a side view showing a cable connecting portion of a submarine cable in Modification 1 of Embodiment 3. It is explanatory drawing regarding the welding part of the cable connection part of the submarine cable in the modification 1 of Embodiment 3. FIG.

  Hereinafter, preferred embodiments for carrying out the present invention will be described with reference to the drawings. However, the embodiments described below are given various technically preferable limitations for carrying out the present invention, but the scope of the present invention is not limited to the following embodiments and illustrated examples.

FIG. 1 is an explanatory view showing an example of a submarine cable according to the present invention.
This submarine cable is formed by connecting power cables having different conductor cross-sectional areas, and a cable having a smaller conductor cross-sectional area of the central conductor is used in the cable closer to the center than to the cable on the end side.
Specifically, the submarine cable C in FIG. 1 includes, for example, a power cable 30 (conductor cross-sectional area 400 mm ² ), a power cable 10 (conductor cross-sectional area 600 mm ² ), and a power cable 20 (conductor cross-sectional area 800 mm ² ). It is a submarine cable that connects the two. In this submarine cable C, the power cable 20 having the largest conductor cross-sectional area of the center conductor is arranged on the end side laid on the brim and the landing part, and the conductor breakage of the center conductor toward the center side of the seabed portion. The power cable 10 having the second largest area and the power cable 30 having the smallest area are sequentially arranged.
That is, the power cable 30 having a relatively thin center conductor is on the seabed side, the power cable 20 having a relatively thick center conductor is on the buttock side and the landing part side, and the power cable having an intermediate thickness between the center conductors therebetween. Submarine cable C is configured such that 10 is laid.
In this way, if the submarine cable C is configured by connecting power cables having a small conductor cross-sectional area of the central conductor from the end side toward the center side, the thermal condition of the laying environment is centered on the submarine side where the laying environment is loose. A power cable having a small conductor cross-sectional area can be laid.
If the submarine cable C is connected to a power cable having a conductor cross-sectional area corresponding to the thermal conditions of the laying environment, the cost is reduced compared to the submarine cable having the same conductor cross-sectional area of the central conductor over the entire length. Can be achieved.
That is, the conductor cross-sectional area can be reduced to reduce the cost in terms of material cost and manufacturing cost, and the weight reduction can also reduce the transportation cost and the laying cost.

  Next, the configuration of the submarine cable formed by connecting power cables having different conductor cross-sectional areas of the center conductor will be described in detail.

(Embodiment 1)
FIG. 2A is a side view showing the cable connecting portion 101 of the submarine cable 100 in a partial cross-sectional view. FIG. 2B is an explanatory diagram relating to a welded portion in the cable connecting portion 101 of the submarine cable 100.

  As shown in FIGS. 2A and 2B, the submarine cable 100 includes one power cable 10 corresponding to the submarine side of the submarine cable 100 and the other corresponding to the saddle and landing portions of the submarine cable 100. The power cable 20 is connected.

As shown in FIGS. 2 (a) and 2 (b), the power cable 10 includes a center conductor 10a composed of a plurality of conductor wires 1 and a cable insulator 10b covering the center conductor 10a. Yes.
Specifically, the power cable 10 includes a center strand 11, a first conductor strand layer 12, a second conductor strand layer 13, a third conductor strand layer 14, and a fourth conductor strand layer 15. The center conductor 10a including the fifth conductor element wire layer 16 is provided. The center conductor 10a has a structure in which a conductor element wire 1 to be the center element wire 11 is a core, and five conductor element wire layers are formed by concentrically twisting a plurality of conductor element wires 1 on the outer side. ing.
More specifically, the center conductor 10a of the power cable 10 is formed by concentrically twisting 91 conductor strands 1 having a strand diameter of 2.93 mm to form a center strand and five conductor strand layers. It is a circular compression conductor having a conductor cross-sectional area of 600 mm ² . The outer diameter of the center conductor 10a is about 29.5 mm.

As shown in FIGS. 2A and 2B, the power cable 20 includes a center conductor 20a composed of a plurality of conductor wires 2, and a cable insulator 20b that covers the center conductor 20a. Yes.
Specifically, the power cable 20 includes a center strand 21, a first conductor strand layer 22, a second conductor strand layer 23, a third conductor strand layer 24, and a fourth conductor strand layer 25. The center conductor 20a including the fifth conductor strand layer 26 is provided. The center conductor 20a has a structure in which a conductor strand 2 serving as a center strand 21 is a core, and a five-layer conductor strand layer is formed by concentrically twisting a plurality of conductor strands 2 on the outside. ing.
More specifically, the central conductor 20a of the power cable 20 is formed by concentrically twisting 61 conductor strands 2 having a strand diameter of 3.5 mm, and the center strand 21 and the four conductor strand layers 22, 23, 24, 25, and 30 conductor strands 2 having a strand diameter of 3.4 mm are concentrically twisted on the outside of the fourth layer to form a fifth conductor strand layer 26. It is a circular compression conductor having a cross-sectional area of 800 mm ² . The outer diameter of the center conductor 20a is about 34.8 mm.

As described above, the power cable 10 and the power cable 20 are formed by concentrically twisting a plurality of conductor strands having different strand diameters with the same number of layers, and a center conductor 10a composed of a center strand and five conductor strand layers. , 20a, respectively. The outer diameter difference between the center conductor 10a and the center conductor 20a is about 5.3 mm, and the outer diameter difference is designed to be 7 mm or less.
The thicknesses of the cable insulators 10b and 20b of the power cable 10 and the power cable 20 are both 12 mm, and the power cable 10 and the power cable 20 are, for example, lead-coated cables with iron wire armor.

  Next, a connection method for connecting the power cable 10 and the power cable 20 will be described.

First, in the central conductor 10a of the power cable 10 serving as the cable connecting portion 101, as shown in FIG. 2 (a), the conductor strand 1 of the center strand 11 protrudes the longest, and the conductor strand layer on the outer layer side is longer. The conductor strands 1 are cut so that the conductor strands 1 of each layer become shorter sequentially. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (12-16) inclines so that an inclined surface may face an outer peripheral side of the center conductor 10a. I cut it.
Further, in the central conductor 20a of the power cable 20 to be the cable connecting portion 101, as shown in FIG. 2A, the conductor element wire 2 of the center element wire 21 is the shortest, and the conductor element wire layer on the outer layer side thereof, The conductor element wires 2 are cut so that the conductor element wires 2 of the respective layers protrude longer in order. In addition, the front-end | tip of the conductor strand 2 is cut diagonally, and in particular, the conductor strand 2 of each conductor strand layer (22-26) inclines so that an inclined surface may face an outer peripheral side of the center conductor 20a. I cut it.

And in the state which opened and raised the conductor strand 2 of each conductor strand layer (22-26) other than the center strand 21 in the center conductor 20a of the power cable 20, the center strand 21 of the center conductor 20a and the power The central strand 11 of the central conductor 10a of the cable 10 is abutted, and the central strand 21 (conductor strand 2) and the central strand 11 (conductor strand 1) are connected by V-cut welding. In addition, the center welding part 71 is formed in the location which welded this center strand 21 and the center strand 11.
Thereafter, the conductor wires 2 of the conductor wire layers (22 to 26) of the central conductor 20a are twisted back in order, and the first conductor wire layer 12, the first conductor wire layer 22, and the second conductor wire layer 13 are twisted back in order. And the second conductor strand layer 23, the third conductor strand layer 14 and the third conductor strand layer 24, the fourth conductor strand layer 15 and the fourth conductor strand layer 25, the fifth conductor strand layer 16 and the second conductor strand layer 24. The conductor wire 1 and the conductor wire 2 are connected to each of the five conductor wire layers 26 by V-cut welding.
Here, the conductor strand 1 of each conductor strand layer (12-16) of the center conductor 10a of the power cable 10 and the conductor strand of each conductor strand layer (22-26) of the center conductor 20a of the power cable 20 The position where 2 is abutted corresponds to the circumference of a concentric circle having the central strand as an axis for each layer. Concentric welds are formed at locations where the conductor wires 1 and 2 are welded for each of these layers, and ring welds 72 to 76 are formed in order from the first layer to the fifth layer. Yes.
As shown in FIGS. 2 (a) and 2 (b), the ring-shaped welds 72 to 76 formed by welding the conductor wires 1 and 2 for each layer of the central conductors 10a and 20a are the lengths of the cables. The ring-shaped welds 76, 75, 74, 73, 72 on the outer layer side are arranged closer to the power cable 10.

And the cable connection part 101 is formed by coat | covering the part which connected the center conductor 10a and the center conductor 20a by welding with a mold insulator.
Thus, the submarine cable 100 in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductors 10a and 20a are connected via the cable connecting portion 101 can be manufactured.

As described above, when the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the center conductors 10a and 20a are connected, the conductor strand 1 that is the minimum unit constituting the center conductor 10a and the center conductor 20a are configured. By using a technique in which the conductor wire 2 which is the minimum unit is connected by welding in a plurality of groups for each layer of concentric strands, a plurality of small welds are formed, and the central conductor 10a and the central conductor are formed. 20a can be connected without difficulty by a welding method. And the softness | flexibility by having connected the center conductor 10a and the center conductor 20a with the welding method to the connection part (cable connection part 101) of the center conductors can be given, and it can function as a flexible joint.
The reason for connecting the power cable 10 and the power cable 20 by such a method is that the difference in outer diameter between the center conductors (the center conductor 10a and the center conductor 20a) is about 5.3 mm, whereas the conductor strands (conductors) The dimensional difference between the conductor strands is smaller than that between the center conductors, so that the strand diameter difference between the strand 1 and the conductor strand 2) is about 1/10 of 0.47 to 0.57 mm. by. That is, if the conductor strands having a smaller dimensional difference are considered as conductor strands having substantially the same diameter, they can be satisfactorily connected by adopting a welding method.
In addition, if the difference of the outer diameter of the center conductor 10a and the center conductor 20a is 7 mm or less, it will function more favorably as a flexible joint.

In particular, in the cable connection portion 101 of the submarine cable 100, the central conductors (the central conductor 10a and the central conductor 20a) formed by concentrically twisting a plurality of conductor wires (1, 2) with the same number of layers, respectively, corresponding layers. The ring-shaped welded portions 72 to 76 that are welded to each other are arranged so as to be shifted from each other in the longitudinal direction of the submarine cable 100, thereby dispersing the ring-shaped welded portions 72 to 76 in the longitudinal direction of the cable.
As described above, by dispersing the center welded portion 71 and the ring-shaped welded portions 72 to 76 in the longitudinal direction of the cable, the heat generated in the welded portion during energization can be dissipated without being partially concentrated. The benefits of being able to

Moreover, like the cable connection part 101 of the submarine cable 100, when the center welding part 71 and the ring-shaped welding parts 72-76 are disperse | distributed to the longitudinal direction of a cable, it originates in the partial concentration of a welding part. Since the increase in rigidity can be reduced, the merit of further improving the flexibility of the cable connecting portion 101 can be expected.
Moreover, since the center conductor 10a and the center conductor 20a are connected by a plurality of welds (the center weld 71 and the ring welds 72 to 76) dispersed in the longitudinal direction of the cable, stress is applied to the cable. In this case, stress can be prevented from concentrating on one welded portion, and a merit of reducing the risk of the cable connecting portion 101 breaking can be expected.
For example, if welds that tend to be thick overlap each other in a concentric manner on one surface that intersects the axial direction of the cable, the welds gather in one place, increasing the rigidity at that part. Therefore, there is a possibility that the flexibility of the cable connecting portion 101 may be lowered, and therefore it is preferable that the arrangement of the plurality of welded portions is dispersed.

On the other hand, as shown in FIG. 3, when the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the center conductors 10a and 20a are connected, the center conductor 10a and the center conductor 20a are collectively V-cut welded. When the welded portion 70 is formed, although the welding method is used for the connection, the welded portion 70 having a large central conductor size has increased rigidity and may have reduced flexibility. When stress is applied to the cable, the stress is concentrated on the welded portion 70 at one place, and the cable connecting portion 107 may be broken.
In particular, when a load is applied to a welded portion 70 in which central conductors having different outer diameters, such as the central conductor 10a and the central conductor 20a, are collectively connected, the welded portion 70 tends to be distorted and easily broken. is there.
Conventionally, there is no example of a flexible joint formed by V-cut welding of central conductors having different conductor cross-sectional areas. Normally, the connection between central conductors having different conductor cross-sectional areas is for connecting different diameter conductors. A technique of compression connection using a sleeve is employed.

Therefore, the submarine cable 100 according to the present invention is an epoch-making submarine cable in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductor are well connected, and the power cables having different conductor cross-sectional areas are connected to each other. It can be used as a submarine cable 100 having a flexible joint.
The submarine cable 100 may have a structure in which three or more power cables having different conductor cross-sectional areas of the central conductor are connected as a whole. For example, the power cable 20 is connected to both ends of the power cable 10, and a cable having a smaller conductor cross-sectional area of the center conductor is used closer to the center side than to the end side. That is, the submarine cable 100 has a conductor cross-sectional area of the center conductor that decreases from one end side toward the center side, and a conductor cross-sectional area of the center conductor increases from the center side toward the other end side.
The power cable 10 having a thin center conductor in the submarine cable 100 is laid on the seabed side, and the power cable 20 having a thick center conductor is laid on the buttock side and the landing part side. In this way, the submarine cable 100 to which the power cable is connected so as to have a conductor cross-sectional area corresponding to the thermal condition of the laying environment, like the conventional submarine cable, has a central conductor covering the entire length. Cost can be reduced as compared with a structure having a large conductor cross-sectional area.

(Modification 1)
The first embodiment is not limited to the above embodiment.
For example, as shown in FIGS. 4A and 4B, a submarine cable 100 having a cable connecting portion 102 that connects the power cable 10 and the power cable 20 may be used.
FIG. 4A is a side view showing the cable connecting portion 102 of the submarine cable 100 in a partial cross-sectional view. FIG. 4B is an explanatory diagram relating to a welded portion in the cable connecting portion 102 of the submarine cable 100.
Below, the connection method which forms the cable connection part 102 of the submarine cable 100 is demonstrated.

First, as shown in FIG. 4A, in the central conductor 10a of the power cable 10 to be the cable connecting portion 102, the second conductor strand layer 13, the fourth conductor strand layer 15, the center strand 11, the fifth strand. The conductor element wire 1 is cut so that the conductor element wire 1 protrudes longer in the order of the conductor element layer 16, the first conductor element layer 12, and the third conductor element layer 14. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (12-16) inclines so that an inclined surface may face an outer peripheral side of the center conductor 10a. I cut it.
Further, in the central conductor 20a of the power cable 20 serving as the cable connecting portion 102, as shown in FIG. 4A, the third conductor strand layer 24, the first conductor strand layer 22, and the fifth conductor strand layer 26 are provided. The conductor strand 2 is cut so that the conductor strand 2 protrudes longer in the order of the center strand 21, the fourth conductor strand layer 25, and the second conductor strand layer 23. In addition, the front-end | tip of the conductor strand 2 is cut diagonally, and in particular, the conductor strand 2 of each conductor strand layer (22-26) inclines so that an inclined surface may face an outer peripheral side of the center conductor 20a. I cut it.

And the conductor strand 1 of each conductor strand layer (12-16) other than the center strand 11 in the center conductor 10a of the power cable 10 is opened outward, and the center strand in the center conductor 20a of the power cable 20 is raised. In the state where the conductor strand 2 of each conductor strand layer (22 to 26) other than 21 is opened and raised outward, the center strand 11 of the center conductor 10a of the power cable 10 and the center of the center conductor 20a of the power cable 20 The element wire 21 is abutted, and the center element wire 11 (conductor element wire 1) and the center element wire 21 (conductor element wire 2) are connected by V-cut welding. In addition, the center welding part 71 is formed in the location which welded this center strand 11 and the center strand 21. FIG.
Then, the conductor strand 1 of each conductor strand layer (12-16) of the power cable 10 and the conductor strand 2 of each conductor strand layer (22-26) of the power cable 20 are twisted back in order, 1 conductor strand layer 12 and 1st conductor strand layer 22, 2nd conductor strand layer 13 and 2nd conductor strand layer 23, 3rd conductor strand layer 14 and 3rd conductor strand layer 24, 4th conductor The conductor element wire 1 and the conductor element wire 2 are connected by V-cut welding for each of the element layer 15 and the fourth conductor element layer 25, the fifth conductor element layer 16 and the fifth conductor element layer 26. .

And the location which welded the conductor wire 1 and the conductor strand 2 for every layer forms the concentric-circular weld part, and becomes the ring-shaped weld parts 72-76 in order of the 1st layer to the 5th layer. Yes.
As shown in FIGS. 4 (a) and 4 (b), ring-shaped welds 72 to 76 formed by welding the conductor wires 1 and 2 for each layer of the central conductors 10a and 20a are the lengths of the cables. The ring-shaped welded portion 74, the ring-shaped welded portion 72, the ring-shaped welded portion 76, the center welded portion 71, and the ring-shaped welded portion are arranged in the order shifted from the power cable 10 side to the power cable 20 side. The portion 75 and the ring-shaped welded portion 73 are arranged.

And the cable connection part 102 is formed by coat | covering the part which connected the center conductor 10a and the center conductor 20a by welding with a mold insulator.
In this way, the submarine cable 100 in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductors 10a and 20a are connected via the cable connecting portion 102 can be manufactured.

The submarine cable 100 having such a cable connection portion 102 is also a submarine cable in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 100 having a flexible joint.
In particular, the arrangement of the center welded portion 71 and the ring-shaped welded portions 72 to 76 in the cable connecting portion 101 described above is an arrangement in which the conductor strand layers are arranged in the layer order in the longitudinal direction of the cable. The portion 102 has a zigzag arrangement in which the ring-shaped welded portions 72 to 76 are on the power cable 10 side or on the power cable 20 side with the center welded portion 71 interposed therebetween.
By arranging the center welded portion 71 and the ring welded portions 72 to 76 in a staggered manner in this way, all the welded portions can be accommodated within a relatively compact range than the cable connecting portion 101. A merit that the cable connecting portion 102 is made small and can be easily covered with a mold insulator can be expected.

(Modification 2)
The first embodiment is not limited to the above embodiment.
For example, as shown in FIGS. 5A and 5B, a submarine cable 100 having a cable connecting portion 103 that connects the power cable 10 and the power cable 20 may be used.
FIG. 5A is a side view showing the cable connecting portion 103 of the submarine cable 100 in a partial cross-sectional view. FIG. 5B is an explanatory diagram relating to a welded portion in the cable connecting portion 103 of the submarine cable 100.
Below, the connection method which forms the cable connection part 103 of the submarine cable 100 is demonstrated.

First, in the center conductor 10a of the power cable 10 that becomes the cable connecting portion 103, as shown in FIG. 5A, the center strand 11, the first conductor strand layer 12, and the second conductor strand layer 13 are partially connected. The conductor wire 1 is cut in a state of being bundled. In addition, the conductor wire 1 of each layer is cut so that the conductor wire layer on the outer layer side of the second conductor wire layer 13 becomes shorter toward the outer peripheral layer. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and in particular, the conductor strand 1 of each conductor strand layer (14-16) inclines so that an inclined surface may face the outer peripheral side of the center conductor 10a. I cut it.
Further, in the central conductor 20a of the power cable 20 serving as the cable connecting portion 103, as shown in FIG. 5A, the central strand 21, the first conductor strand layer 22, and the second conductor strand layer 23 are partially connected. The conductor wire 2 is cut in a state of being bundled. In addition, the conductor strand 2 of each layer is cut so that the conductor strand 2 on the outer layer side of the second conductor strand layer 23 becomes longer toward the outer peripheral layer. In addition, the front-end | tip of the conductor strand 2 is cut diagonally, and especially the conductor strand 2 of each conductor strand layer (24-26) inclines so that an inclined surface may face an outer peripheral side of the center conductor 20a. I cut it.

And the conductor strand 2 of each conductor strand layer (24-26) other than the center strand 21, the 1st conductor strand layer 22, and the 2nd conductor strand layer 23 in the center conductor 20a of the power cable 20 is outside. In the opened state, the center strand 21, the first conductor strand layer 22, the second conductor strand layer 23 of the center conductor 20 a, and the center strand 11 and the first conductor strand of the center conductor 10 a of the power cable 10. The layer 12 and the second conductor strand layer 13 are abutted and the conductor strand 2 and the conductor strand 1 are connected by V-cut welding in a state where they are partially bundled. In addition, the weld part 77 is formed in this welding location.
Then, the conductor strand 2 of each conductor strand layer (24-26) is twisted back in order, and the 3rd conductor strand layer 14, the 3rd conductor strand layer 24, the 4th conductor strand layer 15, and the 4th conductor The conductor element wire 1 and the conductor element wire 2 are connected to each other of the element wire layer 25, the fifth conductor element wire layer 16, and the fifth conductor element wire layer 26 by V-cut welding.
The third conductor element layer 14 and the third conductor element layer 24, the fourth conductor element layer 15 and the fourth conductor element layer 25, the fifth conductor element layer 16 and the fifth conductor element layer 26, Concentric welds are formed at locations where the conductor wires 1 and 2 are welded for each layer, and ring welds 74 to 76 are provided in the order from the third layer to the fifth layer.

And the cable connection part 103 is formed by coat | covering the part which connected the center conductor 10a and the center conductor 20a by welding with a mold insulator.
In this way, the submarine cable 100 in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductors 10 a and 20 a are connected via the cable connecting portion 103 can be manufactured.

The submarine cable 100 having such a cable connecting portion 103 is also a submarine cable in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 100 having a flexible joint.
In particular, several conductor strand layers (in the second modification, the first conductor strand layers 12 and 22 and the second conductor strand layers 13 and 23) are partially bundled and welded, thereby reducing the number of weldings. It is possible to reduce the cable connection work time.
In the second modification, the conductor wire layers on the center side (first and second conductor wire layers 12, 13, 22, 23) are welded together, while the conductor wire layers on the outer peripheral side (third Since the conductor strand layers 14 and 24, the fourth conductor strand layers 15 and 25, and the fifth conductor strand layers 16 and 26) are welded layer by layer, the cable connecting portion 103 becomes flexible.
In addition, in order to make this connection part (cable connection part 103) of this center conductor function suitably as a flexible joint, the number of layers which bundle a conductor strand layer partially and weld is two layers or three layers. It is. If four or more conductor strand layers are partially bundled and welded, the rigidity of the welded portion increases and flexibility may be reduced.

(Modification 3)
The first embodiment is not limited to the above embodiment.
For example, as shown in FIGS. 6A and 6B, a submarine cable 100 having a cable connecting portion 104 that connects the power cable 10 and the power cable 20 may be used.
FIG. 6A is a side view showing the cable connecting portion 104 of the submarine cable 100 in a partial cross-sectional view. FIG. 6B is an explanatory diagram relating to a welded portion in the cable connecting portion 104 of the submarine cable 100.
Below, the connection method which forms the cable connection part 104 of the submarine cable 100 is demonstrated.

First, as shown in FIG. 6A, the conductor strand 1 of the center strand 11 is cut the longest in the center conductor 10a of the power cable 10 serving as the cable connecting portion 104.
Further, the conductor wire 1 is cut in a state where the first conductor wire layer 12 and the second conductor wire layer 13 are partially overlapped, and the third conductor wire layer 14 and the fourth conductor wire layer 15 are further cut. The conductor wire 1 is cut in a state in which are partially overlapped. At this time, the first conductor strand layer 12 and the second conductor strand layer 13 are cut longer than the third conductor strand layer 14 and the fourth conductor strand layer 15.
Further, the conductor wire 1 of the fifth conductor wire layer 16 is cut shortest.
In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (12-16) inclines so that an inclined surface may face an outer peripheral side of the center conductor 10a. I cut it.
In addition, in the central conductor 20a of the power cable 20 serving as the cable connecting portion 104, the conductor strand 2 of the center strand 21 is cut the shortest as shown in FIG.
Further, the conductor wire 2 is cut in a state where the first conductor wire layer 22 and the second conductor wire layer 23 are partially overlapped, and further the third conductor wire layer 24 and the fourth conductor wire layer 25. The conductor wire 2 is cut in a state in which are partially overlapped. At this time, the first conductor strand layer 22 and the second conductor strand layer 23 are cut shorter than the third conductor strand layer 24 and the fourth conductor strand layer 25.
Further, the conductor wire 2 of the fifth conductor wire layer 26 is cut longest.
In addition, the front-end | tip of the conductor strand 2 is cut diagonally, and in particular, the conductor strand 2 of each conductor strand layer (22-26) inclines so that an inclined surface may face an outer peripheral side of the center conductor 20a. I cut it.

And in the state which opened and raised the conductor strand 2 of each conductor strand layer (22-26) other than the center strand 21 in the center conductor 20a of the power cable 20, the center strand 21 of the center conductor 20a, The central strand 11 of the central conductor 10a of the power cable 10 is abutted, and the central strand 21 (conductor strand 2) and the central strand 11 (conductor strand 1) are connected by V-cut welding. A center welded portion 71 is a place where the center strand 21 and the center strand 11 are welded.
Thereafter, the conductor wires 2 of the first conductor strand layer 22 and the second conductor strand layer 23 of the center conductor 20a are twisted back, and the conductor strands of the first conductor strand layer 22 and the second conductor strand layer 23 are turned back on. The wire 2, the first conductor wire layer 12 of the central conductor 10a, and the conductor wire 1 of the second conductor wire layer 13 are connected by V-cut welding. In addition, the ring-shaped weld part 78 is formed in this welding location.
Further, the conductor wires 2 of the third conductor wire layer 24 and the fourth conductor wire layer 25 of the center conductor 20a are twisted back so that the conductor elements of the third conductor wire layer 24 and the fourth conductor wire layer 25 are The wire 2, the third conductor wire layer 14 of the central conductor 10a, and the conductor wire 1 of the fourth conductor wire layer 15 are connected by V-cut welding. In addition, a ring-shaped weld 79 is formed at the welded portion. Further, the conductor wire 2 of the fifth conductor strand layer 26 of the center conductor 20a is twisted back, so that the conductor strand of the fifth conductor strand layer 26 is twisted back. The wire 2 and the conductor wire 1 of the fifth conductor wire layer 16 of the center conductor 10a are connected by V-cut welding. This weld location is a ring-shaped weld 76.

And the cable connection part 104 is formed by coat | covering the part which connected the center conductor 10a and the center conductor 20a by welding with a mold insulator.
In this way, the submarine cable 100 in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductors 10a and 20a are connected via the cable connecting portion 104 can be manufactured.

The submarine cable 100 having such a cable connecting portion 104 is also a submarine cable in which the power cable 10 and the power cable 20 having different conductor cross-sectional areas of the central conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 100 having a flexible joint.
In particular, by welding several conductor wire layers partially together, the number of times of welding can be reduced, and the cable connection work time can be shortened.
Moreover, in this modification 3, in order to ensure the flexibility of the cable connection part 104, the outermost 5th conductor strand layers 16 and 26 were single-layer welded.
In addition, in order to make this connection part (cable connection part 103) of this center conductor function suitably as a flexible joint, the number of the layers which weld a conductor strand layer collectively is two layers (center) (3 layers if wire is included) If conductor strand layers of three layers or more (four or more layers if a central strand is included) are partially bundled and welded, the rigidity of the welded portion increases and flexibility may be reduced. is there.

(Embodiment 2)
Next, Embodiment 2 of the submarine cable according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

  FIG. 7A is a side view showing the cable connecting portion 201 of the submarine cable 200 in a partial cross-sectional view. FIG. 7B is an explanatory diagram relating to a welded portion in the cable connecting portion 201 of the submarine cable 200.

  As shown in FIGS. 7A and 7B, the submarine cable 200 includes one power cable 30 corresponding to the seabed portion side of the submarine cable 200 and the other power cable 30 corresponding to the saddle portion and the landing portion side of the submarine cable 200. The power cable 10 is connected.

As shown in FIGS. 7A and 7B, the power cable 30 includes a center conductor 30a composed of a plurality of conductor strands 3 and a cable insulator 30b covering the center conductor 30a. Yes.
Specifically, the power cable 30 includes a center strand 31, a first conductor strand layer 32, a second conductor strand layer 33, a third conductor strand layer 34, and a fourth conductor strand layer 35. A central conductor 30a is provided. The center conductor 30a has a structure in which a conductor strand 3 serving as a center strand 31 is a core, and a four-layer conductor strand layer is formed by concentrically twisting a plurality of conductor strands 3 on the outside. ing.
More specifically, the center conductor 30a of the power cable 30 is formed by concentrically twisting 61 conductor strands 3 having a strand diameter of 2.93 mm to form a center strand and four conductor strand layers. It is a circular compression conductor having a conductor cross-sectional area of 400 mm ² . The outer diameter of the center conductor 30a is about 24.1 mm.

As shown in FIGS. 7A and 7B, the power cable 10 includes a center conductor 10a composed of a plurality of conductor wires 1 and a cable insulator 10b covering the center conductor 10a. Yes.
Specifically, the power cable 10 includes a center strand 11, a first conductor strand layer 12, a second conductor strand layer 13, a third conductor strand layer 14, and a fourth conductor strand layer 15. The center conductor 10a including the fifth conductor element wire layer 16 is provided. The center conductor 10a has a structure in which a conductor element wire 1 to be the center element wire 11 is a core, and five conductor element wire layers are formed by concentrically twisting a plurality of conductor element wires 1 on the outer side. ing.
More specifically, the center conductor 10a of the power cable 10 is formed by concentrically twisting 91 conductor strands 1 having a strand diameter of 2.93 mm to form a center strand and five conductor strand layers. It is a circular compression conductor having a conductor cross-sectional area of 600 mm ² . The outer diameter of the center conductor 10a is about 29.5 mm.

As described above, the power cable 30 and the power cable 10 each have the central conductors 30a and 10a formed by concentrically twisting a plurality of conductor strands having the same strand diameter with different numbers of layers (four layers and five layers). It is a cable. The outer diameter difference between the central conductor 30a and the central conductor 10a is about 5.4 mm, and the outer diameter difference is designed to be 7 mm or less.
Note that the thicknesses of the cable insulators 30b and 10b of the power cable 30 and the power cable 10 are both 12 mm, and the power cable 30 and the power cable 10 are, for example, lead-coated cables with iron wire armor.

  Next, a connection method for connecting the power cable 30 and the power cable 10 will be described.

First, in the central conductor 30a of the power cable 30 serving as the cable connecting portion 201, as shown in FIG. 7A, the conductor strand 3 of the center strand 31 protrudes the longest, and the conductor strand layer on the outer layer side is longer. The conductor strands 3 are cut so that the conductor strands 3 are sequentially shortened. In addition, the front-end | tip of the conductor strand 3 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (32-35) inclines so that an inclined surface may face the outer peripheral side of the center conductor 30a. I cut it.
Further, in the central conductor 10a of the power cable 10 serving as the cable connecting portion 201, as shown in FIG. 7A, the conductor element wire 1 of the center element wire 11 is the shortest, and the conductor element wire layer on the outer layer side thereof, The conductor element wire 1 is cut so that the conductor element wire 1 protrudes longer in order. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (12-16) inclines so that an inclined surface may face an outer peripheral side of the center conductor 10a. I cut it.

And in the state which opened and raised the conductor strand 1 of each conductor strand layer (12-16) other than the center strand 11 in the center conductor 10a of the power cable 10, the center strand 11 of the center conductor 10a and electric power The central strand 31 of the central conductor 30a of the cable 30 is abutted, and the central strand 11 (conductor strand 1) and the central strand 31 (conductor strand 3) are connected by V-cut welding. In addition, the center welding part 81 is formed in the location which welded this center strand 11 and the center strand 31. FIG.
Then, the conductor wire 1 of each conductor strand layer (12-15) of the center conductor 10a is twisted back in order, and the first conductor strand layer 12, the first conductor strand layer 32, and the second conductor strand layer 13 are twisted back. And the second conductor strand layer 33, the third conductor strand layer 14, the third conductor strand layer 34, the fourth conductor strand layer 15 and the fourth conductor strand layer 35 for each layer. The conductor strand 3 is connected by V cut welding.
Further, since there is no fifth layer corresponding to the center conductor 30a side, the conductor wire 1 of the fifth conductor wire layer 16 remaining in the center conductor 10a is replaced with the fourth conductor wire of the center conductor 30a having a small number of layers. The outer peripheral surface of the layer 35 is connected by welding.
Here, the conductor strand 3 of each conductor strand layer (32 to 35) of the center conductor 30a of the power cable 30 and the conductor strand of each conductor strand layer (12 to 15) of the center conductor 10a of the power cable 10 The position where 1 is abutted corresponds to the circumference of a concentric circle with the central strand as the axis for each layer. The location where the conductor wire 3 and the conductor wire 1 are welded for each of these layers forms a concentric weld, and ring welds 82 to 85 are formed in order from the first layer to the fourth layer. Yes.
Moreover, the ring-shaped welding part 86 is formed in the location which welded the conductor wire 1 of the 5th conductor strand layer 16 of the center conductor 10a to the outer peripheral surface of the center conductor 30a. The ring-shaped welded portion 86 is polished by, for example, a belt sander or the like, and has an outer diameter ranging from the outer peripheral surface of the central conductor 10a (fifth conductor strand layer 16) to the outer peripheral surface of the central conductor 30a (fourth). The diameter is gradually reduced toward the conductor wire layer 35).
In addition, as shown to Fig.7 (a) (b), the ring-shaped welding parts 82-85 formed by welding the conductor strands 3 and 1 for every layer of the center conductors 30a and 10a, and a ring-shaped welding part 86 is arranged so as to be shifted from each other in the longitudinal direction of the cable, and the ring-shaped welds 86, 85, 84, 83, 82 on the outer layer side are arranged closer to the power cable 30.

And the cable connection part 201 is formed by coat | covering the part which connected the center conductor 30a and the center conductor 10a by welding further with a mold insulator.
Thus, the submarine cable 200 in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductors 30a and 10a are connected via the cable connection portion 201 can be manufactured.

As described above, when the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the center conductors 30a and 10a are connected to each other, the conductor strand 3 as the minimum unit constituting the center conductor 30a and the center conductor 10a are configured. Welding conductor strands (conductor strand 3 and conductor strand 1) by using a method in which the conductor strand 1 which is the smallest unit is divided into a plurality of groups for each concentric twisted layer and connected by welding. The center conductor 30a and the center conductor 10a can be connected by a welding method so that a plurality of small welding locations are formed. Further, the outer conductor wire 1 remaining in the one central conductor 10a can be connected to the outer peripheral surface of the other central conductor 30a by welding. And the softness | flexibility by having connected the center conductor 30a and the center conductor 10a with the welding method to the connection part (cable connection part 201) of the center conductors can be given, and it can function as a flexible joint.
The reason for connecting the power cable 30 and the power cable 10 by such a method is that there is an outer diameter difference of about 5.4 mm between the center conductors (the center conductor 30a and the center conductor 10a), whereas the conductor strands ( This is because the conductor strand 3 and the conductor strand 1) have the same strand diameter (2.93 mm) and no difference in strand diameter. In other words, the conductor strand 3 and the conductor strand 1 having the same strand diameter are inevitably left over by one central conductor after being well connected from the inner layer side by a normal welding method for each concentric twisted layer. In addition, by connecting the conductor wire on the outer layer side to the outer peripheral surface of the other central conductor by welding, cable connection employing a welding method can be achieved.
In addition, if the difference of the outer diameter of the center conductor 30a and the center conductor 10a is 7 mm or less, it will function more favorably as a flexible joint.

In particular, in the cable connection portion 201 of the submarine cable 200, ring-shaped weld portions 82 to 86 in which a plurality of conductor strands (conductor strand 3 and conductor strand 1) are welded to each other for each concentric twist layer are connected to the submarine cable. The ring-shaped welds 82 to 86 are dispersed in the longitudinal direction of the cable by disposing them in the longitudinal direction of 200.
Thus, if the center welding part 81 and the ring-shaped welding parts 82-86 are disperse | distributed to the longitudinal direction of a cable, it can thermally radiate, without concentrating the heat which generate | occur | produced in the welding part at the time of electricity supply. Benefits can be expected.

Further, in the cable connecting portion 201 of the submarine cable 200, the conductor wire 1 of the fifth conductor wire layer 16 remaining in the center conductor 10a is welded to the outer peripheral surface of the fourth conductor wire layer 35 of the center conductor 30a. By connecting them, the conductor cross-sectional area at the cable connecting portion 201 is made larger to reduce heat generation during energization.
When there is no need to reduce heat generation during energization, the conductor wire 1 of the fifth conductor wire layer 16 remaining in the center conductor 10a is connected to the outer peripheral surface of the fourth conductor wire layer 15 of the center conductor 10a. You may weld to.

Moreover, if the center welding part 81 and the ring-shaped welding parts 82-86 are disperse | distributed to the longitudinal direction of a cable like the cable connection part 201 of the submarine cable 200, the rigidity increase resulting from the partial concentration of a welding part will be carried out. Therefore, the merit of further improving the flexibility of the cable connecting portion 201 can be expected.
Further, since the central conductor 30a and the central conductor 10a are connected by a plurality of welded portions (the central welded portion 81 and the ring-shaped welded portions 82 to 86) dispersed in the longitudinal direction of the cable, stress is applied to the cable. In this case, it is possible to expect the merit that the breaking strength of the cable connecting portion 201 can be improved without stress being concentrated on one welded portion.
For example, if welded parts that tend to be thick are partially gathered, such as overlapping concentrically on one surface that intersects the axial direction of the cable, the rigidity at that part increases and cable connection Since the flexibility of the part 201 may be lowered, it is preferable that the arrangement of the plurality of welded parts is dispersed.

On the other hand, as shown in FIG. 8, when connecting the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the center conductors 30a and 10a, the center conductor 30a and the center conductor 10a are collectively V-cut welded. When the welded portion 80 is formed, although the welding method is used for the connection, the welded portion 80 having a large central conductor size has increased rigidity and may have reduced flexibility. Then, when stress is applied to the cable, the stress is concentrated on the welded portion 80 at one place, and thus the cable connecting portion 208 may be broken.
In particular, when a load is applied to a welded portion 80 in which central conductors having different outer diameters, such as the central conductor 30a and the central conductor 10a, are collectively connected, the welded portion 80 tends to be distorted and easily broken. is there.
Conventionally, there is no example of a flexible joint formed by V-cut welding of central conductors having different conductor cross-sectional areas. Normally, the connection between central conductors having different conductor cross-sectional areas is for connecting different diameter conductors. A technique of compression connection using a sleeve is employed.

Therefore, the submarine cable 200 according to the present invention is an epoch-making submarine cable in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductor are well connected, and the power cables having different conductor cross-sectional areas are connected to each other. It can be used as a submarine cable 200 having a flexible joint.
The submarine cable 200 as a whole is formed by connecting three or more power cables having different conductor cross-sectional areas of the central conductor. For example, the power cable 30 is connected to both ends of the power cable 30. That is, a cable having a smaller conductor cross-sectional area of the center conductor is used for the power cable 30 on the center side than the power cable 10 on the end side in the submarine cable 200. That is, the submarine cable 200 is a cable in which the conductor cross-sectional area of the center conductor decreases from one end side toward the center side, and the conductor cross-sectional area of the center conductor increases from the center side toward the other end side.
The power cable 30 having a relatively thin center conductor in the submarine cable 200 is laid on the seabed side, and the power cable 10 having a relatively thick center conductor is laid on the buttock side and the landing part side. Thus, if the submarine cable 200 is connected to a power cable having a conductor cross-sectional area corresponding to the thermal conditions of the laying environment, the center is determined in consideration of the environment of the conventional submarine cable, that is, the landing part. The cost can be reduced compared to a conventional submarine cable having a structure in which the conductor cross-sectional area of the conductor is adopted over the entire length.

  In addition, in this Embodiment 2, although the strand diameter of the conductor strand 1 and the conductor strand 3 is the same, the strand diameters of these conductor strand 1 and the conductor strand 3 may differ.

(Modification 1)
The second embodiment is not limited to the above embodiment.
For example, as shown in FIGS. 9A and 9B, a submarine cable 200 having a cable connecting portion 202 that connects the power cable 30 and the power cable 10 may be used.
FIG. 9A is a side view showing the cable connecting portion 202 of the submarine cable 200 in a partial cross-sectional view. FIG. 9B is an explanatory diagram relating to a welded portion in the cable connecting portion 202 of the submarine cable 200.
Below, the connection method which forms the cable connection part 202 of the submarine cable 200 is demonstrated.

First, in the central conductor 30a of the power cable 30 serving as the cable connecting portion 202, as shown in FIG. 9A, the second conductor strand layer 33, the fourth conductor strand layer 35, the center strand 31, the third strand The conductor strand 3 is cut so that the conductor strand 3 protrudes in the order of the conductor strand layer 34 and the first conductor strand layer 32. In addition, the front-end | tip of the conductor strand 3 is cut diagonally, and especially the conductor strand 3 of each conductor strand layer (32-35) inclines so that an inclined surface may face an outer peripheral side of the center conductor 30a. I cut it.
Further, in the central conductor 10a of the power cable 10 serving as the cable connection portion 202, as shown in FIG. 9A, the fifth conductor strand layer 16, the first conductor strand layer 12, and the third conductor strand layer 14 are provided. The conductor strand 1 is cut so that the conductor strand 1 protrudes longer in the order of the center strand 11, the fourth conductor strand layer 15, and the second conductor strand layer 13. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and especially the conductor strand 1 of each conductor strand layer (12-16) inclines so that an inclined surface may face an outer peripheral side of the center conductor 10a. I cut it.

Then, the conductor strand 3 of each conductor strand layer (32 to 35) other than the center strand 31 in the center conductor 30a of the power cable 30 is opened outward, and the center strand in the center conductor 10a of the power cable 10 is raised. 11 with the conductor strands 1 of the conductor strand layers (12 to 16) other than 11 opened outward, and the center strand 31 of the center conductor 30a of the power cable 30 and the center of the center conductor 10a of the power cable 10 The element wire 11 is brought into contact with each other, and the center element wire 31 (conductor element wire 3) and the center element wire 11 (conductor element wire 1) are connected by V-cut welding. In addition, the center welding part 81 is formed in the location which welded this center strand 31 and the center strand 11.
Thereafter, the conductor strand 3 of each conductor strand layer (32 to 35) of the power cable 30 and the conductor strand 1 of each conductor strand layer (12 to 15) of the power cable 10 are twisted back in order, 1 conductor strand layer 32 and 1st conductor strand layer 12, 2nd conductor strand layer 33 and 2nd conductor strand layer 13, 3rd conductor strand layer 34 and 3rd conductor strand layer 14, 4th conductor The conductor strand 3 and the conductor strand 1 are connected to each other of the strand layer 35 and the fourth conductor strand layer 15 by V-cut welding.
There is no fifth layer on the center conductor 30a side, and the conductor element wire 1 of the fifth conductor element layer 16 of the center conductor 10a remains. Therefore, the conductor wire 1 of the fifth conductor strand layer 16 of the center conductor 10a is connected to the outer peripheral surface of the fourth conductor strand layer 35 of the center conductor 30a with a small number of layers by welding.

The portions where the conductor wire 3 and the conductor wire 1 are welded for each layer form a concentric weld, and the ring welds 82 to 85 are formed in order from the first layer to the fourth layer. Further, a ring-shaped welded portion 86 is formed on the outer peripheral surface of the center conductor.
In addition, as shown to Fig.9 (a) (b), the ring-shaped welding parts 82-85 formed by welding the conductor strands 3 and 1 for every layer of center conductor 30a, 10a, and a ring-shaped welding part 86 is arranged so as to be shifted from each other in the longitudinal direction of the cable, and from the power cable 30 side toward the power cable 10 side, a ring-shaped welded portion 86, a ring-shaped welded portion 82, a ring-shaped welded portion 84, A central weld 81, a ring weld 85, and a ring weld 83 are sequentially arranged.

A portion where the central conductor 30a and the central conductor 10a are connected by welding is covered with a mold insulator to form the cable connection portion 202.
Thus, the submarine cable 200 in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductors 30a and 10a are connected via the cable connecting portion 202 can be manufactured.

The submarine cable 200 having such a cable connecting portion 202 is also a submarine cable in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 200 having a flexible joint.
In particular, the arrangement of the center welded portion 81 and the ring-shaped welded portions 82 to 86 in the cable connecting portion 201 shown in FIG. 7 described above is an arrangement arranged in the layer order of the conductor wire layers in the longitudinal direction of the cable. In the cable connecting portion 202 shown in FIG. 9, the ring-shaped welded portions 82 to 86 sandwich the center welded portion 81 and are arranged in a zigzag manner such that they are closer to the power cable 30 side or closer to the power cable 10 side. Yes.
Thus, when the arrangement of the center welded portion 81 and the ring-shaped welded portions 82 to 86 is arranged in a staggered manner as in the cable connecting portion 202 shown in FIG. 9, it is relatively more compact than the cable connecting portion 201 shown in FIG. 7. Since all the welded parts can be accommodated within a certain range, it is possible to expect a merit that the cable connecting part 202 can be made small and easily covered with the mold insulator.

(Modification 2)
The second embodiment is not limited to the above embodiment.
For example, as shown in FIGS. 10A and 10B, a submarine cable 200 having a cable connecting portion 203 that connects the power cable 30 and the power cable 10 may be used.
FIG. 10A is a side view showing the cable connecting portion 203 of the submarine cable 200 in a partial cross-sectional view. FIG. 10B is an explanatory diagram relating to a welded portion in the cable connecting portion 203 of the submarine cable 200.
Below, the connection method which forms the cable connection part 203 of the submarine cable 200 is demonstrated.

First, in the central conductor 30a of the power cable 30 that becomes the cable connecting portion 203, as shown in FIG. 10 (a), the central strand 31, the first conductor strand layer 32, and the second conductor strand layer 33 are partially connected. The conductor wire 3 is cut in a state of being bundled. Further, the conductor wire 3 of the third conductor wire layer 34 is cut shorter than the second conductor wire layer 33. Further, the conductor wire 3 of the fourth conductor strand layer 35 is cut longer than the second conductor strand layer 33. In addition, the front-end | tip of the conductor strand 3 is cut diagonally, and especially the conductor strand 3 of each conductor strand layer (34-35) inclines so that an inclined surface may face the outer peripheral side of the center conductor 30a. I cut it.
Further, in the central conductor 10a of the power cable 10 serving as the cable connecting portion 203, as shown in FIG. 10 (a), the central strand 11, the first conductor strand layer 12, and the second conductor strand layer 13 are partially connected. The conductor wire 1 is cut in a state of being bundled. Further, the conductor wire 1 of the third conductor wire layer 14 is cut longer than the second conductor wire layer 13. Further, the conductor wire 1 of the fourth conductor wire layer 15 is cut shorter than the second conductor wire layer 13. The fifth conductor strand layer 16 is cut longer than the third conductor strand layer 14. In addition, the front-end | tip of the conductor strand 1 is cut diagonally, and in particular, the conductor strand 1 of each conductor strand layer (14-16) inclines so that an inclined surface may face the outer peripheral side of the center conductor 10a. I cut it.

And the conductor strand 3 of each conductor strand layer (34-35) other than the center strand 31, the 1st conductor strand layer 32, and the 2nd conductor strand layer 33 in the center conductor 30a of the electric power cable 30 is outside. Open up. Further, the conductor wires 1 of the respective conductor wire layers (14 to 16) other than the center wire 11, the first conductor wire layer 12, and the second conductor wire layer 13 in the center conductor 10a of the power cable 10 are outward. Open up. With the conductor strand 3 and the conductor strand 1 opened and opened, the center strand 31, the first conductor strand layer 32, the second conductor strand layer 33 of the center conductor 30a, and the center strand of the center conductor 10a 11, the first conductor strand layer 12 and the second conductor strand layer 13 are butted together and the conductor strand 3 and the conductor strand 1 are connected by V-cut welding in a state where they are partially bundled. This weld location forms a weld 87.
Thereafter, the conductor wire 3 of the third conductor wire layer 34 and the conductor wire 1 of the third conductor wire layer 14 are twisted back and connected by V-cut welding. This weld location forms a ring-shaped weld 84.
Further, the conductor strand 3 of the fourth conductor strand layer 35 and the conductor strand 1 of the fourth conductor strand layer 15 are twisted back and connected by V-cut welding. This weld location forms a ring-shaped weld 85.
Further, there is no fifth layer on the center conductor 30a side, and the conductor wire 1 of the fifth conductor wire layer 16 of the center conductor 10a remains. Therefore, the conductor wire 1 of the fifth conductor strand layer 16 of the center conductor 10a is connected to the outer peripheral surface of the fourth conductor strand layer 35 of the center conductor 30a with a small number of layers by welding. In addition, this welding location forms the ring-shaped welding part 86. FIG.

And the part which connected the center conductor 30a and the center conductor 10a by welding is coat | covered with a mold insulator, and the cable connection part 203 is formed.
In this way, it is possible to manufacture the submarine cable 200 in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductors 30a and 10a are connected via the cable connecting portion 203.

The submarine cable 200 having such a cable connection portion 203 is also a submarine cable in which the power cable 30 and the power cable 10 having different conductor cross-sectional areas of the central conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 200 having a flexible joint.
In particular, the number of weldings can be reduced and the cable connection work time can be shortened by partially bundling and welding several conductor wire layers. Moreover, the flexibility of the cable connection part 203 is ensured by carrying out the single layer welding of the 3rd conductor strand layers 14 and 34 and the 4th conductor strand layers 15 and 35 of an outer peripheral side for each layer, respectively. .
In addition, in order to make this connection part (cable connection part 203) of these center conductors function as a flexible joint suitably, the number of layers which bundle and weld a conductor strand layer is three layers. If four or more conductor strand layers are partially bundled and welded, the rigidity of the welded portion increases and flexibility may be reduced.

(Embodiment 3)
Next, Embodiment 3 of the submarine cable according to the present invention will be described. In addition, the same code | symbol is attached | subjected to the same part as Embodiment 1, and only a different part is demonstrated.

  FIG. 11 is a side view showing the cable connecting portion 301 of the submarine cable 300. FIG. 12 is an explanatory diagram relating to a welded portion in the cable connecting portion 301 of the submarine cable 300.

  As shown in FIGS. 11 and 12, the submarine cable 300 includes one power cable 50 corresponding to the seabed portion side of the submarine cable 300 and the other power cable 60 corresponding to the saddle and landing portions of the submarine cable 300. Will be connected.

As shown in FIGS. 11 and 12, the power cable 50 includes a center conductor 50a and a cable insulator 50b that covers the center conductor 50a.
The center conductor 50a of the power cable 50 is a divided conductor formed by twisting five segments having a substantially sector cross section. Each of the segments 51 to 55 is formed by twisting a predetermined number of conductor strands 5 into a sector shape.
Center conductor 50a of the power cable 50, the conductor cross-sectional area is divided into five conductors of 1200 mm ^2. The outer diameter of the center conductor 50a is 42.4 mm.

As shown in FIGS. 11 and 12, the power cable 60 includes a center conductor 60a and a cable insulator 60b that covers the center conductor 60a.
The central conductor 60a of the power cable 60 is a divided conductor formed by twisting five segments having a substantially fan-shaped cross section. Each of the segments 61 to 65 is formed by twisting a predetermined number of conductor strands 6 into a sector shape.
The central conductor 60a of the power cable 60 is a five-divided conductor having a conductor cross-sectional area of 1600 mm ² . The outer diameter of the center conductor 60a is 49.0 mm.

Thus, the power cable 50 and the power cable 60 are power cables each having the center conductors 50a and 60a formed by twisting the same number of segments (5 in the third embodiment) having different cross-sectional areas. The outer diameter difference between the central conductor 50a and the central conductor 60a is 6.6 mm, and the outer diameter difference is designed to be 7 mm or less.
The thicknesses of the cable insulators 50b and 60b of the power cable 50 and the power cable 60 are both 12 mm, and the power cable 50 and the power cable 60 are, for example, leaded cables with iron wire armor.

  Next, a connection method for connecting the power cable 50 and the power cable 60 will be described.

First, in the central conductor 50a of the power cable 50 serving as the cable connecting portion 301, as shown in FIGS. 11 and 12, the conductor element is formed so as to be longer in the order of the segment 52, the segment 53, the segment 51, the segment 54, and the segment 55. Cut line 5 (segments 51-55). The tip of each segment is cut obliquely for V-cut welding.
Further, in the central conductor 60a of the power cable 60 serving as the cable connecting portion 301, as shown in FIGS. 11 and 12, the conductor element is extended in the order of the segment 65, the segment 64, the segment 61, the segment 63, and the segment 62. Cut line 6 (segments 61-65). The tip of each segment is cut obliquely for V-cut welding.

And in the area | region used as the cable connection part 301 in the center conductor 50a of the electric power cable 50, the segment 51, the segment 52, and the segment 55 which are arrange | positioned comparatively upward are opened and raised. Further, the segment 61, the segment 62, and the segment 65, which are disposed on the relatively upper side, are opened up in the region that is the cable connection portion 301 in the central conductor 60a of the power cable 60. In the state of being opened and raised in this manner, the lower segment 53 and the segment 63, and the segment 54 and the segment 64 are brought into contact with each other and connected by V-cut welding. A welded portion 93 is formed at a location where the segment 53 and the segment 63 are welded, and a welded portion 94 is formed at a location where the segment 54 and the segment 64 are welded.
Thereafter, the segment 51, the segment 52, and the segment 55 of the central conductor 50a are untwisted, and the segment 61, the segment 62, and the segment 65 of the central conductor 60a are untwisted so that the segment 51 and the segment 61, the segment 52 and the segment 62, and the segment 55 And segment 65 are connected to each other by V-cut welding. A location where the segment 51 and the segment 61 are welded forms a welded portion 91, a location where the segment 52 and the segment 62 are welded forms a welded portion 92, and a location where the segment 55 and the segment 65 are welded is a welded portion 95. Is forming.
As shown in FIGS. 11 and 12, the welded portions 91 to 95 formed by welding the conductor wires 5 and 6 to the segments of the central conductors 50a and 60a are displaced from each other in the longitudinal direction of the cable. The arrangement is taken, and the welding portions 95, 94, 91, 93, 92 are arranged in the order of the power cable 50.

A portion where the center conductor 50a and the center conductor 60a are connected by welding is covered with a mold insulator to form the cable connection portion 301.
In this way, it is possible to manufacture the submarine cable 300 in which the power cable 50 and the power cable 60 having different conductor cross-sectional areas of the central conductors 50a and 60a are connected via the cable connecting portion 301.

As described above, when the power cable 50 and the power cable 60 having different conductor cross-sectional areas of the center conductors 50a and 60a are connected, the segments 51 to 55 (conductor wire 2) constituting the center conductor 50a and the center conductor 60a are connected. A method of connecting the segments 61 to 65 (conductor strands 6) to each other by welding is repeated, and the segments are repeatedly welded to form a plurality of small welding locations, so that the center conductor 50a and the center conductor 60a are formed. Can be connected by a welding method. The connecting portion (cable connecting portion 301) between the central conductors is flexible and functions as a flexible joint.
The reason why the power cable 50 and the power cable 60 are connected by such a method is that the segments (segments 51 to 55 and segments 61 to 65) have a cross-sectional area rather than the center conductors (center conductor 50a and center conductor 60a). This is because the difference is small. In other words, segments having a smaller difference in cross-sectional area can be regarded as divided conductors having substantially the same diameter and can be connected well by adopting a welding method.
In addition, if the difference of the outer diameter of the center conductor 50a and the center conductor 60a is 7 mm or less, it will function more favorably as a flexible joint.

In particular, in the cable connection portion 301 of the submarine cable 300, the weld portions 91 to 95 in which the same number of the segments 51 to 55 and the segments 61 to 65 are connected by welding are shifted from each other in the longitudinal direction of the submarine cable 300. Thus, the welds 91 to 95 are dispersed in the longitudinal direction of the cable.
Thus, by dispersing the plurality of welded portions 91 to 95 in the longitudinal direction of the cable, a merit that heat can be radiated without partially concentrating the heat generated in the welded portion when energized can be expected. .

Moreover, since the several welding parts 91-95 are disperse | distributed to the longitudinal direction of a cable like the cable connection part 301 of the submarine cable 300, since the rigidity increase resulting from the partial concentration of a welding part can be reduced. The merit of further improving the flexibility and flexibility of the cable connecting portion 301 can be expected.
Further, since the central conductor 50a and the central conductor 60a are connected by a plurality of welded portions 91 to 95 dispersed in the longitudinal direction of the cable, when stress is applied to the cable, stress is applied to one welded portion. Therefore, a merit of reducing the breakage of the cable connecting portion 301 can be expected.
For example, if the welded portion, which tends to be thick, partially gathers on one surface that intersects the axial direction of the cable, the rigidity at that portion increases, and the cable connecting portion 301 Since there exists a possibility that flexibility may fall, it is preferable that arrangement | positioning of several welding parts is disperse | distributing.

On the other hand, as shown in FIG. 13, when connecting the power cable 50 and the power cable 60 having different conductor cross-sectional areas of the center conductors 50a and 60a, the center conductor 50a and the center conductor 60a are collectively V-cut welded. When the welded portion 90 is formed, the welding method is used for the connection, but the welded portion 90 having a large central conductor size has increased rigidity and may have reduced flexibility. When the stress is applied to the cable, the stress may be concentrated on the welded portion 90 at the one location, so that the cable connecting portion 309 may be broken.
In particular, when a load is applied to a welded portion 90 in which central conductors having different outer diameters, such as the central conductor 50a and the central conductor 60a, are collectively connected, the welded portion 90 tends to be distorted and easily broken. is there.
Conventionally, there is no example of a flexible joint formed by V-cut welding of central conductors having different conductor cross-sectional areas. Normally, the connection between central conductors having different conductor cross-sectional areas is for connecting different diameter conductors. A technique of compression connection using a sleeve is employed.

(Modification 1)
The third embodiment is not limited to the above embodiment.
For example, as illustrated in FIGS. 14 and 15, a submarine cable 300 having a cable connecting portion 302 that connects the power cable 50 and the power cable 60 may be used.
FIG. 14 is a side view showing the cable connecting portion 302 of the submarine cable 300. FIG. 15 is an explanatory diagram relating to a welded portion in the cable connection portion 302 of the submarine cable 300.
Below, the connection method which forms the cable connection part 302 of the submarine cable 300 is demonstrated.

First, in the central conductor 50a of the power cable 50 serving as the cable connecting portion 302, as shown in FIGS. 14 and 15, the conductor strands 5 (51, 51, 51) are formed so that the segments 51, 53, and 54 are relatively long. 53, 54), and the conductor wire 5 (52, 55) is cut so that the segments 52 and 55 are relatively short. The tip of the conductor wire 5 is cut obliquely for V-cut welding.
In addition, in the central conductor 60a of the power cable 60 serving as the cable connecting portion 302, as shown in FIGS. 14 and 15, the conductor strands 6 (61, 61, 61) are arranged so that the segments 61, 63, and 64 are relatively long. 63, 64), and the conductor wire 6 (62, 65) is cut so that the segments 62 and 65 are relatively short. The tip of the conductor wire 6 is cut obliquely for V-cut welding.
In particular, the segment pieces 562 and 565 which are segments of the segment 62 and the segment 65 cut relatively short are aligned to a predetermined length.

Then, in the region that becomes the cable connection portion 302 in the central conductor 50a of the power cable 50, the segment 51 is opened and raised outward, and in the region that becomes the cable connection portion 302 in the central conductor 60a of the power cable 60, the segment 61 is outside. Then, the segment 53 and the segment 63, and the segment 54 and the segment 64 are brought into contact with each other and connected by V-cut welding. At this time, the segment 53 and the segment 63 can be welded from between the segment 52 and the segment 62 cut relatively short. Similarly, the segment 54 and the segment 64 can be welded from between the segment 55 and the segment 65 cut relatively short. A welded portion 93 is formed at a location where the segment 53 and the segment 63 are welded, and a welded portion 94 is formed at a location where the segment 54 and the segment 64 are welded.
Thereafter, the segment 51 of the central conductor 50a is twisted back, and the segment 61 of the central conductor 60a is twisted back to connect the segment 51 and the segment 61 by V-cut welding. A welded portion 91 is formed at a location where the segment 51 and the segment 61 are welded.
Further, a segment piece 562 is inserted between the segment 52 of the center conductor 50a and the segment 62 of the center conductor 60a, and one end portion of the segment piece 562 and the segment 52, and the other end portion and the segment 62, Each is connected by V-cut welding. A location where both ends of the segment piece 562 are welded forms a welded portion 922. Similarly, a segment piece 565 is inserted between the segment 55 of the center conductor 50a and the segment 65 of the center conductor 60a, and one end of the segment piece 565 and the segment 55 are connected to each other. Each is connected by V-cut welding. A portion where both ends of the segment piece 565 are welded forms a welded portion 955. In the first modification of the third embodiment, the segment piece is cut out from the segment of the central conductor 60a of the power cable 60 having a large cross-sectional area. However, the segment piece is removed from the segment of the central conductor 50a of the power cable 50 having a small cross-sectional area. The segment piece may be cut out and used for interrupt welding.
As shown in FIGS. 14 and 15, welded portions 91, 93, 94, 922, and 955 formed by welding the conductor wires 5 and 6 to the segments of the central conductors 50a and 60a are connected to the cable. Arranged staggered in the longitudinal direction

And the cable connection part 302 is formed by coat | covering the part which connected the center conductor 50a and the center conductor 60a by welding with a mold insulator.
In this way, the submarine cable 300 in which the power cable 50 and the power cable 60 having different conductor cross-sectional areas of the central conductors 50a and 60a are connected via the cable connecting portion 302 can be manufactured.

The submarine cable 300 having such a cable connection portion 302 is also a submarine cable in which the power cable 50 and the power cable 60 having different conductor cross-sectional areas of the center conductor are connected well, and connects power cables having different conductor cross-sectional areas. It can be used as a submarine cable 300 having a flexible joint.
In particular, in the case of the cable connecting portion 301 described above, although there are few welded portions, the five welded portions 91 to 95 are arranged in a relatively wide range in the longitudinal direction of the cable. Although there are seven welds (91, 93, 94, 922, 922, 955, 955), the welds are relatively gathered in a relatively narrow range in the longitudinal direction of the cable. Specifically, the welded portion 91, the welded portion 93, and the welded portion 94 are relatively arranged in the longitudinal direction of the cable, and similarly, the welded portion 922 and the welded portion 955 are relatively aligned with the longitudinal direction of the cable. Arranged in the same direction.
As described above, since the cable connecting portion 302 can fit all the welded portions 91, 93, 94, 922, and 955 in a relatively compact range, the cable connecting portion 302 is made small and covered with a mold insulator. Benefits can be expected.

  As described above, the technology for manufacturing the submarine cables 100, 200, and 300 in the first to third embodiments, that is, the method of connecting the power cable 10 and the power cable 20 having different conductor cross-sectional areas (the first embodiment), the conductor cross-sectional area If the method of connecting the power cable 30 and the power cable 10 (second embodiment) and the method of connecting the power cable 50 and the power cable 60 having different conductor cross-sectional areas (third embodiment) are appropriately implemented, the above-described FIG. The submarine cable C shown can be manufactured.

The application of the present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the spirit of the present invention.
In the above explanation, the explanation was made on the assumption that the power cable is connected at the factory. However, the submarine cable for the entire length of the laying route may not be wound around the drum or the turntable. It may be necessary to connect the power cables on the ship. The present invention also includes a submarine cable connected on the ship in this way.

  Further, the welding of the conductor strands may be performed not for each strand but for each bundle of a plurality of conductor strands.

100, 200 Submarine cable 101-104 Cable connection part 201-203 Cable connection part 1, 2, 3 Conductor wire 10, 20, 30 Power cable 10a, 20a, 30a Center conductor 10b, 20b, 30b Cable insulator 11, 21 31 Core wire 12-16 Conductor wire layer 22-26 Conductor wire layer 32-35 Conductor wire layer 71 Center welded portion 72-76 Ring-shaped welded portion 77 Welded portion 78, 79 Ring-shaped welded portion 81 Center welded Portion 82 to 86 Ring welded portion 87 Welded portion 300 Submarine cable 301 to 302 Cable connecting portion 5 and 6 Conductor wire 51 to 55 Segment 61 to 65 Segment 562, 565 Segment piece 91 to 95, 922, 955 Welded portion C Submarine cable

Claims (4)

A submarine cable in which a plurality of conductor wires each having a central conductor having a different conductor cross-sectional area are welded by dividing the plurality of conductor wires constituting the central conductor into several parts and connected to each other. Because
Both connected cables have a central conductor formed by concentrically twisting conductor strands having different strand diameters with the same number of layers,
A submarine cable , wherein the conductor wires are concentrically welded for each layer corresponding to the central conductors . A submarine cable in which a plurality of conductor wires each having a central conductor having a different conductor cross-sectional area are welded by dividing the plurality of conductor wires constituting the central conductor into several parts and connected to each other. Because
Both connected cables have a central conductor formed by concentrically twisting conductor wires having the same wire diameter with different numbers of layers,
The conductor wires are welded concentrically for each corresponding layer between the center conductors, and the outer conductor wire remaining in the center conductor with a large number of layers is welded to the outer peripheral surface of the center conductor with a small number of layers. Submarine cable characterized by that . 3. The submarine cable according to claim 1, wherein the welded portions where the conductor strands are welded for each layer of the central conductors are arranged so as to be shifted from each other in the longitudinal direction of the cable. Submarine cable. The submarine cable consists of 3 or more cables.
The submarine cable according to any one of claims 1 to 3, wherein a cable having a smaller conductor cross-sectional area of the central conductor is used in the center side cable than the end side cable.

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