JPH063694B2 - Method for manufacturing conductor for power cable - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a power cable conductor.

[Conventional technology and problems] For large conductors for power cables, a large number of strands are twisted together, compression-molded, and preformed with a segment of, for example, 4
It is formed by a grouping machine of 9 to 9 pieces, and is thereby finished into a circular conductor having a required cross-sectional area.

Conventionally, bare copper wires have been used as the wires forming these segments, but when a large conductor having a cross-sectional area of 2000 mm ² or more is used, the AC resistance increases due to the so-called skin effect.

Therefore, measures have been taken to reduce the skin effect of covering the skin of each strand with a coating having a resistance higher than that of a copper conductor and transferring the current from the strand to the strand to increase the AC resistance.

As one means for applying such a coating, for example, a method is known in which a copper conductor is dipped in an alkaline water-soluble chemical to generate cupric oxide on the surface of the wire. It is called the oxide film method.

This wet oxide film method is shown in, for example, Japanese Patent Laid-Open No. 56-141117, and specifically, to treat the contact portion between the individual wires so that the chemical solution for forming an oxide film is well spread,
It was carried out at the stage of a segment in which many strands were twisted together.

However, if it is carried out at the segment stage, the number of divisions of the conductors that are aggregated into a circle, that is, the number of segments is n (n
Is usually 4 to 9), for example, in order to make a single-length 1 conductor, it is necessary to pass a single-length 1 segment n times in this wet oxide film forming step, which is extremely processable (processing speed). ) Is inferior to.

On the other hand, instead of using the wet oxidation coating method as described above to form the copper oxide coating, the conductor obtained by twisting the copper wires is heated in an oxygen-containing atmosphere, and the gas oxide coating method is used. A method for forming copper oxide of 0.25μ or more is also disclosed
No. 57-80610, and in practice, after forming a circular aggregate conductor by the conductor segments by this method without oxidizing the conductor segments as is,
It is also shown that the above process is performed.

However, if this method is carried out after forming the circular aggregate conductor from the conductor segments, it takes time to obtain the uniform heating temperature for the circular aggregate conductor, and the copper strands are crimped to each other. It is difficult to obtain a uniform insulating layer for all strands.

[Disclosure of the Invention]

As described above, there is a problem in carrying out the conventional wet oxide film method in the segment stage, and also in the case where the gas type oxide film method is carried out in the stage in which the circular aggregate conductor is formed, the problem as described above occurs. The present invention has improved this by forming segments into circular conductors, and then performing a wet coating process to form a uniform cupric oxide coating on each wire forming the circular conductors. The present invention provides a method for manufacturing a conductor for a power cable, which can form a wire.

Therefore, in the present invention, the circular aggregate conductor obtained by assembling the multi-divided segments made of copper wire is bent, and the copper wire is temporarily slipped or softened, and the surface of the copper wire is oxidized. By performing the formation treatment of the second copper coating, it is intended to improve the workability in the production of the power cable collective conductor composed of this kind of multi-divided segment.

The embodiment of the present invention will be described below with reference to the apparatus shown in the drawings.

FIG. 1 shows an example of an apparatus for carrying out the present invention.

The figure mainly shows the parts directly involved in the wet oxide film forming step, but before and after these parts, there are (a) a degreasing step, (b) a preheating step, and (c) a water washing step as in normal steps. , (D) Drying process, etc. are incorporated into one production line as required.

As mentioned earlier, in the case of an n-divided conductor with a gathering machine, the n-segment conductors are gathered together, the binder tape 2 is temporarily wound, and the gathered conductor 1 that holds the gathered shape with a circular cross-section is the supply drum 3. Be prepared for. The collective conductor of this segment is assembled by a conventional assembly machine in the conventional manner.

First, the assembly conductor 1 coming out from the supply drum 3 is obtained by removing the temporary binder tape 2 with a tape removing machine 4 to expose the outer periphery of each segment.

R _{11 to} R ₁₂ are divided tanks that are subjected to an oxide film treatment on the collective conductor 1 that sequentially passes therethrough. The tanks R ₁₁ and R ₁₂ are provided on both side walls and adjacent tank side walls between the adjacent tanks R _{11 to} R _12. Although not shown in between, a packing having a hole through which the collective conductor 1 having a circular cross section is inserted is attached, and a roller for supporting the collective conductor 1 is appropriately arranged in each tank.

Tanks R ₁₁ , R ₂₁ , R ₃₁ , R ₄ , R ₃₂ , R ₂₂ , and R ₁₂ are arranged in order, and a tank R in the center is provided from a reservoir tank 5 that stores the oxide film forming chemical solution 6 via a pump P _{2. The} solution 6 is sent to the tank R ₄ by a pipe 7 reaching the upper part of the tank ₄ , and a pipe 7 ′ reaching the upper parts of the tanks R ₂₁ and R ₂₂ adjacent to the tanks R ₁₁ and R ₁₂ is pumped through the pump P ₁ . The solution 6 is sent.

Also, tanks R ₃₁ , R ₃₂ between the tanks R ₂₁ , R ₂₂ and the central tank R ₄
A pipe 8 is connected to the lower part of the tank for collecting the drained liquid, and the drained liquid is collected in the reservoir tank 5 via the pressure reducing pump VP, and is connected to the lower part of the tanks R ₁₁ and R ₁₂ for collecting pipe 8 ′. Is connected to the drain pipe 8 on the discharge side of the decompression pump VP and reaches the reservoir tank 5.

The chemical liquid 6 for forming an oxide film for forming cupric oxide on the copper conductor is flowed in the direction of the arrow while the aggregate conductor 1 is moving in the direction of the arrow, and is brought into contact with the aggregate conductor 1 during this period to be collected. In the figure, the shaded area indicates the existing level of the chemical solution 6 for forming an oxide film.

Since the chemical solution 6 for forming an oxide film is usually used at a high temperature of, for example, 80 to 100 ° C., it will not be described below, but the solution is stored in advance at elevated temperature and the pipes are kept warm by a heat insulating material. The treatment tank shall also be maintained at the required temperature with a heater and heat insulating material.

Each tank will be further described.

The tanks R ₂₁ and R ₂₂ are tanks that are filled with the solution 6 at atmospheric pressure, and the tank R ₄ is a tank that applies pressure to circulate the solution 6 between conductor wires.

The tanks R ₃₁ and R ₃₂ collect the liquid with the vacuum pump VP,
The pressure in the tank R ₄ is sufficiently reduced so that the pressurized solution in the tank R ₄ flows out while being sufficiently immersed in the conductor. It also serves to pull out air voids so that no voids remain in the conductor entering the tank R ₄ . In addition to the pump VP of FIG. ₁ , it is more effective to attach the pressure reducing pump VP _{1 of} FIG. 2 to the upper surfaces of the tanks R ₃₁ and R ₃₂ .

The tanks R ₂₁ and R ₂₂ hold the chemical solution 6 for forming an oxide film so as to always cover the conductor 1, and air is passed through the gaps in the conductors on the inlet side or the outlet side from the tanks R ₃₁ , R ₃₂ and R _{22. Four}
This is a room to prevent mixing into the conductor inside.

Therefore, the oxide film forming treatment liquid 6 in the tanks R ₂₁ and R ₂₂ should always have a liquid level higher than the conductor. For that purpose, the tanks R ₂₁ and R ₂₂ should be filled with the liquid at a slightly higher pressure. Horsetail
A small amount may be leaked to the R ₁₁ side in the tank R _{21 and} to the R ₁₂ side in the R ₂₂ side, or a liquid level gauge may be installed in the tanks R ₂₁ and R ₂₂ , and a pump P may be installed.
_The liquid level may be maintained in conjunction with ₁ . In this case, as shown in FIG. 2, while maintaining the liquid level, if vacuum the bath R _21, in R ₂₂ above under reduced pump VP ₁ from its surface, the negative even solution in the tank R _21, R ₂₂ As a result, the residual air of the conductor is drawn out into the solution, and a more effective effect of preventing air inclusion is exhibited.

The tanks R ₁₁ and R ₁₂ are packed or packed conductor 1
The solution 6 leaking through the individual wires forming the
It is a tank for collecting. Chemical solution for oxide film formation 6
There too through the tank R _11, R _12, so that it from unexpected Yuka leaks in the supply side or take-up, as shown in FIG. 3, the assembly 1 of the tank R _11, R ₁₂ It is extremely effective to taper the passage in the horizontal direction and lift the collective conductor 1 beyond the outer diameter of the conductor 1 so that the packing sufficiently contacts the outer surface of the collective conductor 1 through the insertion hole. Further, it is more effective if the decompression pump VP ₂ is installed on the bottom side of the tanks R ₁₁ and R ₁₂ to recover the decompressed pressure. Especially, when the collective conductor 1 comes out from the tank R ₁₂ , the collective conductor 1 itself is It is effective in recovering the solution 6 since the solution 6 is carried out.

FIG. 4 shows a group of rollers in tank R ₄
The conductor assembly 1 is lightly bent to temporarily leave a gap between the wires.

Numerals 9, 9 ', 10 and 10' are rollers for fixing the position of the collective conductor 1, and by fixing the center position of the conductor between them and the packing, the sealing effect by the packing provided at the inlet and outlet of the tank is enhanced.

FIG. 5 shows a claw type roller used as the rollers 9, 9 ', 10 and 10', and it is desirable that they are arranged facing each other vertically or vertically.

In FIG. 4, reference numerals 11, 12, 13 denote rollers for bending the collective conductor 1, which may be shaken not only in the vertical direction but also in the horizontal direction while the collective conductor 1 is moving. This temporarily causes slippage and softness between the copper strands of the assembly conductor 1 so that the chemical solution 6 for forming an oxide film is sufficiently permeated between the strands inside the conductor.

As described above, in the tank R ₄ , the means is adopted so as to slightly bend the collective conductor 1 vertically and horizontally, but the same means can be adopted in the tanks R ₂₁ and R ₂₂ .
As shown in FIG. 6, as a bending means of the assembly conductor 1 for causing the sliding and softening between the copper wires as described above, the assembly conductor 1 is connected through the connecting tanks R ₃₁ , R ₄ and R _32. While supplying, the bending position may be changed by changing the moving position from a large number of rollers 14.

The collective conductor 1 which passes through the respective tanks shown in FIG. 1 and advances in the direction of the arrow is the die 15 after passing through the post-treatment tanks etc. attached to the post-cutting.
To the original shape by tightening it again with the die 15 and then immediately winding the binder tape 2 for holding the conductor shape with the binder tape winding machine 16 and winding the drum.
When it is wound on 17, the process of the main processing is completed.

Although the number of dies may be one, the number of dies may be two, and as shown in FIG. 7, rough compression is performed by using a die with a slightly larger diameter as the first stage dies 15 ', and the direction of rotation of the dies 15' is changed. In the reverse rotation, final compression is performed by the second-stage finishing die 15 ″. In this case, the finishing die 15 ″ is rotated in the same direction as the twist pitch of the segments forming the collective conductor 1, This is preferable because it allows the dies to be assembled reliably without damaging them. The dies can be rotated on the supply side in the direction in which the conductor is loosened.

Above described manner of, since the present invention into the tank R ₂₁ to R ₂₂ without binder tape, although the oxide film-forming chemicals solution 6 easily enters to between the strands of the conductor 1, pressurized with the Kiwaso R ₄ Since the pressure is reduced in the tanks R ₃₁ and R ₃₂ at a pressure of, for example, 1 to 3 kg / cm ² , the solution sufficiently penetrates between the strands in the assembly conductor,
The chemical solution for forming an oxide film can penetrate into the inner part of the circular conductor to form a cupric oxide film.

Tank R ₄ filled with a chemical solution for forming an oxide liquid film by pressurization in the center
In addition, dipping is also performed in the tanks R ₂₁ and R _22. By this, the solution is packed between the strands of the assembly conductor 1 which cannot be packed, and air is prevented from being mixed in. Voids of air remaining in the conductor 1 are also removed by reducing the pressure inside ₂₁ and R ₂₂ . Further, it goes without saying that the chemical solution 6 for forming an oxide film has an effect of forming a cupric oxide film.

The insides of the tanks ₁₁ and R ₁₂ also prevent the chemical solution for forming an oxide film from leaking to the outside through the space between the strands in the assembly conductor having no packing effect.

Needless to say, if the apparatus for carrying out this step is a collecting machine and a tandem, the steps of winding the temporary binder tape and removing the tape are not necessary, and this is preferable.

In this manufacturing method, since the circular conductors after assembly are guided to the processing tank as they are, the packing of each tank can be circular, and the sealing capacity of the outside of the conductor is the sealing when processing only with the preformed segment. Much higher than sex,
Therefore, for example, the solution 6 in the tank R ₄ can only flow into the inside of the conductor and flow out into the tanks ₃₁ and ₃₂ , so that the wires inside the conductor are sufficiently immersed. This is also a major feature of this method.

As shown in FIG. 8, the packing 18 is made of nitrile rubber, Viton (trade name), silicone rubber, ethylene tetrafluoride (trade name Teflon), or the like, and preferably has a tubular shape in the conductor moving direction. A conductor having a length equal to or larger than the conductor diameter is used.

Note that it is effective to tighten the tubular portion at appropriate intervals with a binder wire 19 or a band-shaped binder or the like that can cope with changes in the conductor cross-sectional shape.

When this method is applied to 2500mm ² 7-divided conductor, AC resistance is the theoretical effect of the conductor using the completely insulated wire.
Good data of about 7% reduction was obtained when the conventional conductor consisting of bare wire was reduced by about 8%.

Moreover, when the adhesion state of cupric oxide on each wire was investigated,
There was no difference between the outside and the inside of the conductor, and it was within 2 μm.

The present invention can be applied to the manufacture of multi-divided conductors such as OF, Cv, and flexible gas insulated cables.

[Effect] As described above, according to the present invention, the n segments are collectively processed after being assembled.
Is significantly improved.

Further, since the oxide film is provided after the assembly, the quality of the oxide film can be improved without being damaged by the assembly.

[Brief description of drawings]

FIG. 1 shows an example of an apparatus for carrying out the present invention. FIG. 2 is a configuration diagram of a chamber in which the aggregate conductor is immersed in a chemical solution for forming an oxide film in a reduced pressure state. FIG. 3 is a diagram showing the structure of supporting the aggregated conductor before and after the aggregated conductor is subjected to the oxide film forming treatment, when the aggregated conductor is taken into or out of the packed chambers on both sides. FIG. 4 shows an example of a roller layout diagram that bends the collective conductor when the copper wire of the collective conductor is subjected to an oxide film forming treatment. FIG. 5 shows an example of a roller for fixing the position of the moving collective conductor. FIG. 6 is another configuration diagram in which the moving collective conductor is bent. FIG. 7 is an explanatory diagram of re-tightening of the assembly conductor with a die. FIG. 8 is a sectional view showing an example of the tubular packing. 1 ... Collective conductor, 2 ... Binder tape, 3 ... Supply drum, 4 ... Tape remover, 5 ... Reservoir tank, 6 ...
Chemical solution for oxide film formation, 7, 7 ', 8, 8' ... Pipe, 9,
9 ', 10, 10', 11, 12, 13 ... Rollers, 14 ... Roller groups, 15, 15 ', 15 "... Dies, 16 ... Tape winding machine, 17 ... Winding drum, 18 ... Cylindrical packing, 19 … Binder wire

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Satoru Takano Satoru Takano, Osaka Prefecture, Osaka City, 1-3-1 Shimaya, Konohana-ku, Osaka Sumitomo Electric Industries, Ltd. (72) Inventor Susumu Mitsui, Shimano, Osaka, Osaka 1 to 3 Sumitomo Electric Industries, Ltd. Osaka Works (56) Reference JP 56-141117 (JP, A) JP 57-80610 (JP, A) JP 57-128411 (JP, A) ) JP-A-59-79906 (JP, A)

Claims (6)

[Claims] 1. A circular aggregate conductor obtained by assembling multi-divided segments made of copper strands is bent to temporarily slide on the copper strands,
Alternatively, a method for producing a conductor for a power cable, which comprises forming a cupric oxide film on the surface of the copper element wire in a state in which it becomes soft. 2. A process for forming a cupric oxide film on a copper wire,
This is immersed in an oxide film forming chemical solution under pressure, and the oxide film forming chemical solution under pressure is
The pressure tank in which the solution is kept and in which the conductor passes, is collected in two sets of decompression tanks adjacent to the conductor entry side and the conductor exit side, and the side wall separating the pressure vessel and the decompression tank is
A packing having a cylindrical portion, which is circular and is preferably longer than the outer diameter of the conductor, the inner diameter of which is substantially equal to or slightly larger than the outer diameter of the conductor when passing through the conductor,
The method for producing a conductor for a power cable according to claim 1, characterized in that a processing device having a structure for guiding the conductor from the pressure-reducing tank to the pressure-reducing tank and vice versa . 3. A pair of two pressure reducing tanks adjacent to the conductor exit side of one depressurization tank and the conductor entry side of the other depressurization tank, respectively, keep the liquid level of the oxide film forming chemical solution higher than the passing conductors, and For forming an oxide film, there are two sets of tanks each having a tank whose pressure is reduced and which is adjacent to the side where the conductor of one tank exits and the side where the conductor enters the other tank and collects the chemical solution for forming an oxide film under reduced pressure. A packing having a cylindrical portion, which is arranged with a solution tank in between, and has a tubular portion longer than the outer diameter of the conductor and having an inner diameter substantially equal to or slightly larger than the outer diameter of the conductor when passing through the conductor, on each side wall through which the conductor passes. The method for manufacturing a conductor for a power cable according to claim 1, wherein the conductor is for a processing device. 4. The packing according to claim 2, wherein the packing is made of nitrile rubber, silicon rubber, ethylene tetrafluoride or the like or a mixed material thereof, and the fixing property of the packing and the conductor is increased. A method for manufacturing a conductor for a power cable according to item 3. 5. A conductor traveling in a decompression tank, the conductor having an outer diameter equal to or larger than the outer diameter of the conductor at the entrance-side decompression tank toward the inlet and at the exit-side decompression tank toward the exit. The method for producing a conductor for a power cable according to claim 2 or 3, characterized in that the conductor is lifted up to the height. 6. A pair of dies is provided after the formation treatment of the cupric oxide coating and before re-rolling, the die on the processing tank side is in the direction opposite to the twist pitch of the segment, and the final die is the twist pitch of the segment. The method for producing a conductor for a power cable according to any one of claims 1 to 5, wherein the conductor is rotated in the same direction as.