JPH0727791B2 - How to connect conductors - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for connecting power cable conductors.

[Prior Art] A power cable conductor is connected by inserting a power cable conductor to be connected to a cylindrical conductor connecting pipe and using a hexagon die and a hydraulic holder to compress the outer periphery of the conductor connecting pipe from a circle to a hexagon. The method of connecting is widely used. When connecting power cables having the same conductor outer diameter and the same insulator outer diameter, this connection method may be the same conductor connection pipe outer diameter, and the insulation treatment provided on the outer circumference of the connection It can be formed uniformly on the power cable.

However, when connecting power cables with different conductor outer diameters or connecting power cables with different insulator outer diameters,
A step is generated between the outer diameter of one of the cable insulators and the outer diameter of the conductor connecting pipe, which makes it difficult to perform uniform insulation treatment. In particular, in a high-voltage power cable, the step portion of the conductor connecting pipe creates a high electric field, and in order to mitigate this, the step portion is built up with a semiconductor layer or the outer circumference of the cable insulator with a small outer diameter is covered with, for example, insulating rubber. Extra work and parts are required such as providing and connecting an insulating layer with a cylindrical spacer made of a uniform material to make the outer diameter of the power cable insulator uniform.

[Problems to be Solved by the Invention] As described above, in connecting different-diameter conductors of a power cable or connecting different-type power cables, a difference in diameter occurs between the insulator outer diameters of the power cables to be connected. The insulation process is complicated and difficult.

Hereinafter, this point will be described in detail with reference to the drawings. FIG. 9 shows a connection example in the case of the same type of power cable such as a CV cable, in which the conductor sizes are different. That is, the conductor 2 of the power cable on the left side and the conductor 2b of the power cable on the right side are inserted into the connection holes of the connection pipe 3 to be connected, and the outer diameter of the connection pipe 3 is connected to the insulator 1b of the power cable to be connected on the right side. If they are combined, a step will be formed on the insulator 1a side of the left power cable.

FIG. 10 shows an example of connecting different types of power cables. The left power cable insulator 1a is a cross-linked polyethylene insulator (XLPE) cable, and the right power cable insulator 1c is a rubber insulated (PV) cable. This is the case. Insulation performance of the latter is low in XLPE insulation and PV insulation, so it is necessary to design a thick insulation thickness, which causes a step on the right power cable side.

FIG. 11 shows the case where the conductor sizes of the power cables to be connected are remarkably different, and the cross-sectional area of the connecting pipe 3 into which the conductor 2a of the left power cable is inserted is insufficient. If it is matched with the insulator 1a, a large step will be formed on the insulator 1d side of the right power cable. Since the electric field strength increases at such a stepped portion of the connecting pipe 3, the insulating performance is deteriorated.

In order to prevent this, as shown in FIG. 12, the step portion on the outer periphery of the connection portion, which is conductor-connected by the connection pipe 3, is provided on the left side of the insulator 1a.
To the insulator 1d on the right side, a semiconductive tape should be wound to form the connection part semiconductive layer 7, or it should be covered with a molded product to alleviate the electric field. Then, an insulating layer 8 is formed on the outer periphery of the insulators 1a, 1d in a mountain shape, and is connected to the outer semiconductive layer of the power cable 1, 1 '.
An outer semiconductive layer 9 is formed over 4,4 'to insulate the connection portion, and a shield layer (not shown) is formed over the shield layers 5, 5'of the cables 1, 1', though not shown. Then, the outer periphery is covered with a sheath, which makes it difficult to perform insulation processing after connecting the conductors.

The present invention has been made in view of the above circumstances, and provides a conductor connecting method capable of easily connecting conductors of a power cable without generating a step when connecting different power cables or power cables having different diameters. The purpose is to

[Means for Solving the Problems] The present invention relates to a method of connecting cable conductors having different-diameter insulators to each other, in which a conductor connecting pipe having a hole for inserting a cable conductor to be connected is connected to each other. It is formed into a shape that connects the body contours continuously with a straight line or a curved line.Insert the cable conductors to be connected to the holes of this conductor connection pipe, respectively, and convert the conductor connection pipe and the cable conductor to the cable conductor connection pipe outer shape. It is a method of connecting conductors, which is characterized in that fitting metal molds are fitted together and indented and connected. Also, connect the conductor connecting pipe having male contacts to one cable conductor having the different diameter insulator to be connected by indent compression, and connect the conductor connecting pipe having female contacts to the other cable conductor by indent compression. Then, it is a method of connecting conductors in which conductors can be connected by fitting both contacts.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.
1 to 4 are cross-sectional views each showing a connecting portion for explaining the conductor connecting method of the present invention. Fig. 1 shows an example of connecting different-diameter conductors, and the connecting ends of the power cables to be connected are stripped to form insulators 1
Exposing a, 1e and conductors 2a, 2e. Conductors are inserted in the insertion holes of the conductor connection sleeve 13 in which the outer diameters of the insulators 1a and 1e of the power cables to be connected to the left and right are equal to the outer diameters of the ends
2a and 2e are inserted, and the conductor connection sleeve 13 and the conductors 2a and 2b of the power cable are fixed from the left and right by indent compression portions 20 and 20 'by indent compression. The outer diameters of the insulators 1a and 1e are continuously connected by the tapered surface, the formation of the high electric field portion is prevented, and the insulating treatment for the work performed thereafter can be easily performed.

In the above example, the outer shape of the conductor connecting sleeve 13 is formed in a tapered shape, but in FIG. 2, the outer shape of the conductor connecting sleeve 13a is sequentially increased from the outer diameter of the insulator 1a of the left power cable. The taper surface and a straight line parallel to the outer diameter of the insulator 1f of the power cable on the right side may be connected to each other at the center.

Also, as shown in FIG. 3, the outer diameter of the insulator 1a of the left power cable and the outer diameter of the insulator 1g of the right power cable are connected by a conductor connection sleeve 13b having a shape formed by a continuous curve. However, the same effect can be obtained.

The point is that the outer diameter of the left and right ends of the conductor connecting sleeve that are in contact with the insulator should be the same as the outer diameter of the insulator of the power cable to be connected, and the space between them should be continuous with any straight line, curve, taper, etc., or a combination thereof. It is formed in various shapes. In this case, the conventional compression using a hexagonal die cannot be used because the die is linear, but indent compression uses a small pin to locally press-fit by hydraulic pressure, etc., so it can be freely pressed into the tapered part or curved surface. It can be fixed.

Next, a method of indent compression will be described with reference to FIG.
That is, in the connection hole of the conductor connection sleeve 13c, the insulators 1a, 1h and conductors 2a, 2h of the power cables to be connected on the left and right are exposed by step stripping, respectively, and the conductors 2a, 2h are inserted from the left and right, respectively. The indenting die 10 is put on the outer periphery to be in a restrained state, and a cylindrical or polygonal indenting pin 12 is press-fitted into the pin insertion hole 11 provided in the indenting die 10 by hydraulic pressure to connect the conductor connecting sleeve 13c. The conductors 2a and 2h are compressed and connected from, for example, the vertical 180 ° direction.

Since this indent compression presses the pin 12 while the conductor connecting sleeve 13c is constrained, it compresses by applying pressure to the inside due to this volume change. High pressure can be applied. From this point of view, it is preferable that the holes into which the conductors 2a and 2h are inserted are formed as small as possible so that the insertion work can be performed. Also, the diameter of the pin 12 to be press-fitted is increased or the insertion depth is increased to increase the volume change and to compress strongly.

FIG. 5 is a cross-sectional view showing a state in which a straight connecting portion to which the conductor connecting method of the present invention shown in FIG. 1 is applied is subjected to an insulation treatment. That is, the connecting ends of the connecting power cables 1, 1'are connected to the shielding layers 5, 5 ', the outer semiconductive layers 4, 4', the insulators 1c, 1e.
And conductors 2a, 2e are respectively stripped, and conductors 2a, 2e are inserted into the connection insertion holes by using conductor connection sleeves 13d each having an end whose outer periphery is equal to the outer periphery of the insulator 1a, 1e to be connected. , Indent compression 20, 20 'is performed to form a conductor connecting portion. An inner semiconductive layer 7 communicating with the outer circumferences of the insulators 1a and 1e is formed on this outer circumference by tape winding or the like. Since the outer circumferences of the insulators 1a, 1e and the conductor connecting sleeve 13d are continuous, the semiconductive layer 7 may be thinly formed, and it is not necessary to provide the semiconductive layer 7 on the insulators 1a, 1e for a long time. Therefore, it is not necessary to lengthen the straight connecting portion even when connecting different-diameter or different-type cables. The semiconductive layer 7 is wound with tape,
It is made of heat shrinkable tube, mold layer, etc. On this outer circumference, an insulating layer 8 is formed by tape winding, molding, heat shrink tubing, etc. over the cable outer semiconductive layers 4, 4 ', and further, an outer semiconductive layer 9 is formed on this outer circumference. Form over ′. Although not shown, the outer circumference is covered with a shielding layer and a sheath.

Since the insulating layer 8 does not form a high electric field portion in which the conductor connecting sleeve 13d communicates with the cable insulators 1a and 1e, it may be the same as the outer periphery of the insulators 1a and 1e, and unnecessary insulation is not necessary.

In the conventional compression of a round or hexagonal conductor connection pipe, it was impossible to make a compression connection when the outer circumference had a tapered or curved outer shape, but indent compression is connected by local compression with a pin. Therefore, the connection can be made without being affected by the shape of the outer circumference, and the finished outer diameter can be regarded as a circle as a whole because it is local, which facilitates the subsequent insulator treatment.

Next, an embodiment of the detachable conductor connecting method of the present invention will be described with reference to the drawings. In FIG. 6, the conductor connecting pipe 23
Is composed of a connecting pipe 23a having a female contact on the left side and a connecting pipe 23b having a male contact on the right side. That is, the contact is a fitting groove 27 having the leaf spring 15 inside in the connecting pipe 23a.
The connecting pipe 23b has a protrusion 2 that engages with the fitting groove 27.
8 are formed on the connection side, respectively. The outer diameters of these connecting pipes 23a and 23b are the insulators 1a of the power cables to be connected on the left side and the insulators of the power cables to be connected on the right side.
The outer diameter is 1i and the outer diameter is a continuous tapered surface. Next, a conductor connecting method using the detachable conductor connecting tube 23 configured as described above will be described. First, the cable ends of the left and right power cables to be connected are stripped off to expose the insulators 1a, 1i and the cable conductors 2a, 2i, and inserted into the cable conductor fitting holes of the connection pipes 23a, 23b, respectively. Fix it. Next, the outer circumference of each of the connecting pipes 23a, 23b is covered with an indent die to be restrained, and the indent pin is press-fitted by hydraulic pressure from a pin insertion hole provided in the die to connect the cable conductors 2a, 2i and the connecting pipe 23a, 23b and 23 are compressed and fixed. Subsequently, the cables to which these connecting pipes 23a, 23b are fixed are butted against each other from the left and right to be fitted to complete the conductor connection.

In the above example which constitutes the conductor connecting pipe 23, the connecting pipes 23a, 23b
The outer diameters on the left and right of the taper surface are described as linear taper surfaces. However, as shown in FIGS. 2 and 3, the outer diameter is the line connecting the taper surface and the outer diameter of the insulator. Needless to say, the shape may be used, and as the indenting die, one having a shape that fits the above shape may be used.

In addition, in the above example, the indent compression is described for each connecting pipe having individual contactors. For example, as shown in FIG. 7, the contactors of the left and right connecting pipes 23a and 23b are fitted together. In this state, the connecting pipes 23a, 23b are constrained by covering the outer peripheries of the connecting pipes 23a, 23b, and the indenting pin 12 is hydraulically pressed into the cable conductors 2a, 2i through the pin insertion hole 11.
By compressing, it is possible to completely eliminate a minute step between the fitting groove 27 and the outer periphery of the fitting portion of the protruding portion 28 due to the working tolerance at the time of working the fitting groove 27.

Next, with reference to FIG. 8, an example of the insulator treatment performed after the connection will be described. Connected conductor connection tube 13 and cable insulator 1
An inner semiconductive layer 17 such as a tape winding or heat shrink tape is formed over a and 1i. Since the inner semiconductive layer 17 has no step between the cables 1 and 1'to be connected and the circumference is relatively round, a sufficient shielding effect can be obtained with a thin layer. Instead of this internal semiconductive layer 17, the impedance is 10 ⁹ to 10 ¹⁰ Ω-c.
You may provide the electric field relaxation layer which is m and has a nonlinear characteristic.

Further, an insulating layer 18 is formed around the outer periphery of the insulator 1a, 1b in a mountain shape by tape winding, heating mold, heat shrinking tube, etc., but since the conductor connecting portion has no protrusions or the like, the insulator thickness is connected. Equal to the left and right cables 1, 1 ',
Also, the lengths can be made equal. Further, an outer semiconductive layer 19 is formed on the outer circumference of the outer diameter semiconductive layers 4 and 4 ', and a sheath (not shown) is provided on the outer circumference of the outer semiconductive layer 19 to complete a small-sized and lightweight connection portion.

If the inner semiconductive layer 17, the insulating layer 18, and the outer semiconductive layer 19 are integrally molded with a rubber mold or the like, the cables 1 and 1'can be pulled out as needed to easily connect to other cables. It also becomes possible.

[Effects of the Invention] As described above, according to the conductor connecting method of the present invention, it is possible to easily connect the different-diameter power cables and the different-type power cables by the conductor connection sleeve having the connected outer diameter and the indent compression. The connection part can be downsized.

The internal semiconductive layer processing work can be simplified.

You don't have to use unnecessary materials.

And the like, the excellent action and effect are exhibited.

[Brief description of drawings]

1 to 4 are cross-sectional views of a connecting portion for explaining the conductor connecting method of the present invention, and FIG. 5 is a cross-sectional view showing only an upper half portion showing a state in which the connecting portion is insulated. FIG. 6 is a cross-sectional view of a connecting portion for conductor connection using the detachable connecting pipe of the present invention, FIG. 7 is a cross-sectional view showing a step of indenting the connecting portion, and FIG. FIG. 9 to FIG. 11 are horizontal cross-sectional views showing only the upper half part showing the state where the parts are insulated, and FIG. 9 to FIG. FIG. 12 is a cross-sectional view showing a state in which the conductor connecting portion of FIGS. 9 to 11 is subjected to insulation treatment. 1,1 ′ …… Power cable 1a to 1i …… Insulator 2a to 2i …… Cable conductor 3,13,13a to 13d, 23,23a, 23b …… Connecting tube 4,4 ′ …… External semiconductive layer 5 , 5 '…… Shielding layer 7,17 …… Inner semiconductor layer 8,18 …… Insulating layer 9,19 …… Outer semiconductor layer 10 …… Indent mold, 11 …… Pin insertion hole 12 …… Pin , 15 ...... Leaf spring 20, 20 '...... Indent compression part 27 ...... Fitting groove, 28 ...... Projection part

Front page continued (72) Inventor Masahiro Sakaba 5-1-1 Hidaka-cho, Hitachi-shi, Ibaraki Electric Cable Research Laboratory, Hitachi Cable, Ltd. (56) Reference JP-A-60-109191 (JP, A) 63-73859 (JP, U) JP-B 39-24237 (JP, B1) JP-B 54-33115 (JP, Y2)

Claims (2)

[Claims] 1. A method of connecting cable conductors having different-diameter insulators to each other, wherein a conductor connecting pipe provided with a hole for inserting a cable conductor to be connected has a straight line or a curved line between the outer shapes of the cable insulators to be connected. It is formed in a shape that is connected continuously.Insert the cable conductors that connect to the holes of this conductor connection pipe, and fit the conductor connection pipe and the cable conductor into a mold that matches the outer shape of the cable conductor connection pipe. A method of connecting conductors, which comprises compressing and indenting and connecting. 2. A conductor connecting pipe having a male contactor is connected to one cable conductor having a different-diameter insulator to be connected by indent compression, and a conductor connecting pipe having a female contactor is indented to the other cable conductor. 2. The conductor connection method according to claim 1, wherein the conductor connection is made by connecting the two contacts and fitting the contacts.