JP2015082872A - Oil stopper structure of end edge connection part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil stopper structure of an end edge connection part which reduces the manufacturing costs and the workload of installation.SOLUTION: An oil stopper structure 10 of an end edge connection part 100, which is formed between a conductor part 91 of an electric cable 90 housed in a porcelain tube 120 filled with an insulation oil 128 and a conductor lead-out rod 111, includes: an oil stopper reinforcement layer 20 which is formed around the conductor part in an area ranging from an insulator layer 92 of the electric cable to the conductor lead-out rod; a shrinkable tube 31 which covers an entire region of an outer peripheral surface of the oil stopper reinforcement layer; and a cover part 32 which covers at least a boundary part between one end part of the shrinkable tube and an outer peripheral surface of the conductor lead-out rod and a boundary part between the other end part of the shrinkable tube and an outer peripheral surface of the insulator layer. The oil stopper reinforcement layer includes: self-fusing tape layers 21, 23, 25 and a watertight tape layer 24.

Description

  The present invention relates to an oil stop structure for a terminal connection portion.

2. Description of the Related Art Conventionally, an oil-immersion-type terminal connection portion in which an end portion of a power cable is accommodated in a soot pipe and an insulating oil is filled in the soot pipe is known as a power cable end connection part (hereinafter referred to as a “terminal connection part”) Yes. At the tip of the power cable housed in the soot tube, the insulating layer or the like is stripped and the conductor is exposed, and a conductor lead bar is connected to the exposed conductor.
In such a terminal connection portion, the insulating pipe is filled with insulating oil. Therefore, in order to prevent infiltration of insulating oil from between the conductor and the insulating layer at the end of the power cable, the conductor from the tip of the insulating layer An oil stop structure is formed around a portion extending over the draw bar (see, for example, FIG. 7 of Patent Document 1).
This oil stop structure is, for example, an oil stop reinforcing layer made of a self-bonding tape wound around the outer peripheral surface of a conductor from the end of the insulating layer of the power cable to the end of the conductor lead bar, and the end of the insulating layer. It consists of a heat-shrinkable tube provided on the outer peripheral surface of the oil retaining reinforcement layer over the end of the conductor lead bar, and a mold layer formed at both ends of the heat-shrinkable tube. One mold layer is formed in advance at the factory shipment stage, and one end of the heat shrinkable tube is joined to the outer peripheral surface of the conductor lead bar.

JP-A-56-148111

However, in the conventional oil stopper structure, since the mold layer is formed by heat treatment that requires temperature control, the manufacturing cost of the terminal connection portion is increased.
Also, the mold layer is formed at the factory for one end of the heat-shrinkable tape, but the mold layer is formed at the other end, so the heating device and temperature control device for that purpose are carried to the site. It had to be put in, and the work burden was large.

  An object of the present invention is to reduce the manufacturing cost and the work burden of installation for the oil stop structure of the terminal connection portion.

The present invention is an oil stop structure of a terminal connection portion formed between a conductor portion of a power cable housed inside a soot tube filled with insulating oil and a conductor lead bar,
From the insulating layer of the power cable to the conductor lead bar, an oil stop reinforcing layer formed around the conductor part,
A shrinkable tube covering the entire outer peripheral surface of the oil stop reinforcing layer;
A covering portion covering at least a boundary portion between one end portion of the shrinkable tube and the outer peripheral surface of the conductor lead bar and a boundary portion between the other end portion of the shrinkable tube and the outer peripheral surface of the insulating layer;
The oil stop reinforcing layer includes a self-bonding tape layer and a watertight tape layer.

In the said invention, since the oil stop reinforcement layer has a self-adhesive tape layer and a watertight tape layer, it is excellent in oil tightness compared with the case where it comprises only a self-adhesive tape. Oil tightness refers to the property of not allowing oil to permeate.
According to this oil stop structure, high oil tightness can be achieved without providing a mold layer for sealing by strict temperature control using a heating device or a temperature control device at both ends of the shrink tube on the outer peripheral surface of the oil stop reinforcing layer. Can be maintained.
Therefore, it is not necessary to form a mold layer at the factory shipment stage, and the shrinkable tube and its covering portion can be formed by a simpler method, reducing the manufacturing cost of the oil stop structure of the terminal connection portion and the burden of installation work. It becomes possible to plan.

The self-bonding tape layer may be formed using a compound mainly composed of synthetic resin and synthetic rubber.
In this case, the self-bonding tape layer has excellent self-bonding properties, and it is possible to reduce the occurrence of gaps and irregularities. Thereby, it is possible to exhibit high oil tightness.

The watertight tape layer may contain butyl rubber and have a self-bonding property.
In this case, the layer made of the water-tight tape exhibits excellent water-tightness and self-fusing properties, and it becomes possible to improve water-tightness and reduce gaps and irregularities at the tape interface. Thereby, it is possible to exhibit high oil tightness.

In the above invention, the oil stop reinforcing layer may include a curable resin layer formed from the outer peripheral surface of the conductor lead bar to the outer peripheral surface of the insulating layer.
In this case, since the curable resin layer suppresses the behavior between the conductor lead bar and the insulating layer, it is possible to reduce the occurrence of peeling and cracking in the oil stop reinforcing layer formed between them, which is high. It becomes possible to maintain oil tightness.

  As the covering portion, a layer in which a tape made of a thermoplastic resin such as polyethylene is wound around the outer periphery of the shrinkable tube may be further formed.

  Moreover, in the said invention, it is good also considering any termination | terminus connection part as an air termination | terminus connection part, a gas termination | terminus connection part, and an oil termination | terminus connection part.

  As described above, according to the present invention, it is possible to reduce the manufacturing cost and the installation work load for the oil stop structure of the terminal connection portion.

It is sectional drawing of the air termination | terminus connection part of the electric power cable which is embodiment of invention. It is an expanded sectional view of the oil stop structure of an air termination connection part. It is a fragmentary sectional view of the terminal termination part in oil to which an oil stop structure is applied. It is a fragmentary sectional view of the terminal termination part in gas to which an oil stop structure is applied.

An embodiment of the present invention will be described with reference to FIGS.
In this embodiment, the oil stop structure 10 at the distal end portion of the power cable 90 provided inside the air termination connection portion 100 as the termination connection portion is illustrated.

[Air termination connection]
As shown in FIG. 1, the air end connection portion 100 is installed in a standing state, and one end portion of the stripped power cable 90 is inserted from the lower end of the soot tube 120. In this embodiment, when referring to “upper” or “lower”, as shown in FIG. 1, the upper or lower side is indicated in a state in which the air end connection portion 100 is erected.

The soot tube 120 is made of an electrically insulating material, for example, porcelain. The lower portion has an equal-diameter cylindrical shape, and the upper portion has a cylindrical shape whose diameter decreases toward the upper end. Further, a hook-shaped umbrella 121 is formed on the outer peripheral surface of the tub tube 120 over substantially the entire length.
In addition, the soot tube 120 is not limited to porcelain, and can be formed of other materials having high insulating properties. For example, the inner side of the tub tube 120 may be a tube made of fiber reinforced plastic (FRP), and the entire outer peripheral surface including the umbrella portion 121 may be formed of highly insulating silicone or the like.

An upper metal part 122 that supports the conductor lead bar 111 connected to the tip part of the cable conductor 91 as a conductor part is provided at the upper end part of the soot tube 120, and a lower metal part 123 is provided at the lower end part. An internal region formed by the soot tube 120, the upper metal member 122, and the lower metal member 123 is filled with an insulating oil 128.
A cable receiving port 123 a into which the power cable 90 is inserted is formed at the center of the lower metal fitting 123. The lower metal fitting 123 is connected to the gantry 125 via the support lever 124. Thereby, the soot pipe 120 is fixed on the mount 125 in the standing state.

In addition, a cylindrical cable protection fitting 126 is provided in the cable receiving port 123a of the lower fitting 123, and a seal pipe 127 is disposed on the inside thereof. The seal pipe 127 is attached from the outer semiconductive layer 93 to the shielding layer 94 of the power cable 90.
And the lower tape winding layer 140 for oil stop is formed so that the lower end part of the cable protection metal fitting 126, the lower end part of the seal pipe 127, and the sheath 95 of the electric power cable 90 may be wrapped. This lower tape winding layer 140 seals between the cable protection fitting 126 and the seal pipe 127 so that the insulating oil 128 inside the soot tube 120 does not leak from between these.

  Further, as shown in FIG. 1, a stress cone 150 is attached at a boundary position between the external semiconductive layer 93 and the insulating layer 92. The stress cone 150 is molded in advance and includes a semiconductive rubber portion 151 and an insulating rubber portion 152. Further, an oil film 153 is formed in advance on the surface of the insulating rubber portion 152 by application of oil, thereby suppressing bubbles of the insulating oil 128 from adhering to the surface.

  An upper tape winding layer 160 for shielding the cable is formed between the upper part of the seal pipe 127 and the lower part of the semiconductive rubber part 151 of the stress cone 150. The upper tape winding layer 160 performs sealing so that the insulating oil 128 does not enter the inside from the upper end of the seal pipe 127.

At the upper end portion of the power cable 90, the insulating layer 92 is removed, and the upper end portion of the cable conductor 91 is exposed, and is inserted into the lower end portion of the conductor lead bar 111.
And the oil stop structure 10 which seals the front-end | tip part of the power cable 90 from the insulation oil 128 is formed from the insulating layer 92 to the conductor extraction rod 111.

[Oil stop structure]
As shown in FIG. 2, the oil stopper structure 10 includes an oil stopper reinforcing layer 20 formed around the cable conductor 91 from the insulating layer 92 of the power cable 90 to the conductor lead bar 111, and an outer periphery of the oil stopper reinforcing layer 20. A contraction tube 31 covering the entire surface and a polyethylene tape layer 32 as a covering portion covering the entire outer peripheral surface of the contraction tube 31 are provided. Note that the left side in FIG. 2 shows the upper part of the aerial termination connection part 100, and the right side shows the lower part of the aerial termination connection part 100.
The oil retaining reinforcing layer 20 includes a first self-adhesive tape layer 21, a curable resin layer 22, a second self-adhesive tape layer 23, a water-tight tape layer 24, and a third self-adhesive layer in order from the inside. The tape layer 25 is laminated.

In a state where the conductor extraction rod 111 is attached to the tip end portion of the cable conductor 91, a valley portion exists between the lower end portion of the conductor extraction rod 111 and the upper end portion of the insulating layer 92.
The first self-bonding tape layer 21 is formed by overlapping the self-bonding tape by wrapping around the valley. Note that wrap winding is a method of winding a part of the tapes of adjacent layers in the width direction when the tape is wound spirally.
The self-bonding tape used here is made of an insulating compound mainly composed of synthetic resin and synthetic rubber, and the gap between the tape and the tape is filled with the passage of time since winding. Has the property of disappearing and integrating. In addition, the self-bonding tape does not have an adhesive layer, and the self-bonding property allows the tapes to be in close contact with each other and integrated to maintain a layered form.
In the following description, the term “self-adhesive tape” refers to a self-adhesive tape having the above configuration.

Groove portions 111a and 92a are formed in the vicinity of the lower end portion of the conductor lead bar 111 and the upper end portion of the insulating layer 92 along the respective outer peripheral surfaces. A curable resin layer 22 is formed so as to cover the entire outer peripheral surface of the first self-bonding tape layer 21 from the groove 111 a of the conductor lead bar 111 to the groove 92 a of the insulating layer 92.
The curable resin layer 22 is formed of a curable resin having a property of being cured with time or by performing a predetermined curing process, for example, an epoxy resin heat-resistant putty. This epoxy resin-based heat-resistant putty can be obtained by adding a curing process to those that cure over time, such as those that start curing by mixing two liquids or those that cure by maintaining at a predetermined temperature. Any one that cures may be used.
The curable resin layer 22 is cured in a state in which the heat-resistant putty enters the groove portion 111a of the conductor lead bar 111 and the inner side of the groove portion 92a of the insulating layer 92, thereby maintaining a constant distance between them. Can be suppressed.

The second self-bonding tape layer 23 is formed from the outer peripheral surface of the conductor lead bar 111 to the outer peripheral surface of the insulating layer 92 so as to cover the entire outer peripheral surface of the curable resin layer 22.
The second self-bonding tape layer 23 is formed by wrapping a self-bonding tape. The second self-bonding tape layer 23 may be composed of a plurality of layers of self-bonding tape.

The watertight tape layer 24 is formed from the outer peripheral surface of the conductor lead bar 111 to the outer peripheral surface of the insulating layer 92 so as to cover the entire outer peripheral surface of the second self-bonding tape layer 23.
The watertight tape layer 24 is formed by wrapping a watertight tape. The watertight tape used here contains butyl rubber or the like as a material, and has self-bonding properties. Therefore, the gap between the tapes is filled with the passage of time after winding, and the contact portions between the tapes have a property of being in close contact and being integrated. And since this watertight tape layer 24 also has oil tightness, the penetration | invasion of the insulating oil 28 to the cable conductor 91 from the outside can be suppressed.

The third self-bonding tape layer 25 is formed from the outer peripheral surface of the conductor lead bar 111 to the outer peripheral surface of the insulating layer 92 so as to cover the entire outer peripheral surface of the watertight tape layer 24.
The third self-bonding tape layer 25 is also formed by wrapping the self-bonding tape. The third self-bonding tape layer 25 may also be composed of a plurality of layers of self-bonding tape.

The shrinkable tube 31 is attached from the outer peripheral surface of the conductor lead bar 111 to the outer peripheral surface of the insulating layer 92 so as to cover the entire outer peripheral surface of the third self-bonding tape layer 25.
The shrinkable tube 31 has heat shrinkability, and after being mounted in the above arrangement, the whole is shrunk by heating from the outside, and all the layers inside thereof are tightened. And thereby, the tapes of the first to third self-bonding tape layers 21, 23, 25 and the watertight tape layer 24 are pressure-bonded to each other, and self-fusion is promoted, and the disappearance of the mutual gap is promoted.

The polyethylene tape layer 32 is formed from the outer peripheral surface of the conductor lead bar 111 to the outer peripheral surface of the insulating layer 92 so as to cover the entire outer peripheral surface of the shrinkable tube 31.
The polyethylene tape layer 32 is formed by wrapping a polyethylene tape having an adhesive layer mainly made of polyethylene having heat resistance and insulation.

Next, a method for forming the oil stop structure 10 having the above configuration will be described.
First, in a state where the conductor lead bar 111 is attached to the tip of the cable conductor 91 of the power cable 90, the self-bonding tape is formed on the outer peripheral surface of the cable conductor 91 exposed between the conductor lead bar 111 and the insulating layer 92. Wrapping is performed to form the first self-bonding tape layer 21. At this time, the self-bonding tape is overlapped and wound until the first self-bonding tape layer 21 becomes equal to the outer diameter of the conductor lead bar 111.
Then, a curable resin layer 22 is formed by applying an epoxy resin heat-resistant putty from the groove 111 a of the conductor lead bar 111 to the groove 92 a of the insulating layer 92.
Thereafter, the second self-adhesive tape layer 23, the water-tight tape layer 24, and the third self-adhesive tape layer 25 are coated with a self-adhesive tape or a water-tight tape so as to cover the outer peripheral surface of the lower layer in order. Wrap to form.

Next, the shrinkable tube 31 is attached so as to cover the entire outer peripheral surface of the third self-bonding tape layer 25 which is the outermost layer of the oil stopper reinforcing layer 20. The shrinkable tube 31 may be mounted in advance at a position retracted from the formation position of the oil stop reinforcing layer 20 in the insulating layer 92 or the conductor lead bar 111.
Next, the shrink tube 31 is heated from the periphery of the shrink tube 31 with a hot air dryer. As a result, the shrinkable tube 31 is thermally shrunk, the inner oil-proof reinforcing layer 20 is tightened toward the center side, and the first to third self-bonding tape layers 21, 23, 25 and the watertight tape layer 24 are respectively The tapes are self-fused to fill the gaps and integrate to complete layer formation.
Thereafter, a polyethylene tape is wrapped so as to cover the entire outer peripheral surface of the shrinkable tube 31, and the polyethylene tape is softened or melted by heating with a hot air drier from the periphery thereof to form the polyethylene tape layer 32. As a result, a polyethylene layer is molded around the first to third self-bonding tape layers 21, 23, 25, the watertight tape layer 24 and the shrinkable tube 31.
Thus, the oil retaining structure 10 is formed.

[Technical effects of the embodiment]
As described above, the oil stopper structure 10 of the air end connection portion 100 includes the oil stopper reinforcing layer 20 having the plurality of self-bonding tape layers 21, 23, 25 and the watertight tape layer 24 interposed therebetween. It has excellent oil tightness because it is equipped. For this reason, even when the oil stopper reinforcing layer 20 is held by the shrinkable tube 31 from the outside, it is possible to exhibit high oil tightness.
Therefore, it is possible to eliminate the need for a mold layer formed by strict temperature management using a heating device or a temperature management device.
Therefore, the manufacturing cost of the oil stopper structure 10 can be reduced, and the forming operation can be performed quickly and easily.

In addition, since each of the self-bonding tape layers 21, 23, 25 and the watertight tape layer 24 has self-bonding properties, the occurrence of gaps between the tapes is reduced, and higher oil-tightness is exhibited. It is possible.
Further, since the oil retaining reinforcing layer 20 includes the curable resin layer 22 formed so as to straddle the groove portion 111a of the conductor lead bar 111 and the groove portion 92a of the insulating layer 92, the influence of the expansion and contraction of the power cable 90 is exerted. It is possible to suppress the occurrence of peeling and cracking at each part of the oil stopper structure 10 and maintain high oil tightness over a long period of time.

Moreover, in the oil stopper structure 10 of this embodiment, the oil stopper reinforcing layer 20 is pressed and tightened by the shrinkable tube 31 and the polyethylene tape layer 32, so that self-fusion of the oil stopper reinforcing layer 20 is promoted, and the oil tightness is excellent. An oil stop structure can be formed.
In addition, since the polyethylene tape layer 32 is formed by winding, heating, softening and melting the polyethylene tape, and molding the polyethylene, the oil-resisting structure is more excellent in oil tightness.

[Another example of termination connection]
Although the air termination connection part 100 was illustrated as a termination | terminus connection part, it cannot be overemphasized that the oil stop structure 10 may be provided in other termination | terminus connection parts.
For example, as shown in FIG. 3, in the end-of-oil connecting portion 100A in which the soot tube 120A is accommodated in the container 171A filled with insulating oil, in the region 172A where the insulating oil is filled inside the soot tube 120A, The cable conductor 91 of the power cable 90 is connected to the conductor lead bar 111A. The oil stopper structure 10 may be provided from the outer peripheral surface of the conductor lead bar 111A to the outer peripheral surface of the insulating layer 92 of the power cable 90. In this case, the same technical effect as that obtained when the oil stopper structure 10 is provided in the air end connection portion 100 can be obtained.

In addition, as shown in FIG. 4, for example, in the in-gas termination connection portion 100B in which the soot tube 120B is accommodated in a container 171B filled with an insulating gas such as SF ₆ , insulating oil is filled inside the soot tube 120B. Within the region 172B, the cable conductor 91 of the power cable 90 is connected to the conductor lead bar 111A. The oil stopper structure 10 may be provided from the outer peripheral surface of the conductor lead bar 111B to the outer peripheral surface of the insulating layer 92 of the power cable 90. In this case, the same technical effect as that obtained when the oil stopper structure 10 is provided in the air end connection portion 100 can be obtained.

[Others]
The polyethylene tape layer 32 covers the entire outer peripheral surface of the shrinkable tube 31, but is not limited to this. The polyethylene tape layer 32 covers at least a boundary portion between the shrink tube 31 and the outer peripheral surface of the conductor lead bar 111 at both ends of the shrink tube 31 and a boundary portion between the shrink tube 31 and the outer peripheral surface of the insulating layer 92. What is necessary is not to form in the part between these.
Further, the polyethylene tape layer 32 can be replaced with a tape layer made of another thermoplastic resin.
Furthermore, as the shrinkable tube 31, not only a heat shrinkable tube but also a normal temperature shrinkable tube can be used.

DESCRIPTION OF SYMBOLS 10 Oil stop structure 20 Oil stop reinforcement layer 21 1st self-fusing tape layer 22 Curable resin layer 23 2nd self-fusing tape layer 24 Watertight tape layer 25 3rd each self-fusing tape layer 28 Insulating oil 31 Shrinkable tube 32 Polyethylene tape layer (coating layer)
90 Power cable 91 Cable conductor (conductor part)
92 Insulating layer 92a Groove portion 100 In-air termination connection portion 100A In-oil termination connection portion 100B In-gas termination connection portion 111, 111A, 111B Conductor lead bar 111a Groove portions 120, 120A, 120B 碍 pipe 128 Insulating oil

Claims (5)

In the oil stop structure of the terminal connection portion formed between the conductor portion of the power cable housed inside the soot tube filled with insulating oil and the conductor lead bar,
From the insulating layer of the power cable to the conductor lead bar, an oil stop reinforcing layer formed around the conductor part,
A shrinkable tube covering the entire outer peripheral surface of the oil stop reinforcing layer;
A covering portion covering at least a boundary portion between one end portion of the shrinkable tube and the outer peripheral surface of the conductor lead bar and a boundary portion between the other end portion of the shrinkable tube and the outer peripheral surface of the insulating layer;
The oil stop structure for an end connection portion, wherein the oil stop reinforcing layer includes a self-bonding tape layer and a watertight tape layer.   2. The oil stop structure for an end connection portion according to claim 1, wherein the self-bonding tape layer is made of a compound mainly composed of synthetic resin and synthetic rubber.   3. The oil stop structure for a terminal connection portion according to claim 1, wherein the watertight tape layer contains butyl rubber and has a self-bonding property.   The said oil stop reinforcement layer contains the curable resin layer formed ranging from the outer peripheral surface of the said conductor extraction rod to the outer peripheral surface of the said insulating layer, It is any one of Claim 1 to 3 characterized by the above-mentioned. The oil stop structure of the end connection part.   5. The oil stopper for a terminal connection portion according to claim 1, wherein a layer of a thermoplastic resin tape is wound around the outer periphery of the shrinkable tube as the covering portion. Construction.

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