JP6169118B2 - Power cable air termination connection - Google Patents

Description

  The present invention relates to an air termination connection portion in which an end portion of a power cable is accommodated in a soot tube.

2. Description of the Related Art Conventionally, an oil-immersed aerial 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 portion (hereinafter referred to as a termination connection portion). It has been. In recent years, in the air termination connection part, a pre-molded insulator that is attached without providing an epoxy seat to a conductor that has been exposed by stepping off at the tip of a power cable housed in a soot pipe has been provided. It is used.
And the conventional air termination | terminus connection part is a cylindrical oil stop metal fitting extended toward the inner side (upper) of the said pipe from the bottom of a pipe, and a cylindrical cable extended toward the outer side (downward) from the bottom of the pipe And protective metal fittings. In addition, this air terminal connection part is designed to prevent leakage of insulating oil by a rubber tube from the upper end of the oil stopper to the outer peripheral surface of the insulating part of the power cable. The waterproof tape layer prevents the intrusion of moisture from the outside over the outer peripheral surface of the insulating portion (see, for example, Patent Document 1).

JP 2000-152482 A

  However, since the above-mentioned air termination connection portion is equipped with a cylindrical oil stopper and a cylindrical cable protection bracket at the bottom of the soot tube, it increases the number of parts and increases the burden of installation work. There was an inconvenience.

  An object of the present invention is to reduce the number of parts and the burden of installation work.

The invention described in claim 1
A vertically placed vertical pipe that houses one end of the power cable;
An insulating oil placed inside the tub,
An insulator provided on the outer periphery of the power cable inside the pipe,
In the terminal connection part of the power cable comprising a lower metal fitting attached to the lower part of the steel pipe,
The lower metal fitting has a cylindrical portion that extends toward the inside of the soot tube while the power cable is inserted,
An oil stop tube provided between the distal end portion of the cylindrical portion and the outer peripheral surface of the power cable;
A water shielding tube provided between the distal end portion of the cylindrical portion and the outer peripheral surface of the power cable and provided inside the oil retaining tube is provided.

The invention according to claim 2 is the air termination connection part according to claim 1,
The insulator is a pre-molded insulator formed in advance before being attached to the power cable.

The invention according to claim 3 is the aerial termination connection part according to claim 1 or 2,
A gap between the oil retaining tube and the water shielding tube is filled between the oil retaining tube and the water shielding tube, which electrically connects the shielding layer of the power cable and the lower metal fitting. A water shielding layer is provided.

Since the present invention has a lower metal fitting having a cylindrical portion extending toward the inside of the pipe, and a water shielding tube and an oil stop tube are provided between the cylindrical portion and the power cable, It is possible to effectively suppress leakage of the insulating oil in the dredger by the oil stop tube, and to effectively prevent external moisture from entering the dredger by the water shielding tube.
Furthermore, since the water shielding tube is arranged inside the oil stopper tube, both the oil stopper tube and the water shielding tube can be attached to the cylindrical portion of the lower metal fitting. This eliminates the need for the cylindrical cable protection metal fitting, which makes it possible to reduce the number of parts in the aerial termination connection part and reduce the burden of installation work.

It is sectional drawing which shows schematic structure of the air termination | terminus connection part which concerns on embodiment. It is an expanded sectional view of the lower part of the termination | terminus connection part of FIG.

[Air termination connection]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a cross-sectional view illustrating a schematic configuration of an aerial termination connection unit 1 (hereinafter simply referred to as “termination connection unit 1”) according to an embodiment. In this figure, the power cable 11 is a power cable (for example, a CV cable) insulated with rubber or plastic. The power cable 11 includes a conductor 111, an insulating layer 112 formed on the outer periphery of the conductor 111, an external semiconductive layer 113 formed on the outer periphery of the insulating layer 112, and a shielding layer 115 formed on the outer periphery of the external semiconductive layer 113. A sheath 114 as an anticorrosion layer covering the outer periphery of the shielding layer 115 is provided, and each layer is stepped and the outer peripheral surface of each layer is sequentially exposed. In addition, a conductive lead bar 13 having conductivity is connected to the tip of the conductor 111.

[Power cable]
A rubber stress cone 14, which is a pre-molded insulator as an insulator, is attached to the outer peripheral surface of the power cable 11 from the outer semiconductive layer 113 to the insulating layer 112. The rubber stress cone 14 is mainly composed of a semiconductive rubber portion 141 for electric field relaxation and an insulating rubber portion 142, and the semiconductive rubber portion 141 is electrically connected to the external semiconductive layer 113 of the power cable 11.
Before the rubber stress cone 14 is attached to the power cable 11, the rubber stress cone 14 is integrally molded in advance by molding or the like, and the inner diameter of the through hole provided at the center is formed to be smaller than the outer diameter of the power cable 11. The rubber stress cone 14 is lowered from above through the insulating layer 112 and is set at a position where the lower end portion of the semiconductive rubber portion 141 for electric field relaxation reaches the upper end portion of the external semiconductive layer 113.

[Tube]
The soot tube 12 is, for example, a composite soot tube in which the outer periphery of a hollow cylinder 121 made of fiber reinforced plastic (FRP) is covered with a jacket 122 having a collar made of rubber or plastic. The soot tube 12 may be made of other highly insulating materials such as those made of porcelain or glass.
The vertical pipe 12 is a vertical type installed with its longitudinal direction along the vertical direction.

An upper metal fitting 15 is attached to the upper end portion of the soot tube 12 via an O-ring (not shown). The upper metal fitting 15 fastens and holds the conductor lead bar 13 connected to the tip of the conductor 111 of the power cable 11 with a fastening metal 151, and a cover 152 is attached to the upper surface side of the upper metal fitting 15.
The conductor lead bar 13 passes through the centers of the upper metal fitting 15 and the cover 152, and the upper end portion thereof is led out to the outside.
On the other hand, the power cable 11 is fixed by cleats or the like below the air end connection portion 1. As a result, the power cable 11 is supported by its own weight so as not to come out of the air end connection portion 1.

Further, a lower metal fitting 16 is attached to the bottom of the soot tube 12.
And the insulating space 20 is filled in the internal space of the soot tube 12. That is, the end connection portion 1 is configured such that the end portion of the power cable 11 and a part of the conductor lead bar 13 are accommodated in the soot tube 12, and the soot tube 12 is filled with the insulating oil 20.
Examples of the insulating oil 20 include insulating oil or gel mainly composed of silicone oil.

[Lower bracket]
FIG. 2 is an enlarged cross-sectional view of the lower portion of the termination connection portion 1.
As shown in the figure, the lower metal fitting 16 is mainly concentric with the lower surface of the attachment metal 161 and the attachment metal 161 having a circular shape in plan view and having a wide opening at the center and supporting the lower end portion of the vertical tube 12 from below. The seal pipe 162 is attached.
The mounting bracket 161 supports the soot tube 12 in a state where a cylindrical portion 161 a raised upward from the center inserts the lower end portion of the hollow cylinder 121 of the soot tube 12.
The mounting bracket 161 is connected to the gantry 164 via a plurality of support levers 163. Thereby, the soot pipe 12 is fixed on the mount 125 in the standing state.

The seal pipe 162 is provided in a cylindrical portion 162a inserted into the inside of the tub tube 12 from the central opening of the mounting bracket 161, and a circular shape that closes the central opening of the mounting bracket 161. The flange portion 162b is integrally formed of a metal having corrosion resistance and sufficient strength.
The outer diameter of the flange portion 162b is larger than the inner diameter of the central opening of the mounting bracket 161, and the flange portion is clamped by the bolt 166 with the O-ring 165 interposed between overlapping portions of the upper surface of the flange portion 162b and the lower surface of the mounting bracket 161. 162b is fixed to the mounting bracket 161. That is, between the seal pipe 162 and the mounting bracket 161, the O-ring 165 prevents insulation oil leakage and moisture intrusion.

  The inner diameter of the cylindrical portion 162a of the seal pipe 162 is somewhat larger than the outer diameter of the sheath 114 of the power cable 11, and the power cable 11 is in a state where a gap is generated with respect to the inner peripheral surface of the cylindrical portion 162a. It inserts from the lower end part of the said cylindrical part 162a. In addition, the power cable 11 is held in the soot tube 12 in a state where the boundary between the outer semiconductive layer 113 and the sheath 114 is higher than the upper end of the cylindrical portion 162a.

  As described above, a slight gap is formed between the cylindrical portion 162a of the seal pipe 162 and the sheath 114 of the power cable 11, so that the gap is formed between the power cable 11 and the cylindrical portion 162a of the seal pipe 162. Are equipped with an oil stop tube 17 and a water shielding tube 18.

The water shielding tube 18 is a cylindrical tube made of a material that is open at both ends and does not transmit moisture. For the water shielding tube 18, for example, a shrinkable tube including a lead foil layer is used.
In the state where the power shielding tube 18 is inserted through the power cable 11, the inner peripheral surface of one end portion (the upper end portion side in FIG. 2) of the water shielding tube 18 is the outer peripheral surface of the sheath 114 of the power cable 11. It adheres without gaps over the entire circumference. Further, the inner peripheral surface of the other end portion (the lower end side in FIG. 2) of the water shielding tube 18 is in close contact with the entire outer periphery of the cylindrical portion 162 a of the seal pipe 162 without any gap. The close contact state at both ends of the water shielding tube 18 may be realized by forming the water shielding tube 18 from a shrinkable material and self-shrinking, or by welding the water shielding tube 18. . Moreover, you may adhere | attach with a waterproof adhesive.

The oil stopper tube 17 is a cylindrical tube made of a material that is open at both ends and does not transmit oil. As the oil stop tube 17, for example, a shrinkable tube made of crosslinked polyethylene is used.
The oil retaining tube 17 has the inner peripheral surface of one end portion (the upper end portion side in FIG. 2) of the oil retaining tube 17 in the state where the power cable 11 is inserted inside, and the outer semiconductive layer 113 of the power cable 11. It adheres without a gap over the entire circumference of the outer peripheral surface. Further, the inner peripheral surface of the other end portion (the lower end side in FIG. 2) of the oil stop tube 17 is in close contact with the entire outer periphery of the cylindrical portion 162 a of the seal pipe 162 without any gap. The close contact state at both ends of the oil stop tube 17 may also be realized by forming the oil stop tube 17 from a shrinkable material and self-shrinking, or by welding the oil stop tube 17. good. Moreover, you may adhere | attach with an adhesive agent with oil resistance.

The upper end of the oil retaining tube 17 is in close contact with the power cable 11 above the upper end of the water shielding tube 18, and the lower end of the oil retaining tube 17 is sealed below the lower end of the water shielding tube 18. The pipe 162 is in close contact with the cylindrical portion 162a. Further, the water shielding tube 18 is disposed inside the oil stop tube 17.
For this reason, the oil stop tube 17 effectively suppresses the leakage of the insulating oil 20 from the gap between the cylindrical portion 162a of the seal pipe 162 and the power cable 11 and the adhesion of the insulating oil 20 to the water shielding tube 18. be able to. Further, since the upper end portion of the oil stop tube 17 is in close contact with the outer peripheral surface of the outer semiconductive layer 113 of the power cable 11, the insulating oil 20 between the outer semiconductive layer 113 of the power cable 11 and the sheath 114 is used. It is also possible to suppress the intrusion.
Further, the water shielding tube 18 can effectively suppress the intrusion of external moisture from the gap between the cylindrical portion 162 a of the seal pipe 162 and the power cable 11 and the adhesion of moisture to the oil stopper tube 17. .
In addition, since the upper end portion of the water shielding tube 18 is in close contact with the outer peripheral surface of the sheath 114 of the power cable 11, it is possible to suppress moisture from entering between the outer semiconductive layer 113 and the sheath 114 of the power cable 11. Is possible.

[Assembling the aerial termination connection part]
When assembling the termination connection portion 1 shown in FIG. 1, first, one end portion that becomes the termination side of the power cable 11 is raised vertically, and the sheath 114, the shielding layer 115, the external semiconductive layer 113, and the insulating layer 112 are externally provided. Steps are stripped in order with a predetermined length (power cable stripping step).
The power cable 11 is passed through the seal pipe 162, the mounting bracket 161, the water shielding tube 18 and the oil stop tube 17 in advance, and one end of the power cable 11 is inserted inside the rubber stress cone 14. Then, the rubber stress cone 14 is lowered to the boundary between the external semiconductive layer 113 and the insulating layer 112 (stress cone attaching step).

Next, the seal pipe 162 is positioned at an appropriate position of the power cable 11 (slightly below the boundary position between the outer semiconductive layer 113 and the sheath 114), and the water shielding tube 18 is inserted into the cylindrical portion 162a of the seal pipe 162. And the sheath 114 of the power cable 11. Next, the shielding layer 115 and the seal pipe 162 are electrically connected by a flat knitted copper wire 22 as a connecting portion. The flat knitted copper wire 22 is covered with a water shielding tape so as not to damage the tube 18 and the oil stopper tube 17, and the gap between the flat knitted copper wire 22 and the tube 18 or the oil stopper tube 17 is filled with the water barrier tape. The water shielding layer 21 is formed.
And the oil stop tube 17 is piled up on the outer side of the water shielding layer 21, and the said oil stop tube 17 is attached between the cylindrical part 162a and the external semiconductive layer 113 of the electric power cable 11 (tube attachment process). For example, a self-bonding tape FB-W (manufactured by Fujikura) can be used as the water shielding tape.

Next, the conductor lead bar 13 is attached to the conductor 111 of the power cable 11. The conductor lead bar 13 can be fastened and fixed to the conductor 111 by being compressed from the outside.
And the one end part of the electric power cable 11 is inserted from the lower end part of the soot pipe 12, and the attachment metal fitting 161 and the seal pipe 162 are fixed to the lower end part of the soot pipe 12 (power cable accommodation process).

Next, liquid insulating oil 20 is filled from the upper part of the soot tube 12 into the interior space of the soot tube 12 and the lower metal fitting 16 (insulating oil filling step).
Then, the conductor lead bar 13 is fixed to the upper metal fitting 15 by the fastening metal 151, and the upper metal fitting 15 and the cover 152 are attached to the upper end portion of the soot tube 12. Thereby, the termination connection part 1 is completed.

[Technical effects of the embodiment of the invention]
The above-mentioned air terminal connection part 1 has a seal pipe 162 having a cylindrical part 162 a extending toward the inside of the soot tube 12, and has a water shielding property between the cylindrical part 162 a and the sheath 114 of the power cable 11. Tube 18 is provided, and oil stop tube 17 is provided between cylindrical portion 162 a and outer semiconductive layer 113 of power cable 11.
As a result, leakage of the insulating oil 20 in the dredge pipe 12 can be effectively suppressed by the oil retaining tube 17, and entry of external moisture into the dredge pipe 12 can be effectively suppressed by the water shielding tube 18. .

  Furthermore, since the water shielding tube 18 is disposed inside the oil stopper tube 17, both the oil stopper tube 17 and the water shielding tube 18 can be attached to one cylindrical portion 162a. In addition, it is possible to eliminate the need for a cylindrical cable protection metal fitting that has been conventionally required, and to reduce the number of parts of the air end connection portion 1 and the burden of installation work.

  Further, since the rubber stress cone 14 is brought into close contact with the cable by the contraction force of the rubber stress cone 14 itself, it is not necessary to provide an epoxy seat on the outer periphery of the power cable 11, thereby the oil stop tube 17 and the water shielding tube. It is possible to easily secure the mounting location of the tube 18.

  Further, the cylindrical portion 162a of the seal pipe 162 is inserted into the inside of the soot tube 12, the oil stop tube 17 is cylindrical, and the inner peripheral surface thereof is electrically connected to the outer peripheral surface of the cylindrical portion 162a of the seal pipe 162. This structure is in close contact with the outer peripheral surface of the outer semiconductive layer 113 of the cable 11. Accordingly, the oil retaining tube 17 receives the tightening pressure from the surroundings by the insulating oil 20 in the vertical pipe 12. For this reason, both the tight contact portion with the cylindrical portion 162a and the close contact portion with the external semiconductive layer 113 in the oil stop tube 17 are strongly tightened from the periphery, exhibit high sealing performance, and are more effective. In addition, leakage of insulating oil can be suppressed.

  Also, the flat braided copper wire 22 and the oil retaining tube 17 that electrically connect the shielding layer 115 of the power cable 11 and the cylindrical portion 162a of the seal pipe 162 between the oil retaining tube 17 and the water shielding tube 18. Since the tape layer 21 made of a water shielding tape that fills the gap between the water shielding tube 18 and the water shielding tube 18 is provided, it is possible to maintain a high sealing performance while ensuring an electrical connection between the shielding layer 115 and the lower metal fitting 16. It becomes.

DESCRIPTION OF SYMBOLS 1 Air termination | terminus connection part 11 Electric power cable 12 Steel pipe 13 Conductor extraction rod 14 Rubber stress cone (insulator, premold insulator)
15 Upper metal fitting 16 Lower metal fitting 17 Oil retaining tube 18 Water shielding tube 20 Insulating oil 21 Water shielding layer 22 Flat knitted copper wire (connection part)
111 Conductor 112 Insulating layer 113 External semiconductive layer 114 Sheath (corrosion protection layer)
115 Shielding layer 162 Seal pipe 162a Tubular part

Claims (3)

A vertically placed vertical pipe that houses one end of the power cable;
An insulating oil placed inside the tub,
An insulator provided on the outer periphery of the power cable inside the pipe,
In the terminal connection part of the power cable comprising a lower metal fitting attached to the lower part of the steel pipe,
The lower metal fitting has a cylindrical portion that extends toward the inside of the soot tube while the power cable is inserted,
An oil stop tube provided between the distal end portion of the cylindrical portion and the outer peripheral surface of the power cable;
An air terminal connection portion of a power cable, comprising: a water shielding tube provided between a distal end portion of the cylindrical portion and an outer peripheral surface of the power cable and inside the oil stop tube. .   The air cable terminal connection part according to claim 1, wherein the insulator is a pre-molded insulator formed in advance before being attached to the power cable.   A gap between the oil retaining tube and the water shielding tube is filled between the oil retaining tube and the water shielding tube, which electrically connects the shielding layer of the power cable and the lower metal fitting. The in-air terminal connection part of the power cable according to claim 1, further comprising a water shielding layer.

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