JP2002209320A - Method for repairing plumb joint part of cable and lead joint part reinforcing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an urgent oil leakage repairing method and its structure which enable an instant repair without needing skill, in the case of repair when oil leakage is generated in a plumb joint part of an OF cable. SOLUTION: In the repairing method, an elastic material tape is wound around the outer periphery of the plumb joint part of the OF cable connecting part, where the oil leakage is generated, a binding wire is laminated and wound from above the tape, the wire is surrounded from above by using a thermal contraction tube with a fastener, and the tube is contracted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for repairing oil leakage in a lead section used for a terminal connection section or an intermediate connection section of an OF cable (oil immersion power cable), and a reinforcement structure for the lead section. About.

[0002]

2. Description of the Related Art In a connection portion of an OF cable or the like, a seal between a cable sheath and a box of the cable connection portion is usually processed by a lead work. FIG. 4 is an explanatory cross-sectional view of the structure of a lead portion of a conventionally used OF cable connecting portion. At the end of the OF cable 1, the anticorrosion layer 2 made of vinyl chloride resin or the like is peeled off to expose a metal sheath 3 made of aluminum or the like, and the metal sheath 3 is further cut at an appropriate position to form a cable core 4 at an appropriate position. Will be exposed. The cable core 4 is composed of an oil passage, a conductor, insulating paper, a shielding layer, and the like. The conductor is exposed rightward in the drawing (not shown) and is electrically connected to a conductor of another cable or a terminal portion of a power device. The OF cable 1 is filled with insulating oil in an oil passage therein, and a hydraulic pressure adjusting tank provided outside always applies a hydraulic pressure higher than the atmospheric pressure to suppress the generation of voids in the insulating oil and obtain a withstand voltage characteristic. It has a mechanism.

[0003] At the end of the OF cable 1, a connection box 5 is provided.
Is mounted, and the inside of the connection box 5 is filled with the pressurized insulating oil 6. The connecting portion between the connection portion box 5 and the metal sheath 3 is sealed by a lead processing to form a lead processed portion 7. The lead processing is performed by flowing the molten lead to the connecting portion between the connection portion box 5 and the metal sheath 3 and raising it. Since the lead portion 7 is not very strong, a resin reinforcing layer 8 of an epoxy resin or the like is provided around the lead portion. The resin reinforcing layer 8 is formed by raising and curing an uncured epoxy resin putty from the periphery of the lead portion 7 to the connection portion box 5 and the metal sheath 3. Around the resin reinforcing layer 8, a self-fusing rubber tape 9, a waterproof tape 10, an adhesive PVC tape 11
Are wound in order.

[0004] The lead connection structure of the cable is formed in this manner. However, oil leakage may rarely occur due to various factors such as expansion and contraction of each part due to use and load of external force. Oil leakage mainly occurs when a gap is formed at the boundary between the lead processing part 7 and the connection part box 5 or at the boundary between the lead processing part 7 and the metal sheath 3. Conventionally, when such oil leakage occurs, repair is performed by performing lead processing again. In other words, the adhesive PVC tape 11, the waterproof tape 10,
After the self-fusing rubber tape 9 is peeled off and the resin reinforcing layer 8 is removed, the work of flowing molten lead and raising the lead is performed again to perform the lead processing again. Thereafter, a resin reinforcing layer is formed again by raising an epoxy putty, and each tape is wound thereon.

[0005]

By performing the above-described lead processing again, permanent oil leakage can be repaired. However, the lead processing has the following inconveniences. (A) The lead work and the subsequent formation of the epoxy resin reinforcing layer are performed by manually pouring in and raising lead and raising the epoxy putty, and the quality of the finish depends largely on the skill of the worker. (B) Therefore, the repair work of the oil leak requires an appointed skilled worker, and it is difficult for the power line operator to immediately repair the work. Therefore, emergency response at the time of oil leakage cannot be performed, and the amount of oil leakage increases. (C) Lead work is a large-scale operation that uses fire, and requires pre-curing of surrounding equipment. (D) It is necessary to stop the power line during the lead work.

Accordingly, the present invention is to provide an emergency oil leak repair method and its structure that can be constructed immediately without the above-mentioned inconvenience and without skill.

[0007]

A first aspect of the present invention is a method for repairing oil leakage at a lead connection portion of an OF cable, wherein the oil leakage repair method is provided at or around a lead connection portion provided at the OF cable connection portion. A method of repairing a lead connection portion by winding an elastic tape around the reinforcing layer, then surrounding the above with a shrinkable tube with a fastener, and then performing a shrinkage treatment of the shrinkable tube with a fastener ( Claim 1).

The present invention also relates to a method for repairing oil leakage of a lead connection portion of an OF cable, wherein an elastic tape is wound around a lead connection portion provided at the OF cable connection portion or a reinforcing layer provided therearound. Turn, then wind a bind wire from above the wound layer of the elastic tape, then surround it with a zippered shrinkable tube from above, then shrink the zippered shrinkable tube to form a lead connection It is a repair method (claim 2).

The above-mentioned winding of the elastic tape can also be performed by sequentially winding a first elastic tape having a small size and a second elastic tape having a large size.

The lead connection thus repaired includes an OF cable end having a metal sheath, a cable connection box attached to the OF cable end, and the cable connection box and the OF cable. A lead portion formed by being raised at the connection boundary of the metal sheath, a resin reinforcing layer covering the lead portion, an elastic tape winding layer covering the resin reinforcing layer, and an elastic tape winding layer A lead joint connecting portion reinforcing structure comprising a shrinkable tube with a zipper that further envelops the circulating layer (claim 4).

Further, an OF cable terminal having a metal sheath, a cable connecting box attached to the OF cable terminal, and a connection boundary between the cable connecting box and the metal sheath of the OF cable. A formed lead portion, a resin reinforcing layer surrounding the lead portion, an elastic tape wound layer enclosing the resin reinforcing layer, and a bind wound around the elastic tape wound layer. A lead connection connecting portion reinforcing structure comprising a wire wound layer and a shrinkable tube with a zipper further encapsulating the bind wire wound layer is provided (claim 5).

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for repairing a lead connection section according to the present invention will be described in order with reference to FIGS. 4, 5, 1, and 2. FIG. In these figures, the same parts are denoted by the same reference numerals. FIG. 4 is a lead connection structure of an OF cable conventionally used as described above, FIG. 5 is a sectional view showing a state in the middle of repair work, and FIG. 1 is a sectional view showing a state after repair according to the present invention. FIG. 2 is an enlarged explanatory view showing details of the laminated structure in FIG.

[0013] The conventional O described in FIG.
When oil leakage occurs in the lead cable connection structure of the F cable, repair work is performed in the following procedure after identifying the oil leakage location and confirming the safety of the working environment.

(1) Adhesive PVC tape 1 having lead connection structure
1. The waterproof tape 10 and the self-fusing rubber tape 9 are peeled off from the outside to expose the resin reinforcing layer 8 made of epoxy resin. The state at this time is shown in the cross-sectional explanatory view of FIG.

(2) Next, a first elastic tape is wound so as to cover from the periphery of the resin reinforcing layer 8 to above the connection box 5 and the metal sheath 3, as shown in FIGS. 1 and 2. The first tape winding layer 12 is formed. As the first elastic tape, a silicon rubber tape having a width of about 10 to 15 mm and a thickness of about 1 mm, which is relatively small in size and which is rich in elasticity and flexibility is used. The use of such a thin tape having an appropriate size and high elasticity provides good sealing performance against oil leakage. Since the lead portion 7 and the resin reinforcing layer 8 are formed by being raised by hand as described above, the surface shape thereof is not a fixed shape like a mold but an irregular shape by being raised. And has complicated irregularities. The metal sheath 3 is also provided with uneven folds as shown in the figure, and the boundary between the resin reinforcing layer 8 and the metal sheath 3 and the connection box 5 is formed as a valley when viewed from the outside. In many cases, the shape becomes concave. As described above, the lead connection portion has a complicated shape having irregularities, but as described above, if a tape having a relatively small size and high elasticity and flexibility is wound while applying tension, the tape expands and contracts. The seal can be effectively fitted to a complicated shape, and oil leakage can be reliably sealed.

(3) Next, a second elastic tape is wound so as to cover from the periphery of the first tape winding layer 12 to above the connection box 5 and the metal sheath 3, and the second tape winding is performed. The layer 13 is formed. The second elastic tape is made of vulcanized rubber having high elasticity and strength, and has a width and thickness of about 80 to 100 mm and a thickness of about 2 mm. Wrapping such a wide elastic tape is not only efficient because it can cover a large area and requires a small number of windings if the width is wide. Is to be used as a base for winding. In other words, if such a wide and thick tape is used as the base, the bind wire is easily wound up neatly, and even if the bind wire bites into the elastic tape, it does not go under. It is needless to say that the tape winding layer can be constituted by only one kind of elastic tape without dividing the elastic tape into two layers.

(4) Next, a bind wire is wound around the second tape wound layer 13 from the end into a layer winding to form a bind wire wound layer 14. This bind wire has a diameter of 1
A tin-plated copper wire of about 2 mm is used. In the OF cable, a pressure higher than the atmospheric pressure is applied to the insulating oil 6. Therefore, in order to seal oil leakage,
It is necessary to tighten more strongly than the surroundings at a pressure not to be defeated by the hydraulic pressure, and the bind wound layer is for that purpose.
When high oil leakage prevention characteristics are not required, for example, when the oil pressure of the insulating oil 6 is not so high, the bind wire winding layer 14 can be omitted.

(5) Next, the heat-shrinkable tube 15 with zipper is used to cover the periphery of the bind wire wound layer 14 from above the anticorrosion layer 2 of the OF cable 1 and the connection box 1. The structure of the heat-shrinkable tube with fastener 15 will be described later.

(6) Next, the heat-shrinkable tube 15 with the fastener is heated and shrunk by a heater, a hot air gun or the like, and is brought into close contact with the bind wire winding layer 14, the anticorrosion layer 2, and the connection box 1.

(7) Finally, the self-fusing tape 9, the waterproof tape 10, and the adhesive PVC tape 11 are sequentially wound so as to cover the entire connecting portion in the same manner as performed in the conventional lead connecting portion. Turn to complete the repair work. The work may be completed in the above-described step without winding the self-fusing tape 9, the waterproof tape 10, and the adhesive PVC tape 11.

The zippered heat shrinkable tube 15 used in the above embodiment will be described with reference to FIG. 3A is an external view illustrating a state before use of the heat-shrinkable tube 15 with a fastener, and FIG. 3B is an external view illustrating a state where the heat-shrinkable tube 15 is wound around a long body. The heat-shrinkable tube 15 with a zipper is, as shown in FIG. 1A, a substantially rectangular sleeve layer 16 made of a heat-shrinkable material such as radiation-crosslinked polyolefin, and a pair of fasteners provided on two opposite sides of the sleeve layer. It has a structure including rails 16a and 16b, an adhesive layer 17 provided on the lower surface of the sleeve layer, and a flap 18 provided in connection with one of the fastening rails 16a. Then, as shown in FIG. 2 (b), the pair of fastening rails 16a, 16b
The metal channel 19 is attached in a state where the butts are abutted to form a cylinder. The metal channel 19 has a shape obtained by bending a metal strip into a substantially C-shape, and has ladder-like slits 19a at regular intervals so that bendability can be obtained. Thus, the heat-shrinkable tube with zipper 1
When the elongate body 20 is enveloped in 5 and then heated by a heater or a hot air gun, the sleeve layer 16 is thermally contracted and adheres to the elongate body 20. A heat-shrinkable tube with a zipper having such a structure is known as a repair material for a long body, and is disclosed in Japanese Patent Application Laid-Open No. 58-1978.

Such a heat-shrinkable tube with a zipper can be quickly installed in a repair work site of an OF cable, and can be fitted to a curved surface portion by heat-shrinking to exhibit adhesion. Since the heat-shrinkable tube with a zipper is made of an integral sheet, the heat-shrinkable tube exhibits a higher sealing property against oil leakage as compared with the elastic tape wound around the lower layer.

However, if the winding of the lower elastic tape is omitted and the heat-shrinkable tube with the zipper is directly covered directly with the lead portion 7 or the resin reinforcing layer 8, a sufficient effect of oil leakage repair can be always obtained. I can't. The lead portion 7, the resin reinforcing layer 8, or their joints have complicated irregularities and valleys, and even though the heat-shrinkable tube with fasteners fits by heat-shrinking, the tubing at the depth of those valleys can be fitted. It does not completely adhere to the part, and cannot leak oil leaking from such a valley. In addition, the fastener part of the heat-shrinkable tube with the fastener is a fastener rail 16.
Since the sealing force is obtained by abutting the a and 16b by the elasticity of the metal channel 19, the sealing force is obtained. Therefore, when a high internal pressure of the insulating oil is directly applied, the internal pressure exceeds the sealing force due to the elasticity, and oil leakage occurs. It will be.

Therefore, in this embodiment, by providing an elastic tape winding layer as a lower winding of the heat-shrinkable tube with a zipper, the lead work portion 7, the resin reinforcing layer 8, the unevenness of the seam thereof,
The valley is sealed. Then, since the elastic tape winding layer fills the valley portion, there is no dent on the surface, and the heat-shrinkable tube with fastener can be fitted and adhered. Further, by providing a bind wire winding layer as needed, a sufficient sealing force can be obtained even with a high insulating oil pressure.

The present invention is not limited to the above embodiment. Although the lead section in the above embodiment is an example provided at the boundary between the OF cable and its connection box,
The present invention can be applied to other parts as long as it is a lead section of the F cable. In the above embodiment, the elastic tape is wound while the resin reinforcing layer 8 covering the lead portion 7 is left in the lead connection structure in which oil leakage has occurred, but the resin reinforcing layer 8 is removed. Then, the elastic tape may be wound directly on the lead portion 7. The shrinkable tube with a fastener to be used is not limited to the shape shown in FIG. 3 and may have a fastening mechanism different from the illustrated one.

[0026]

As described above, the repair of the lead work connection portion according to the present invention is performed by winding the tapes, binding wires and installing the shrink tubing with the fastener, and the conventional lead work and formation of the epoxy resin reinforcing layer. It does not require any special skills compared to work. Therefore, it is not necessary to dispatch full-time construction personnel, and it is also possible to perform construction by power line maintenance and management staff, and if oil leakage occurs suddenly, repair can be performed immediately and oil leakage is minimized be able to. In addition, since fire is not used as in the lead processing, construction can be performed immediately even at a site where there is combustible material, and oil leakage can be repaired without stopping the power line. Further, the lead joint connecting portion reinforcing structure according to the present invention is excellent in sealing power for insulating oil, and is also effective for sealing pressurized insulating oil. The present invention is intended for urgent oil leak repair prior to permanent oil leak repair by lead processing again, but it has semi-permanent use because it has high oil leak sealing performance. is there.

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional view showing a reinforcement structure for a lead connection portion of an OF cable after repairing according to the present invention.

FIG. 2 is an enlarged cross-sectional explanatory view for explaining details of a laminated structure of a lead joint connection part reinforcing structure according to the present invention.

FIG. 3 is an explanatory explanatory view showing an example of a heat-shrinkable tube with a fastener used in the present invention.

FIG. 4 is an explanatory sectional view showing a structure of a lead portion of an OF cable connecting portion.

FIG. 5 is an explanatory cross-sectional view showing a state in the middle of a repair work of the OF cable lead connection portion.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 OF cable 3 Metal sheath 4 Cable core 5 Connection box 6 Insulating oil 7 Leaded section 8 Resin reinforcing layer 12 First tape wound layer 13 Second tape wound layer 14 Bind wire wound layer 15 Heat shrink with zipper tube

Claims (5)

[Claims] 1. A method for repairing oil leakage at a lead connection portion of an OF cable, wherein an elastic tape is wound around a lead connection portion provided at the OF cable connection portion or a reinforcing layer provided therearound. A method for repairing a lead joint by turning, then surrounding the above with a shrinkable tube with a zipper, and then performing a shrinkage treatment of the shrinkable tube with a zipper. 2. A method of repairing oil leakage at a lead connection portion of an OF cable, comprising: wrapping an elastic tape around a lead connection portion provided at the OF cable connection portion or a reinforcing layer provided therearound. Turn, then wind a bind wire from above the wound layer of the elastic tape, then surround it with a zippered shrinkable tube from above, then shrink the zippered shrinkable tube to form a lead connection Repair method. 3. The method according to claim 1, wherein the winding of the elastic tape is performed by sequentially winding a first elastic tape having a small dimension and a second elastic tape having a large dimension. 3. The method for repairing a lead connection part according to any one of claims 1 to 2. 4. An OF cable terminal having a metal sheath,
A cable connection portion attached to the OF cable terminal, a lead portion formed by being raised at a connection boundary between the cable connection portion and the metal sheath of the OF cable, and a cover of the lead portion A lead joint connection reinforcement structure comprising a resin reinforcing layer to be formed, a wound elastic tape layer encapsulating the resin reinforcing layer, and a shrinkable tube with a fastener further enclosing the elastic tape wound layer. 5. An OF cable terminal having a metal sheath,
A cable connection portion attached to the OF cable terminal, a lead portion formed by being raised at a connection boundary between the cable connection portion and the metal sheath of the OF cable, and a cover of the lead portion A resin-reinforcing layer, an elastic tape-wound layer encasing the resin-reinforcing layer, a bind wire-wound layer wound around the elastic tape-wound layer, and the bind wire-wound layer. Reinforcement structure for lead joints consisting of a shrinkable tube with a zipper to cover the skin