Oil leak repair method for oil-filled cables

Abstract

To provide an OF cable oil leakage place repair technique that uses no fire, requires no special skill, and can save the trouble and cost for work and perform processing work efficiently in a short time, and further can provide long-period maintenance after the processing work.SOLUTION: There is provided an OF cable oil leakage place repair technique comprising: a first agent application step of applying a curable first adhesive bond 2 to at least one side between one surface side of a metal plate 3 of the same material with a metal layer 11 having a larger area than an oil leakage place P and the oil leakage place P; and a metal coating formation step of sticking the one surface side of the metal plate 3 on the oil leakage place P of the metal layer 11 and curing the first adhesive bond 2 to impart fluid tightness between the metal plate 3 and a surface of the metal layer 11.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for repairing an oil leakage portion of an oil-filled cable. [Background technology]

[0002] Conventionally, in an oil-filled (OF) cable with an oil passage, insulating oil is injected and filled inside the cable at a certain pressure to ensure insulation. In an OF cable, oil leakage can occur when the metal coating that maintains the hydraulic pressure is damaged due to aging or accidentally damaged during construction. In such cases, it is necessary to cut the OF cable to a certain length, including the oil-leaking area, and replace it. However, since replacement requires a lot of time and effort, it is necessary to repair the oil-leaking area (temporary oil stop treatment) as an initial response in order to minimize the amount of oil leakage prior to replacement (full repair).

[0003] A known technique for repairing such cables is to wind rubber or plastic tape with high tension around the cracked portion of the outer coating of the OF cable to provide a temporary fixing layer, and then to laminate a layer of glass fiber tape and an epoxy resin layer on top of that to provide an oil-stopping layer (see, for example, Patent Document 1).Another known technique is to strip away the anticorrosive layer around the oil leak, provide a pedestal to surround the oil leak, install a copper pipe across the pedestal, and join the copper pipe and the pedestal with leadwork (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 02-037530 [Patent Document 2] JP 2000-341820 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional end treatment of an OF cable, which involves lead work as shown in Patent Documents 1 and 2, has the following problems. That is, in the method of Patent Document 1, in order to stop the oil leak, it is necessary to apply appropriate tension to the rubber, plastic tape, and glass fiber tape, and moreover, the two tapes must be wound one after the other while overlapping each other. Therefore, there is a problem that special skills are required for construction and the work takes a lot of time. Furthermore, in the conventional treatment method shown in Patent Document 1, the surface pressure on the oil stop tape applied to the lead work is not uniform, and therefore it is necessary to reinforce it with, for example, plated wire, but this creates the risk of the corrosion prevention structure itself becoming larger, resulting in increased costs.

[0006] In addition, in Patent Document 2, the work of joining the copper pipe and the base requires the special skills of a plumber, and the work requires a great deal of time and cost, as well as the need to handle open flames at the construction site.

[0007] Furthermore, in the conventional repair method of overlapping and winding oil-blocking tapes, after a certain period of time the oil-blocking tape swells with oil and becomes easily damaged. Also, once oil leaks, it continues to leak, making it difficult to maintain over the long term, and in this respect there was room for improvement.

[0008] The present invention has been made in consideration of the above circumstances, and its purpose is to provide a method for repairing oil leakage points in OF cable which does not require the use of fire or special skills, reduces the effort and cost required for the work, and allows the treatment work to be completed efficiently in a short time. Another object of the present invention is to provide a method for repairing an oil leaking portion of an oil-filled cable that can be maintained for a long period of time after the treatment work is completed. [Means for solving the problem]

[0009] (1) A first aspect of the OFC cable oil leakage point repair method according to the present invention is a method for repairing an oil leakage point in an OFC cable, which is applied to an oil leakage point in a metal layer of a cable having an oil passage, and includes a first agent application step of applying a first agent having hardening properties to one side of a metal plate made of the same material as the metal layer and having an area larger than the size of the oil leakage point and to at least one side of the oil leakage point; and a metal coating formation step of attaching one side of the metal plate to the oil leakage point of the metal layer, hardening the first agent, and creating liquid-tightness between the metal plate and a surface of the metal layer. A second agent application process for applying a second agent to the other side of the metal plate and the surface of the metal layer; and a coating layer formation process for covering the metal plate and the metal layer from the upper layer side of the second agent with a coating member to form a coating layer. The present invention is characterized by the following.

[0010] According to the method for repairing an oil leak point on an OF cable of the present invention, the metal plate made of the same material as the metal layer is attached to an area of ​​the metal layer of the cable larger than the oil leak point through a first agent, which is a simple process that allows the metal plate and the metal layer to adhere to each other as the first agent hardens, resulting in a structure in which it is difficult for an oil passage to form. This allows the cable to be repaired efficiently in a short time using inexpensive materials, sealing the oil leak point and preventing oil leakage. In addition, according to the present invention, since the method forms an adhesive layer by hardening the first agent, the necessary equipment and materials can be minimized, and the effect time of the first agent can be set as desired. Therefore, by adopting the first agent with a short hardening time, the first agent hardens before an oil passage is formed between the metal layer and the metal plate, preventing oil leakage, and allowing the work to be performed more quickly. Furthermore, since the metal plate is attached to the metal layer by hardening the first agent as described above, the method has excellent peel resistance and can be maintained longer and more stably than the conventional corrosion prevention method using only a leak stopper tape.

[0011] In addition, according to the present invention, compared to conventional repair work involving leadwork using a burner to melt lead, no special techniques are required because lead is not used, and there is no need to secure workers with advanced construction techniques, which improves work efficiency and reduces costs. Moreover, compared to leadwork, terminal treatment can be performed without the need to handle fire.

[0012] Furthermore, according to the method for repairing an oil leak point on an OF cable of the present invention, a metal plate is attached to the oil leak point together with the hardened first agent, so that higher toughness can be ensured compared to the conventional treatment of wrapping multiple leak-stop tapes around the oil leak point. In other words, a highly tough and robust treatment structure that can withstand the internal pressure from the oil in the oil passage and the external pressure from the outside can be obtained, and can be maintained stably for a long time. Furthermore, in the present invention, the first agent fills the gap between the metal plate and the metal layer without leaving any gaps even if there is some oil, and hardens.

[0014] Also, In this case, the second agent is also applied to the upper layer of the metal plate, so the hardened second agent can further increase the strength of the metal layer, resulting in a structure that is more resistant to external damage. Moreover, since a covering member is provided so as to cover the metal plate via the second agent, there is an advantage that oil leakage is further prevented. Effect of the Invention

[0021] The method for repairing an oil leaking portion of an OF cable according to the present invention does not require the use of fire or special skills, reduces the effort and cost required for the work, and enables the treatment work to be completed efficiently in a short time. Furthermore, the method for repairing an oil leakage point on an OF cable according to the present invention can be maintained for a long period of time after the treatment work is completed. [Brief description of the drawings]

[0022] [Figure 1] 1 is a side cross-sectional view showing a processing structure for an OF cable according to an embodiment of the present invention. [Diagram 2] 1(a) to 1(c) are diagrams illustrating a procedure for repairing an oil leakage point in an OF cable. [Diagram 3] 2(a) and (b) are diagrams showing the procedure following FIG. 2(c). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] Hereinafter, an embodiment of a repair method for an oil leakage point in an OF cable according to the present invention will be described with reference to the drawings. Note that in each drawing, the scale of each component may be appropriately changed as necessary to make each component large enough to be visible.

[0024] As shown in Fig. 1, the method for repairing an oil leakage point in an OF cable of this embodiment is a repair method for closing an oil leakage point P in a metal layer 11 arranged on the outer periphery of an OF cable 1 having an oil passage with oil injected therein. That is, the method for repairing an oil leakage point in an OF cable repairs the oil leakage point P by applying a cable treatment structure 10 to the oil leakage point P. The oil leakage point P is a pinhole that has occurred in a lead treatment part (metal layer 11) made of a meta-lead plate at the connection part of the OF cable 1.

[0025] Here, the OF cable oil leakage location repair method according to this embodiment is intended for application as a temporary repair carried out as an initial response prior to a permanent repair, but depending on the oil leakage condition, the number of years of use of the OF cable 1, the installation environment, etc., it may also be an OF cable oil leakage location repair method applied as a permanent repair.

[0026] The cable treatment structure 10 has a metal plate 3 attached to a metal layer 11. The cable treatment structure 10 includes a first adhesive bond 2 (first agent) applied to a surface (outer peripheral surface 11a of metal layer 11) including an oil leakage location P of an OF cable 1, a metal plate 3 attached by adhesion to the outer peripheral surface 11a of the metal layer 11 via the first adhesive bond 2, a second adhesive bond 4 (second agent) applied to the outer surface 3a (other side) of the metal plate 3 and the outer peripheral surface 11a of the metal layer 11, and a covering layer 5 formed by covering the metal plate 3 and the metal layer 11 from the upper layer side of the second adhesive bond 4 with a casting tape 51 (covering member).

[0027] The first adhesive bond 2 is applied over an area larger than the oil leakage location P so as to cover the oil leakage location P. That is, the application area of ​​the first adhesive bond 2 corresponds to the attachment area of ​​the metal plate 3. As the first adhesive bond 2, for example, the Y618H type of Metallock (manufactured by Cemedine Co., Ltd.), which has hardening properties and is mainly composed of modified acrylic, has high strength, and is a room temperature fast curing type adhesive that does not require heating, can be used. The Y618H type adhesive bond has a higher bonding strength to metal than the Y610 type manufactured by the same company. When the Y618H type is used, it can perform the oil stop function regardless of the surface pressure of the metal plate 3. In addition, the Y618H type does not contain a flammable solvent, hardens even with a rough mixture, can harden at a temperature of 0°C, and has the property of obtaining adhesive strength even in a slightly oily surface state. In addition, it is preferable that the hardening time is fast, for example, about 2 minutes 30 seconds to 10 minutes 0 seconds. In addition, it can be stored for long periods at room temperature between 5 and 25°C and does not emit any foul odors like conventional acrylic adhesives. It can also be used to bond dissimilar materials such as metal and CFRP.

[0028] The metal plate 3 is made of the same material as the metal layer 11, for example, lead. The metal plate 3 has an area larger than the size of the oil leakage location P. Therefore, the planar shape of the metal plate 3 can be set to, for example, a rectangular shape, but is not particularly limited. The thickness of the metal plate 3 is, for example, about 0.3 to 1.0 mm.

[0029] The metal plate 3 is adhered to the outer peripheral surface 11a of the metal layer 11 by the first adhesive bond 2, and when the first adhesive bond 2 hardens, a liquid-tight state is created between the metal plate 3 and the outer peripheral surface 11a of the metal layer 11. The timing for attaching the metal plate 3 to the outer peripheral surface 11a of the metal layer 11 is preferably such that after the first adhesive bond 2 starts to harden, a predetermined time is waited, and then the metal plate 3 is adhered to the outer peripheral surface 11a of the metal layer 11 when the viscosity of the first adhesive bond 2 has increased to, for example, 15,000 mPa s at 23°C.

[0030] The second adhesive bond 4 is applied to the entire area of ​​the outer surface 3a of the metal plate 3 and to the outer peripheral surface 11a of the metal layer 11 including the metal plate 3, up to a predetermined area around the metal plate 3. The second adhesive bond 4 has a hardening property. Specifically, the same material as the first adhesive bond 2 can be used.

[0031] The casting tape 51 is wrapped around the entire area of ​​the applied second adhesive bond 4. As a result, the casting tape 51 forms a coating layer 5 that covers the entire area of ​​the outer surface 3a of the metal plate 3 and the metal plate 3 on the outer peripheral surface 11a of the metal layer 11, and covers a predetermined area around the metal plate 3. The area covered by the casting tape 51 is large compared to the size of the metal plate 3. One surface (inner peripheral surface 5a) of the coating layer 5 is in a state where the second adhesive bond 4 is applied.

[0032] Next, the repair procedure of the OF cable oil leakage point repair method applied to the oil leakage point P in the metal layer 11 of the OF cable 1 having an oil passage will be described in detail with reference to Figures 2(a) to (c) and Figures 3(a) and (b).

[0033] As shown in FIG. 1 and FIG. 2( a ), an oil leakage point P occurs in the metal layer 11 of the OF cable 1 . First, a predetermined area of ​​the metal layer 11 including the oil leakage location P is hit with a hammer to reduce the amount of oil leakage (leakage reduction step). That is, a caulking process is performed using a hammer to close holes and cracks in the oil leakage portion of the oil leakage location P.

[0034] 2(b), a first adhesive bond 2 having hardening properties is applied to at least one side of the oil leakage site P and one side of a metal plate 3 made of the same material as the metal layer 11 having an area larger than the size of the oil leakage site P (first chemical application step). The first adhesive bond 2 is hardenable when applied to the application surface containing oil.

[0035] Next, as shown in FIG. 2(c), the inner surface 3b of the metal plate 3 is attached to the oil leakage location P of the metal layer 11, the first adhesive bond 2 is cured, and a metal coating is formed between the metal plate 3 and the outer peripheral surface 11a of the metal layer 11 to provide liquid-tightness (metal coating forming process). In the metal coating forming process, a predetermined time is waited after the hardening of the first adhesive bond 2 starts, and the metal plate 3 is brought into close contact at the timing when the viscosity of the first adhesive bond 2 increases (oil path formation prevention process). By carrying out the oil path formation prevention process in this manner, the hardening time of the first adhesive bond 2 after the metal plate 3 is brought into close contact can be shortened, and the formation of an oil path for oil leaking from the oil leakage location P can be prevented. That is, the first adhesive bond 2 is cured in the area where the first adhesive bond 2 is applied, and the area between the metal plate 3 and the metal layer 11 can be sealed without any gaps, and the oil in the oil path of the OF cable 1 can be prevented from leaking out from the oil leakage location P.

[0036] Next, as shown in Fig. 3(a), the second adhesive bond 4 is applied to the outer surface 3a of the metal plate 3 and the outer peripheral surface 11a of the metal layer 11 (second chemical application step). The second adhesive bond 4 can be cured even when applied to an oily application surface. The second adhesive bond 4 applied to the metal layer 11 in Fig. 3(a) is applied to the entire periphery of the metal plate 3.

[0037] 3(b), the metal plate 3 and the metal layer 11 are covered with a casting tape 51 from the upper layer side of the second adhesive bond 4 to form a covering layer 5 (covering layer forming step). Specifically, the casting tape 51 is wrapped around the upper layer side of the second adhesive bond 4 so as to cover and encase it. The casting tape 51 is provided in a state of liquid-tight adhesion to the second adhesive bond 4.

[0038] It is also possible to wrap an anticorrosive tape (not shown) made of, for example, polyvinyl chloride (PVC) or the like around the entire coating layer 5 from the upper layer side so as to encase it. This provides corrosion protection to the portion reinforced by the casting tape 51 due to the anticorrosive properties of the anticorrosive tape. In this way, by wrapping the anticorrosive tape around the upper layer side of the casting tape 51, in addition to providing an anticorrosive effect, it is possible to prevent the casting tape 51 from swelling.

[0039] Next, the operation of the method for repairing an oil leakage point in an OF cable will be described in detail with reference to Figs. The OF cable oil leakage point repair method according to this embodiment is applied to an oil leakage point P in a metal layer 11 of a cable having an oil passage. The OF cable oil leakage point repair method includes a first chemical application step of applying a hardenable first adhesive bond 2 to at least one side of the oil leakage point P and one side of a metal plate 3 made of the same material as the metal layer 11 having an area larger than the size of the oil leakage point P, and a metal coating formation step of attaching the one side of the metal plate 3 to the oil leakage point P of the metal layer 11 to harden the first adhesive bond 2 and create liquid-tightness between the metal plate 3 and the surface of the metal layer 11.

[0040] According to the method for repairing an oil leakage point in an OF cable according to this embodiment, the metal plate 3 made of the same material as the metal layer 11 is attached via the first adhesive bond 2 to an area of ​​the metal layer 11 of the cable that is larger than the oil leakage point P, and the metal plate 3 and the metal layer 11 are brought into close contact with each other as the first adhesive bond 2 hardens, resulting in a structure in which it is difficult for a path for oil to form. This allows the cable oil leakage point P in the cable to be sealed, and cable repair processing that prevents oil leakage can be performed efficiently in a short time using inexpensive materials.

[0041] In addition, according to this embodiment, since the method forms an adhesive layer by hardening the first adhesive bond 2, the necessary materials and equipment can be minimized, and the effective time of the first adhesive bond 2 can be set arbitrarily. Therefore, by adopting the first adhesive bond 2 with a short hardening time, the first adhesive bond 2 hardens before an oil passage is formed between the metal layer 11 and the metal plate 3, preventing oil leakage, and allowing the work to be performed more quickly. Furthermore, since the metal plate 3 is attached to the metal layer 11 by hardening the first adhesive bond 2 as described above, the method has excellent peel resistance and can be maintained longer and more stably than the conventional corrosion prevention method using only a leak stopper tape.

[0042] In addition, in this embodiment, compared to conventional repair work involving lead work using a burner to melt lead, no special techniques are required because lead is not used, and there is no need to secure workers with advanced construction techniques, which improves work efficiency and reduces costs. Moreover, compared to the case of lead work, terminal treatment can be performed without the need to handle fire.

[0043] Furthermore, according to the OF cable oil leakage point repair method of this embodiment, the metal plate 3 is attached to the oil leakage point P together with the hardened first adhesive bond 2, so that higher toughness can be ensured compared to the conventional treatment of wrapping multiple leak stop tapes. That is, a highly tough and robust treatment structure that can withstand the internal pressure from the oil in the oil passage and the external pressure from the outside can be obtained, and can be maintained stably for a long time. Furthermore, in this embodiment, even if there is some oil, the first adhesive bond 2 fills the gap between the metal plate 3 and the metal layer 11 without leaving any gaps, and hardens.

[0044] In addition, this embodiment includes a second agent application process for applying a second adhesive bond 4 to the other side of the metal plate 3 and the outer peripheral surface 11a of the metal layer 11, and a coating layer formation process for covering the metal plate 3 and the metal layer 11 from the upper layer side of the second adhesive bond 4 with a casting tape to form a coating layer 5.

[0045] Therefore, since the second adhesive bond 4 is also applied to the upper layer side of the metal plate 3, the strength of the metal layer 11 can be further increased by the hardened second adhesive bond 4, resulting in a structure that is more resistant to external damage. Moreover, since the casting tape is provided so as to cover the metal plate 3 via the second adhesive bond 4, there is an advantage that oil leakage is further prevented.

[0046] Furthermore, this embodiment includes a leakage reduction step of hitting a predetermined area of ​​the metal layer 11 including the oil leakage point P with a hammer to reduce the amount of oil leakage. Therefore, by first caulking the oil leakage area with a hammer to reduce the size of the oil leakage area, and then applying the first adhesive bond 2 and attaching the metal plate 3, a cable processing structure can be provided that can achieve the above-mentioned effect even if the amount of oil leaking at the oil leakage location P is large.

[0047] In addition, in this embodiment, the metal coating formation process waits for a predetermined time after the start of hardening of the first adhesive bond 2, and then adheres the metal plate 3 when the viscosity of the agent has increased, thereby shortening the hardening time of the first adhesive bond 2 after adhesion and also including an oil passage formation prevention process that prevents the formation of an oil passage for oil leaking from the oil leakage location P. Therefore, the metal plate 3 is attached to the metal layer 11 when the viscosity of the first adhesive bond 2 increases, so that an oil passage is less likely to form between the metal plate 3 and the metal layer 11 after attachment, and the adhesion of the metal plate 3 can be improved.

[0048] In addition, in this embodiment, the metal layer 11 and the metal plate 3 are made of lead, so that by bringing the lead plates into close contact with each other, it is possible to carry out a process that makes it more difficult for oil passages to be formed.

[0049] The OF cable oil leakage repair method according to this embodiment, configured as described above, does not require the use of fire or special skills, reduces the effort and cost required for the work, and enables the treatment work to be completed efficiently in a short time. Moreover, the method for repairing an oil leakage portion of an OF cable according to this embodiment can be maintained for a long period of time after the treatment work is completed.

[0050] Although the embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. The embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the gist of the invention. The embodiments and their modifications include, for example, those that can be easily imagined by a person skilled in the art, those that are substantially the same, those that are within the scope of the equivalents, and the like.

[0051] For example, in the above embodiment, after the metal plate 3 is attached, the coating layer 5 is applied by wrapping the casting tape 51 around the upper layer side via the second adhesive bond 4, but it is also possible to omit the casting tape 51 and the second adhesive bond 4.

[0052] In addition, this embodiment includes a leakage reduction process in which a specific area of ​​the metal layer 11, including the oil leakage location P, is struck with a hammer to reduce the amount of oil leakage, but the leakage reduction process can be performed as needed and can also be omitted. [Explanation of symbols]

[0053] 1 OF cable 2. First adhesive bond (first drug) 3 metal plate 4. Second adhesive bond (second medicine) 5 Covering layer 51 Casting tape (covering material) 10 Cable management structure 11 Metal layer 11a Outer surface P Oil leakage location

Claims

[Claim 1] An oil leakage repair method for an oil-filled cable that is applied to an oil leakage location in a metal layer of a cable having an oil passage, comprising: A first agent application process for applying a first agent having hardening properties to at least one side of the oil leakage location and one side of a metal plate made of the same material as the metal layer and having an area larger than the size of the oil leakage location; a metal coating forming process in which one side of the metal plate is attached to the oil leakage portion of the metal layer to harden the first agent and create liquid-tightness between the metal plate and the surface of the metal layer; A second agent application step of applying a second agent to the other side of the metal plate and the surface of the metal layer; A coating layer forming step of covering the metal plate and the metal layer with a coating member from the upper layer side of the second drug to form a coating layer. Repair method for oil leaks in oil-filled cables.

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