JP2014192969A - Power cable covering member, and covering structure of power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power cable covering member improved in workability when constructing a terminal connection part or an intermediate connection part of a power cable, and a covering structure of the power cable.SOLUTION: A power cable covering member 1 comprises a cylindrical main body 10 which is mounted over an outer periphery of a power cable. The main body 10 is formed from an organic polymer material. A fluorinated layer (e.g., an outer lubrication layer 12, an inner lubrication layer 14) is included which is formed by fluorinating the organic polymer material in at least a portion of a surface part of the main body 10. The outer lubrication layer 12 is included so that, when mounting the covering member 1 to the power cable by partially folding and further returning a portion of the covering member 1, a folded portion can be easily returned without being adhered. The inner lubrication layer 14 is included so that the covering member 1 can be easily inserted into the power cable. The covering member 1 is used so that workability is improved in constructing a terminal connection part or an intermediate connection part of the power cable.

Description

  The present invention relates to a cylindrical power cable covering member used for construction of a terminal connection portion and an intermediate connection portion of a power cable, and a power cable covering structure. In particular, the present invention relates to a covering member for a power cable excellent in workability.

  Usually, the purpose of waterproofing, insulation, electric field relaxation, mechanical protection, etc. is used at the connection points of power cables such as terminal connections that connect power cables and external devices, and intermediate connections that connect power cables. Apply coating treatment. One example of this covering process is to cover the outer periphery of a power cable or the like with a cylindrical member. As this cylindrical member, there is a rubber mold part having a self-shrinking property.

  As described in Patent Document 1, the rubber mold component used for the terminal connection part is a bag-like one in which a connection terminal is connected to one end and only the other end is opened, or both ends are opened and one end is opened. There is a cylindrical thing penetrated to the other end. Such a rubber mold part is used as follows, for example. As described in Patent Document 1, the opening side region of the rubber mold part is folded back, and the rubber mold part having the folded part is inserted into the end of the stepped power cable and fitted to a predetermined position. When it is inserted, return the folded part. By carrying out like this, the edge part of an electric power cable can be covered with the said rubber mold components.

  Examples of the rubber mold component used for the intermediate connection part include a cylindrical cold-shrinkable tube having both ends opened and penetrated from one end to the other end. This rubber mold component is used as follows, for example. Expand the rubber mold part so that it has a diameter sufficiently larger than the outer diameter of the connection part of the power cable to which the rubber mold part is to be mounted, and place an expanded cylinder that maintains this expanded state inside the rubber mold part. deep. A rubber mold part having the diameter-expanded cylinder is fitted on the outer periphery of the connection portion, and then the diameter-expanded cylinder is removed. By carrying out like this, the outer periphery of the said connection location can be covered with the said rubber mold component. The diameter-expanded cylinder includes, for example, a tube formed by winding a thin strip described in Patent Document 2 in a spiral shape.

Japanese Patent Laid-Open No. 11-289648 Japanese Patent Publication No.49-046190

  In constructing a terminal connection part and an intermediate connection part of a power cable, improvement in workability is desired.

  When a part of the rubber mold part is folded as described above, the parts that are folded back and face each other on the outer surface of the rubber mold part may be in close contact with each other, making it difficult to return the folded part to its original state. In particular, in a rubber mold component made of a relatively soft material such as silicone rubber, the above-described folded portion is likely to be in close contact. Therefore, a lubricant such as grease is applied to the above-mentioned folded and facing portions to reduce the close contact of the folded portions and make it easier to return the folded portions to their original positions. However, a lubricant such as grease is sticky, and if it adheres to the operator's hand during the return operation, workability may be reduced, such as difficulty in grasping the rubber mold part. In addition, when stored for a long time in a state where a lubricant such as grease is applied, dust or the like may adhere to the lubricant and the lubricity may be lowered. Further, when a tape material or the like is wound around the outer periphery of the rubber mold component after being mounted, the tape material or the like may not be sufficiently adhered unless the lubricant such as grease is wiped away after returning. For this reason, a lubricant removal step is required after returning the folded portion. Then, workability | operativity is further reduced by the number of processes increasing.

  In addition, when a rubber mold part that has not been expanded by the above-mentioned diameter-expanding cylinder is fitted to the outer periphery of a covering target such as a power cable, the outer surface of the covering target (at least the outer surface of the thick part) and the inner surface of the rubber mold part rub against each other. In some cases, the frictional resistance between the two becomes large, and the insertability is lowered. By folding a part of the rubber molded part, the insertion length of the rubber molded part into the power cable can be shortened compared to the case where the rubber molded part is not folded, but rubbing with a thick part to be coated can occur. Therefore, in order to improve the insertability, a lubricant such as grease is applied to both the outer periphery of the power cable and the inner periphery of the rubber mold part. However, in this case, a coating operation is required, which increases the number of processes. In addition, as described above, the grease is likely to adhere to the worker during insertion, which leads to a decrease in workability.

  On the other hand, as described above, a rubber mold part having a diameter-expanded cylinder usually has a large clearance between the outer periphery of the power cable and the inner periphery of the diameter-expanded cylinder, and is excellent in insertability. However, since the rubber mold parts are in close contact with each other so as to tighten the diameter-expanding cylinder by its self-shrinkage, it may be difficult to remove the diameter-expanding cylinder. In this case, workability is also reduced.

  The present invention has been made in view of the above-described circumstances, and one of its purposes is to provide a power cable covering member that is excellent in workability in constructing a terminal connection portion and an intermediate connection portion of a power cable. There is. Another object of the present invention is to provide a power cable covering structure excellent in construction workability.

  This invention achieves the said objective by making the surface of the coating | coated member fitted in the outer periphery of an electric power cable into a specific state.

  The covering member for power cables of the present invention is attached to the outer periphery of the power cable, and has a cylindrical main body made of an organic polymer material, and the organic polymer in at least a part of the surface portion of the main body. A fluorinated layer formed by fluorinating the material.

The covering member for power cables of the present invention can use a fluorinated layer as a lubricating layer. Specifically, the following usage forms are listed.
(1) When a part of the main body is folded back and returned to the original state, at least a part of the outer surface of the main body, in particular, the folded part is provided with a fluorinated layer. Adhesion can be suppressed and can be easily restored. The surface of the fluorinated layer is substantially non-viscous and smooth, and there is no problem such as adhesion of grease to an operator as in the case of using a lubricant such as the above-mentioned grease.
(2) By providing a fluorinated layer on at least a part of the inner surface of the main body, particularly the portion that can be in sliding contact with the coating target during insertion, the lubricity of this fluorinated layer makes it possible to insert the power cable into a coating target. It can be improved.
(3) When providing a diameter-expanded cylinder, which will be described later, by providing a fluorinated layer on at least a part of the inner surface of the main body (preferably the entire region in contact with the diameter-expanded cylinder), the lubricity of the fluorinated layer As a result, the friction between the main body and the enlarged cylinder can be reduced, and the enlarged cylinder can be easily removed (removed).
From these things, the covering member for electric power cables of this invention is excellent in workability | operativity in the construction | assembly of the terminal connection part and intermediate | middle connection part of an electric power cable.

  Further, in the configuration including the fluorinated layer, post-processing such as the above-described grease removing operation after folding can be omitted. Also from this point, the covering member for a power cable of the present invention is excellent in workability in constructing a terminal connection portion of the power cable.

  The fluorinated layer is formed by combining the constituent material of the main body itself (particularly carbon element) and fluorine. That is, unlike the case where a lubricant layer made of a material independent of the main body such as a lubricant such as grease is provided on the outer periphery of the main body, the power cable covering member of the present invention is one of the constituent materials of the main body. The part is a constituent material of the lubricating layer. For this reason, the fluorinated layer is unlikely to peel off from the main body or to adhere to dust or the like to deteriorate the lubricating effect, and preferably cannot substantially occur. Therefore, the covering member for electric power cables of this invention is excellent in the sustainability of the lubrication effect by a fluorinated layer. For example, even when the main body is folded and held for a long period of time, the folded portion can be easily restored after being attached to the power cable. Furthermore, when the lubricating layer is formed by applying grease or the like, there is a risk that the worker may have unevenness in the thickness of the lubricating layer or a portion without the lubricating layer. The covering member for a power cable of the present invention in which the constituent material of the main body itself is a constituent material of the lubricating layer is easily provided with a lubricating layer having a uniform thickness on the surface of the main body, and there are no spots or lubricating layers as described above. Substantially does not occur.

  As one form of the covering member for power cables of the present invention, there is a form in which the main body is composed of a rubber molded part and the fluorinated layer is provided on the outer surface of the rubber molded part.

  The above configuration is particularly suitable when the rubber mold part is attached to the outer periphery of the covering target such as a power cable by folding back the opening area of the rubber mold part and returning it to its original state (typically when constructing a terminal connection part) ), The folded portion is not in close contact with the fluorinated layer, the return work can be easily performed, and the workability is excellent. In addition, when the outer surface is provided with a fluorinated layer other than the bent portion, the surface of the main body exposed to the external environment is smooth, so that it is difficult for dust to adhere to it and maintains a good appearance and creepage resistance. it can.

  As one form of the covering member for power cables of the present invention, there is a form in which the main body is composed of a rubber molded part and the fluorinated layer is provided on the inner surface of the rubber molded part.

  In the above-described embodiment, the friction during the rubbing with the covering target such as the power cable can be reduced by the fluorinated layer, so that it can be easily inserted into the covering target and has excellent workability.

  As one form of the covering member for power cables of the present invention, there is a form in which the main body is composed of a rubber molded part and the fluorinated layer is provided on both the outer surface and the inner surface of the rubber molded part.

  In the above-described embodiment, the above return operation can be easily performed by the outer surface side fluorinated layer, and the inner surface side fluorinated layer can be easily inserted into an object to be covered such as a power cable, and is excellent in workability. Further, in a form in which the entire outer surface and inner surface of the rubber mold part are provided with a fluorinated layer, if these fluorinated layers are formed using a fluorine-containing gas as described later, the entire surface of the rubber mold part is formed. A fluorinated layer having a uniform and uniform thickness can be easily formed, and the productivity is excellent.

  As another form of the power cable covering member of the present invention, a cylindrical main body that is mounted on the outer periphery of the power cable and is made of an organic polymer material, and disposed inside the main body, the main body is expanded in diameter. And a diameter expansion cylinder that is removed when the main body is attached to the power cable. The diameter-expanded cylinder includes a fluorinated layer formed by fluorinating the organic polymer material in at least a part of the outer surface portion.

  The above-mentioned form is excellent in insertability into a covering object such as a power cable by providing a diameter-expanded cylinder, and the diameter-expanded cylinder is provided with a fluorinated layer, regardless of the presence or absence of the fluorinated layer in the main body, The diameter-expanded cylinder can be easily removed, and the workability is excellent.

  As one form of the covering member for electric power cables of this invention, the form whose average thickness of the said fluorinated layer is 1 micrometer or more is mentioned.

  Since the fluorinated layer is present in an appropriate thickness, the above form can function sufficiently as a lubricating layer. In the form in which the main body made of the rubber molded part is provided with the appropriate thickness of the fluorinated layer, the main body can be sufficiently flexible, and the above-described folding and returning operations can be easily performed. Also, it can be easily inserted into the object to be coated.

  As one form of the covering member for power cables of the present invention, there is a form in which the organic polymer material is one selected from silicone rubber, ethylene propylene rubber, chloroprene rubber, and polypropylene.

  The various rubbers listed are excellent in electrical insulation, water shielding, strength and the like. Therefore, the above-mentioned form can be suitably used as a covering material for the purpose of insulation, waterproofing, mechanical protection, etc. with respect to the terminal connection part and the intermediate connection part of the power cable when the main body made of the rubber is provided.

  The power cable covering structure of the present invention includes a configuration including the power cable and the power cable covering member of the present invention attached to the outer periphery of the power cable.

  The covering structure of the power cable of the present invention is excellent in workability in the construction by using a specific covering member or a diameter-expanded cylinder having a fluorinated layer functioning as a lubricating layer as a constituent member.

  The covering member for a power cable of the present invention is excellent in workability in constructing a terminal connection part and an intermediate connection part of a power cable. The power cable connection structure of the present invention is excellent in workability in its construction.

(A) is a plan view of the power cable covering member of Embodiment 1, and (B) is a partial cross-sectional view thereof. FIG. 3 is an explanatory diagram for explaining a usage state of the power cable covering member according to the first embodiment. FIG. 3 is a partial cross-sectional view illustrating an outline of a terminal connection portion of a power cable including the power cable covering member according to the first embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In the figure, the same reference numerals indicate the same names. In FIG. 1B, for easy understanding, the thickness of the fluorinated layer (the outer lubricating layer 12 and the inner lubricating layer 14) is shown to be thicker than the actual thickness. In FIG. 3, the fluorinated layers (the outer lubricating layer 12 and the inner lubricating layer 14) are omitted.

(Embodiment 1)
The power cable covering member 1 is a cylindrical member attached to the outer periphery of the power cable 100 (FIGS. 2C and 3) for the purpose of electrical insulation, water shielding, mechanical protection, and the like. The covering member 1 includes a cylindrical main body 10 and a lubricating layer on at least a part of the surface (outer surface and inner surface) of the main body 10. In the example shown in FIG. 1, the outer lubricating layer 12 is provided over the entire outer surface of the main body 10, and the inner lubricating layer 14 is provided over the entire inner surface. One of the features of the covering member 1 is that the lubricating layer is a fluorinated layer in which the organic polymer material constituting the main body 10 is fluorinated. Hereinafter, each configuration will be described in detail.

  The main body 10 can be made of various organic polymer materials used for covering the power cable 100. The organic polymer material typically includes various rubbers. In particular, the main body 10 can suitably use a rubber molded part.

  Specific materials for the main body 10 include one selected from silicone rubber, ethylene propylene rubber (EP rubber), and chloroprene rubber. The listed rubber is widely used as a constituent material of rubber mold parts to be attached to a power cable, and is preferable because of excellent electrical insulation, water shielding, heat resistance, and the like. In particular, silicone rubber is excellent in heat resistance and water resistance, is relatively soft, and can be easily folded and folded. EP rubber is excellent in electrical insulation, weather resistance, and water resistance. Chloroprene rubber is excellent in weather resistance and heat resistance, is excellent in processability, and can be easily produced in various shapes. A rubber molded part made of such rubber can be manufactured by a known method. Examples of the rubber mold component include those shown in FIG. 1, a normal temperature shrinkable tube, and the like.

  The shape (outer shape, inner peripheral shape) and size (opening diameter, inner diameter, outer diameter, thickness, length, etc.) of the main body 10 can be appropriately selected. Here, the main body 10 has a cylindrical shape that is open at both ends and penetrates from one end to the other end, but is connected to a connection terminal (not shown) or the like at one end and has a bag shape in which only the other end is open. can do. Alternatively, at least one umbrella part (not shown) may be provided on the outer periphery of the main body 10. The umbrella part is an annular body protruding outward from the main body 10 (see FIG. 4 of Patent Document 1). By providing an umbrella, the creepage distance can be extended. In addition, the creepage distance can be extended by providing appropriate irregularities on the outer periphery of the main body 10.

  The lubricating layer (fluorinated layer) such as the outer lubricating layer 12 and the inner lubricating layer 14 is a combination of at least carbon element (C) and fluorine element (F) contained in the organic polymer material constituting the surface portion of the main body 10. Material, so-called direct fluorinated material. Typically, the main body 10 has a form in which the material constituting the surface portion of the main body 10 is cross-linked by fluorine element, that is, when viewed in the thickness direction of the main body 10, the surface side region is cross-linked by fluorine. And a form in which the intermediate part is a non-crosslinked region. The material constituting the surface portion of the main body 10 is directly fluorinated and a portion having a carbon-fluorine bond is used as a fluorinated layer, and this fluorinated layer is used as a lubricating layer. It is integral and does not substantially peel from the body 10 and can be permanently present. By providing such a lubricating layer, the power cable covering member 1 can obtain the lubricating effect over a long period of time.

  The lubricating layer (fluorinated layer) is expected to have a sufficient lubricating effect if its average thickness is 1 μm or more. The thicker the lubricating layer, the thicker the fluorinated region, so that the lubricating layer can be sufficiently provided. Therefore, a lubricating effect can be obtained over a long period of time. On the other hand, if the fluorinated region is too thick, that is, the region cross-linked by the fluorine element (the portion having a carbon-fluorine bond) is excessive or the cross-linking density is too high, the rigidity of the surface of the main body 10 is increased ( High hardness). Then, since it is too hard, for example, it may be difficult to perform folding or the like, or it may be difficult to insert or insert. Also, if the fluorinated region is too thick or the crosslink density is too high, the flexibility and stretchability of the main body 10 will be poor, and for example, the adhesion between the main body 10 and the object to be coated such as the power cable 100 will be reduced. There is a fear. Therefore, it is considered that the average thickness of the lubricating layer is preferably about several μm to about several tens of μm.

  The average thickness of the lubricating layer (fluorinated layer) is measured, for example, as follows. Take a longitudinal section or a transverse section of the covering member 1 for power cables, measure the thickness of a plurality of points in the fluorinated region existing in the longitudinal section or the transverse section, and take the average of these thicknesses. In the fluorinated region, for example, the color, hardness, and the like change as compared with the main body 10 due to the combination of the original constituent material of the main body 10 and fluorine. Therefore, simply, when viewed from the outermost surface of the covering member 1 in the depth direction, it is considered that a point having a different color or hardness can be regarded as a fluorinated region. The composition may be analyzed in the depth direction from the outermost surface of the covering member 1 by XPS (X-ray photoelectron spectroscopy) or the like to examine the region where fluorine is present, and the region where fluorine is present may be a fluorinated region. Note that the outermost surface of the lubricating layer (fluorinated layer) tends to have a lighter hue in addition to excellent lubricity as compared to a non-fluorinated region.

  A region including the lubricating layer (fluorinated layer) in the main body 10 can be appropriately selected. For example, only a part of the outer surface of the main body 10 can be provided with a lubricating layer. Specifically, when the above-described folded portion is provided, the lubricating layer can be provided only on the folded portion (region A in FIG. 2C) on the outer surface of the main body 10. This configuration can easily return the folded portion. For example, the lubricating layer can be provided only on the entire outer surface of the main body 10. In this case, by providing a lubricating layer over the entire area including the folded portion, it is possible to easily perform the returning operation of the folded portion, and to prevent dust and the like from adhering to the outer surface exposed to the external environment. And the outer surface can be kept clean.

  For example, only a part of the inner surface of the main body 10 can be provided with a lubricating layer. Specifically, when the power cable covering member 1 is inserted into a covering target such as the power cable 100, the lubricating layer can be provided only in a portion that can be in sliding contact with the outer surface of the covering target. This form is excellent in insertability into a covering object such as the power cable 100. For example, a lubricating layer can be provided only on the entire inner surface of the main body 10. In this case, it is excellent in insertability into the covering target such as the power cable 100, and it is possible to prevent dust and the like from adhering to the inner surface of the main body 10 until the covering member 1 is attached to the object to be duplicated. A clean state can be maintained.

  Of course, the above-described four forms (a part of the outer surface, a whole surface of the outer surface, a part of the inner surface, and a whole surface of the inner surface) can be combined. In particular, when the outer lubricating layer 12 is provided over the entire outer surface of the main body 10 and the inner lubricating layer 14 is provided over the entire inner surface as shown in FIG. In addition, it is excellent in insertability into an object to be covered such as the power cable 100, and is excellent in workability in constructing a terminal connection part and an intermediate connection part. In addition, dust and the like can be prevented from adhering to both the inner and outer surfaces of the main body 10, and problems caused by the dust and the like can be prevented. In this embodiment, when the lubricating layer is formed using a fluorine-containing gas described later, both the outer lubricating layer 12 and the inner lubricating layer 14 can be easily formed, and the productivity is excellent.

  For the formation of the lubricating layer composed of the fluorinated layer, so-called direct fluorination in which fluorine and the organic polymer material constituting the surface portion of the main body 10 are directly reacted can be suitably used. Fluorine atoms have relatively low dissociation energy and are highly reactive, and can be easily fluorinated without using external energy such as thermal energy, electrical energy, and high pressure. The so-called direct fluorination includes a method using a fluorine-containing gas. In this method, the surface of the main body 10 and the fluorine-containing gas can be uniformly contacted. For this reason, a fluorinated layer having a uniform thickness can be easily formed on the surface of the main body 10, and the productivity is excellent. When providing a fluorinated layer only at a desired location, masking or the like may be performed as appropriate. Or, for example, when a fluorinated layer is provided only on the outer surface of the main body 10, a core is inserted into the main body 10 so that the inner surface of the main body 10 and the core are in close contact with each other, and the fluorine-containing gas wraps around the inner surface. To prevent this. The core may be removed after the fluorination treatment.

  Examples of the fluorine-containing gas include a mixed gas of fluorine and an inert gas. Examples of the inert gas include one or more selected from argon, helium, and nitrogen. The inert gas may be one kind or a mixture of two or more kinds. The fluorine-containing gas can be single fluorine, but since single fluorine has high reactivity, a mixed gas is easier to adjust the reaction state. The fluorine concentration in the mixed gas can be appropriately selected. The degree of fluorination and the thickness of the lubricating layer can be adjusted by adjusting the fluorine concentration, the temperature in the reaction tank (typically a vacuum chamber), the reaction time, and the like. The greater the fluorine concentration, the temperature in the reaction tank, and the reaction time, the greater the degree of fluorination and the thickness of the lubricating layer. When fluorinated at room temperature (20 ° C to 25 ° C) and normal pressure, it is easy to control and has excellent workability.

  Direct fluorination using a fluorine-containing gas is performed, for example, as follows. After an object (here, a rubber mold part) is stored in the vacuum chamber, the inside of the chamber is evacuated to remove moisture, air, and the like in the chamber. In a state of a predetermined degree of vacuum, a fluorine mixed gas is supplied into the chamber and held for a predetermined time. The object is taken out after a predetermined time. By this step, the power cable covering member 1 having a lubricating layer made of a fluorinated layer on the surface of the main body 10 is obtained.

  The power cable covering member 1 shown in FIG. 1 is used as follows, for example. As shown in FIG. 2 (A), one end side region of the covering member 1 (here, a region A disposed on the base side (large diameter side) of the stepped power cable 100 as shown in FIG. 2 (C)) Is folded back to a predetermined position. As shown in FIG. 2 (B), it is preferable to provide a mark (here, an arrow) indicating the folding position on the inner surface of the covering member 1, since the folding length does not vary. Here, the covering member 1 is provided with an outer lubricating layer 12 (FIG. 1, fluorinated layer) over the entire outer surface of the main body 10, but this fluorinated layer is extremely thin (here, average thickness 1 μm), and the main body 10 itself It has sufficient flexibility and stretchability (here, silicone rubber) and can be bent easily.

  Next, the stripped power cable 100 as shown in FIG. 2 (C) is inserted into the power cable covering member 1 (FIG. 2 (B)) having the folded portion. Here, the covering member 1 is provided with an inner lubricating layer 14 (FIG. 1, a fluorinated layer) over the entire inner surface of the main body 10, so that the friction is small even when rubbing against the power cable 100 (particularly the large diameter portion), Even if a lubricant or the like is not applied to the outer periphery of the power cable 100, it can be easily inserted. It is preferable that the above folding is performed in advance and the covering member 1 having the folded portion shown in FIG. 2 (B) is brought to a construction site or the like because of excellent workability at the site.

  When the power cable covering member 1 is disposed at a predetermined position of the power cable 100, the bent portion is returned to the original position as shown in FIG. Here, the covering member 1 includes the outer lubricating layer 12 (fluorinated layer) on the outer surface of the main body 10 so that the folding back operation can be easily performed. In this return operation, the lubricant does not adhere to the worker.

  Through the above steps, a power cable covering structure in which a predetermined region on the outer periphery of the power cable 100 is covered with the power cable covering member 1 can be constructed. FIG. 3 shows a terminal connecting portion as an example of a power cable covering structure. The terminal connection portion includes a stripped power cable 100 and a covering member 1 attached to a part of the outer periphery of the power cable 100. The power cable 100 includes a conductor 110, an inner semiconductive layer, an electrical insulator 112, an outer semiconductive layer, a shielding layer, and a sheath 114 in order from the inside. The connection terminal 200 is crimped to the end portion of the conductor 110 exposed by the stripping. An insulating tape 210 made of an insulating material is provided by winding an insulating tape or the like so as to cover the outer periphery of the connection portion between the conductor 110 and the connection terminal 200 and the outer periphery of the conductor-side end portion of the covering member 1. When the ground wire 130 is attached, the end portion of the ground wire 130 is pulled out from the sheath-side end portion of the covering member 1 to the outside. A fastening band 140 may be attached to the outer periphery of the sheath side end of the covering member 1.

  In addition, it is possible to use a rubber mold component provided with the electric field relaxation layer 16 on the inner surface. In this case, the electric field relaxation layer 16 can also be provided with a lubricating layer (fluorinated layer). When a covering structure using a rubber mold part including the electric field relaxation layer 16 is constructed, a semiconductive tape layer 120 is provided inside the electric field relaxation layer 16. The semiconductive tape layer 120 may be formed by winding a semiconductive tape around the outer periphery of the shielding layer of the power cable 100. A rubber mold part that does not have the electric field relaxation layer 16 may be used, or an electric field relaxation layer may be separately provided on the outer periphery of the semiconductive tape layer 120 after winding the semiconductive tape. When grease or the like is applied to a portion (for example, a contact portion with the electric field relaxation layer 16 such as an end portion of the above-described semiconductive tape layer 120) where adhesion with the main body 10 is particularly required in the coating target, the main body 10 (electric field relaxation layer) Even if the inner surface of the fluorinated layer is provided, the main body 10 and the object to be coated can be brought into close contact with each other, and for example, corona characteristics can be improved. However, although application | coating of grease etc. is needed, since the application | coating area | region in this case is few, the fall of workability | operativity can be suppressed.

(Embodiment 2)
As another form, it can be set as the form which further provides a diameter expansion cylinder (not shown) inside a rubber mold component. In this embodiment, by providing the diameter-expanded cylinder, it can be easily inserted into a covering object such as a power cable and is excellent in workability.

  In this embodiment, when an inner lubricating layer made of a fluorinated layer is provided on at least a part of the inner surface of the rubber mold part, preferably the entire inner surface, the diameter-expanded cylinder can be easily removed. Therefore, in this embodiment, the insertion work can be easily performed as described above, and the diameter-expanded cylinder can be easily removed, and the workability is excellent. In this embodiment, the outer surface of the rubber molded part may or may not have an outer lubricating layer made of a fluorinated layer. When the outer lubricating layer is also provided, dust and the like can be prevented from adhering to the outer surface of the rubber molded part, and the appearance is excellent.

  Alternatively, the rubber mold component does not include a fluorinated layer, and may be configured to include a fluorinated layer on at least a part of the outer surface of the diameter-expanded cylinder. This fluorinated layer is formed by fluorinating an organic polymer material in at least a part of the outer surface portion of the diameter-expanded cylinder. With this configuration, the diameter-expanded cylinder can be easily removed regardless of the presence or absence of the fluorinated layer of the rubber mold component. Moreover, a fluorinated layer can also be provided in both the outer surface and inner surface of a diameter expansion cylinder. Or it can also be set as the form which provides a fluorinated layer in both the inner surface of a rubber mold component, and the outer surface of a diameter expansion cylinder. Alternatively, it is possible to provide a fluorinated layer on both the outer surface and the inner surface of the rubber mold part and on both the outer surface and the inner surface of the expanded diameter cylinder. The direct fluorination technique using the above-mentioned fluorine-containing gas can also be suitably used for forming the fluorinated layer provided in the diameter-expanded cylinder.

  The form of the expanded diameter cylinder is not particularly limited. Specifically, there are a form in which a thin strip described in Patent Document 2 is spirally wound, and a form in which a plurality of arc-shaped divided pieces are combined. In the former form, the diameter-expanded tube can be easily disassembled by removing the strip in the direction opposite to the spiral winding direction, and is easy to remove. The latter form has a simple configuration of the diameter-expanded cylinder and is excellent in manufacturability. However, the latter form has a large contact area between the divided pieces constituting the diameter-expanded cylinder and the rubber mold part, and is difficult to remove as compared with the form of the above-described narrow strip. Therefore, this form can improve the removal workability of the diameter-expanded cylinder by providing the fluorinated layer. Examples of the constituent material of the expanded diameter cylinder include PP (polypropylene), cellulose acetate butyrate, and polyvinyl chloride. The size (especially the inner diameter) of the diameter-expanding cylinder may be appropriately selected from those that can expand the diameter of the rubber mold component to a desired size.

  The diameter-expanding cylinder keeps the rubber mold part expanded to a predetermined size until the rubber mold part is attached to the covering target such as a power cable, and is fitted on the outer periphery of the covering target. Removed. That is, the diameter-expanding cylinder is merely a part that is temporarily fitted on the outer periphery of the object to be covered.

(Embodiment 3)
For the rubber mold component described in Embodiment 1 and the diameter-expanded cylinder described in Embodiment 2, only a part of the inner surface or only a part of the outer surface can be provided with a fluorinated layer. .

  For example, the form which provides a fluorinated layer in the shape of a some dot or a plurality of lines on the inner surface or the outer surface of a rubber mold part or a diameter-expanding cylinder is mentioned. Examples of the plurality of points and lines include a form aligned along the axial direction of the rubber mold part and the expanded cylinder, a form aligned along the circumferential direction, and a form aligned in a spiral. In the form in which the fluorinated layer partially exists on the surface of the rubber mold part or the diameter expansion cylinder, a part of the surface is composed of the fluorination layer, and the other part is the original material of the rubber mold part or the diameter expansion cylinder. Consists of. Therefore, in particular, the rubber mold component of this embodiment can have both effects of improving lubricity by the fluorinated layer and ensuring flexibility and stretchability by the non-fluorinated region. By having flexibility or the like, it is expected that, for example, it is easy to ensure adhesion with a covering target such as a power cable. Therefore, the non-fluorinated region in the rubber mold component may be a location where adhesion to the object to be coated is required, typically a location that easily becomes an electrical weak point. The region where the fluorinated layer in the rubber mold component is formed is a place where it is difficult to become an electrical weak point. In addition, it can also be set as the form which provides a fluorinated layer in one whole region of the inner surface and outer surface of a rubber mold component, and provides a fluorinated layer only in the other part.

  The above-mentioned form in which the partially fluorinated layer exists is, for example, a treatment using the above-described fluorine-containing gas using a cylindrical core having a through hole at a position corresponding to the above-described point or line. It can be formed by doing.

(Test example)
A covering member for a power cable having a lubricating layer on the surface was prepared, and workability of folding and returning work, insertion into a power cable, and electrical characteristics were examined.

  Here, a power cable covering member having the structure described in the above-described first embodiment, that is, an inner lubricating layer and an outer lubricating layer made of a fluorinated layer over the entire surface of the cylindrical main body was produced. The cylindrical main body was a rubber molded part made of silicone rubber, and had a size (model number NPAT-F11T manufactured by Sumiden Asahi Seiko Co., Ltd.) having a size that can be attached to a power cable described later.

  The prepared cylindrical main body was fluorinated. The fluorination treatment was so-called direct fluorination using a mixed gas of fluorine gas and inert gas. Here, fluorination treatment was performed by changing the concentration of the fluorine gas in the mixed gas, and three samples No. 1 to No. 3 having different fluorination treatment conditions were produced. Regarding the concentration of fluorine gas, sample No. 1 having the smallest sample number was set to the lowest (low concentration), and the concentration of fluorine gas was increased (the concentration was increased) as the sample number was increased. When the appearance of each sample after the fluorination treatment was visually confirmed, all of the samples No. 1 to No. 3 appeared to be lightly clouded on the entire surface.

  For the prepared samples No. 1 to No. 3 and the sample No. 100 prepared as a comparison and not subjected to fluorination treatment, the lower part of the cylindrical body is folded back to a predetermined folding position, and then returned to the original state. The workability was examined repeatedly. The results are shown in Table 1. In Table 1, ○ indicates that the folding work and the returning work can be performed repeatedly, △ indicates that the folding work and the returning work can be performed to some extent, and × indicates at least one of the folding work and the returning work. Indicates something difficult to do. This workability test was performed without applying grease to the outer surfaces of Sample No. 1 to No. 3 and the outer surface of Sample No. 100.

The produced samples No. 1 to No. 3 and the comparative sample No. 100 were each inserted into a power cable to be covered, and the insertability was examined. The results are shown in Table 1. In Table 1, ○ indicates that insertion can be performed easily, Δ indicates that insertion can be performed, and X indicates that insertion is difficult. This insertability test was performed without applying grease to any of the inner surfaces of Sample No. 1 to No. 3, the inner surface of Sample No. 100, and the outer surface to be coated. A power cable having a conductor cross-sectional area of 22 mm ^{2 and} a power cable having a conductor cross-sectional area of 38 mm ² were prepared as objects to be covered. Each of the power cables is a commercially available conductor composed of seven twisted copper wires and an insulating layer made of cross-linked polyethylene.

The produced samples No. 1 to No. 3 and the comparative sample No. 100 were examined for corona characteristics as electrical characteristics. Here, in compliance with the provisions of JCAA (Nippon power cabling Technology Association), the conductor cross-sectional area described above with reference to power cables of 22 mm ^2, performs commercial frequency partial discharge test, each corona generating voltage and extinction voltage Examined. Specifically, the main body of each sample is inserted and arranged in a power cable, a power source is connected to one end of the power cable, the other end is grounded, and power is applied to the power cable. Then, the corona generation voltage and the corona annihilation voltage were measured, and a case where the corona generation voltage satisfied at least one of 10 kV or more and an annihilation voltage of 5.5 kV or more was evaluated as ◯, and a case where none was satisfied was evaluated as x. The results are shown in Table 1. The charge amount at the generated voltage is 20 pC for all samples. This electrical property test was performed without applying grease to any of the inner surfaces of Sample No. 1 to No. 3, the inner surface of Sample No. 100, and the outer surface to be coated.

  Samples No. 1 to No. 3, which have a fluorinated layer formed by fluorination treatment on the outer surface of the main body as a lubricating layer, can be folded and returned without applying grease, as shown in Table 1. It can be seen that the workability is excellent. In this test, in particular, Sample No. 1 having a low fluorine concentration during the fluorination treatment and a relatively thin fluorinated layer was easily folded and returned. This is probably because in Sample No. 3, the fluorinated layer became relatively thick and the hardness of the main body increased. Note that the thickness of the fluorinated layer included in Sample No. 1 to Sample No. 3 is about several μm.

  In addition, as shown in Table 1, samples No. 1 to No. 3 having the fluorinated layer as a lubricating layer on the inner surface of the main body are excellent in insertability into the object to be coated.

  Further, it can be seen that Samples No. 1 to No. 3 having the fluorinated layer as a lubricating layer on the inner surface of the main body have high corona generation voltage and extinction voltage and are excellent in electrical characteristics. In particular, Sample No. 1 satisfied both the corona generation voltage of 10 kV or more and the extinction voltage of 5.5 kV or more. From this, it is considered that the fluorinated layer of Sample No. 1 has a thickness that allows the main body including the fluorinated layer and the power cable to be in close contact with each other. In addition, when grease was applied only to the surface of the electric field relaxation layer provided in the main body and attached to the power cable and the partial discharge test was performed as described above, all of the samples No. 1 to No. 3 Generated voltage and extinction voltage increased. From this, it can be said that the electrical characteristics can be improved by partially applying grease to the power cable.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist of the present invention.

  The covering member for electric power cables of this invention can be utilized for the structural member of the terminal connection part of an electric power cable, or an intermediate | middle connection part. In addition, the covering member with a fluorinated layer protects long materials such as pipes and rods from the external environment in addition to power cables and electric wires (prevents contact with water and dust, etc.) It is expected to be used as a protective member for mechanical protection (increasing strength) or electrical protection (increasing electrical insulation). The covering structure of the power cable of the present invention can be used for the construction of the terminal connection part and the intermediate connection part of the power cable.

1 Power cable sheathing 10 Body 12 Outer lubrication layer 14 Inner lubrication layer
16 Electric field relaxation layer
100 Power cable 110 Conductor 112 Electrical insulator 114 Sheath
120 Semiconductive tape layer 130 Ground wire 140 Tightening band
200 Connection terminal 210 Insulation layer

Claims (8)

A power cable covering member attached to the outer periphery of the power cable,
A cylindrical body composed of an organic polymer material;
A power cable covering member comprising: a fluorinated layer formed by fluorinating the organic polymer material on at least a part of a surface portion of the main body. The main body is composed of rubber mold parts,
2. The covering member for a power cable according to claim 1, wherein the fluorinated layer is provided on an outer surface of the rubber mold part. The main body is composed of rubber mold parts,
2. The covering member for a power cable according to claim 1, wherein the fluorinated layer is provided on an inner surface of the rubber mold part. The main body is composed of rubber mold parts,
2. The covering member for a power cable according to claim 1, wherein the fluorinated layer is provided on both an outer surface and an inner surface of the rubber mold part. A cylindrical body mounted on the outer periphery of the power cable and made of organic polymer material;
The inner diameter of the main body is maintained, the diameter of the main body is maintained in an expanded state, and the diameter expansion cylinder is removed when the main body is attached to the power cable.
The diameter-expanding cylinder is a power cable covering member comprising a fluorinated layer formed by fluorinating an organic polymer material on at least a part of the outer surface portion thereof.   6. The power cable covering member according to claim 1, wherein an average thickness of the fluorinated layer is 1 μm or more.   7. The power cable covering member according to claim 1, wherein the organic polymer material is one selected from silicone rubber, ethylene propylene rubber, chloroprene rubber, and polypropylene.   A power cable covering structure comprising: a power cable; and the power cable covering member according to any one of claims 1 to 7 attached to an outer periphery of the power cable.

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