JP2011259558A - Cable terminal connection portion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a surface processing range of a cable insulator, to reduce trouble when a rubber stress cone is inserted and to save power of assembly construction.SOLUTION: A cable terminal connection portion includes a cable terminal where a cable external semiconductor layer 13 and a cable insulator 12 are exposed; a rubber stress cone; and a porcelain tube with which insulation fluid is filled inside. A periphery of the cable insulator is divided into a first processing portion L1 on which the rubber stress cone is installed and a second processing portion L2 reaching to a tip portion of the cable insulator from a tip portion of the first processing portion L1. An external diameter of the first processing portion L1 is made thicker than an inner diameter of the rubber stress cone, and an outer diameter of the second processing portion L2 is made thinner than an inner diameter of the rubber stress cone. The cable insulator has thickness so that an electric field V(kV/mm) on a radial direction of the cable insulator 12 becomes larger than an electric field V(kV/mm) on an axial direction of the second processing portion L2.

Description

  The present invention relates to a cable terminal connection part, and more particularly to a cable terminal connection part in which a rubber stress cone is mounted on the outer periphery of a cable insulator.

  Conventionally, in a terminal connection portion of a 275 kV class high-voltage CV cable (cross-linked polyethylene cable), as shown in FIG. 6, a rubber stress cone 110 is attached to the outer periphery of the cable insulator 100, and the rubber stress cone 110 is epoxy-bonded. By pressing toward the seat 120, insulation at the interface between the cable insulator 100 and the rubber stress cone 110 is secured (for example, Patent Document 1).

  By the way, in the cable termination connection part of such a structure, in order to apply a predetermined surface pressure between the outer peripheral part of the cable insulator 100 and the inner peripheral part of the rubber stress cone 110, the inner diameter of the rubber stress cone 110 is set. It is necessary to make it smaller than the outer diameter of the cable insulator 100, and it is necessary to treat the outer peripheral portion of the cable insulator 100 at the construction site in order to improve the adhesion of the interface. Specifically, a section (hereinafter referred to as “finishing range”) L0 extending from the tip of the outer semiconductive layer 130 to the tip of the cable insulator 100 is polished by, for example, glass shaving or sandpaper. It was necessary to process (for example, patent document 2).

  However, in the cable end connection portion having such a configuration, the finishing range L0 is, for example, about 2 to 3 m, so that the stroke length of insertion of the rubber stress cone 110 becomes long, and as a result, the cable 200 is stripped. It took a lot of time (about 2 to 3 hours per phase), and it took a lot of time to wear the rubber stress cone 110.

  In the figure, reference numeral 210 is a pressing device for the rubber stress cone 110, 220 is an anticorrosion layer, 300 is a saddle tube, 310 is a bottom fitting, 320 is a lower fitting, 400 is an insulating fluid, 500 is an upper fitting, 600 is an upper covering, Reference numeral 700 denotes a support insulator.

Japanese Patent Laid-Open No. 9-261832 JP-A-8-172712

  The present invention has been made in order to solve the above-mentioned problems. By reducing the surface treatment range of the cable insulation and reducing the labor for inserting the rubber stress cone, the assembly work is greatly saved. It is intended to provide a cable termination connection that can be used.

  In the cable termination connecting portion according to the first aspect of the present invention, the cable external semiconductive layer and the cable insulator are exposed by stepping off the end of the cable, and a predetermined process is performed on the distal end side of the cable external semiconductive layer. A cable end having an external semiconductive layer formed by application, a rubber stress cone mounted on the outer periphery of the cable insulator across the external semiconductive layer, and surrounding the cable end and the rubber stress cone and insulating inside A cable-filled soot tube, and an outer peripheral portion of the cable insulator includes a first processing portion to which a rubber stress cone is attached, and a first processing portion extending from the distal end portion of the first processing portion to the distal end portion of the cable insulator. The outer diameter of the first processing section is larger than the inner diameter of the rubber stress cone, the outer diameter of the second processing section is smaller than the inner diameter of the rubber stress cone, and Cable insulation in the second processing unit are those having a thickness of at least a second electric field applied in the radial direction of the cable insulation than the electric field applied in the axial direction of the processor is increased.

  According to a second aspect of the present invention, in the cable termination connecting portion according to the first aspect, the first processing unit side to the second processing unit side between the first processing unit and the second processing unit. The taper part which is diameter-reduced toward is provided.

  According to a third aspect of the present invention, in the cable termination connecting portion according to the second aspect, a predetermined surface treatment is applied to the outer surface of the first processing portion.

  According to a fourth aspect of the present invention, in the cable termination connecting portion according to the third aspect, the outer surface of the tapered portion is subjected to a predetermined surface treatment.

  According to the cable termination connection portion of the first to third aspects of the present invention, the following effects are obtained.

  First, the outer peripheral portion of the cable insulator exposed by the stripping process at the end of the cable is positioned on the distal end side of the first processing portion to which the rubber stress cone is attached and the first processing portion. Since the outer diameter of the second processing section is narrower than the inner diameter of the rubber stress cone, the rubber stress cone is inserted into the second processing section. As a result, the labor required for attaching the rubber stress cone is greatly reduced as compared with the conventional cable terminal connection portion.

  Second, the outer surface of the first processing unit is subjected to a predetermined surface treatment, and the cable insulator in the second processing unit having a low electric field is at least a cable insulator than the electric field applied in the axial direction of the second processing unit. Therefore, the outer peripheral portion of the cable insulator is completed by roughing, for example, and the surface treatment of the cable insulator using conventional sandpaper or the like is completed. Therefore, the labor required for cable processing can be greatly reduced as compared with the conventional cable terminal connection portion.

The partial sectional view of the cable termination connection part in one example of the present invention. Explanatory drawing which shows the process condition of the outer peripheral part of the cable insulator in this invention. The partial sectional view showing one example of the rubber stress cone in the present invention. Explanatory drawing which shows the mounting condition to the cable insulator of the rubber stress cone in this invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an electric field analysis diagram of a cable terminal connection portion in one embodiment of the present invention, wherein a partial diagram (a) is an electric field analysis diagram in a state where an outer peripheral portion of a cable insulator is matched with an inner diameter of a stress cone; The electric field analysis figure in the state which sharpened the outer peripheral part of the insulator. The partial sectional view of the conventional cable termination connection part.

  Hereinafter, a preferred embodiment to which the cable termination connecting portion of the present invention is applied will be described with reference to the drawings.

  FIG. 1 is a partial cross-sectional view of a cable termination connection portion of the present invention that is suitable for an air termination connection portion of a 275 kV CV cable, and FIG. .

  In FIG. 1 and FIG. 2, the cable termination connection portion of the present invention includes a cable terminal 2 in which an end portion of the CV cable 1 is stepped, and a distal end portion of an outer semiconductive layer 13 ′ described later on the outer periphery of the cable insulator 12. A rubber stress cone 3 mounted across the (high-pressure side), and a soot pipe 5 made of a porcelain soot pipe or the like surrounding the cable terminal 2 and the rubber stress cone 3 and filled with an insulating fluid 4 made of insulating oil. I have.

  The cable termination connecting portion having such a configuration is assembled as follows.

  First, the CV cable 1 has a cable shielding layer 14 formed of a cable inner semiconductive layer (not shown), a cable insulator 12, a cable outer semiconductive layer 13, an aluminum corrugated sheath, and a vinyl chloride sheath on the cable conductor 11 in sequence. The cable sheath 15 which consists of is comprised. The cable inner semiconductive layer, the cable insulator 12 and the cable outer semiconductive layer 13 are usually formed by extrusion coating of three layers simultaneously.

  The end portion of the CV cable 1 having such a configuration is stripped, so that the cable shielding layer 14, the cable external semiconductive layer 13, the cable insulator 12, and the cable conductor 11 are exposed in sequence.

  Before the rubber stress cone 3 is attached, the outer peripheral portion of the cable insulator 12 exposed in this manner is connected to the first processing portion L1 on the rear end side (lower side in the drawing) as shown in FIG. The cable processing is performed by being divided into a second processing portion L2 on the distal end side (upper side in the drawing) and a tapered portion 16 provided between the first processing portion L1 and the second processing portion L2.

  Specifically, the outer peripheral portion of the cable insulator 12 includes a first processing portion L1 to which the rubber stress cone 3 is attached, and a distal end side (second side) from the distal end portion (high pressure side) of the first processing portion L1. Tapered taper portion 16 that is smoothly reduced in diameter toward the processing portion L2 side, and a second processing portion that extends from the distal end portion (high-pressure side) of the tapered portion 16 to the distal end portion (high-pressure side) of the cable insulator 12. It is divided into L2.

  In the outer peripheral portion of the cable insulator 12 corresponding to the first processing portion L1, “predetermined surface treatment”, that is, “electrical characteristics necessary for the interface between the rubber stress cone 3 and the cable insulator 12 can be obtained. Surface treatment ". For example, in this embodiment, the first processing portion L1 is mirror-finished by polishing with glass shaving or sandpaper. When applied to a class with a low voltage, for example, it is only necessary to finish with sandpaper and not to have a mirror finish.

  Moreover, the outer diameter of the 1st process part L1 is made thicker than the internal diameter of the rubber stress cone 3 mentioned later. In this embodiment, the diameter difference between the outer diameter of the first processing portion L1 and the inner diameter of the insertion hole of the rubber stress cone 3 is at least about 2 mm, and the cable difference is set to at least about 2 mm. The adhesion of the interface between the outer periphery of 12 and the inner periphery of the insertion hole of the rubber stress cone 3 can be improved.

  Next, since the electric field of the cable insulator 12 corresponding to the second processing part L2 is lower than that of the first processing part L1 as follows, the cable insulator 12 corresponding to the second processing part L2 is as follows. The outer peripheral portion of the rubber can be made thinner than the inner diameter of the rubber stress cone 3 by roughing, for example.

Here, the electric field applied in the radial direction of the cable insulator 12 corresponding to the second processing unit L2 is V ₁ (kV / mm), and the electric field applied in the axial direction (creeping direction) of the second processing unit is V ₂ ( kV / mm), if V ₁ > V ₂ , the electric field applied to the cable insulator 12 corresponding to the second processing unit L2 is low, so the cable insulation corresponding to the second processing unit L2 Even if the outer diameter of the body 12 is made smaller than the inner diameter of the stress cone, that is, even if the outer diameter is made thinner than a prescribed thickness, no electrical problem will occur. This point will be described later with reference to FIG. Accordingly, the cable insulator 12 corresponding to the second processing portion L2 is scraped off by, for example, a dedicated stripping tool (not shown), so that the outer diameter of the cable insulator 12 is made thinner than the inner diameter of the rubber stress cone 3. Can do.

In this case, if the cable insulator 12 corresponding to the second processing portion L2 has a relationship of V ₁ > V ₂ , the cable insulator 12 only exists on the cable conductor 11 even if the thickness is extremely thin. It is sufficient electrically. Therefore, the cable insulator 12 corresponding to the second processing portion L2 may be in a state in which the outer peripheral portion of the cable insulator 12 is roughly cut by machining (machining), in a state where irregularities are formed on the outer surface, or in an elliptical shape. In particular, there is no risk of problems in electrical characteristics. Thereby, the conventional surface treatment is unnecessary for the outer surface of the cable insulator 12 corresponding to the second processing portion L2.

  Moreover, the taper part 16 is provided between the 1st process part L1 of the cable insulator 12, and the 2nd process part L2, and the outer surface of the said taper part 16 is also the above-mentioned 1st process part L1. Similarly, “predetermined surface treatment”, that is, “surface treatment for obtaining necessary electrical characteristics at the interface between the rubber stress cone 3 and the cable insulator 12” is performed.

  Thereby, when the rubber stress cone 3 is inserted into the cable insulator 12, the inner periphery of the rubber stress cone 3 starts to come into close contact with the outer periphery of the cable insulator 12 from the taper portion 16 to the first processing portion L1. Since minute air can be prevented from being caught at the interface between the cone 3 and the cable insulator 12, it is possible to provide a cable terminal connection portion having excellent electrical characteristics.

  Further, by applying “predetermined processing” to the distal end side (high voltage side) of the cable external semiconductive layer 13, the external semiconductive layer 13 ′ necessary for assembly is formed. That is, the “predetermined process” is “to form the external semiconductive layer 13 ′ necessary for assembling the rubber stress cone 3”. In FIG. 1, as a predetermined treatment, a stepped cable insulator is formed at the tip (high voltage side) of the cable external semiconductive layer 13 in order to eliminate the step between the cable external semiconductive layer 13 and the cable insulator 12. 12 and a molded semiconductive layer 17 processed by winding a semiconductive self-bonding tape (ACP tape or the like) so as to straddle the tip of the cable outer semiconductive layer 13 and rubber. An external semiconductive layer 13 'necessary for assembling the stress cone 3 is formed. In addition, when necessary electrical characteristics can be obtained after assembling the rubber stress cone, as a predetermined process, only the external cable semiconductive layer 13 that has been stripped without winding a semiconductive self-adhesive tape is used. A semiconductive layer 13 ′ may be formed.

  In the figure, reference numeral 18 is a seat provided on the outer periphery of the cable shielding layer 14, 19 is a ground wire, 20 is a conductor terminal attached to the tip of the cable conductor 11, 21 is an upper fitting, and 22 is a bottom fitting. , 23 is a cylindrical metal adapter that is airtightly attached to the upper surface of the bottom metal fitting 22, 24 is a lower copper tube, 25 is a corrosion protection layer provided between the cable sheath and the lower copper tube 24, and 26 is a bolt. , 27 are supporting insulators, and 28 is a frame.

  FIG. 3 shows a cross-sectional view of a fitting-integrated stress cone as an embodiment of the rubber stress cone 3 according to the present invention. In the figure, parts common to those in FIGS. 1 and 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  1, FIG. 2 and FIG. 3, the metal-integrated stress cone according to the present invention has an outer semiconductive layer 13 'on the outer periphery of the first processing portion L1 of the cable insulator 12 (high voltage side, upper side in the figure). ) And a metal fitting 32 that surrounds the outer semiconductive layer 13 ′ and is integrally provided on the low pressure side of the stress cone body 31. It has a cylindrical shape. In this embodiment, the overall length of the bracket-integrated stress cone is about 405 mm, the outer diameter of the stress cone body 31 is about 180 mm, and the inner diameter of the insertion hole 33 provided at the center of the stress cone body 31 is about 64 mm. Yes.

  The stress cone main body 31 includes a cylindrical semi-conductor portion 34 made of a rubber-like elastic body such as silicone rubber disposed on the rear end side (low-pressure side, lower side in the figure), and the front end side of the semi-conductor portion 34. A cylindrical insulator portion 35 made of a rubber-like elastic body such as silicone rubber whose rear end portion (lower side in the drawing) is concentrically connected to the semi-conductor portion 34 on the upper side in the drawing, and an insulator And a cylindrical insulating protective layer 36 made of a rubber-like elastic body such as silicone rubber and provided integrally with the outer periphery of the semi-conductor part 34. The part 34, the insulator part 35, and the insulating protective layer 36 are integrated with a metal fitting 32, which will be described later, by molding.

  The tip of the semiconductive portion 34 has a bell mouth shape that gradually increases in diameter from the inner peripheral portion (rising portion) near the tip of the semiconductive portion 34 toward the outer peripheral portion of the distal end portion of the insulator portion 35. An electric field relaxation portion 37 having a curved interface is provided, and a cylindrical semiconductive skirt portion 38 is concentric with the semiconductive portion 34 toward the rear end side at the outer peripheral edge portion of the rear end portion. It protrudes in a shape. The semiconductive body portion 34 and the semiconductive skirt portion 38 are integrally formed. In this embodiment, the length of the semiconductive portion 34 including the semiconductive skirt portion 38 is about 180 mm and the outer diameter is about 156 mm, of which the semiconductive skirt portion 38 has an axial length of about 40 mm. It is said that. Further, in the vicinity of the rising portion of the semiconductive portion 34, the stress cone main body 31 has a thickness that allows a sufficient tightening force to act on the interface between the cable insulator 12 and the cable external semiconductive layer 13. Yes.

  A cone-shaped outer surface 39 that is gradually reduced in diameter toward the tip is provided on the outer periphery of the tip of the insulator 35, and the inner periphery of the high-pressure end is near the high-pressure end. A tulip-like recessed portion 40 having an inner surface that gradually increases in diameter from the high pressure side end portion is provided concentrically with the insulator portion 35. Providing such a recessed portion 40 prevents electric field concentration at the insulating fluid 4 at the distal end portion of the stress cone body 31, the insulator portion 35 of the stress cone body 31, and the triple junction (triple junction) P of the cable insulator 12. be able to. In this embodiment, the depth of the recessed portion 40 is about 60 mm, the diameter of the small diameter portion of the recessed portion 40 is about 80 mm, and the diameter of the large diameter portion is about 120 mm.

  In addition, a cylindrical insulating skirt portion 41 projects from the rear end portion of the insulating protective layer 36 concentrically with the insulating protective layer 36 toward the rear end side. The insulating protective layer 36 and the cylindrical insulating skirt portion 41 are integrally formed. Here, the insulating skirt portion 41 is integrally provided on the outer periphery of the semiconductive skirt portion 38, and the rear end portion of the insulating skirt portion 41 extends further toward the rear end side than the rear end portion of the semiconductive skirt portion 38. An annular protrusion 32e is provided on the inner periphery of the extended low side end portion of the insulating skirt portion 41. In this embodiment, the length of the insulating skirt portion 41 in the axial direction is about twice that of the semiconductive skirt portion 38. Further, the thickness of the insulating skirt portion 41 is about twice the thickness of the semiconductive skirt portion 38. Further, the outer diameter of the insulator 35 including the insulating protective layer 36 including the insulating skirt 41 is about 180 mm, and the axial length including the insulating protective layer 36 including the insulating skirt 41 is about 370 mm. Has been.

  The metal fitting 32 has a first cylindrical portion 32a whose outer peripheral portion is in close contact with the inner peripheral portion of the semiconductive skirt portion 38, and a concentric continuous connection on the rear end side of the first cylindrical portion 32a. A second cylindrical portion 32b that is in close contact with the inner peripheral portion of the portion 41, and a third cylindrical portion that is concentrically connected to the rear end side of the second cylindrical portion 32b and has a flange 32c on the outer periphery of the rear end portion. 32d, and the inner peripheral surfaces of the first cylindrical portion 32a, the second cylindrical portion 32b, and the third cylindrical portion 32d are flush with each other. The outer diameter of the first cylindrical portion 32a is smaller than the outer diameter of the second cylindrical portion 32b, and an annular concave groove that engages with the annular protrusion 32e at the rear end portion of the second cylindrical portion 32b. 32f is provided. In this embodiment, the metal fitting 32 is made of aluminum, the outer diameter of the flange 32c is about 195 mm, and the inner diameter of the metal fitting 32 is about 136 mm.

  Such a stress cone main body 31 and the metal fitting 32 including the metal fitting 32 are formed as follows. First, the semiconductive rubber portion of the stress cone main body 31, that is, the semiconductive portion 34 and the semiconductive skirt portion 38, is molded (molded), and the semiconductive rubber portion (semiconductive portion formed) is molded. 34 and the semiconductive skirt portion 38) are fitted into the metal fitting 32. In this case, the inner peripheral part of the semiconductive skirt part 38 is brought into contact with the outer peripheral part of the first cylindrical part 32a. Then, the integrated semiconductive rubber portion (semiconductor portion 34 and semiconductive skirt portion 38) and the metal fitting 32 are set in a mold, and the insulating rubber portion of the stress cone main body 31, that is, the insulating portion 35, the insulating portion. The protective layer 36 and the insulating skirt portion 41 are molded (molded). As a result, a bracket-integrated stress cone in which the bracket 32 is integrally provided on the low-pressure side of the stress cone body 31 is obtained. Specifically, the outer peripheral portion of the first cylindrical portion 32a of the metal fitting 32 is the inner peripheral portion of the semiconductive skirt portion 38 of the stress cone main body 31, and the outer peripheral portion of the second cylindrical portion 32b of the metal fitting 32 is the stress cone main body. A metal fitting integrated type in which the protrusion 32e of the insulating skirt portion 41 of the stress cone main body 31 is fitted into the groove 32f of the second cylindrical portion 32b of the metal fitting 32. A stress cone is obtained.

  Next, based on FIG. 4, the mounting method to the cable insulator of the metal fitting integrated type stress cone as the rubber stress cone 3 in a present Example is demonstrated. In the figure, parts common to those in FIGS. 1, 2 and 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  First, a lubricant (not shown) such as silicone oil is applied to the outer surfaces of the first and second processing portions L1 and L2 of the cable insulator 12. Further, as shown in FIG. 1, an annular bottom metal fitting 22 disposed in the vicinity of the end of the cable sheath 15 of the cable terminal 2 is fixed via a support lever 27 and the like, and the outer semiconductive layer 13 of the cable terminal 2 is fixed. A flange 23a on the lower surface side (rear end surface side) of the cylindrical adapter 23 arranged so as to surround the outer periphery of 'is airtightly fixed to the upper surface side (front end surface side) of the bottom fitting 22.

  In such a state, as shown in FIG. 4, the bracket-integrated stress cone as the rubber stress cone 3 is placed on the outer periphery of the cable insulator 12 as the second processing portion L2 (at the high end side of the cable terminal 2). ), The fitting 32 of the fitting-integrated stress cone is inserted toward the adapter 23 (see FIG. 1).

  Then, since the outer diameter of the second processing portion L2 of the cable insulator 12 is formed to be narrower than the inner diameter of the stress cone main body 31 constituting the bracket-integrated stress cone, when inserting the bracket-integrated stress cone, The stress cone main body 31 can be easily inserted through the outer peripheral portion of the second processing portion L2 of the cable insulator 12 without frictional resistance.

  When the stress cone body 31 reaches the tapered portion 16 and the distal end portion (high pressure side) of the first processing portion L1, the outer diameter of the first processing portion L1 is larger than the inner diameter of the stress cone body 31. Since it is formed, the stress cone main body 31 is slid to a predetermined position by the same method as the conventional method for attaching the rubber stress cone from the reaching position. As a result, the stress-contained stress cone is placed in a state where the inner peripheral portion of the stress cone main body 31 is in close contact with the outer peripheral portion of the first processing portion L1, that is, the outer peripheral portion of the first processing portion L1 and the stress cone main body 31. A predetermined surface pressure is applied between the insertion hole 33 (see FIG. 3) and the inner periphery of the insertion hole 33 (see FIG. 3), so that it can be mounted in a state where insulation at the interface is secured.

  The lower surface side of the flange 32c of the fitting-integrated stress cone fitting 32 thus mounted is brought into contact with the upper surface side of the flange 23b of the adapter 23 via an O-ring (not shown), and a bolt (not shown). By fixing both, the seal part (oil stop part) is formed.

  Next, as shown in FIG. 1, the outer periphery of the cable terminal 2 is surrounded by the soot tube 5, the low-pressure side end portion is placed on the bottom metal fitting 22, and both are fixed by bolts 26. Or the like.

  Thereby, the electrical insulation performance of the space in the soot pipe 4 is ensured. Next, the upper metal fitting 21 is attached to the upper part of the soot tube 4, and the conductor terminal 20 on the cable terminal 2 side penetrates the upper metal fitting 21 and is electrically connected to the upper conductor 30. By forming the anticorrosion layer 25 at the rear end portion of the cable terminal 2, the assembly of the cable terminal connection portion is completed. The upper conductor 30 is connected to a high voltage conductor such as an overhead wire or a lead-in wire (not shown).

  FIG. 5 is an electric field analysis diagram showing the electric field strength (electric field stress) in the cable terminal connection portion together with a comparative example. FIG. 5A is a partial diagram (a) showing the outer diameter of the cable insulator 12 as a comparative example. An electric field analysis diagram and a partial diagram (b) in a state matched to the inner diameter show an electric field in a state where the outer peripheral portion of the portion corresponding to the second processing portion L2 of the cable insulator 12 is extremely shaved as another embodiment. An analysis diagram is shown. 5 (a) and 5 (b), the contour lines of the cable conductor 11, the cable insulator 12, the inner peripheral surface of the soot tube 5 and the outer peripheral surface (the soot portion) of the soot tube are described from the central axis to the outside. Contour lines in the vicinity of the tip of the rubber stress cone 3 are described between the insulator 12 and the soot tube 5, and the electric field strength on these contour lines is indicated by arrows. 5A and 5B, the arrow indicates the electric field strength, and the longer the length of the arrow line, the higher the electric field strength.

5 (a) and 5 (b), the length of the arrow line on the outer peripheral surface of the cable insulator 12 (a line parallel to the central axis on the outer side (right side in FIG. 5) of the line 12). It can be seen that the vicinity where the rubber stress cone 3 is disposed is long, and gradually decreases from the rubber stress cone 3 toward the tip. That is, it can be seen that the electric field on the outer peripheral surface of the cable insulator 12 is concentrated in the vicinity where the rubber stress cone 3 is disposed. Therefore, it can be seen that the portion corresponding to the second processing portion L2 of the cable insulator 12 has no electrical problem even if it is extremely thin. However, when the relationship of V ₁ > V ₂ is not satisfied, that is, when the electric field V ₂ applied in the axial direction of the second processing unit L2 is greater than or equal to the electric field applied in the radial direction of the cable insulator, the cable insulator There is a risk of flashing damage in the radial direction, which is a problem. Further, when the cable conductor 11 is exposed in the second processing portion L2, the creepage distance on the cable insulator is shortened accordingly, and the electric field is concentrated on the cable conductor 11 in the exposed portion. As a result, there is a possibility that necessary electrical characteristics may not be obtained. Therefore, the thickness of the cable insulator 12 that satisfies the relationship of V ₁ > V ₂ is necessary.

  As described above, according to the cable terminal connection portion using the bracket-integrated stress cone of the present embodiment, the following effects can be obtained.

  1stly, the outer peripheral part of the cable insulator 12 exposed by the stripping process of the edge part of the CV cable 1 is the 1st process part L1 with which the rubber stress cone 3 is mounted | worn, and the 1st process part L1. It is divided into a taper-shaped taper portion 16 that is smoothly reduced in diameter from the tip portion toward the tip side, and a second processing portion L2 that extends from the tip portion of the taper portion 16 to the tip portion of the cable insulator 12, and Since the outer diameter of the second processing portion L2 is made thinner than the inner diameter of the rubber stress cone 3, the insertion operation of the rubber stress cone 3 in the second processing portion L2 becomes extremely simple. The labor required for installation is greatly reduced compared to the conventional cable terminal connection. Specifically, in the past, two to three workers were wearing the rubber stress cone 3, but in the present invention, one worker can also wear the rubber stress cone 3. it can.

  Second, it is sufficient to perform the predetermined surface treatment of the cable insulator 12 only on the first treatment portion L1 to which the rubber stress cone 3 is attached and preferably the taper portion 16, and therefore, compared with the conventional cable termination connection portion. Thus, the surface treatment range of the cable insulator 12 can be greatly reduced. Specifically, since about 80% of the processing length of the cable insulator 12 exposed by the stripping process can be processed by, for example, machining, a cable that takes a very long time as the surface treatment work of the cable insulator 12 The range of the predetermined surface treatment of the insulator 12 can be about 20%.

  Third, a predetermined surface treatment may be performed on the first processing unit L1, and the second processing unit L2 may be machined, for example, the second processing unit L2 is in a machined state (cable Since the processing of the outer peripheral portion of the cable insulator 12 is completed in a state where the outer peripheral portion of the insulator 12 is roughened), a predetermined surface treatment such as mirror finishing of the cable insulator 12 by sandpaper or the like is unnecessary, and thus The labor required for cable processing can be greatly reduced as compared with the conventional cable terminal connection portion.

  Fourth, when the tapered taper portion 16 is provided between the first processing portion L1 and the second processing portion L2, when the rubber stress cone 3 is inserted into the cable insulator 12, The rubber stress cone 3 can be reliably adhered to the outer periphery of the taper portion 16 without any gap, and as a result, generation of voids between the rubber stress cone 3 and the taper portion 16 after the adhesion can be eliminated.

  Fifth, when the taper portion 16 between the first processing portion L1 and the second processing portion L2 is subjected to a predetermined surface treatment in the same manner as the first processing portion L1, rubber stress during insertion is applied. Since the inner periphery of the cone 3 can be prevented from being damaged, and further, minute air can be prevented from being caught at the interface between the rubber stress cone 3 and the cable insulator 12, so that the cable termination connection having excellent electrical characteristics can be achieved. Department can be provided.

  In the above-described embodiments, the present invention is described with specific embodiments shown in the drawings. However, the present invention is not limited to these embodiments, and as long as the effects of the present invention are exhibited, You may comprise as follows.

  First, in the above-described embodiment, a metal-integrated stress cone is used as the rubber stress cone 3, but it is usually composed of a semiconductive portion and an insulator portion, and the entire shape is a spindle shape. A rubber stress cone having the structure (rubber stress cone having no metal fitting) may be used.

  Secondly, in the above-described embodiment, the case where the rubber stress cone 3 is formed of silicone rubber has been described. However, the rubber stress cone 3 may be formed of, for example, ethylene propylene rubber.

Thirdly, in the above-described embodiment, the case where the insulating oil 4 is filled with the insulating oil 4 as the insulating fluid 4 is described, but an insulating gas such as SF ₆ gas may be filled instead of the insulating oil. .

  Fourthly, in the above-described embodiment, the case where the metal fitting-integrated stress cone metal fitting 32 is attached to the adapter 23 is described. You may attach to the bottom metal fitting 22 airtightly.

  Fifth, in the above-described embodiment, the case where the present invention is applied to the aerial terminal connection portion has been described.

  Sixth, in the above-described embodiment, the case where the rated voltage is 275 kV has been described, but the present invention may be applied to a voltage lower than or higher than 275 kV.

1 ... CV cable (cable)
DESCRIPTION OF SYMBOLS 12 ... Cable insulator L1 ... 1st process part L2 ... 2nd process part 13 ... Cable outer semiconductive layer 16 ... Tapered part 2 ... Cable terminal 3 ... Rubber stress cone 4 ... Insulating fluid 5 ... Steel pipe

Claims (4)

A cable terminal having an external semiconductive layer formed by exposing a cable external semiconductive layer and a cable insulator by a stepping process at an end of the cable and performing a predetermined process on a distal end side of the cable external semiconductive layer; A rubber stress cone mounted on the outer periphery of the cable insulator across the outer semiconductive layer, and a soot tube surrounding the cable end and the rubber stress cone and filled with an insulating fluid inside,
The outer periphery of the cable insulator includes a first processing unit to which the rubber stress cone is mounted and a second processing unit that extends from the tip of the first processing unit to the tip of the cable insulator. Divided,
The outer diameter of the first processing section is made larger than the inner diameter of the rubber stress cone,
The outer diameter of the second processing section is made smaller than the inner diameter of the rubber stress cone, and the cable insulator in the second processing section is at least from an electric field applied in the axial direction of the second processing section. And a cable termination connecting portion characterized by having a thickness that increases an electric field applied in a radial direction of the cable insulator.   Between the first processing unit and the second processing unit, there is provided a taper portion that decreases in diameter from the first processing unit side toward the second processing unit side. The cable termination connection part according to claim 1.   The cable termination connecting portion according to claim 2, wherein a predetermined surface treatment is applied to an outer surface of the first processing portion.   The cable termination connecting portion according to claim 3, wherein a predetermined surface treatment is applied to an outer surface of the tapered portion.

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