JP2011188684A - Polymer bushing, and cable terminal connection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer bushing and a cable terminal connection, having improved resistance to bending load. <P>SOLUTION: The polymer bushing 100 includes an annular shielding metal fixture 140 on a continuing part between a large-diameter insulated cylinder 121 and a small-diameter insulated cylinder 122. The shielding metal fixture 140 has: a cylindrical part 141 embedded so as to expose only its outer surface; a tapered funnel-like part 142 formed to continue concentrically with the cylindrical part 141 on the upper end part of the cylindrical part 141 and concentrically embedded with the upper end part toward the small-diameter insulated cylinder 122; and a cylindrical part 143 formed in substantially parallel to the axial core of a conductor extracting bar 110 on the distal end of the funnel-like part 142. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polymer cannula and a cable termination connection mainly used in the air.

  Recently, from the viewpoint of reducing the weight of the cannula, slimming, reducing the size of the cannula, standardizing the cannula type and simplifying the work process, a polymer covering such as silicone rubber has been applied to the surface of an insulator such as an epoxy bushing. Directly molded, completely dry polymer sleeves are used.

  Patent Document 1 discloses a cable terminal connection portion having a small number of parts and a simple structure with improved flashing performance.

  FIG. 1 is a cross-sectional view showing a cable termination connecting portion described in Patent Document 1. As shown in FIG.

  As shown in FIG. 1, a polymer cannula 10 is provided on the outer periphery of a hard insulating tube 16 having a conductor lead bar 12 at the center and a cable receiving port 14 at the lower end, and on the outer periphery of the polymer sleeve 10. Are provided with a polymer covering body 20 formed so as to be spaced apart in the longitudinal direction, and a support fitting 24 having a flange portion 22 projecting outward from the peripheral surface of the insulating tube 16.

  The support fitting 24 is connected to the cylindrical portion 23 concentrically embedded in the lower portion of the insulating cylinder 16 with the conductor lead bar 12 and the lower end portion of the cylindrical portion 23, and is provided outside the peripheral surface of the insulating cylinder 16. And a flange portion 22 protruding in the direction.

  The cable terminal portion 28 is attached to the cable receiving port 14 of the insulating cylinder 16. The polymer covering 20 is positioned higher than the support bracket 24, and the cable receiving port 14 is positioned lower than the support bracket 24. The flange portion 22 of the support bracket 24 has a curved corner portion 30 on the outer surface, and a lower surface portion 32 is provided with a screw hole 34 that does not penetrate. The screw hole 34 of the flange portion 22 does not penetrate the flange portion 22. The mounting bolt 35 is screwed into the screw hole 34 from the lower side of the flange portion 22 and does not protrude from the upper surface of the flange portion 22.

  The polymer sleeve 10 thus configured has a curved corner 30 on the outer surface, and the mounting bolt 35 does not protrude from the upper surface of the flange 22. Therefore, it is necessary to cover with a shield cap to prevent a flashover. Absent. For this reason, the number of parts is small, and the flashing performance can be improved with a simple structure.

  Patent Document 2 discloses a polymer cannula that increases the operating voltage while suppressing an increase in the diameter of the polymer cannula.

  FIG. 2 is a cross-sectional view showing a cable termination connecting portion described in Patent Document 2. As shown in FIG.

  As shown in FIG. 2, the polymer cannula 50 is provided with a conductor lead bar 52 having a conductor insertion hole 52a at the lower end and a cable end 57 that is provided on the outer periphery of the conductor lead bar 52 at the lower end. A hard insulator 53 having a mouth 531a and a polymer coating 54 provided on the outer periphery of the insulator 53 and having a plurality of flanges 54a formed on the outer periphery so as to be spaced apart in the longitudinal direction are provided.

  A large-diameter portion 533 is provided in the vicinity of the lower end portion of the insulator 53 and above the conductor insertion hole 52 a, and a cylindrical shielding fitting 56 is concentric with the conductor lead-out rod 52 in the large-diameter portion 533. Further, an electric field relaxation layer 55 is provided at the interface between the large diameter portion 533 and the polymer covering 54.

  The shielding metal fitting 56 extends outward in the radial direction from the position of the upper end portion of the cylindrical portion 561, the tapered funnel-like portion 562 concentrically embedded with the large-diameter portion 533, and the large-diameter insulator 531. And an annular flange portion 563.

  The thus configured polymer cannula 50 can reduce the electric field strength on the air surface of the polymer cannula 50 by providing the electric field relaxation layer 55 at the interface between the large diameter portion 533 and the polymer coating 54. In addition, the heat generation of the electric field relaxation layer 55 can be suppressed.

JP 2006-33899 A JP 2009-5514 A

  In such a conventional polymer sleeve, the shielding metal part embedded in the insulating cylinder in the lower part of the polymer cover is subjected to stress against bending load resistance. The bending fracture load of the conventional polymer sleeve is about 700 kgf. When completely dry type polymer sleeves are used in the air, it is necessary to consider the case where a combined load of wind pressure load, seismic load, and short-circuit electromagnetic force is applied, and higher bending load resistance is required. .

  This invention is made | formed in view of this point, and it aims at providing the polymer cannula and the cable termination | terminus connection part which can improve a bending load capacity performance.

  The polymer sleeve of the present invention has a conductor lead bar in the center, a hard insulating cylinder provided on the outer periphery of the conductor lead bar, and a shielding fitting embedded in the insulating cylinder concentrically with the conductor lead bar. The shielding shell includes a cylindrical portion, and a funnel extending from the inner side of the cylindrical portion and extending while inclining in the axial direction of the conductor lead bar so that the tip is tapered. And a cylindrical portion formed substantially parallel to the axis of the conductor lead bar at the tip of the funnel-shaped portion, and the funnel-shaped portion and the cylindrical portion are embedded in the insulating cylinder. The structure is adopted.

  The cable termination connecting portion of the present invention adopts a configuration in which a cable end is attached to the lower end portion of the conductor lead bar of the polymer sleeve having the above-described configuration.

  According to the present invention, the bending load bearing performance can be improved, and the quality of the polymer cannula can be improved.

Sectional drawing which shows the structure of the polymer sleeve of patent document 1 Sectional drawing which shows the structure of the polymer sleeve of patent document 2 The fragmentary sectional view which shows the structure of the polymer sleeve which concerns on embodiment of this invention Sectional drawing explaining the structure of the shield fitting of the polymer sleeve concerning the said embodiment, and contrasting the structure of the shielding fitting of the conventional polymer sleeve Sectional drawing which shows the structure by which the insulation cylinder and polymer coating body of the polymer sleeve concerning other embodiment of this invention were integrally formed with the epoxy resin Sectional drawing which shows the penetration bushing structure of the polymer sleeve which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 3 is a partial cross-sectional view showing the configuration of the polymer cannula according to the embodiment of the present invention. The present embodiment is an example in which the tip is connected to an overhead wire, a lead-in wire, etc., and the lower end is applied to an air termination connection for connecting the terminal of a power cable.

  In the following description, the “leading end” of the inner conductor, the insulating cylinder, and the shielding metal fitting means the high voltage side, and corresponds to the upward direction in the drawing, and the “lower end” of the inner conductor, the insulating cylinder portion, and the shielding metal fitting. "Part" means the low pressure side, and corresponds to the downward direction in the figure.

  As shown in FIG. 3, the polymer sleeve 100 has a conductor extraction rod 110 in the center, a hard insulating cylinder 120 provided on the outer periphery of the conductor extraction rod 110, and a polymer insulating material on the outer periphery of the insulating cylinder 120. Accordingly, a plurality of flanges are formed on the outer periphery of the polymer covering body 130 so as to be spaced apart in the longitudinal direction.

  The conductor extraction rod 110 is formed of a metal rod suitable for energization, such as copper or copper alloy, or aluminum or aluminum alloy.

  The leading end portion of the conductor leading rod 110 protrudes from the leading end portion (not shown) of the insulating cylinder 120, and a conductor insertion hole 110 a is provided at the rear end portion of the conductor leading rod 110.

  The insulating cylinder 120 is a solid insulator in which the conductor extraction rod 110 is disposed on the central axis, and is integrally formed on the outer periphery of the conductor extraction rod 110 by a mold. The insulating cylinder 120 is formed of a material having high mechanical strength, for example, a hard plastic resin such as an epoxy resin or FRP (Fiber Reinforced Plastics).

  The insulating cylinder 120 is connected to the outer peripheral portion of the lower portion of the conductor extraction rod 110, that is, the large-diameter insulating cylinder 121 provided at the outer peripheral portion corresponding to the conductor insertion hole 110a, and the upper portion of the large-diameter insulating cylinder 121. And a small-diameter insulating tube 122 provided on the outer peripheral portion of the portion excluding the tip portion of the conductor lead bar 110.

  As in FIG. 1, a cone-shaped receiving port 160 for receiving a stress cone (not shown in FIG. 3) of the cable end is provided at the lower end portion of the large-diameter insulating cylinder 121. The receiving port 160 is a conductor. The lead rod 110 communicates with the conductor insertion hole 110a.

  The polymer covering 130 is formed of a polymer insulating material that is disposed in the air, has electrical insulation and weather resistance, and is excellent in electrical insulation and weather resistance, for example, a silicone polymer (silicone rubber). The

  The polymer cover 130 is provided on the outer peripheral portion of the small-diameter insulating cylinder 122, and a plurality of flanges 130 a are formed on the outer peripheral portion so as to be separated along the longitudinal direction of the polymer cover 130. The flange portion 130a leaks from the surface of the polymer cover 130 in order to prevent the upper end portion (not shown) of the conductor lead bar 110 on the high voltage side and a shielding metal fitting 140 (described later) on the ground side from flashing. It is provided for the purpose of securing the distance. As for the collar part 130a, the large diameter collar part and the small diameter collar part are provided alternately.

  The polymer covering 130 is integrally formed by molding on the outer periphery of the insulating cylinder 120 (small-diameter insulating cylinder 122 in FIG. 3).

  The polymer cannula 100 includes an annular shielding metal fitting 140 for electric field relaxation at a continuous portion of the large diameter insulating cylinder 121 and the small diameter insulating cylinder 122.

  As shown in FIG. 3, the shielding metal fitting 140 has a cylindrical portion 141 embedded in the connecting portion between the large-diameter insulating cylinder 121 and the small-diameter insulating cylinder 122 of the insulating cylinder 120 so that only the outer surface is exposed. Further, the shielding metal fitting 140 is a tapered funnel-like portion that is concentrically connected to the upper end portion of the tubular portion 141 and concentrically with the upper end portion toward the small-diameter insulating tube 122 side. 142, a cylindrical portion 143 formed substantially parallel to the axis of the conductor lead bar 110 at the tip of the funnel-shaped portion 142, and a flange portion 144 projecting radially outward from the peripheral surface of the cylindrical portion 141. . The cylindrical part 141, the funnel part 142, the cylindrical part 143, and the flange part 144 are connected. The shielding metal fitting 140 is a metal such as aluminum or an aluminum alloy. In FIG. 3, the cylindrical portion 141, the funnel-shaped portion 142, the cylindrical portion 143, and the flange portion 144 are integrally formed, and are usually used as a ground potential. .

  The funnel-shaped portion 142 rises from the inside of the tubular portion 141 and extends while being gently inclined in the axial direction of the conductor lead bar 110 so that the tip thereof is tapered, and the cross-sectional shape is a C-shape. . The length of the cylindrical portion 143 formed at the tip of the funnel-shaped portion 142 is formed so as to be approximately 1: 3 with respect to the entire length of the funnel-shaped portion 142.

  Here, (1) the total length of the funnel-shaped portion 142 and the length of the cylindrical portion 143, (2) from the base end portion of the funnel-shaped portion 142, that is, from the inner peripheral surface of the cylindrical portion 141 to the outer peripheral surface of the conductor lead bar 110 And a distance from the cylindrical portion 143 to the outer peripheral surface of the conductor lead bar 110 have a certain relationship as will be described later with reference to FIG. (3) The funnel-shaped portion 142 has a tapered shape with a cross-sectional shape that is gently inclined in the axial center direction of the conductor lead bar 110. With respect to the configuration of the funnel-shaped portion 142, the cylindrical portion 143 that forms the tip of the funnel-shaped portion 142 does not have such an inclination and is formed substantially parallel to the axis of the conductor lead bar 110.

  Further, an annular bottom metal fitting 145 is fixed to the lower end surface of the outer peripheral edge of the flange 144 via a fastening bolt (not shown).

  A part of the cylindrical portion 141 and the funnel-shaped portion 142 are embedded in the insulating cylinder 120 in the lower part of the polymer cover 130. Moreover, the weather resistance and corrosion resistance of the surface are maintained by performing the dacro process with respect to the outer surface of the shielding metal fitting 140.

  In FIG. 3, the polymer sleeve 100 is provided with a lower fitting 150 whose upper end is attached to the lower surface of the flange portion 144 of the shielding fitting 140 on the outer peripheral portion of the large-diameter insulating tube 121 below the shielding fitting 140. .

  Hereinafter, the shielding metal fitting 140 of the polymer cannula 100 configured as described above will be described in detail.

  The conventional polymer sleeve has a bending fracture load of about 700 kgf, and a higher bending load resistance performance has been demanded.

  The inventors paid attention to the stress against the bending load resistance of the shielding metal part embedded in the insulating cylinder in the lower part of the polymer coating.

  FIG. 4 is a cross-sectional view for explaining the structure of the shielding member of the polymer sleeve, and FIG. 4A is a sectional view of the main part of the shielding member 140 of the polymer sleeve 100 of the present embodiment. ) Is a cross-sectional view of a main part of a conventional metal shell shielding metal fitting.

  As shown in FIG. 4A, the polymer cannula 100 according to the present embodiment has a height H1 from the lower end surface of the flange portion 144 of the shielding metal fitting 140 to the tip end of the cylindrical portion 143, from the upper end of the cylindrical portion 141. The creeping distance A1 to the tip of the cylindrical portion 143, the distance B1 from the inner peripheral surface of the cylindrical portion 141 to the outer peripheral surface of the conductor extraction rod 110, and the distance from the inner peripheral surface of the cylindrical portion 143 to the outer peripheral surface of the conductor extraction rod 110 Let T1.

  A conventional polymer cannula shielding fitting 60 shown as a comparison object with respect to the polymer cannula 100 of the present embodiment has the following configuration and dimensions.

  As shown in FIG. 4 (b), a conventional polymer sleeve shield fitting 60 includes a cylindrical portion 61 embedded so as to expose only the outer surface of the insulating cylindrical portion, and an upper end portion of the cylindrical portion 61. The embedded portion 62 is embedded with the upper end portion being linear, and the flange portion 63 protrudes radially outward from the peripheral surface of the tubular portion 61.

  The height H2 from the lower end surface of the flange portion 63 of the shielding metal fitting 60 to the tip of the embedded portion 62, the creepage distance A2 from the upper end of the cylindrical portion 61 to the tip of the embedded portion 62, the inner peripheral surface of the cylindrical portion 61 And a distance T2 from the inner peripheral surface of the embedded portion 62 to the outer peripheral surface of the conductor lead bar 71.

  H1, A1, B1, and T1 of the shielding metal fitting 140 of the present embodiment correspond to H2, A2, B2, and T2 of the conventional shielding metal fitting 6, respectively.

  Hereinafter, the performances of the polymer cannula 100 of the present embodiment and the shielding fitting 60 of the conventional polymer cannula will be compared.

  The shielding metal fitting 140 of the present embodiment has a funnel-shaped portion 142 having a cross-sectional shape of a cross-section, and a short cylinder formed at the tip of the funnel-shaped portion 142 substantially parallel to the axis of the conductor lead bar 110. There is a feature having a portion 143. For this reason, H1, A1, B1, and T1 of the shielding metal fitting 140 are different in dimensions from H2, A2, B2, and T2 of the conventional shielding metal fitting 60 when the same electrical performance is obtained. The elements other than the shape of the shielding metal fitting 140 (the shape and material of the conductor lead bar 110 and the insulating cylinder 120) are the same. Here, an epoxy resin is used for the insulating cylinder 120.

  H (H1 of shielding metal fitting 140, H2 of shielding metal fitting 60) and T (T2 of shielding metal fitting 140, T2 of shielding metal fitting 60) affect the electrical performance. For this reason, in order to obtain the same electrical performance, it is necessary for H and T to satisfy H1 = H2 and T1 = T2. Since H determines the position of the tip of the shielding metal fitting, it affects the electric field on the surface of the flange portion 130a of the polymer coating 130 on the outer periphery of the insulating cylinder 120, and T denotes the conductor lead bar 110 on the high voltage side and the ground side. This is because a predetermined insulation thickness is required in relation to the insulation strength. Therefore, A (A1 of the shielding metal fitting 140 with respect to A2 of the shielding metal fitting 60) and B (B1 of the shielding metal fitting 140 with respect to B2 of the shielding metal fitting 60) are determined so as to satisfy H1 = H2 and T1 = T2. .

  The shielding metal fitting 140 is a structure having a funnel-shaped portion 142 having a cross-sectional shape, that is, an oblique shape. Therefore, as can be seen by comparing FIGS. 4A and 4B, A1> A2 and B1> B2, and the following characteristics are obtained.

  A1> A2: Compared with the conventional polymer sleeve, the contact area between the shielding metal fitting 140 and the insulating cylinder 120 made of epoxy resin increases.

  B1> B2: Compared to the conventional polymer sleeve, the cross-sectional area of the portion that supports the shielding fitting (the funnel-shaped portion 142 in the shielding fitting 140) with the epoxy resin is increased.

  As described above, in the present embodiment, the mechanical strength is increased by increasing the contact area and the cross-sectional area between the shielding metal fitting 140 and the epoxy resin.

  Furthermore, in this Embodiment, H1 of the shielding metal fitting 140 can be earned by having the cylindrical part 143, acquiring sufficient intensity | strength. Specifically, since the cylindrical portion 143 has a structure that extends substantially parallel to the axis of the conductor lead bar 110, the required shielding strength can be easily changed by adjusting the length of the cylindrical portion 143. For example, if the shielding metal fitting 140 has only the funnel-shaped portion 142 (a structure that does not have the cylindrical portion 143, for example, the structure of the shielding metal fitting 56 in FIG. 2), the funnel-shaped portion 142 that matches the application target must be individually designed. I must. That is, it is necessary to change the angle of the funnel-shaped part 142 (degree of slanted inclination) each time, and by changing the angle, the outer peripheral side of the base end part of the funnel-shaped part 142 and the epoxy resin having a particularly severe rising angle. The degree of adhesion of the (insulating cylinder 120) and the residual stress after the molding of the epoxy resin (insulating cylinder 120) change, resulting in a complicated design and manufacturing.

  On the other hand, when the cylindrical portion 143 is connected to the tip of the funnel-shaped portion 142, the required shielding strength can be adjusted by extending the length of the cylindrical portion 143, and versatility can be expanded. it can. That is, it is possible to increase the specifications according to the voltage and the contamination category without changing the angle of the funnel-shaped portion 142 (degree of inclination of the oblique shape). Specifically, since the degree of freedom of design is widened and the angle does not have to be changed, the degree of adhesion between the outer peripheral side of the proximal end portion of the funnel-shaped portion 142 and the epoxy resin (insulating tube 120) or the epoxy resin (insulating tube 120). ) There is no need to worry about the residual stress after molding, and the time required for designing and manufacturing can be greatly shortened when increasing the specifications according to the voltage and fouling classification. This also leads to cost reduction.

  Further, the cylindrical portion 143 extends substantially parallel to the axial center direction of the conductor lead bar 110, and the angle from the oblique funnel-shaped portion 142 to the cylindrical portion 143 is gradually changed as the shielding metal fitting 140. For this reason, it becomes difficult for the epoxy resin and the funnel-shaped part 142 and the cylindrical part 143 to peel off. In addition, the mechanical strength is further increased by increasing the contact friction.

  As described in detail above, the polymer cannula 100 according to the present embodiment includes the annular shielding metal fitting 140 at the connecting portion between the large-diameter insulating cylinder 121 and the small-diameter insulating cylinder 122. The shielding metal fitting 140 has a cylindrical portion 141 embedded so as to expose only the outer surface, and is connected to the upper end portion of the cylindrical portion 141 concentrically with the cylindrical portion 141, and the upper end portion is connected to the small-diameter insulating cylinder 122 side. A tapered funnel-shaped portion 142 that is concentrically embedded toward the end, and a cylindrical portion 143 that is formed at the tip of the funnel-shaped portion 142 substantially in parallel with the axis of the conductor lead bar 110.

  Thereby, the contact area and cross-sectional area of the shielding metal fitting 140 and the epoxy resin can be increased while maintaining the electrical performance, and the mechanical strength can be increased.

  Moreover, since the cylindrical part 141, the funnel-shaped part 142, and the cylindrical part 143 are provided in series, the mechanical strength can be further increased.

  The shielding metal fitting 140 has a flange portion 144 that protrudes radially outward from the peripheral surface of the insulating cylinder 120. As a result, the polymer sleeve 100 has a structure with better mechanical strength.

  At least a part of the outer surface of the cylindrical portion 141 is exposed. Thereby, the shielding metal fitting 140 can be set to the ground potential in the tubular portion 141. Therefore, even when the flange portion 144 is formed of the same material as the insulating cylinder 120 instead of the shielding metal fitting 140 of FIG. 3, the shielding metal fitting 140 can be set to the ground potential, so that the shielding metal fitting without the flange portion 144 is provided. 140 may be sufficient.

  The inventors of the present invention produced a polymer sleeve 100 of the rated voltage 66/77 kV class according to the present embodiment and conducted a bending load performance test under the following conditions.

  This polymer sleeve 100 was applied to the end-of-air connection. Considering the case where a wind pressure load, a seismic load, and a combined load of short-circuit electromagnetic force are applied to the end-of-air connection portion, the test load is set to be twice or more the combined load. Moreover, after carrying out a bending load performance test, even if it applied a voltage to 160 kV as a partial discharge test, it confirmed that generation | occurrence | production of partial discharge did not occur.

  As a result of the bending load performance test, it was confirmed that the polymer cannula 100 of the present embodiment has no bending failure even when the bending fracture load is 1000 kgf or more, and that no partial discharge occurs at AC 100 kV. Thereby, the quality of the polymer sleeve can be improved.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. For example, in the above-described embodiment, the case where the polymer covering is a silicone polymer (silicone rubber) as the polymer insulating material has been described. However, the present invention is characterized by the shape of the shielding fitting embedded in the insulating cylinder. An epoxy resin may be used as the polymer insulating material constituting the covering. That is, as shown in FIG. 5, the polymer cover may be formed by integral molding with the insulating cylinder 120.

  Further, a polymer sleeve (also called a bushing) that does not have the polymer coating 130 may be used regardless of the presence or absence of the polymer coating 130. Furthermore, although the polymer sleeve and the cable terminal connection part are described as an example applied to the air terminal connection part of the CV cable, it is not limited to the air terminal connection part, but the gas terminal connection part, the oil terminal terminal You may apply to a connection part etc.

  FIG. 5 is a cross-sectional view showing a structure in which an insulating cylinder and a polymer cover of the polymer sleeve according to the present embodiment are integrally formed of an epoxy resin. As shown in FIG. 5, in the polymer sleeve 100A, the insulating cylinder 120 and the polymer cover 130 are integrally formed of an epoxy resin. That is, the small-diameter insulating cylinder 122 and the polymer cover 130 are integrally formed of the same material. Therefore, in the case of FIG. 5, the outer diameter of the small-diameter insulating cylinder 122 means the outer diameter of the substantially polymer coating 130, and thus the outer diameter of the large-diameter insulating cylinder 121 is smaller than the outer diameter of the small-diameter insulating cylinder 122. ing.

  Further, in the embodiment of the present invention, the large-diameter insulating cylinder 121 has a structure having a cable terminal receiving port in FIG. 3, but the present invention can also be applied to a polymer sleeve having a through bushing structure as shown in FIG. Good. That is, the polymer cannula of the present invention is not limited to the aerial terminal connection part, and may be applied to an aerial part such as a through bushing.

  FIG. 6 is a sectional view showing a through bushing structure of the polymer sleeve according to the present embodiment. As shown in FIG. 6, in the case of the through bushing, the lower part of the insulating tube 120 below the shielding metal fitting 140 is replaced with the shape of a bushing head arranged in a device such as a transformer, and the lower end of the conductor lead bar is a bushing. The structure penetrates the head. This will be described in more detail.

  In FIG. 6, the polymer cannula 100B includes a lower bushing 170 that is a bushing head. Further, the lower end surface of the flange portion 144 of the shielding metal fitting 140 is airtightly fixed to the top plate 2 of the device.

  The lower bushing 170 has a truncated cone portion whose outer diameter decreases in the downward direction, and is disposed inside the device when the polymer cannula 100B is installed on the top plate 2 of the device. The lower bushing 170 is formed of the same material as that of the insulating cylinder 120 in which the conductor extraction rod 110 is disposed at the axial center. Here, the lower bushing 170 is integrally formed on the outer periphery of the conductor lead bar 110 together with the insulating cylinder 120 by molding. Further, in the lower bushing 170, a concave groove having a U-shaped cross section is provided on the circumference at the upper end portion of the truncated cone portion, and the large-diameter insulating cylinder 121 extends from the lower end surface of the flange portion 144 of the shielding metal fitting 140. A conductive layer 155 formed by application of a conductive paint such as silver paint is provided so as to pass through the lower end surface of the substrate, thereby forming a bell mouth portion 171 for electric field relaxation in the lower bushing 170 in the device. Yes. The lower end portion of the conductor extraction rod 110 has a structure that penetrates the lower end portion of the lower bushing, and the lower end portion of the conductor extraction rod 110 is used by being connected to a conductor in a device (not shown).

  In the above-described embodiment, the insulating cylinder 120 including the large-diameter insulating cylinder 121 and the small-diameter insulating cylinder 122 is described. However, the portion corresponding to the conductor insertion hole 110a is thinned in the same manner as the small-diameter insulating cylinder 122. You may use the insulation pipe | tube reduced in diameter.

  Further, in the above embodiment, the case where the insulating cylinder 120 is an epoxy resin has been described, but an FRP or the like may be used as long as it is a hard insulator.

  Furthermore, the structure of the cable terminal connection portion has been described in the above embodiment as a so-called inner cone type structure in which the stress cone is received in the receptacle of the cable end of the insulating cylinder. However, the cable conductor of the cable end is a polymer sleeve. For example, a so-called outer cone type structure in which a polymer sleeve and a cable are connected by a rubber unit used in an RBJ (rubber block joint) known to those skilled in the art. But it ’s okay. Specifically, the shape of the polymer sleeve constituting the cable terminal connection portion is such that the lower end portion of the insulating tube 120 from the shielding metal fitting 140 corresponds to the bushing head portion of FIG. It has a cylindrical or conical shape (not shown) without 171 and a cable conductor is connected to the conductor lead-out rod 110 penetrating the lower end, and the outer circumference of the lower bushing is made of silicone rubber, EP rubber or the like. By disposing a rubber unit known to those skilled in the art comprising a conductive layer, an insulating layer, an external semiconductive layer, and a stress cone portion, the cable end can be connected to the lower end portion of the conductor lead bar of the polymer sleeve.

  The polymer sleeve and the cable terminal connecting portion according to the present invention have an effect of being able to electrically connect the shielding metal fitting and the conductive layer, and are used for the air bushing or the air terminal connecting portion of the power cable. Useful as a tube.

100, 100A, 100B Polymer sleeve 110 Conductor extraction rod 120 Insulating cylinder 121 Large diameter insulating cylinder 122 Small diameter insulating cylinder 130 Polymer sheath 140 Shield metal fitting 141 Tubular part 142 Funnel part 143 Cylindrical part 144 Flange part 145 Bottom metal part 150 Lower part Bracket 170 Lower bushing

Claims (9)

A hard insulating tube provided at the outer periphery of the conductor lead bar, having a conductor lead bar at the center;
A polymer sleeve comprising a shielding fitting embedded concentrically with the conductor lead bar in the insulating cylinder,
The shielding metal fitting includes a tubular portion, a funnel-shaped portion that rises from the inside of the tubular portion and extends while inclining in the axial direction of the conductor lead bar so that a tip thereof is tapered, and the funnel-shaped portion. A cylindrical portion formed at the tip portion substantially parallel to the axis of the conductor lead bar;
With
The funnel-shaped portion and the cylindrical portion are polymer sleeves embedded in the insulating cylinder.   The polymer sleeve according to claim 1, wherein the cylindrical portion, the funnel-shaped portion, and the cylindrical portion are continuously provided.   The polymer according to claim 1 or 2, wherein a distance from an inner peripheral surface of the cylindrical portion to an outer peripheral surface of the conductor extraction rod is larger than a distance from an inner peripheral surface of the cylindrical portion to an outer peripheral surface of the conductor extraction rod. Cannula.   The polymer sleeve according to any one of claims 1 to 3, wherein at least a part of the outer surface of the cylindrical portion is exposed.   The polymer shielding tube according to any one of claims 1 to 4, wherein the shielding metal fitting has a flange portion that protrudes radially outward from a peripheral surface of the insulating cylinder.   The outer periphery of the insulating cylinder is provided with a polymer covering body formed of a polymer insulating material, and a plurality of flanges are formed on the outer periphery of the insulating cylinder so as to be spaced apart in the longitudinal direction. The polymer cannula according to any one of claims 1 to 5, wherein the polymer cannula is provided.   The polymer sleeve according to claim 6, wherein the insulating cylinder and the polymer covering are integrally formed of an epoxy resin.   The polymer sleeve according to any one of claims 1 to 7, wherein a bushing head is provided at a lower end portion of the insulating cylinder. A cable terminal connection portion, wherein a cable end is connected to a lower end portion of the conductor lead bar of the polymer cannula according to any one of claims 1 to 7.

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