Cable terminal structure

Abstract

To maintain insulation of a cable terminal structure.SOLUTION: A cable terminal structure comprises a power cable and a terminal body to which an end of the power cable is connected. The power cable comprises a conductor, a cable insulating layer, and a cable sheath so as to be exposed in this order from a tip of the conductor in an axial direction of the cable conductor. A heat-shrinkable tube is provided so as to cover an outer periphery of a part of the terminal body and an outer periphery of the cable sheath and to connect a part of the terminal body and the cable sheath.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure relates to a cable terminal structure.

Background Art

[0002] A cable terminal structure is provided to connect an opening / closing device or an overhead line, etc. to a power cable (for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of this disclosure is to maintain the insulation of the cable terminal structure.

Means for Solving the Problems

[0005] According to one aspect of this disclosure, a power cable, a terminal body part to which an end of the power cable is connected, are provided, the power cable has a conductor, a cable insulation layer, and a cable sheath exposed in this order along the axial direction of the conductor from the tip of the conductor, a heat shrinkable tube is provided to cover a part of the outer periphery of the terminal body part and the outer periphery of the cable sheath and connect the part of the terminal body part and the cable sheath A cable terminal structure is provided.

Effects of the Invention

[0006] According to this disclosure, the insulation properties of the cable terminal structure can be maintained. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic cross-sectional view showing a cable terminal structure according to the first embodiment of this disclosure. [Figure 2] Figure 2 is a schematic cross-sectional view, enlarged from a portion of Figure 1. [Figure 3] Figure 3 is a schematic diagram showing a cable terminal structure according to the second embodiment of this disclosure. [Figure 4] Figure 4 is a schematic diagram that is an enlarged portion of Figure 3. [Figure 5] Figure 5 is a schematic cross-sectional view showing the cable terminal structure according to Comparative Example 1. [Figure 6] Figure 6 is an enlarged schematic diagram of a part of the cable terminal structure according to Comparative Example 2. [Modes for carrying out the invention]

[0008] [Description of Embodiments in this Disclosure] <Insights gained by the inventor> First, the findings obtained by the inventors will be explained with reference to Figures 5 and 6.

[0009] The inventors have identified the following novel problems with respect to the cable terminal structures of Comparative Example 1 and Comparative Example 2.

[0010] [Comparative Example 1: Terminal directly connected to the device] As shown in Figure 5, the cable terminal structure 80 of Comparative Example 1 is configured as a direct-connection terminal for connecting a power cable 100 to equipment. The cable terminal structure 80 has, for example, an insulating cylinder 830 into which the power cable 100 is inserted and into which the equipment bushing 882 is fitted. The power cable 100 is inserted into the cable insertion hole 831 of the insulating cylinder 830 with, for example, a cylindrical spacer 840 fitted inside.

[0011] Here, the power cable 100 is stripped step by step (so-called "step stripping") from the axial tip of the conductor 110 in the opposite direction.

[0012] In Comparative Example 1 as shown in FIG. 5, a tape layer 890 was provided so as to cover an outer peripheral region including a part of the insulating cylinder 830, the rear end (base end portion) of the spacer 840 exposed outside the cable insertion hole 831, and the tip of the cable sheath 160 of the power cable 100.

[0013] However, in Comparative Example 1, since the winding force FA of the tape layer 890 is applied to the rear end (tapered surface) of the spacer 840 exposed outside the cable insertion hole 831, a force (hereinafter, "insulating cylinder displacement force") FB for displacing the insulating cylinder 830 along the axial direction of the power cable 100 has occurred. Due to the insulating cylinder displacement force FB thus generated, the insulating cylinder 830 may be pushed up with respect to the power cable 100, and there is a risk that the insulating cylinder 830 may come off from the power cable 100. Further, since the insulating cylinder 830 is pushed up with respect to the power cable 100, the surface pressure at which the bushing 882 of the device abuts against the insulating cylinder 830 or the surface pressure at which the insulating plug 884 abuts against the insulating cylinder 830 may become non-uniform. As a result, there is a risk that the insulation performance of the cable terminal structure 80 may deteriorate.

[0014] Furthermore, in Comparative Example 1, in order to smooth the step on the outer peripheral surface of the insulating cylinder 830, the tape layer 890 may be wound a lot. For this reason, a bulge of the tape layer 890 was formed near the step of the insulating cylinder 830. As a result, a part of the outer shape of the cable terminal structure 80 tended to become large.

[0015] [Comparative Example 2: Cable Terminal Structure] As shown in FIG. 6, the cable terminal structure 90 of Comparative Example 2 is configured as an insulator-type cable head that connects the power cable 100 to an overhead transmission line. The cable terminal structure 80 has an insulating tube 920, a metal tube 960, and a clamp 970.

[0016] The metal pipe 960 closes the lower opening of the grommet 920 into which the power cable 100 is inserted. The clamp 970 surrounds the metal pipe 960. The clamp 970 holds the power cable 100 around which the linen cloth 984 is wound.

[0017] Here, also in the cable terminal structure 90, the power cable 100 is gradually peeled off from the axial tip of the conductor 110 in the opposite direction.

[0018] In Comparative Example 2 as shown in FIG. 6, a composite layer 980 including a stopper (sheath piece) and a tape winding layer was provided so as to connect the lower end of the metal pipe 960 and the cable sheath 160 of the power cable 100.

[0019] In the normal cable terminal structure having the above-described configuration, even when the composite layer 980 was provided, the lower space in the clamp 970 was secured. Thus, even if rainwater invaded into the clamp 970, the water drained through the linen cloth 984 wound around the power cable 100.

[0020] However, in order to reliably protect the lower end of the metal pipe 960 as in the cable terminal structure 90 of Comparative Example 2, many composite layers 980 were sometimes wound in the narrow space between the metal pipe 960 and the clamp 970. In this case, the portion where the clamp 970 holds the power cable 100, that is, the path through which the water drains, was completely blocked by the composite layer 980.

[0021] In such a state, when rainwater invaded into the clamp 970, water accumulated in the clamp 970. Therefore, when the ambient temperature became below the freezing temperature of water during the winter period, the water in the clamp 970 was frozen. When the water froze, at least one of the clamp 970 and the metal pipe 960 was deformed due to the volume expansion of the freezing. For this reason, the composite layer 980 might be deformed or the power cable 100 might be excessively pressed. As a result, the insulation of the cable terminal structure 90 might be deteriorated.

[0022] In order to solve the novel problems described above, the inventors of this invention have diligently studied and found a configuration that can maintain insulation in each cable terminal structure.

[0023] The following disclosure is based on the above findings made by the inventors.

[0024] <Embodiments of this disclosure> Next, embodiments of this disclosure will be listed and described.

[0025] [1] A cable terminal structure relating to one aspect of this disclosure is: Power cables and The terminal body to which the end of the power cable is connected, Equipped with, The power cable has a conductor, a cable insulation layer, and a cable sheath, which are exposed in this order from the tip of the conductor along the axial direction of the conductor. A heat-shrinkable tube is provided to cover the outer circumference of a portion of the terminal body and the outer circumference of the cable sheath, and to connect the portion of the terminal body and the cable sheath. This configuration allows for the maintenance of the cable terminal structure's insulation properties.

[0026] [2] In the cable terminal structure described in [1] above, The aforementioned terminal body is The conductor of the power cable is connected by compression, and a compression terminal is configured to be connectable to the terminal of the equipment, An insulating cylinder having a cable insertion hole into which the power cable with the compression terminal connected is inserted, and which ensures insulation of the outside of the compression terminal and the power cable, A spacer is provided so as to surround the outer circumference of the power cable and is interposed between the inner surface of the cable insertion hole and the outer surface of the power cable, Equipped with, The heat-shrinkable tube covers the outer circumference of a portion of the insulating cylinder, the rear end of the spacer exposed outside the cable insertion hole, and the outer circumference of the cable sheath, and is provided to connect the portion of the insulating cylinder and the cable sheath. This configuration allows for even application of the heat-shrink tubing's shrinking force across a portion of the insulating tube, the spacer, and the entire cable sheath.

[0027] [3] In the cable terminal structure described in [2] above, The insulating cylinder is provided in the portion covered by the heat shrink tubing and has an air release section for releasing air mixed into the heat shrink tubing. With this configuration, air mixed into the heat-shrinkable tube can be released (confined) into the air vent of the insulating cylinder.

[0028] [4] In the cable terminal structure described in [3] above, The insulating tube is An internal semiconducting layer is arranged to surround the outer circumference of the compression terminal and the tip of the power cable, An insulating layer is provided so as to cover the outer periphery of the internal semiconducting layer, An external semiconducting layer is provided so as to cover the outer periphery of the insulating layer, A semiconducting portion is provided in a region close to the opening into which the power cable is inserted, and has an inner diameter that gradually widens in the direction in which the power cable is inserted. It has, The air vent portion is provided in the insulating cylinder at a position closer to the outer circumference than the semiconducting portion. With this configuration, the mold marks (marks from the retaining piece) can be used as air vents.

[0029] [5] In the cable terminal structure described in [1] above, The aforementioned terminal body is An insulator tube erected vertically, having a hollow section into which the power cable is inserted, an upper opening at the upper axial end of the hollow section, and a lower opening at the lower end opposite to the upper end of the hollow section, An upper fitting that closes the upper opening of the insulator tube and fixes the conductor, A metal tube is provided so as to surround the outer circumference of the power cable and close the lower opening of the insulator, A clamp surrounds the metal pipe with a predetermined space and grips the power cable, Equipped with, The heat-shrinkable tube covers the outer circumference of the lower end of the metal pipe and the outer circumference of the cable sheath, and is provided to connect the lower end of the metal pipe and the cable sheath. This configuration makes it possible to reliably suppress the shrink-back of the cable sheath even in the narrow space between the metal pipe and the clamp.

[0030] [6] In the cable terminal structure described in [5] above, The terminal body includes a burlap cloth interposed between the clamp and the power cable. The burlap is exposed in the space between the metal pipe and the clamp, with the heat shrink tubing installed inside the clamp. With this configuration, water can be drained from inside the clamp through the burlap cloth.

[0031] [7] In the cable terminal structure described in [6] above, The heat-shrinkable tubing extends vertically below the lower end of the clamp and is interposed between the burlap and the power cable. This configuration allows for stable suppression of cable sheath shrink-back and efficient drainage of water from within the clamp.

[0032] [Details of the embodiments of this disclosure] Next, embodiments of the present disclosure will be described below with reference to the drawings. However, the present disclosure is not limited to these examples, but is indicated by the claims, and all modifications within the meaning and scope of the claims are intended to be included.

[0033] <First Embodiment of this Disclosure> (1) Cable terminal structure The cable terminal structure 12 according to this embodiment will be described with reference to Figures 1 and 2.

[0034] Note that in Figures 1 and 2, the power cable 100 is shown in a side view, not a cross-section. In Figures 1 and 2, some hatching of the cross-section has been omitted. In Figure 1, parts of the bushing 282 and insulating plug 284 have been omitted.

[0035] In the following explanation, "axial direction" of the power cable 100 refers to the direction of the central axis of the power cable 100. "Radial direction" of the power cable 100 refers to the direction from the central axis outward. The same terminology can also be used for cylindrical members other than the power cable 100.

[0036] As shown in Figures 1 and 2, the cable terminal structure 12 of this embodiment is configured as a direct connection terminal for connecting a power cable 100 to a switching device such as a GIS. Specifically, the cable terminal structure 12 comprises, for example, a power cable 100 and a terminal body 22. The terminal body 22 comprises, for example, a compression terminal 220, an insulating tube 230, and a spacer 240.

[0037] [Power Cables] As shown in Figure 1, the power cable 100 is configured as a solid-insulated cable that is a high-voltage power transmission cable. Examples of power cables 100 include CV cables (Crosslinked polyethylene insulated PVC sheathed cable, also called XLPE cables). The power cable 100 may be for AC or DC. In this embodiment, the power cable 100 is assumed to be for AC, for example.

[0038] The power cable 100 has, for example, a conductor (cable conductor) 110, an internal semiconducting layer (not shown), a cable insulation layer 130, an external semiconducting layer 140, a cable shielding layer (cable metal layer, not shown), and a cable sheath 160, in this order from the central axis of the conductor 110 outwards.

[0039] The power cable 100 is stripped in stages from the axial end of the conductor 110 toward the opposite side (so-called "step stripping"). That is, the conductor 110, the internal semiconducting layer of the cable, the cable insulation layer 130, the external semiconducting layer 140, the cable shielding layer, and the cable sheath 160 are exposed in this order from the end of the conductor 110 toward the opposite side.

[0040] [Compression terminal] The compression terminal 220 is configured to connect the conductor 110 of the power cable 100 by compression and to be connectable to a terminal (not shown) of equipment. Specifically, the compression terminal 220 has, for example, a cylindrical portion 222 and a plate-shaped portion 224.

[0041] The cylindrical portion 222 has an insertion hole (not shown) into which the conductor 110 of the power cable 100 is inserted. The cylindrical portion 222 is configured such that the conductor 110 of the power cable 100 is connected when it is compressed radially with the power cable 100 inserted.

[0042] The plate-shaped portion 224 is connected to the opposite side of the opening of the cylindrical portion 222 and is configured as a flat plate. The plate-shaped portion 224 is provided with a screw hole (not shown) that penetrates in the thickness direction. A connecting terminal (not shown), such as a stud bolt connected to the terminal of a device, is screwed into the screw hole of the plate-shaped portion 224. The male threaded portion of the connecting terminal protrudes from the plate-shaped portion 224 toward the plug fitting hole 231c described later. A nut (not shown) is provided on the opposite side of the plate-shaped portion 224 from the connecting terminal and is tightened onto the male threaded portion of the connecting terminal.

[0043] [Insulating tube] The insulating tube 230 is configured to ensure insulation on the outside of the compression terminal 220 and the power cable 100.

[0044] The insulating tube 230 has, for example, a T-shaped outer shape and a T-shaped hole. Specifically, the insulating tube 230 has, for example, a cable insertion hole 231a, a bushing fitting hole 231b, and a plug fitting hole 231c. The cable insertion hole 231a, the bushing fitting hole 231b, and the plug fitting hole 231c are connected to each other.

[0045] The cable insertion hole 231a is, for example, opened in a straight line along the vertical section of the T-shaped insulating cylinder 230. The power cable 100, with the compression terminal 220 connected and the spacer 240 described later fitted, is inserted into the cable insertion hole 231a. The plate-shaped portion 224 of the compression terminal 220 is positioned at the connection point between the cable insertion hole 231a, the bushing fitting hole 231b, and the plug fitting hole 231c.

[0046] Furthermore, the insulating tube 230 has an outer diameter that gradually decreases from the center toward the opening of the cable insertion hole 231a. As a result, the insulating tube 230 has a tapered surface (not shown) near the opening of the cable insertion hole 231a.

[0047] The bushing fitting hole 231b is, for example, formed in the insulating cylinder 230 in a cone shape (frustoconical shape) that tapers from the first end of the lateral section of the insulating cylinder 230 toward the center. The bushing 282 of the equipment is elastically fitted into the bushing fitting hole 231b. As a result, the terminal provided inside the bushing 282 of the equipment is connected to the connection terminal fixed to the plate-shaped portion 224 of the compression terminal 220.

[0048] The plug fitting hole 231c is, for example, in the insulating cylinder 230, and is opened in a cone shape (frustoconical shape) that tapers from the second end of the insulating cylinder 230 toward the center. The insulating plug 284 is elastically fitted into the plug fitting hole 231c. The insulating plug 284 has, for example, a female threaded portion extending from the center of the tapered tip toward the rear end. The female threaded portion of the insulating plug 284 is configured to screw into the male threaded portion of the connection terminal that protrudes from the plate-shaped portion 224 of the compression terminal 220.

[0049] The insulating cylinder 230 is divided into four parts, for example, that have different electrical properties. Specifically, the insulating cylinder 230 has, for example, an internal semiconducting layer 232, an insulating layer 234, an external semiconducting layer 236, and a semiconducting part (stress cone part) 238. These are molded together as a single unit.

[0050] The internal semiconducting layer 232 includes, for example, semiconducting rubber. The internal semiconducting layer 232 is arranged to surround, for example, the compression terminal 220 inserted into the cable insertion hole 231a and the outer circumference of the end of the power cable 100. The internal semiconducting layer 232 constitutes part of the cable insertion hole 231a. The internal semiconducting layer 232 can mitigate the electric field around the compression terminal 220 and the conductor 110.

[0051] The insulating layer 234 includes, for example, insulating rubber. The insulating layer 234 is provided, for example, to cover the outer circumference of the internal semiconducting layer 232 and constitutes the main part of the insulating cylinder 230. The insulating layer 234, for example, together with the internal semiconducting layer 232, constitutes part of the cable insertion hole 231a.

[0052] The outer semiconducting layer 236 includes, for example, semiconducting rubber. The outer semiconducting layer 236 is provided to cover the insulating layer 234 and constitutes at least a portion of the outer circumferential surface of the insulating cylinder 230. The outer semiconducting layer 236 is grounded.

[0053] The semiconductive portion 238 includes, for example, semiconductive rubber. The semiconductive portion 244 is provided in a region close to the opening of the cable insertion hole 231a into which the power cable 100 is inserted. The semiconductive portion 238 has a cone shape and an inner diameter that gradually widens in the direction in which the power cable 100 is inserted into the cable insertion hole 231a. That is, the semiconductive portion 238 forms a so-called stress cone. The semiconductive portion 238 is electrically connected to the semiconductive portion 244 of the spacer 240, which will be described later.

[0054] Furthermore, the insulating cylinder 230 of this embodiment has, for example, an air vent 239. This will be discussed later.

[0055] [Spacer] The spacer 240 is, for example, cylindrical in shape and is provided to surround the outer circumference of the power cable 100. The spacer 240 is configured to be interposed between, for example, the inner surface of the cable insertion hole 231a and the outer surface of the power cable 100.

[0056] The outer diameter of the spacer 240 is set to be equal to or slightly larger than the inner diameter of the cable insertion hole 231a of the insulating cylinder 230. The inner diameter of the spacer 240 is set to be equal to or slightly smaller than the outer diameter of the cable insulation layer 130 of the power cable 100. This allows appropriate surface pressure to be applied from the insulating cylinder 230 to the power cable 100 via the spacer 240, depending on the size of the power cable 100.

[0057] The spacer 240 has, for example, a claw portion 410 at its tip. The claw portion 410 protrudes radially inward from the spacer 240 and has an inner diameter smaller than the portion into which the power cable 100 is inserted. This allows the claw portion 410 of the spacer 240 to engage with the tip of the cable insulation layer 130 of the power cable 100.

[0058] The spacer 240 has an outer diameter that gradually decreases from the axial tip to the rear end. As a result, the spacer 240 has a tapered surface (not shown) at its rear end.

[0059] The spacer 240 is divided into two parts with different electrical properties. Specifically, the spacer 240 has, for example, an insulating part 242 and a semiconducting part 244. These are molded together as a single cylindrical shape.

[0060] The insulating portion 242 includes, for example, insulating rubber. The insulating portion 242 is provided in the region including the tip of the spacer 240.

[0061] On the other hand, the semiconducting portion 244 includes, for example, semiconducting rubber. The semiconducting portion 244 is provided in the spacer 240 in the region opposite to the insulating portion 242. The semiconducting portion 244 has a cone shape and an inner diameter that gradually widens from the rear end to the front end in the axial direction of the spacer 240. That is, the semiconducting portion 244 forms a so-called stress cone.

[0062] In the cable terminal structure 12, the insulating portion 242 is positioned to be in contact with the outer circumferential surface of the exposed cable insulating layer 130. The semiconducting portion 244 is positioned to be in contact with the outer circumferential surface of the exposed cable outer semiconducting layer 140. Furthermore, the semiconducting portion 244 is positioned to be in contact with the inner circumferential surface of the semiconducting portion 238 of the insulating cylinder 230. With this configuration, equipotential lines can be evenly distributed by the cone-shaped semiconducting portion 238 and the cone-shaped semiconducting portion 244 around the exposed cable outer semiconducting layer 140 where a relatively high electric field is generated, thereby suppressing electric field concentration.

[0063] (2) Configuration near the lower end of the cable terminal structure Referring to Figures 1 and 2, the configuration near the lower end of the cable terminal structure 12 in this embodiment will be described.

[0064] Here, the cable sheath 160 of the power cable 100 can shrink in a direction away from the tip of the conductor 110 along the central axis. Such axial shrinkage of the cable sheath 160 is called "shrinkback." It is thought that the shrinkback of the cable sheath 160 occurs when the stress that was stretched during extrusion is released over time.

[0065] Therefore, as shown in Figures 1 and 2, in this embodiment, a heat-shrinkable tube 280 is provided to cover the outer circumference of a part of the terminal body 22 and the outer circumference of the cable sheath 160, and to connect the part of the terminal body 22 and the cable sheath 160. The heat-shrinkable tube 280 refers to a tubular member containing an elastic material that shrinks radially when heated. The heat-shrinkable tube 280 contains, for example, a polyolefin resin. Specific examples of resins include electronically crosslinked flexible polyolefin resin. By providing the heat-shrinkable tube 280, shrink-back of the cable sheath 160 can be suppressed.

[0066] In this embodiment, the heat shrink tubing 280 is provided to cover, for example, the outer circumference of a portion of the insulating cylinder 230, the rear end (base end) of the spacer 240 exposed outside the cable insertion hole 231a, and the outer circumference of the cable sheath 160, thereby connecting a portion of the insulating cylinder 230 and the cable sheath 160.

[0067] In other words, the heat shrink tubing 280 shrinks due to heating. As a result, the heat shrink tubing 280 tightens the outer peripheral region, including a portion of the insulating cylinder 230, the rear end (base end) of the spacer 240 exposed outside the cable insertion hole 231a, and the tip of the cable sheath 160 of the power cable 100, in the radial direction of the heat shrink tubing 280. Consequently, the heat shrink tubing 280 can connect a portion of the insulating cylinder 230 to the cable sheath 160.

[0068] An adhesive layer (not shown) may be provided on the inner circumference of the heat-shrinkable tube 280. This can improve the adhesion between the outer peripheral region, including the insulating cylinder 230, spacer 240, and cable sheath 160, and the heat-shrinkable tube 280.

[0069] In this embodiment, if the heat-shrinkable tube 280 is provided so as to cover a portion of the outer circumference of the insulating cylinder 230 and the outer circumference of the cable sheath 160, there is a possibility that air may be mixed into the heat-shrinkable tube 280.

[0070] Therefore, in this embodiment, the insulating cylinder 230 has, for example, an air release section (air containment section) 239. The air release section 239 is provided in the portion of the insulating cylinder 230 that is covered by the heat shrink tubing 280. The air release section 239 is configured to release (contain) air that has entered into the heat shrink tubing 280.

[0071] In this embodiment, the air vent portion 239 is provided, for example, in the insulating cylinder 230 at a position closer to the outer circumference than the semiconducting portion 238.

[0072] Specifically, the air vent portion 239 is, for example, a trace of a retaining piece that suppresses the rising (deformation, curvature) of the semiconducting portion 238 toward the outer circumference of the insulating cylinder 230 in a mold used for molding the insulating cylinder 230 (it also serves as a trace of the retaining piece). In other words, the air vent portion 239 is a cylindrical hole that extends from the rear end face of the insulating cylinder 230 along the axial direction of the cable insertion hole 231a.

[0073] This configuration allows air mixed inside the heat-shrinkable tube 280 to escape (be trapped) in the air release section 239.

[0074] (3) Method for manufacturing cable terminal structure Next, a method for manufacturing the cable terminal structure according to this embodiment will be described.

[0075] The manufacturing method for the cable terminal structure 12 of this embodiment includes, for example, a preparation step S10 and a terminal body connection step S20.

[0076] [S10: Preparation process] First, prepare power cable 100.

[0077] The power cable 100 is peeled off in stages axially from the tip of the conductor 110, exposing the conductor 110, the cable insulation layer 130, and the cable outer semiconducting layer 140 in that order.

[0078] [S20: Terminal unit connection process] Once the power cable 100 is prepared, the terminal body connection process S20 is performed to connect the end of the power cable 100 to the terminal body 22.

[0079] The terminal body connection step S20 of this embodiment includes, for example, a spacer placement step S21, a compression connection step S22, an insulating tube insertion step S23, a heat shrink tube placement step S24, a terminal connection step S25, and an insulating plug fitting step S26.

[0080] (S21: Spacer placement process) After gradually stripping the power cable 100, the spacer 240 is positioned to surround the outer circumference of the power cable 100. At this time, the power cable 100 is inserted up to the tip of the spacer 240. This causes the claw portion 410 of the spacer 240 to engage with the tip of the cable insulation layer 130 of the power cable 100.

[0081] (S22: Compression connection process) Once the spacer 240 is in place, the compression terminal 220 is connected to the conductor 110 of the power cable 100 by compression.

[0082] (S23: Insertion into insulating cylinder process) Once the compression connection process S22 is complete, the power cable 100, with the spacer 240 fitted and the compression terminal 220 connected, is inserted into the cable insertion hole 231a of the insulating cylinder 230. The spacer 240 is interposed between the inner surface of the cable insertion hole 231a and the outer surface of the power cable 100.

[0083] (S24: Heat shrink tubing placement process) Once the insertion process S23 into the insulating cylinder is complete, the heat shrink tubing 280 is positioned to cover a portion of the outer circumference of the insulating cylinder 230, the rear end of the spacer 240 exposed outside the cable insertion hole 231a, and the outer circumference of the cable sheath 160. In this state, the heat shrink tubing 280 is shrunk by heating. This tightens the aforementioned outer circumference region in the radial direction of the heat shrink tubing 280. As a result, a portion of the insulating cylinder 230 and the cable sheath 160 can be connected by the heat shrink tubing 280.

[0084] At this time, the air mixed inside the heat shrink tube 280 is released (contained) in the air release section 239.

[0085] (S25: Terminal connection process) Once the heat shrink tubing placement process S24 is complete, connection terminals such as stud bolts are attached to the bushing 282 of the equipment. The bushing 282 of the equipment, with the connection terminals attached, is elastically fitted into the bushing fitting hole 231b of the insulating cylinder 230. At this time, the male threaded portion of the connection terminal is made to protrude from the plate-shaped portion 224 toward the plug fitting hole 231c. Then, the connection terminal is fixed to the plate-shaped portion 224 of the compression terminal 220 with a nut.

[0086] (S26: Insulating plug fitting process) Once the terminal connection process S25 is completed, the insulating plug 284 is elastically fitted into the plug fitting hole 231c of the insulating cylinder 230. At this time, by screwing the insulating plug 284 into the plug fitting hole 231c, the female threaded portion provided on the insulating plug 284 is screwed into the male threaded portion of the connection terminal protruding from the plate-shaped portion 224 of the compression terminal 220. This causes the reduced diameter tip of the insulating plug 284 to come into contact with the plate-shaped portion 224 of the compression terminal 220.

[0087] Based on the above, the cable terminal structure 12 of this embodiment is manufactured.

[0088] (4) Summary of this embodiment This embodiment provides one or more of the following effects.

[0089] (a) In this embodiment, a heat-shrinkable tube 280 is provided so as to cover the outer circumference of a part of the terminal body 22 and the outer circumference of the cable sheath 160, and to connect a part of the terminal body 22 and the cable sheath 160. This makes it possible to suppress shrink-back of the cable sheath 160. By suppressing shrink-back of the cable sheath 160, for example, the occurrence of tearing of the cable shielding layer made of copper tape can be suppressed. As a result, it is possible to maintain the insulation of the cable terminal structure 12.

[0090] (b) In this embodiment, by using the heat shrink tubing 280, shrink-back of the cable sheath 160 can be suppressed without causing excessive bulging on the outside of the insulating cylinder 230. This makes the cable terminal structure 12 slimmer.

[0091] (c) In this embodiment, the heat shrink tubing 280 covers the outer circumference of a portion of the insulating cylinder 230, the rear end of the spacer 240 exposed outside the cable insertion hole 231a, and the outer circumference of the cable sheath 160, and is provided to connect the portion of the insulating cylinder 230 and the cable sheath 160. This allows the heat shrink tubing 280 to provide even shrinkage force over the entire portion of the insulating cylinder 230, the spacer 240, and the cable sheath 160.

[0092] This configuration allows for the connection of a portion of the insulating cylinder 230 to the cable sheath 160 while suppressing the generation of a displacement force that would cause the insulating cylinder 230 to shift along the axial direction of the power cable 100. This suppresses the upward pushing of the insulating cylinder 230 relative to the power cable 100 and prevents the insulating cylinder 230 from coming loose from the power cable 100. Furthermore, by suppressing the upward pushing of the insulating cylinder 230 relative to the power cable 100, it is possible to prevent uneven surface pressure between the equipment's bushing 282 and the inner circumferential surface of the bushing fitting hole 231b, or between the insulating plug 284 and the inner circumferential surface of the plug fitting hole 231c.

[0093] (d) In this embodiment, the insulating cylinder 230 has, for example, an air vent 239.

[0094] In the case where a heat-shrinkable tube 280 is provided, as described above, there is a possibility that air may be mixed into the heat-shrinkable tube 280. When the power cable 100 is energized in this state, the reheating caused by the energization will concentrate the air mixed into the heat-shrinkable tube 280 locally, forming a large air layer. When a large air layer is formed, the heat-shrinkable tube 280 may be more susceptible to damage or may crack due to heat. If such damage or cracking occurs, water may seep into the heat-shrinkable tube 280 from these defective areas. As a result, the insulation performance of the cable terminal structure 12 may decrease.

[0095] In contrast, in this embodiment, the insulating cylinder 230 has an air release section 239, which allows air mixed into the heat shrink tube 280 to escape (be trapped) in the air release section 239 of the insulating cylinder 230. In other words, it is possible to suppress the localized concentration of air mixed into the heat shrink tube 280. This can suppress damage or cracking of the heat shrink tube 280, and prevent water from entering the heat shrink tube 280 from these defective areas. As a result, it is possible to suppress a decrease in the insulation performance of the cable terminal structure 12.

[0096] (e) In this embodiment, the air vent portion 239 is provided in the insulating cylinder 230 at a position closer to the outer circumference than the semiconducting portion 238. This allows the trace of the retaining piece that suppresses the rising (deformation, curvature) of the semiconducting portion 238 toward the outer circumference of the insulating cylinder 230 in the mold used for molding the insulating cylinder 230 to be used as the air vent portion 239. As a result, the air vent portion 239 can be easily realized.

[0097] <Second Embodiment of the Present Invention> Next, a second embodiment of the present invention will be described. In the following description, only elements that differ from the above-described embodiment will be explained, and elements that are substantially the same as those described in the above-described embodiment will be denoted by the same reference numerals and their descriptions will be omitted.

[0098] (1) Cable terminal structure The cable terminal structure 14 according to this embodiment will be described with reference to Figures 3 and 4. In Figures 3 and 4, the power cable 100 is shown in a side view rather than a cross-section. Also, in Figures 3 and 4, some of the hatching in the cross-section has been omitted.

[0099] As shown in Figures 3 and 4, the cable terminal structure 14 of this embodiment is configured as an insulator-type cable head (air-insulated termination connector, air-insulated termination box, EB-A) for connecting a power cable 100 to an overhead transmission line (not shown), etc. Specifically, the cable terminal structure 14 comprises, for example, a power cable 100 and a terminal body 24. The terminal body 24 comprises, for example, an insulator tube 420, an upper fitting 432, a lower fitting 450, a metal tube 460, and a clamp 470.

[0100] [Power Cables] As shown in Figures 3 and 4, the power cable 100 is stripped in stages from the axial end of the conductor 110 toward the opposite side, similar to the first embodiment described above.

[0101] [Power cable accessories] The power cable 100, which has been stripped in stages, is fitted with, for example, a conductor lead rod 431 and an insulating tube (rubber unit, stress relief cone, pre-molded insulator, insulating rubber block) 440. The power cable 100 is fixed in the cable terminal structure 14 in a state where it is raised along the vertical direction.

[0102] (Conductor lead rod) The conductor lead rod 431 is configured so that an overhead power transmission line or the like is connected to its tip. The end of the exposed conductor 110 is connected by compression to the base end of the conductor lead rod 431 opposite to the tip. A sealing portion (not shown) is provided around the connection between the conductor lead rod 431 and the end of the conductor 110.

[0103] (Insulating tube) The insulating tube 440 is provided in a cylindrical shape within the hollow portion 420h of the insulator tube 420, surrounding the outer circumference of the power cable 100. The insulating tube 440 is configured to mitigate the electric field around the power cable 100 as it is stripped in stages.

[0104] Specifically, the insulating cylinder 440 has, for example, an insulating portion 442 and a semiconducting portion 444. These are molded together as a single cylindrical shape. The insulating portion 442 contains, for example, insulating rubber. On the other hand, the semiconducting portion 444 also contains, for example, semiconducting rubber. Furthermore, the semiconducting portion 444 has a cone shape and an inner diameter that gradually widens from the lower end to the upper end in the axial direction of the insulating cylinder 440. That is, the semiconducting portion 444 forms a so-called stress cone.

[0105] The insulating cylinder 440 is placed inside the hollow portion 420h of the insulator tube 420. The insulating portion 442 is positioned to be in contact with the outer surface of the exposed cable insulation layer 130. The semiconducting portion 444 is positioned to be in contact with the outer surface of the exposed cable outer semiconducting layer 140. With this configuration, equipotential lines can be evenly distributed around the exposed cable outer semiconducting layer 140 by the cone-shaped semiconducting portion 444, thereby suppressing electric field concentration.

[0106] (Other accessories) Furthermore, a protective tape 448 is provided to cover the outer circumference of the area from the conductor 110 of the power cable 100 to the insulating cylinder 440. In addition, a grounding wire 462 is drawn out from the cable's outer semiconducting layer 140 of the power cable 100, away from the end of the power cable 100.

[0107] [Insulator] The insulator tube 420 is provided so as to surround the outer circumference of the power cable 100 and is configured in a cylindrical shape to ensure insulation around the power cable 100 as it is stripped in stages. The insulator tube 420 is made of, for example, porcelain or polymer.

[0108] The insulator pipe 420 is erected vertically and fixed to a frame (not shown) or the like. The insulator pipe 420 has, for example, a hollow section 420h, an upper opening 420u, and a lower opening 420d.

[0109] A portion of the conductor lead rod 431, a power cable 100 that has been stripped in stages, and an insulating tube 440 are inserted into the hollow section 420h of the insulator tube 420. The power cable 100 is arranged in a straight line along the central axis of the hollow section 420h of the insulator tube 420.

[0110] The upper opening 420u of the insulator tube 420 is located at the upper axial end of the hollow section 420h. On the other hand, the lower opening 420d of the insulator tube 420 is located at the lower end opposite to the upper end of the hollow section 420h.

[0111] The insulator tube 420 has a plurality of flange portions (folds) 210 on its outside, which are widened in diameter. The plurality of flange portions 421 are arranged at predetermined intervals in the axial direction of the insulator tube 420. This ensures an insulating distance (creepage distance) between the conductor lead rod 431 and the ground.

[0112] The hollow portion 420h of the insulator tube 420, excluding the power cable 100, is filled with an insulating mixture 422.

[0113] [Upper fitting] The upper fitting 432 is configured, for example, in the shape of a disc, and is configured to close the upper opening 420u at the upper axial end of the insulator tube 420.

[0114] The upper fitting 432 is configured to secure the conductor 110. Specifically, a conductor lead rod 431 is inserted through the upper fitting 432. The conductor lead rod 431 is fixed to the upper fitting 432 by a predetermined jig.

[0115] [Metal tube] The metal tube 460 is provided, for example, below the insulator tube 420, surrounding the outer circumference of the power cable 100. The metal tube 460 is configured, for example, to close the lower opening 420d at the axial lower end of the insulator tube 420. The metal tube 460 contains, for example, lead.

[0116] The lower part of the metal conduit 460 gradually narrows from the top to the bottom in the axial direction of the metal conduit 460. The lower part of the metal conduit 460 is attached to the outer circumference of the cable sheath 160, for example, with a stopper (not shown) and a grounding wire 462 in between. The grounding wire 462 is electrically connected to the lower part of the metal conduit 460.

[0117] The connection point between the lower part of the metal pipe 460 and the grounding wire 462 may be covered with insulating tape (not shown in the diagram).

[0118] The upper part of the metal pipe 460 is connected to, for example, a disc-shaped lower fitting 450. The lower fitting 450 is fixed to a frame (not shown) or the like. As a result, the metal pipe 460 is grounded together with the lower fitting 450.

[0119] [Clamp] The clamp 470 surrounds the metal pipe 460, for example, leaving a predetermined space between them. This protects the metal pipe 460 and other components inside the clamp 470.

[0120] The lower part of the clamp 470 grips, for example, the power cable 100. Specifically, near the lower part of the clamp 470, the burlap 484 is provided so as to surround the outer circumference of the cable sheath 160 of the power cable 100. The burlap 484 is interposed between, for example, the lower part of the clamp 470 and the power cable 100. As a result, the clamp 470 grips the cable sheath 160 of the power cable 100, for example, by sandwiching the burlap 484. The burlap 484, including its relationship with the heat shrink tubing 482, will be described later.

[0121] The upper part of the clamp 470 is connected, for example, to the lower fitting 450 described above.

[0122] (2) Configuration to suppress shrink-back of cable sheath Referring to Figures 3 and 4, a configuration for suppressing shrink-back of the cable sheath 160 in the cable terminal structure 14 of this embodiment will be described.

[0123] As shown in Figures 3 and 4, in this embodiment, the heat shrink tubing 482 is provided to cover, for example, the outer circumference of the lower end of the metal pipe 460 and the outer circumference of the cable sheath 160, connecting the lower end of the metal pipe 460 and the cable sheath 160.

[0124] In other words, the heat shrink tubing 482 shrinks due to heating. As a result, the heat shrink tubing 482 tightens the outer region, including the lower end of the metal pipe 460 and a portion of the cable sheath 160 of the power cable 100, in the radial direction of the heat shrink tubing 482. Consequently, the heat shrink tubing 482 can connect the lower end of the metal pipe 460 to the cable sheath 160.

[0125] An adhesive layer (not shown) may be provided on the inner circumference of the heat shrink tube 482. This improves the adhesion between the heat shrink tube 482 and, for example, the outer region including the lower end of the metal pipe 460 and a part of the cable sheath 160 of the power cable 100.

[0126] In this embodiment, the heat-shrinkable tube 482 does not completely seal the bottom of the clamp 470, for example. As a result, the burlap 484 is exposed in the space between the metal pipe 460 and the clamp 470, with the heat-shrinkable tube 482 installed inside the clamp 470. Consequently, when water enters the clamp 470, it can be drained from inside the clamp 470 through the burlap 484 (thick arrow in Figure 4).

[0127] In this embodiment, the heat-shrinkable tube 482 extends, for example, vertically below the lower end of the clamp 470. The heat-shrinkable tube 482 is interposed, for example, between the burlap 484 and the power cable 100. This allows for stable suppression of shrink-back of the cable sheath 160 and drainage of water from the clamp 470.

[0128] (3) Method for manufacturing cable terminal structure Next, a method for manufacturing the cable terminal structure according to this embodiment will be described.

[0129] [S10: Preparation process] First, a mounting frame for attaching the cable terminal structure 14 of this embodiment is installed. Then, the various parts constituting the cable terminal structure 14 are prepared.

[0130] Next, prepare the power cable 100 to be terminated. Erect the power cable 100 vertically from the frame. Pass the metal pipe 460 and clamp 470 through the power cable 100 and leave them to hang vertically downwards.

[0131] Next, the power cable 100 is peeled off in stages axially from the tip of the conductor 110, exposing the conductor 110, the cable insulation layer 130, and the cable outer semiconducting layer 140 in that order.

[0132] [S40: Terminal body connection process] Once the power cable 100 is prepared, the terminal body connection process S40 is performed to connect the end of the power cable 100 to the terminal body 22.

[0133] The terminal body connection step S40 of this embodiment includes, for example, an insulating tube placement step S41, a conductor lead rod connection step S42, a metal tube installation step S43, an insulator tube insertion step S44, a metal tube placement step S45, a heat shrink tube placement step S46, a clamp placement step S47, an insulating mixture filling step S48, and an upper fitting placement step S49.

[0134] (S41: Insulation cylinder placement process) Once the power cable 100 is prepared, the insulating cylinder 440 is fitted onto the outer circumference of the power cable 100, and the insulating cylinder 440 is positioned near the tip of the cable's outer semiconducting layer 140.

[0135] (S42: Conductor lead rod connection process) Next, the axial end of the conductor 110 is connected to the base end of the conductor lead rod 431 by compression.

[0136] After connecting the conductor lead rod 431, wrap the protective tape 448 around the outer circumference of the area from the conductor 110 of the power cable 100 to the insulating tube 440.

[0137] (S43: Metal pipe installation process) Furthermore, the metal conduit 460, which had been previously threaded onto the power cable 100, is moved and attached so as to surround the outer circumference of the power cable 100 in the portion below the tip of the exposed outer semiconducting layer 140 of the cable.

[0138] (S44: Insertion process into insulator tube) Next, using the insulator tube 420, the power cable is inserted into the hollow portion 420h of the insulator tube 420, and the insulator tube 420 is erected vertically.

[0139] (S45: Metal pipe arrangement process) Once the insulator pipe 420 is erected, the metal pipe 460 is positioned to close the lower opening 420d of the insulator pipe 420.

[0140] (S46: Heat shrink tubing placement process) After positioning the metal pipe 460, the heat shrink tubing 280 is positioned so as to cover the outer circumference of the lower end of the metal pipe 460 and the outer circumference of the cable sheath 160. In this state, the heat shrink tubing 280 is heated to shrink it. This causes the heat shrink tubing 280 to tighten the aforementioned outer circumference region in the radial direction of the heat shrink tubing 280. As a result, the lower end of the metal pipe 460 and the cable sheath 160 can be connected by the heat shrink tubing 280.

[0141] At this time, the heat shrink tubing 482 is positioned so that it extends vertically below the lower end of the clamp 470 which will be placed in a later process.

[0142] (S47: Clamp placement process) Once the heat shrink tubing 482 is in place, the burlap 484 is wrapped around the outside of the cable sheath 160 of the power cable 100, surrounding the outer circumference of the heat shrink tubing 482.

[0143] After wrapping the burlap 484, move the clamp 470, which had been previously threaded onto the power cable 100. Position the clamp 470 so that it surrounds the metal pipe 460 with a predetermined space and grips the power cable 100. In this way, the clamp 470 grips the cable sheath 160 of the power cable 100 by sandwiching the burlap 484 and the heat shrink tubing 482.

[0144] At this time, with the heat shrink tubing 482 installed inside the clamp 470, the burlap 484 is exposed in the space between the metal pipe 460 and the clamp 470.

[0145] (S48: Insulating compound filling process) Once the clamp placement process S47 is completed, the hollow portion 420h of the insulator tube 420, excluding the power cable 100, is filled with the insulating mixture 422.

[0146] (S49: Upper fitting placement process) Once the insulating mixture filling process S48 is complete, the conductor 110 is fixed to the upper fitting 432, and the upper opening 420u at the upper end opposite the lower end of the insulator tube 420 is closed by the upper fitting 432.

[0147] Based on the above, the cable terminal structure 14 of this embodiment is manufactured.

[0148] (4) Summary of this embodiment This embodiment provides one or more of the following effects.

[0149] (a) In this embodiment, the heat shrink tubing 482 is provided to cover the outer circumference of the lower end of the metal pipe 460 and the outer circumference of the cable sheath 160, connecting the lower end of the metal pipe 460 and the cable sheath 160. This allows the lower end of the metal pipe 460 and the cable sheath 160 to be stably connected by the shrinking force of the heat shrink tubing 482 without causing excessive bulging of the heat shrink tubing 482. As a result, shrink-back of the cable sheath 160 can be stably suppressed even in the narrow space between the metal pipe 460 and the clamp 470.

[0150] (b) In this embodiment, the heat shrink tube 482 does not bulge excessively inside the clamp 470, so that the heat shrink tube 482 does not completely seal the bottom of the clamp 470. As a result, with the heat shrink tube 482 installed inside the clamp 470, the burlap 484 can be exposed in the space between the metal pipe 460 and the clamp 470. Consequently, when rainwater enters the clamp 470, the water can be drained from inside the clamp 470 through the burlap 484 (thick arrow in Figure 4).

[0151] With this configuration, even if rainwater enters the clamp 470, it is possible to prevent water from accumulating inside the clamp 470 and thus prevent the water from freezing inside the clamp 470. By preventing the freezing of water, deformation of at least one of the clamp 470 and the metal pipe 460 caused by the volume expansion due to freezing can be suppressed. This prevents excessive compression of the power cable 100. As a result, it is possible to suppress a decrease in the insulation performance of the cable terminal structure 90.

[0152] (c) In this embodiment, the heat shrink tubing 482 extends vertically below the lower end of the clamp 470. The heat shrink tubing 482 is interposed between the burlap 484 and the power cable 100. This allows the cable sheath 160 to be gripped by the heat shrink tubing 482 over a long area of ​​the cable sheath 160, while the burlap 484 is exposed in the space between the metal pipe 460 and the clamp 470. As a result, both the suppression of shrink-back of the cable sheath 160 and the drainage of water from inside the clamp 470 can be reliably achieved.

[0153] <Note> The details of this disclosure are described below.

[0154] (Note 1) Power cables and The terminal body to which the end of the power cable is connected, Equipped with, The power cable has a conductor, a cable insulation layer, and a cable sheath, which are exposed in this order from the tip of the conductor along the axial direction of the conductor. A heat-shrinkable tube is provided to cover the outer circumference of a portion of the terminal body and the outer circumference of the cable sheath, and to connect the portion of the terminal body and the cable sheath. Cable terminal structure.

[0155] (Note 2) The aforementioned terminal body is The conductor of the power cable is connected by compression, and a compression terminal is configured to be connectable to the terminal of the equipment, An insulating cylinder having a cable insertion hole into which the power cable with the compression terminal connected is inserted, and which ensures insulation of the outside of the compression terminal and the power cable, A spacer is provided so as to surround the outer circumference of the power cable and is interposed between the inner surface of the cable insertion hole and the outer surface of the power cable, Equipped with, The heat-shrinkable tube covers the outer circumference of a portion of the insulating cylinder, the rear end of the spacer exposed outside the cable insertion hole, and the outer circumference of the cable sheath, and is provided to connect the portion of the insulating cylinder and the cable sheath. Cable terminal structure as described in Appendix 1.

[0156] (Note 3) The insulating cylinder is provided in the portion covered by the heat shrink tubing and has an air release section for releasing air mixed into the heat shrink tubing. Cable terminal structure as described in Appendix 2.

[0157] (Note 4) The insulating tube is An internal semiconducting layer is arranged to surround the outer circumference of the compression terminal and the tip of the power cable, An insulating layer is provided so as to cover the outer periphery of the internal semiconducting layer, An external semiconducting layer is provided so as to cover the outer periphery of the insulating layer, A semiconducting portion is provided in a region close to the opening into which the power cable is inserted, and has an inner diameter that gradually widens in the direction in which the power cable is inserted. It has, The air vent portion is provided in the insulating cylinder at a position closer to the outer circumference than the semiconducting portion. Cable terminal structure as described in Appendix 3.

[0158] (Note 5) The aforementioned air release portion is configured as a trace of a retaining piece in a mold for molding the insulating cylinder, which suppresses the rise of the semiconducting portion toward the outer circumference of the insulating cylinder. Cable terminal structure as described in Appendix 4.

[0159] (Note 6) The aforementioned terminal body is An insulator tube erected vertically, having a hollow section into which the power cable is inserted, an upper opening at the upper axial end of the hollow section, and a lower opening at the lower end opposite to the upper end of the hollow section, An upper fitting that closes the upper opening of the insulator tube and fixes the conductor, A metal tube is provided so as to surround the outer circumference of the power cable and close the lower opening of the insulator, A clamp surrounds the metal pipe with a predetermined space and grips the power cable, Equipped with, The heat-shrinkable tube covers the outer circumference of the lower end of the metal pipe and the outer circumference of the cable sheath, and is provided to connect the lower end of the metal pipe and the cable sheath. Cable terminal structure as described in Appendix 1.

[0160] (Note 7) The terminal body includes a burlap cloth interposed between the clamp and the power cable. The burlap is exposed in the space between the metal pipe and the clamp, with the heat shrink tubing installed inside the clamp. Cable terminal structure as described in Appendix 6.

[0161] (Note 8) The heat shrink tubing does not completely seal the bottom of the clamp. Cable terminal structure as described in Appendix 7.

[0162] (Note 9) The heat-shrinkable tube extends vertically below the lower end of the clamp and is interposed between the burlap and the power cable. Cable terminal structure as described in Appendix 7 or Appendix 8.

[0163] (Note 10) The process of preparing power cables, The process of connecting the end of the power cable to the terminal body, Equipped with, In the process of preparing the aforementioned power cable, The conductor, cable insulation layer, and cable sheath are exposed in this order, starting from the tip of the conductor and proceeding along the axial direction of the conductor. The step of connecting to the terminal body is: The process includes a step of arranging a heat-shrinkable tube so as to cover the outer circumference of a portion of the terminal body and the outer circumference of the cable sheath, and to connect the portion of the terminal body and the cable sheath. A method for manufacturing cable terminal structures. [Explanation of symbols]

[0164] 12 Cable Termination Structure 14 Cable Termination Structure 22 Main body of the terminal 24 Terminal main unit 80 Cable Termination Structure 90 Cable Termination Structure 100 Power Cables 110 conductor 130 Cable insulation layer 140 Cable outer semiconducting layer 160 Cable Sheath 210 Pipe 220 Compression terminal 222 Cylindrical part 224 Plate-like part 230 Insulating tube 231a Cable insertion hole 231b Bushing fitting hole 231c Plug fitting hole 232 Internal semiconducting layer 234 Insulating layer 236 Outer semiconducting layer 238 Semiconductive part 239 Air vent section 240 Spacer 242 Insulation part 244 Semiconductive part 280 Heat Shrink Tubing 282 Bushing 284 Insulating plug 410 Claw part 420 Pipe 420d Lower opening 420h Hollow part 420u top opening 421 Guard section 422 Insulating compound 431 Conductor lead rod 432 Upper fitting 440 Insulating tube 442 Insulation part 444 Semiconductive part 448 Protective Tape 450 Lower fitting 460 Metal tube 462 Ground wire 470 Clamp 480 protective tape 482 Heat shrink tubing 484 Azabu 820 Compression terminal 830 Insulating tube 831 Cable insertion hole 840 Spacer 882 Bushing 884 Insulating plug 890 Insulating Tape 920 Pipe 960 Metal tube 970 Clamp 980 Protective Tape 984 Azabu

Claims

1. Power cables and The terminal body to which the end of the power cable is connected, Equipped with, The power cable has a conductor, a cable insulation layer, and a cable sheath, which are exposed in this order from the tip of the conductor along the axial direction of the conductor. The aforementioned terminal body is The conductor of the power cable is connected by compression, and a compression terminal is configured to be connectable to the terminal of the equipment, An insulating cylinder having a cable insertion hole into which the power cable with the compression terminal connected is inserted, and which ensures insulation of the outside of the compression terminal and the power cable, A spacer is provided so as to surround the outer circumference of the power cable and is interposed between the inner surface of the cable insertion hole and the outer surface of the power cable, Equipped with, A heat-shrinkable tube is provided to cover the outer circumference of a portion of the insulating cylinder, the rear end of the spacer exposed outside the cable insertion hole, and the outer circumference of the cable sheath, and to connect the portion of the insulating cylinder and the cable sheath. The insulating cylinder is provided in the portion covered by the heat shrink tubing and has an air release section for releasing air mixed into the heat shrink tubing. Cable terminal structure.

2. The insulating tube is An internal semiconducting layer is arranged to surround the outer circumference of the compression terminal and the tip of the power cable, An insulating layer is provided so as to cover the outer periphery of the internal semiconducting layer, An external semiconducting layer is provided so as to cover the outer periphery of the insulating layer, A semiconducting portion is provided in a region close to the opening into which the power cable is inserted, and has an inner diameter that gradually widens in the direction in which the power cable is inserted. It has, The air vent portion is provided in the insulating cylinder at a position closer to the outer circumference than the semiconducting portion. The cable terminal structure according to claim 1.

3. Power cable and The terminal body to which the end of the power cable is connected, Equipped with, The power cable has a conductor, a cable insulation layer, and a cable sheath, which are exposed in this order from the tip of the conductor along the axial direction of the conductor. The aforementioned terminal body is An insulator tube erected vertically, having a hollow section into which the power cable is inserted, an upper opening at the upper axial end of the hollow section, and a lower opening at the lower end opposite to the upper end of the hollow section, An upper fitting that closes the upper opening of the insulator tube and fixes the conductor, A metal tube is provided so as to surround the outer circumference of the power cable and close the lower opening of the insulator, A clamp surrounds the metal pipe with a predetermined space and grips the power cable, Equipped with, A heat-shrinkable tube is provided to cover the outer circumference of the lower end of the metal pipe and the outer circumference of the cable sheath, and to connect the lower end of the metal pipe and the cable sheath. Cable terminal structure.

4. The terminal body includes a burlap cloth interposed between the clamp and the power cable. The burlap is exposed in the space between the metal pipe and the clamp, with the heat shrink tubing installed inside the clamp. The cable terminal structure according to claim 3.

5. The heat-shrinkable tube extends vertically below the lower end of the clamp and is interposed between the burlap and the power cable. The cable terminal structure according to claim 4.

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