JP2019193515A - Cable connection part - Google Patents

Abstract

To provide a plug-in type cable connection part using a rubber block insulator, which has a high cable holding force against axial force and has excellent long-term stability.SOLUTION: A cable connection part includes a first conductor connection terminal, a second conductor connection terminal engaging with the first conductor connection terminal, a retaining portion that holds the engagement state of the first conductor connection terminal and the second conductor connection terminal, and a reinforcing insulating portion disposed in close contact with an outer periphery of the conductor connecting portion formed by connecting the first conductor connection terminal and the second conductor connection terminal, and when a plug portion of the first conductor connection terminal is fitted into a plug receiving portion of the second conductor connection terminal inside the reinforcing insulating portion, a part of the internal electrode of the reinforcing insulating part is held in a space formed by the first and second conductor connection terminals.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a cable connecting portion for connecting a terminal portion of a power cable to a connection destination (for example, another power cable), and more particularly to a plug-in type cable connecting portion.

  Conventionally, as a cable connection portion (so-called intermediate connection portion) for connecting two power cables, a cable conductor of one power cable (hereinafter referred to as “first power cable”) and the other power cable (hereinafter referred to as “ A configuration in which a reinforcing insulator is disposed so as to electrically connect a cable conductor of a “second power cable”) via a conductor connection terminal and cover the conductor connection portion is known. In particular, as a reinforcing insulator, a rubber block joint (hereinafter referred to as “RBJ”) using a one-piece rubber block insulator in which an internal electrode, a rubber insulating portion, a stress cone portion, and an external shielding layer are integrally formed. (See, for example, Patent Documents 1 to 5). Since RBJ is excellent in workability, it is useful for shortening the construction period and consequently reducing costs. The construction of RBJ is mainly performed by a diameter expansion method or a temporary insertion method.

  In the diameter expansion method, the first power cable is inserted into the rubber block insulator held in a state where the diameter of the cable insertion hole is expanded, and the first power cable and the second power are outside the rubber block insulator. In this method, after connecting the cable conductors of the cable with the conductor connection terminals, the rubber block insulator is moved to a predetermined position (conductor connection portion) and reduced in diameter (see Patent Documents 1 to 3). As the diameter expansion method, there are a factory diameter expansion method in which the rubber block insulator is expanded in advance at the factory and a field expansion method in which the rubber block insulator is expanded at the construction site by a diameter expansion device.

  In the case of the factory diameter expansion method, the rubber block insulator is held in an expanded state by, for example, a diameter expansion member called a spiral core, and is reduced in diameter by pulling out the diameter expansion member. Since the rubber block insulator is stored in an expanded state until it is constructed, there is a concern that the contact pressure may decrease due to the stress relaxation of the rubber. Therefore, the expiration date is often set for the rubber block insulator used in the factory expansion method. On the other hand, in the case of the on-site diameter expansion method, since the diameter is expanded immediately before the construction, the problem due to rubber stress relaxation is reduced. However, it is necessary to bring a diameter expansion device to the construction site, and quality control is performed at the construction site so that foreign matter does not adhere to the stepped part of the power cable that becomes the interface with the rubber block insulator when connected. Need to be thorough.

  In the temporary insertion method, the first power cable is inserted into the rubber block insulator, and the cable conductors of the first power cable and the second power cable are electrically connected to the outside of the rubber block insulator by the conductor connection terminals. In addition, after mechanical connection, the rubber block insulator is moved to a predetermined position. In the diameter expansion method, the power cable can be inserted into the cable insertion hole of the rubber block insulator including the part where the cable sheath is not removed, whereas in the temporary insertion method, only the cable core is a cable of the rubber block insulator. It is inserted through the insertion hole. Therefore, in the temporary insertion method, the removal length of the cable sheath or the like, that is, the exposed length of the cable core (especially the exposed length of the external semiconductive layer) is set to the length in the longitudinal direction of the rubber block insulator as compared with the diameter expansion method. Need to be long.

  In the case of the temporary insertion method, since the exposed length of the cable core is long and the portion needs to be waterproofed, the cable connecting portion becomes long. It is effective when a large installation space can be secured, such as when the cable connection is directly buried in the ground, but it cannot be installed when a large installation space cannot be secured, such as when laying in a manhole or a cave. There is also.

  Further, in Patent Document 4, as a method for constructing RBJ, a male first conductor connecting terminal is attached to a cable conductor of a first power cable, and a female second conductor is attached to a cable conductor of a second power cable. A plug-in method is disclosed in which the conductor connection terminals are attached, each of which is press-fitted into a rubber block insulator and connected at a predetermined position. Patent Document 5 discloses a construction method that combines a diameter expansion method and a plug-in method. The plug-in method has an advantage that it can be easily constructed as compared with the diameter expansion method and the temporary insertion method.

Japanese Patent Laying-Open No. 2015-142476 Japanese Patent Laying-Open No. 2015-142477 JP2015-142478A Japanese Utility Model Publication No. 61-14831 JP-A-11-266521

  By the way, in RBJ, in order to implement | achieve long-term stability, the interface state of a rubber block insulator and a cable insulator is important. In particular, in a metal-clad cable such as a CAZV cable (aluminum-clad CV cable) that is often used for a super-high-voltage cable of 275 kV class or higher, an axial force is generated in the cable core and the conductor connection portion even if it is fixed with a cleat. In the conventional plug-in method, the rubber block insulator grips the connection part of the power cable by the elastic force of the rubber, so a large cable holding force (the force that holds the cable so that it does not shift in the axial direction) ) Is difficult to achieve, and the interface state between the rubber block insulator and the cable insulator may change due to the axial force. Therefore, in the plug-in type cable connecting portion for the ultra high voltage cable, further improvement of the cable holding force against the axial force is desired.

  An object of the present invention is to provide a cable connection portion of a plug-in system using a rubber block insulator, which has a high cable holding force against an axial force and has excellent long-term stability.

The cable connecting portion according to one aspect of the present invention is
A first conductor connection terminal connected to the first cable conductor;
A second conductor connection terminal connected to a second cable conductor and engaged with the first conductor connection terminal;
A retaining portion that holds the engagement state of the first conductor connection terminal and the second conductor connection terminal;
A reinforcing insulating portion disposed in close contact with an outer periphery of a conductor connecting portion formed by connecting the first conductor connecting terminal and the second conductor connecting terminal;
A plug-in cable connection comprising:
The first conductor connection terminal has a plug portion inserted into the second conductor connection terminal, and a first large diameter portion having a diameter larger than that of the plug portion connected to the plug portion. ,
The second conductor connection terminal includes a small diameter portion whose end surface faces the step surface of the first conductor connection terminal, and a second large diameter portion having a larger diameter than the small diameter portion connected to the small diameter portion. A plug receiving portion for receiving the plug portion inside the small diameter portion and the second large diameter portion,
The reinforcing insulating part has a rubber insulating part and an internal electrode disposed on the inner peripheral surface of the rubber insulating part,
Inside the reinforcing insulating part, when the plug part is fitted into the plug receiving part, the space formed by the outer peripheral surfaces of the first conductor connection terminal and the second conductor connection terminal, A part of the internal electrode is sandwiched.

  According to the present invention, in a plug-in type cable connection portion using a rubber block insulator, it is possible to improve the cable holding force against the axial force, and to realize excellent long-term stability.

FIG. 1 is a diagram showing an overall configuration of a cable connecting portion according to an embodiment of the present invention. FIG. 2A and FIG. 2B are diagrams showing a set of conductor connection terminals constituting the conductor connection member of the first embodiment. 3A to 3C are diagrams illustrating a construction process of the cable connecting portion according to the first embodiment. 4A and 4B are diagrams showing a set of conductor connection terminals constituting the conductor connection member of the second embodiment. FIG. 5A to FIG. 5C are diagrams showing a construction process of the cable connecting portion according to the second embodiment.

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

[First Embodiment]
FIG. 1 is a half cross-sectional view showing the overall configuration of a cable connecting portion 1A according to the first embodiment of the present invention. Note that the schematic configuration of a cable connecting portion 1B according to a second embodiment to be described later is the same as that of the first embodiment, and is shown in FIG. Further, in FIG. 1, the detailed structure of the conductor connection members 20A and 20B and the detailed structure of the internal electrodes 32A and 32B are omitted for convenience of explanation.
As shown in FIG. 1, the cable connecting portion 1A according to the first embodiment includes a terminal portion of the first power cable 11, a terminal portion of the second power cable 12, a conductor connecting member 20A, and a reinforcing insulating portion 30A. And a protective case 40 and the like. Hereinafter, when the first power cable 11 and the second power cable 12 are not distinguished from each other, they are simply referred to as “power cables 11 and 12”. Further, when viewed from each of the power cables 11 and 12, the central side in the axial direction of the cable connecting portion 1 </ b> A is referred to as “front end side”, and both end sides are referred to as “rear end side”.

  The power cables 11 and 12 are power cables (for example, CV cables) insulated with rubber or plastic. The power cables 11 and 12 are, in order from the inside, the cable conductors 111 and 121, the inner semiconductive layer (not shown), the cable insulators 112 and 122, the outer semiconductive layers 113 and 123, the cable shielding layers 114 and 124, and the cable. Sheaths 115 and 125 are included. Each layer is exposed by stepping off the terminal portions of the power cables 11 and 12 with a predetermined length. In the power cables 11 and 12, portions where the interiors after the outer semiconductive layers 113 and 123 excluding at least the cable sheaths 115 and 125 and the cable shielding layers 114 and 124 are referred to as “cable cores”.

  The conductor connection member 20 </ b> A electrically and mechanically connects the cable conductor 111 of the first power cable 11 and the cable conductor 121 of the second power cable 12. 20 A of conductor connection members are formed with the electroconductive material suitable for electricity supply which consists of copper, aluminum, copper alloy, or aluminum alloy etc., for example. The outer diameter of the conductor connecting member 20A (the outer diameter of the large diameter portions 21a and 22a (see FIGS. 2A and 2B)) is equal to the outer diameter of the cable insulators 112 and 122 of the power cables 11 and 12.

  In the present embodiment, the conductor connecting member 20A includes a pair of conductor connecting terminals 21 and 22 that are connected in a plug-in structure so that they cannot be removed (see FIGS. 2A and 2B). The conductor connection terminal 21 compressed and connected to the cable conductor 111 of the first power cable 11 is referred to as “first conductor connection terminal 21”, and the conductor connection terminal 22 that is compressed and connected to the cable conductor 121 of the second power cable 12. This is referred to as “second conductor connection terminal 22”. The structures of the first conductor connection terminal 21 and the second conductor connection terminal 22 will be described later.

  The reinforcing insulating portion 30 </ b> A is disposed in close contact with the outer periphery of the conductor connecting portion formed by connecting the first conductor connecting terminal 21 and the second conductor connecting terminal 22. The reinforcing insulating portion 30A is a one-piece rubber block insulator in which the rubber insulating portion 31, the internal electrode 32A, the stress cone portions 33 and 34, and the external shielding layer 35 are integrally molded. For example, silicone rubber or ethylene propylene rubber (EP rubber) is suitable for the rubber material forming the reinforcing insulating portion 30A.

  The internal electrode 32A, the stress cone portions 33 and 34, and the external shielding layer 35 (in the case of molding) are preferably formed of the same material (preferably semiconductive rubber) in terms of molding. The rubber insulating portion 31 is also preferably formed of an insulating material that does not have the same type of conductivity. Below, the case where ethylene propylene rubber (EP rubber) is applied is demonstrated.

  The reinforcing insulating portion 30A has a cylindrical shape as a whole. The end portion of the first power cable 11 to which the first conductor connection terminal 21 is attached and the second conductor connection terminal 22 to which the first conductor connection terminal 22 is attached are inserted into the insertion hole 30a (see FIG. 3A) of the reinforcing insulating portion 30A. The terminal portion of the second power cable 12 is press-fitted. Due to the elastic force of the reinforcing insulating portion 30A (mainly the rubber insulating portion 31), the reinforcing insulating portion 30A and the cable cores of the power cables 11 and 12 are in close contact. That is, the inner diameter of the insertion hole 30 a is set slightly smaller than the outer diameter of the cable insulators 112 and 122 of the power cables 11 and 12. As a result, an insulating interface between the cable insulators 112 and 122 and the rubber insulating portion 31 is formed, and the internal electrode 32A electrically connected to the conductor connecting member 20A and the external semiconductive layers 113 and 123 are electrically connected. The stress cone portions 33 and 34 are used to relax the electric field at the insulating interface.

  The rubber insulating part 31 is made of, for example, insulating EP rubber and occupies most of the reinforcing insulating part 30A.

  The internal electrode 32 </ b> A is formed of a semiconductive rubber material, for example, semiconductive EP rubber, and is disposed on the inner peripheral surface of the central portion in the axial direction of the rubber insulating portion 31. The internal electrode 32A is in close contact with the conductor connection member 20A by the elastic force of the reinforcing insulating portion 30A and is electrically connected.

  In the present embodiment, the axial center portion 32a of the internal electrode 32A is formed so as to protrude inward in the radial direction from the main portion (portion extending in the axial direction) (see FIGS. 3A to 3C, hereinafter). Referred to as "protrusion 32a"). The protrusion 32a is accommodated in a space 25 (see FIG. 2B) formed by the engagement of the first conductor connection terminal 21 and the second conductor connection terminal 22. In addition, the protrusion part 32a may be formed in the ring shape continuously in the circumferential direction, and may be intermittently dotted.

  The protrusion 32a may be integrally formed of the same rubber material as the main part of the internal electrode 32A (in this embodiment, semiconductive EP rubber), or may be formed by embedding a metal piece in the main part. Good. In addition, when embedding a metal piece in the main part of the internal electrode 32A, it may be embedded by molding or may be embedded by forming a recess in the main part and adhering to the recess.

  The stress cone portions 33 and 34 are made of, for example, semiconductive EP rubber. The stress cone portions 33 and 34 have a bell mouth shape that expands toward the center of the connecting portion. The stress cone portion 33 extends from the cable insulator 112 of the first power cable 11 to the outer semiconductive layer 113, and the end portion extends outward from one end portion (the right end portion in FIG. 1) of the rubber insulating portion 31. It is formed to come out. The stress cone portion 34 extends from the cable insulator 122 of the second power cable 12 to the external semiconductive layer 123, and the end portion is outside the other end portion (left end portion in FIG. 1) of the rubber insulating portion 31. It is formed to extend.

  The external shielding layer 35 is made of, for example, semiconductive EP rubber. The outer shielding layer 35 is disposed on the outer peripheral surface of the rubber insulating portion 31, and is at least the end portion on the center side of the connection portion of the stress cone portions 33 and 34 (the end portion on the side where the diameter of the stress cone portions 33 and 34 is increased). It is formed longer than the length between them. Thereby, it can prevent that the edge part of the external shielding layer 35 becomes an electrical protrusion. The external shielding layer 35 is not limited to molding, and may be formed by applying a conductive paint. In the present embodiment, an edgeless structure in which both ends of the external shielding layer 35 are in contact with the stress cone portions 33 and 34 is shown, but the end portion of the external shielding layer 35 is the stress cone portion 33 or the stress cone. A single-sided edge cutting structure that contacts either one of the parts 34 or a double-sided edge cutting structure that does not contact the stress cone parts 33 and 34 at both ends of the external shielding layer 35 may be used.

  The inner peripheral surfaces of the rubber insulating portion 31, the internal electrode 32A (excluding the protruding portion 32a), and the stress cone portions 33 and 34 are formed flush with each other. An insertion hole 30a (see FIG. 3A) of the reinforcing insulating portion 30A is formed by the inner peripheral surfaces of the rubber insulating portion 31, the internal electrode 32A, and the stress cone portions 33 and 34.

  The protective case 40 is disposed so as to surround the terminal portions of the power cables 11 and 12 and the reinforcing insulating portion 30A. The protective case 40 is formed of, for example, a copper pipe, and a PVC layer (not shown), for example, is provided integrally with the copper pipe on the outer periphery thereof for corrosion protection. The protective case 40 is formed on the cable sheaths 115 and 125 of the power cables 11 and 12 by forming the anticorrosion layer 50 by, for example, tape winding so as to straddle the end of the copper tube, specifically the end of the PVC layer. Fixed. Further, a waterproof mixture (reference numeral is omitted, eg, a waterproof compound such as urethane) is filled between the reinforcing insulating portion 30A and the protective case 40. Due to the protective case 40 and the waterproof mixture, the water shielding property of the cable connecting portion 1A is ensured.

  Here, the cable shielding layers 114 and 124 of the power cables 11 and 12 are formed of wire shields. A plurality of wire shields are collectively crimped together with one end of a braided wire (reference numeral omitted) by a crimp sleeve (reference numeral omitted), and the other end of the braided wire is soldered to the protective case 40. Thereby, the cable shielding layers 114 and 124 are electrically connected to the protective case 40 and grounded. The cable shielding layers 114 and 124 may be formed of copper tape instead of the wire shield.

  2A and 2B are diagrams showing the structure of the conductor connection member 20A according to the first embodiment. FIG. 2A is a half sectional view showing a state before the first conductor connecting terminal 21 and the second conductor connecting terminal 22 are engaged. FIG. 2B is a half sectional view showing a state after the first conductor connection terminal 21 and the second conductor connection terminal 22 are engaged. In FIG. 2B, illustration of the compressed power cables 11 and 12 is omitted for convenience of explanation.

  As shown in FIGS. 2A and 2B, the first conductor connection terminal 21 has a multistage cylindrical shape. In the present embodiment, the first conductor connection terminal 21 has a multistage cylindrical shape including a small diameter portion 21a, a large diameter portion 21b (first large diameter portion), and a compression portion 21g.

  The small diameter portion 21 a is a plug portion that is inserted into the second conductor connection terminal 22. The small diameter portion 21a has a retaining ring recess 21d and a contact recess 21e on the outer peripheral surface. The retaining member 23 is disposed in the retaining ring recess 21d, and the conductor contact 24 is disposed in the contact recess 21e. The retaining ring recess 21 d has a depth that can accommodate the retaining member 23.

  In the present embodiment, a retaining ring recess 21d is arranged on the distal end side (side connected to the second conductor connection terminal 22) of the small diameter portion 21a, and the rear end side (side connected to the large diameter portion 21b). ) Is provided with the contact recess 21e, but these arrangements may be reversed. When the conductor contactor 24 is disposed on the front end side of the small diameter portion 21a and the retaining member 23 is disposed on the rear end side, the retaining member 23 and the inner peripheral surface of the plug receiving port 22d of the second conductor connecting terminal 22 are slid. Since the contact distance is shortened, it is possible to suppress the abrasion of the plug receiving port 22d.

  The large diameter portion 21b is connected to the rear end side (the right side in FIGS. 2A and 2B) of the small diameter portion 21a and has an outer diameter larger than that of the small diameter portion 21a. A compression portion 21g for compressing and connecting the cable conductor 111 of the first power cable 11 is connected to the rear end side of the large diameter portion 21b. In the present embodiment, the compression portion 21g has a bottomed cylindrical shape having a cable conductor receiving port 21c inside the rear end before compression, and has a smaller diameter than the large diameter portion 21b. The compression part 21g is formed with the same outer diameter as the large-diameter part 21b, and the deformation of the large-diameter part 21b due to compression is prevented between the large-diameter part 21b and the compression part 21g (specifically, the distal end side of the compression part 21g). For this purpose, a groove may be provided.

  The continuous surface 21f of the small diameter portion 21a and the large diameter portion 21b stands substantially vertically and forms a step surface. The connecting surface 21f (step surface) of the first conductor connection terminal 21 is connected to the conductor connection terminals 21 and 22 inside the reinforcing insulating portion 30A, and then the small-diameter portion 22a of the second conductor connection terminal 22 described later. It becomes the surface opposite to the end face of. Further, the radially outer side of the connecting surface 21f is the side surface (surface perpendicular to the axial direction) of the protruding portion 32a of the internal electrode 32A described later after the conductor connecting terminals 21 and 22 are connected to each other inside the reinforcing insulating portion 30A. (Refer to FIG. 3C).

  When the cable conductor 111 of the first power cable 11 is inserted into the cable conductor receiving port 21c and the compression portion 21g is compressed, the cable conductor 111 of the first power cable 11 is electrically connected to the first conductor connection terminal 21. Connected mechanically and mechanically.

  As shown in FIGS. 2A and 2B, the second conductor connection terminal 22 has a multistage cylindrical shape. In the present embodiment, the second conductor connection terminal 22 has a multistage cylindrical shape including a small diameter portion 22a, a large diameter portion 22b (second large diameter portion), and a compression portion 22g.

  The small-diameter portion 22a and the large-diameter portion 22b connected to the small-diameter portion 22a are plug receiving portions that have a plug receiving port 22d therein and receive the small-diameter portion 21a of the first conductor connection terminal 21, and have a bottomed cylinder. It has become a shape. The length of the plug receiving port 22d is substantially the same as or slightly longer than the length of the small diameter portion 21a of the first conductor connecting terminal 21, and the inner diameter of the plug receiving port 22d is the small diameter portion 21a of the first conductor connecting terminal 21. Is substantially the same as the outer diameter. In the present embodiment, a retaining ring recess 22e (groove portion) with which the retaining member 23 is engaged is formed on the inner peripheral surface of the plug receiving port 22d corresponding to the large diameter portion 22b.

  The compression part 22g is connected to the rear end side (left side in FIGS. 2A and 2B) of the large diameter part 22b. In the present embodiment, the compression portion 22g has a smaller diameter than the large diameter portion 22b before compression, and is a portion to which the cable conductor 121 of the second power cable 12 is compression-connected. The compression part 22g is formed with the same outer diameter as the large-diameter part 22b, and the deformation of the large-diameter part 22b due to compression is prevented between the large-diameter part 22b and the compression part 22g (specifically, the distal end side of the compression part 22g). For this purpose, a groove may be provided.

  The compression portion 22g has a bottomed cylindrical shape having a cable conductor receiving port 22c for receiving the cable conductor 121 of the second power cable 12 inside the rear end before compression. The continuous surface 22f of the small-diameter portion 22a and the large-diameter portion 22b stands substantially vertically, and after connecting the conductor connecting terminals 21 and 22 inside the reinforcing insulating portion 30A, a protruding portion of an internal electrode 32 described later It becomes a surface facing the side surface (surface perpendicular to the axial direction) of 32a. When the cable conductor 121 of the second power cable 12 is inserted into the cable conductor receiving port 22c and the compression portion 22g is compressed, the cable conductor 121 of the second power cable 12 is electrically connected to the second conductor connection terminal 22. Connected mechanically and mechanically.

  The tension member 23 is, for example, an eccentric C-shaped ring having end portions separated from each other and having elasticity. When the first conductor connection terminal 21 is engaged with the second conductor connection terminal 22, the retaining member 23 fastens both of them so that they cannot be removed. The retaining member 23 is engaged with the first conductor connection terminal 21 and the second conductor connection terminal 22 together with the retaining ring recesses 21 d and 22 e of the first conductor connection terminal 21 and the second conductor connection terminal 22. It functions as a retaining part that holds

  The retaining member 23 is attached to the retaining ring recess 21 d of the first conductor connection terminal 21. The tension member 23 is in a state in which the ends are separated from each other in an unloaded state with no external force, and even when attached to the retaining ring recess 21d, the retaining member 23 is lifted from the bottom of the recess (see FIGS. 3A and 3C). . On the other hand, when the tension member 23 receives an external force from the inner surface of the plug receiving port 22d of the second conductor connection terminal 22 when connecting the first conductor connection terminal 21 to the second conductor connection terminal 22, the tension member 23 is elastically deformed. Thus, the diameter is reduced, and the ring is recessed into the retaining ring recess 21d (see FIG. 3B).

  The conductor contactor 24 is a conductive member for electrically connecting the first conductor connection terminal 21 and the second conductor connection terminal 22. As the conductor contactor 24, for example, a multi-ram band known as a multi-surface contact type contactor can be applied.

  As shown in FIG. 2B, when the small-diameter portion 21a (plug portion) of the first conductor connection terminal 21 is fitted into the plug receiving port 22d (plug reception portion) of the second conductor connection terminal 22, at least the first A concave space 25 is formed so as to include the outer peripheral surface of the small-diameter portion 22a of the two conductor connection terminals 22. In the present embodiment, a space 25 is formed by the continuous surface 21f of the small diameter portion 21a and the large diameter portion 21b, the continuous surface 22f of the small diameter portion 22a and the large diameter portion 22b, and the outer peripheral surface of the small diameter portion 22a. The axial length of the space 25 is equal to or less than the axial length of the protruding portion 32a of the internal electrode 32A. The depth in the radial direction of the space 25 is equal to or less than the radial height of the protruding portion 32a of the internal electrode 32A. Thereby, the protrusion 32a of the internal electrode 32A is sandwiched by the space 25 (see FIG. 3C).

  3A to 3C are diagrams illustrating a construction process of the cable connecting portion 1A according to the first embodiment.

  First, the first conductor connection terminal 21 is compression-connected to the cable conductor 111 of the first power cable 11 exposed by stripping, and the second conductor connection terminal 22 is connected to the cable conductor 121 of the second power cable 12. Connect with compression. Further, the retaining member 23 and the conductor contact 24 are attached to the first conductor connection terminal 21.

  Next, as shown in FIG. 3A, the terminal portion of the first power cable 11 to which the first conductor connection terminal 21 is attached and the second power cable 12 to which the second conductor connection terminal 22 is attached. The terminal portions are respectively press-fitted into the insertion holes 30a of the reinforcing insulating portion 30A.

  The small diameter portion 21 a of the first conductor connection terminal 21 is inserted into the plug receiving port 22 d of the second conductor connection terminal 22. In the process until the insertion, when the distal end surface (the right side in FIGS. 2A and 2B) of the second conductor connection terminal 22 comes into contact with the retaining member 23, the retaining member 23 is pressed inward, and the retaining ring recess 21d. (See FIG. 3B).

  When the terminal portion of the first power cable 11 and the terminal portion of the second power cable 12 are further inserted, the retaining member 23 engages with the retaining ring recess 22e of the second conductor connection terminal 22 (see FIG. 3C). . That is, due to the plug-in structure, the first conductor connection terminal 21 and the second conductor connection terminal 22 are connected so that they cannot be removed. Accordingly, the power cables 11 and 12 cannot be pulled out unless the reinforcing insulating portion 30A is torn and the conductor connecting portion 20A is disassembled.

  At this time, the protruding portion 32a of the internal electrode 32A is sandwiched between the first conductor connecting terminal 21 and the second conductor connecting terminal 22 (specifically, between the connecting surface 21f and the connecting surface 22f). It becomes. Thereby, even if an axial force is generated in the power cables 11 and 12, the interface state between the reinforcing insulating portion 30A and the cable core (particularly, the cable insulators 112 and 122) is not changed by this axial force. Insulation is ensured.

As described above, the cable connection portion 1A according to the present embodiment includes the first conductor connection terminal 21 connected to the cable conductor 111 (first cable conductor) of the first power cable 11 and the second power. A second conductor connection terminal 22 that is connected to the cable conductor 121 (second cable conductor) of the cable 12 and engages with the first conductor connection terminal 21, and the first conductor connection terminal 21 and the second conductor connection. A retaining member 23 and retaining ring recesses 21d and 22e (stretching portions) for maintaining the engagement state of the terminal 22, and a conductor connecting portion formed by connecting the first conductor connecting terminal 21 and the second conductor connecting terminal 22 to each other. A plug-in cable connecting portion including a reinforcing insulating portion 30A disposed in close contact with the outer periphery.
In the cable connecting portion 1A, the first conductor connecting terminal 21 is larger in diameter than the small diameter portion 21a (plug portion) inserted into the second conductor connecting terminal 22 and the small diameter portion 21a connected to the small diameter portion 21a. Large-diameter portion 21b (first large-diameter portion). The second conductor connection terminal 22 has a small diameter portion 22a whose end face is opposed to the step surface of the first conductor connection terminal 21 (the connection surface 21f in the present embodiment), and a small diameter portion connected to the small diameter portion 22a. Large diameter portion 22b (second large diameter portion) larger than 22a, and plug receiving port 22d for receiving small diameter portion 21a (plug portion) inside small diameter portion 22a and large diameter portion 22b (second large diameter portion) (Plug receiving portion). The reinforcing insulating portion 30 </ b> A includes a rubber insulating portion 31 and an internal electrode 32 </ b> A disposed on the inner peripheral surface of the rubber insulating portion 31.
When the small diameter portion 21a (plug portion) of the first conductor connection terminal 21 is fitted into the plug receiving port 22d (plug reception portion) of the second conductor connection terminal 22 inside the reinforcing insulating portion 30, the small diameter is reduced. A part of the internal electrode 32 is sandwiched in the space 25 formed by the portions 21a and 22a.

  According to the cable connecting portion 1A, since the protruding portion 32a of the internal electrode 32A is held in a state of being sandwiched between the first conductor connecting terminal 21 and the second conductor connecting terminal 22, the cable holding force against the axial force And high long-term stability is achieved. In particular, the cable connecting portion 1A is useful as a cable connecting portion for an ultra-high voltage cable of 275 kV class or higher.

[Second Embodiment]
As shown in FIG. 1, the cable connecting portion 1B according to the second embodiment includes a terminal portion of the first power cable 11, a terminal portion of the second power cable 12, a conductor connecting member 20B, and a reinforcing insulating portion 30B. And a protective case 40 and the like. In the cable connecting portion 1B, the description of the same or corresponding components as those in the cable connecting portion 1A according to the first embodiment is omitted. Here, the structure of the conductor connecting member 20B and the fixing structure of the conductor connecting member 20B and the reinforcing insulating portion 30B will be described mainly.

  In the second embodiment, the conductor connection member 20B includes a pair of conductor connection terminals 61 and 62 that are connected in a non-detachable manner by a plug-in structure (see FIGS. 4A and 4B). The conductor connection terminal 61 compressed and connected to the cable conductor 111 of the first power cable 11 is referred to as “first conductor connection terminal 61”, and the conductor connection terminal 62 that is compressed and connected to the cable conductor 121 of the second power cable 12. This will be referred to as “second conductor connection terminal 62”.

  The reinforcing insulating portion 30B has a cylindrical shape as a whole. In the reinforcing insulating portion 30B, the inner peripheral surface of the internal electrode 32B is formed flush. The end portion of the first power cable 11 to which the first conductor connection terminal 61 is attached and the second conductor connection terminal 62 to which the first conductor connection terminal 61 is attached are inserted into the insertion hole 30a (see FIG. 5A) of the reinforcing insulating portion 30B. The terminal portion of the second power cable 12 is press-fitted. Due to the elastic force of the reinforcing insulating portion 30B (mainly the rubber insulating portion 31), the reinforcing insulating portion 30B, the conductor connecting member 20B, and the cable cores of the power cables 11, 12 are in close contact.

  In the second embodiment, the first conductor connection terminal 61 and the second conductor connection terminal 62 are press-fitted into the reinforcing insulating portion 30B. Due to the difference in diameter between the outer diameter and the inner diameter of the reinforcing insulating part 30B, a force is exerted on a part of the internal electrode 32B to return radially inward due to the self-shrinking force of the reinforcing insulating part 30B. As a result, the central portion 32b in the axial direction of the internal electrode 32B protrudes radially inward and is sandwiched between the spaces 65 (see FIGS. 6A to 6C). This is different from the first embodiment in which the protrusion 32 a formed in advance on the inner peripheral surface of the internal electrode 32 </ b> A is held in the space 25. That is, the inner diameter of the insertion hole 30a of the reinforcing insulating portion 30B is a press-fit of the first conductor connection terminal 61 and the second conductor connection terminal 62, rather than the outer diameter of the conductor connection member 20B and the cable core of the power cables 11 and 12. Accordingly, the axial center portion 32b is set small enough to protrude radially inward.

  4A and 4B are diagrams illustrating the structure of the conductor connection member 20B according to the second embodiment. FIG. 4A is a half sectional view showing a state before the first conductor connection terminal 61 and the second conductor connection terminal 62 are engaged. FIG. 4B is a half sectional view showing a state after the first conductor connecting terminal 61 and the second conductor connecting terminal 62 are engaged. In FIG. 4B, illustration of the compressed power cables 11 and 12 is omitted for convenience of explanation.

  As shown in FIGS. 4A and 4B, the first conductor connection terminal 61 has a multistage cylindrical shape. In the second embodiment, the first conductor connection terminal 61 has a multistage cylindrical shape including a small diameter portion 61a, a large diameter portion 61b (first large diameter portion), and a compression portion 61g.

  The small diameter portion 61 a is a plug portion that is inserted into the second conductor connection terminal 62. The small-diameter portion 61a has a first small-diameter portion 61h on the front end side and a second small-diameter portion 61i connected to the rear end side of the first small-diameter portion 61h. The small diameter portion 61a (specifically, the first small diameter portion 61h) has a retaining ring recess 61d and a contact recess 61e on the outer peripheral surface. The retaining member 23 is disposed in the retaining ring recess 61d, and the conductor contact 24 is disposed in the contact recess 61e. The retaining ring recess 61 d has a depth that can accommodate the retaining member 23.

  In the second embodiment, a retaining ring recess 61d is disposed on the distal end side of the small diameter portion 61a (specifically, the first small diameter portion 61h) (the side connected to the second conductor connection terminal 62). Although the contact concave portion 61e is disposed on the end side (large diameter portion 61b side), these arrangements may be reversed. When the conductor contactor 24 is disposed on the front end side of the small diameter portion 61a and the retaining member 23 is disposed on the rear end side, the retaining member 23 and the inner peripheral surface of the plug receiving port 62d of the second conductor connecting terminal 62 are slid. Since the contact distance is shortened, it is possible to suppress the abrasion of the plug receiving port 62d.

  In addition, after connecting the first conductor connection terminal 61 and the second conductor connection terminal 62, the tip surface of the second small diameter portion 61 i (hereinafter referred to as “step surface 61 j”) is the second conductor connection terminal 62. It faces the end surface of the small diameter portion 62a. The outer diameter of the second small diameter portion 61 i is the same as the outer diameter of the small diameter portion 62 a of the second conductor connection terminal 62. That is, when the first conductor connection terminal 61 and the second conductor connection terminal 62 are engaged, the small diameter portion 62a contacts the step surface 61j, and the second small diameter portion 61i (step) of the first conductor connection terminal 61 is obtained. Portion) and the outer peripheral surface of the small diameter portion 62a of the second conductor connection terminal 62 are flush with each other.

  The large diameter portion 61b is connected to the small diameter portion 61a (second small diameter portion 61i) and has an outer diameter larger than that of the small diameter portion 61a (second small diameter portion 61i). A compression portion 61g for compressing and connecting the cable conductor 111 of the first power cable 11 is connected to the rear end side of the large diameter portion 61b. In the second embodiment, the compression portion 61g has a bottomed cylindrical shape having a cable conductor receiving port 61c inside the rear end before compression, and has a smaller diameter than the large diameter portion 61b. The compression part 61g is formed with the same outer diameter as the large-diameter part 61b, and the deformation of the large-diameter part 61b due to compression is prevented between the large-diameter part 61b and the compression part 61g (specifically, the distal end side of the compression part 61g). For this purpose, a groove may be provided. When the cable conductor 111 of the first power cable 11 is inserted into the cable conductor receiving port 61c and the compression portion 61g is compressed, the cable conductor 111 of the first power cable 11 is electrically connected to the first conductor connection terminal 61. Connected mechanically and mechanically.

  The connecting surface 61f of the small diameter portion 61a (second small diameter portion 61i) and the large diameter portion 61b has a tapered shape that increases in diameter toward the rear end side. Thereby, after connecting the first conductor connection terminal 61 and the second conductor connection terminal 62, the axial center portion 32b of the internal electrode 32B is fitted into the space 65 described later by the self-shrinkage force of the reinforcing insulating portion 30B. This can be facilitated (see FIG. 5C).

  As shown in FIGS. 4A and 4B, the second conductor connection terminal 62 has a multistage cylindrical shape. In the second embodiment, the second conductor connection terminal 62 has a multistage cylindrical shape including a small diameter portion 62a, a large diameter portion 62b (second large diameter portion), and a compression portion 62g.

  The small-diameter portion 62a and the large-diameter portion 62b connected to the small-diameter portion 62a are plug receiving portions that have a plug receiving port 62d therein and receive the small-diameter portion 61a of the first conductor connection terminal 61. It has become a shape. The length of the plug receiving port 62d is formed to be approximately the same as or slightly longer than the length of the first small diameter portion 61h of the first conductor connecting terminal 61. The inner diameter of the plug receiving port 62d is the same as that of the first conductor connecting terminal 61. It is substantially the same as the outer diameter of one small diameter part 61h. In the second embodiment, a retaining ring recess 62e (groove portion) with which the retaining member 23 is engaged is formed on the inner peripheral surface of the plug receiving port 62d corresponding to the large diameter portion 62b.

  The compression part 62g is connected to the rear end side (left side in FIGS. 4A and 4B) of the large diameter part 62b. In the second embodiment, the compression portion 62g has a smaller diameter than the large diameter portion 62b before compression, and is a portion to which the cable conductor 121 of the second power cable 12 is compression-connected. The compression part 62g is formed with the same outer diameter as the large-diameter part 62b, and the deformation of the large-diameter part 62b due to compression is prevented between the large-diameter part 62b and the compression part 62g (specifically, the distal end side of the compression part 62g). For this purpose, a groove may be provided.

  The compression portion 62g has a bottomed cylindrical shape having a cable conductor receiving port 62c for receiving the cable conductor 121 of the second power cable 12 inside the rear end before compression. When the cable conductor 121 of the second power cable 12 is inserted into the cable conductor receiving port 62c and the compression portion 62g is compressed, the cable conductor 121 of the second power cable 12 is electrically connected to the second conductor connection terminal 62. Connected mechanically and mechanically.

  The connecting surface 62f of the small diameter portion 62a and the large diameter portion 62b has a tapered shape that increases in diameter toward the rear end side. Thereby, after connecting the first conductor connection terminal 61 and the second conductor connection terminal 62, the axial center portion 32b of the internal electrode 32B is fitted into the space 65 described later by the self-shrinkage force of the reinforcing insulating portion 30B. This can be facilitated (see FIG. 5C).

  As shown in FIG. 4B, when the small-diameter portion 61a (plug portion) of the first conductor connection terminal 61 is fitted into the plug receiving port 62d (plug reception portion) of the second conductor connection terminal 62, at least the first A concave space 65 is formed so as to include the outer peripheral surface of the small diameter portion 62 a of the second conductor connection terminal 62. In the present embodiment, the continuous surface 61f of the small diameter portion 61a (second small diameter portion 61i) and the large diameter portion 61b, the continuous surface 62f of the small diameter portion 62a and the large diameter portion 62b, the outer peripheral surface of the second small diameter portion 61i, A space 65 is formed by the outer peripheral surface of the small diameter portion 62a.

  5A to 5C are diagrams illustrating a construction process of the cable connecting portion 1B according to the second embodiment.

  First, the first conductor connection terminal 61 is compression-connected to the cable conductor 111 of the first power cable 11 exposed by stripping, and the second conductor connection terminal 62 is connected to the cable conductor 121 of the second power cable 12. Connect with compression. Further, the retaining member 23 and the conductor contactor 24 are attached to the first conductor connection terminal 61.

  Next, as shown in FIG. 5A, the terminal portion of the first power cable 11 to which the first conductor connection terminal 61 is attached and the second power cable 12 to which the second conductor connection terminal 62 is attached. The terminal portions are respectively press-fitted into the insertion holes 30a of the reinforcing insulating portion 30B. The inner diameter of the insertion hole 30a of the reinforcing insulating portion 30B is the outer diameter of the first conductor connection terminal 61 (the outer diameter of the large diameter portion 61b) and the outer diameter of the second conductor connection terminal 62 (the outer diameter of the large diameter portion 62b). In this embodiment, it is smaller than the outer diameters of the second small diameter portion 61i and the small diameter portion 62a. Therefore, the outer circumferences of the large-diameter portions 61b and 62b of the first and second conductor connection terminals 61 and 62 as the first conductor connection terminal 61 and the second conductor connection terminal 62 are press-fitted into the reinforcing insulating portion 30B. The portion in contact with the surface (the inner peripheral surface of the internal electrode 32B) is expanded outward in the radial direction, and the internal electrode 32B in the expanded portion attempts to return radially inward due to the self-shrinking force of the reinforcing insulating portion 30B. The power to do works.

  The small diameter portion 61 a of the first conductor connection terminal 61 is inserted into the plug receiving port 62 d of the second conductor connection terminal 62. In the process until the insertion, when the distal end surface (the right side in FIGS. 4A and 4B) of the second conductor connection terminal 62 comes into contact with the retaining member 23, the retaining member 23 is pressed inward, and the retaining ring recess 61d. (See FIG. 5B).

  When the terminal portion of the first power cable 11 and the terminal portion of the second power cable 12 are further inserted, the retaining member 23 engages with the retaining ring recess 62e of the second conductor connection terminal 62 (see FIG. 5C). . That is, due to the plug-in structure, the first conductor connection terminal 61 and the second conductor connection terminal 62 are connected so as not to be removable. Thus, the power cables 11 and 12 cannot be pulled out unless the reinforcing insulating portion 30B is torn and the conductor connecting portion 20B is disassembled.

  At this time, the axial center portion 32b of the internal electrode 32B protrudes radially inward due to the self-shrinking force of the reinforcing insulating portion 30B, and is a space formed by the first conductor connection terminal 61 and the second conductor connection terminal 62. 65, and is sandwiched between the first conductor connecting terminal 21 and the second conductor connecting terminal 22 (specifically, between the connecting surface 61f and the connecting surface 62f). . Thereby, even if an axial force is generated in the power cables 11 and 12, the interface state between the reinforcing insulating portion 30B and the cable core (particularly, the cable insulators 112 and 122) is not changed by this axial force. Insulation is ensured.

As described above, the cable connecting portion 1B according to the present embodiment includes the first conductor connecting terminal 61 connected to the cable conductor 111 (first cable conductor) of the first power cable 11 and the second power. A second conductor connection terminal 62 that is connected to the cable conductor 121 (second cable conductor) of the cable 12 and engages with the first conductor connection terminal 61, and the first conductor connection terminal 61 and the second conductor connection. The drawing member 23 and the retaining ring recesses 61d and 62e (drawing portions) for holding the engagement state of the terminal 62, and the conductor connecting portion formed by connecting the first conductor connecting terminal 61 and the second conductor connecting terminal 62 are provided. A plug-in type cable connecting portion including a reinforcing insulating portion 30B disposed in close contact with the outer periphery.
In the cable connection portion 1B, the first conductor connection terminal 61 has a smaller diameter than the small diameter portion 61a (plug portion) inserted into the second conductor connection terminal 62 and the small diameter portion 61a connected to the small diameter portion 61a. Large-diameter portion 61b (first large-diameter portion). The second conductor connection terminal 62 has a small diameter portion 62a whose end surface faces the stepped surface 61j of the first conductor connection terminal 61, and a large diameter portion 62b having a larger diameter than the small diameter portion 62a connected to the small diameter portion 62a. (Second large diameter portion) and a small diameter portion 62a and a plug receiving port 62d (plug receiving portion) for receiving the small diameter portion 61a (plug portion) inside the large diameter portion 62b (second large diameter portion). The reinforcing insulating part 30 </ b> B includes a rubber insulating part 31 and an internal electrode 32 </ b> B disposed on the inner peripheral surface of the rubber insulating part 31.
When the small diameter portion 61a (plug portion) of the first conductor connection terminal 61 is fitted into the plug receiving port 62d (plug reception portion) of the second conductor connection terminal 62 inside the reinforcing insulating portion 30B, the small diameter is reduced. A part of the internal electrode 32B is sandwiched in the space 65 formed by the portions 61a and 62a.

  According to the cable connecting portion 1B, the axial central portion 32b of the internal electrode 32B protrudes radially inward by the self-shrinkage force of the reinforcing insulating portion 30B and is sandwiched by the space 65, whereby the first conductor connecting terminal 61 is provided. And the second conductor connection terminal 62 are held in a state of being sandwiched between them, the cable holding force with respect to the axial force is high, and excellent long-term stability is realized. In particular, the cable connecting portion 1B is useful as a cable connecting portion for an ultra-high voltage cable of 275 kV class or higher.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiment. However, the present invention is not limited to the above embodiment, and can be changed without departing from the gist thereof.

  For example, in the cable connection portions 1 and 2, the structure for maintaining the engagement state of the first conductor connection terminals 21 and 61 and the second conductor connection terminals 22 and 62 is the same as the retention structure described in the embodiment. The structure is not limited as long as it cannot be removed after plug-in connection.

  Also, for example, in the first and second embodiments, the case where ethylene propylene rubber (EP rubber) is used as the rubber material (both insulating and semiconductive) has been described, but silicone rubber may be used. . Moreover, although the case where the multi-ram band (multi-contact) was used as the conductor contact 23 was demonstrated, it is not limited to this, For example, you may use a coil spring-like contact.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1A, 1B Cable connection portion 11, 12 Power cable 111, 121 Cable conductor 112, 122 Cable insulator 113, 123 External semiconductive layer 114, 124 Cable shielding layer 115, 125 Cable sheath 20A, 20B Conductor connection portion 21, 61 1 conductor connection terminal 22, 62 second conductor connection terminal 23 drawing member 24 conductor contactor 30A, 30B reinforcing insulation part 31 rubber insulation part 32A, 32B internal electrode 32a protruding part 32b axial center part 33, 34 stress cone part 35 External shielding layer

Claims (7)

A first conductor connection terminal connected to the first cable conductor;
A second conductor connection terminal connected to a second cable conductor and engaged with the first conductor connection terminal;
A retaining portion that holds the engagement state of the first conductor connection terminal and the second conductor connection terminal;
A reinforcing insulating portion disposed in close contact with an outer periphery of a conductor connecting portion formed by connecting the first conductor connecting terminal and the second conductor connecting terminal;
A plug-in cable connection comprising:
The first conductor connection terminal has a plug portion inserted into the second conductor connection terminal, and a first large diameter portion having a diameter larger than that of the plug portion connected to the plug portion. ,
The second conductor connection terminal includes a small diameter portion whose end surface faces the step surface of the first conductor connection terminal, and a second large diameter portion having a larger diameter than the small diameter portion connected to the small diameter portion. A plug receiving portion for receiving the plug portion inside the small diameter portion and the second large diameter portion,
The reinforcing insulating part has a rubber insulating part and an internal electrode disposed on the inner peripheral surface of the rubber insulating part,
Inside the reinforcing insulating part, when the plug part is fitted into the plug receiving part, the space formed by the outer peripheral surfaces of the first conductor connection terminal and the second conductor connection terminal, A cable connecting portion, wherein a part of the internal electrode is sandwiched. The internal electrode has a main part, and a protrusion formed to protrude inward in the radial direction from the main part,
The space is formed including at least the outer peripheral surface of the small diameter portion,
The cable connecting portion according to claim 1, wherein the protruding portion is sandwiched in the space. The main part of the internal electrode is formed of a semiconductive rubber material,
The cable connecting portion according to claim 2, wherein the protruding portion is made of the same material as the rubber material. The main part of the internal electrode is formed of a semiconductive rubber material,
The cable connecting portion according to claim 2, wherein the protruding portion is formed by embedding a metal piece in the main portion.   The cable connecting portion according to claim 1, wherein an axially central portion of the internal electrode protrudes radially inward due to a self-shrinking force of the reinforcing insulating portion and is sandwiched between the spaces.   The retaining portion includes a retaining member disposed on the outer peripheral surface of the plug portion so as not to fall off, and a groove portion formed on an inner peripheral surface of the plug receiving portion and engaged with the retaining member. The cable connection part as described in any one of Claim 1 to 5 characterized by the above-mentioned.   A conductor contact that is interposed between the first conductor connection terminal and the second conductor connection terminal and electrically connects the first conductor connection terminal and the second conductor connection terminal; The cable connection part as described in any one of Claim 1 to 6 characterized by the above-mentioned.

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