JP2001177975A - Prefabricated joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized, light, low-cost, and moreover highly reliable prefabricated joint which avoids deterioration electrical characteristics, by electrically connecting an insulated unit and a metallic case using a simple constitution. SOLUTION: In a prefabricated joint 1, a metallic case 15 is installed integrally with the periphery of an insulated unit 3, and a conductive elastic member 15 is arranged between the insulated unit 3 and the metallic case 15, and the insulated unit 3 and the metallic case 15 are electrically connected with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prefabricated joint for connecting cables, and more particularly to a linear joint (linear connection) in which a cable connecting material can be attached to opposite ends of one insulating unit. Part) or a Y-branch joint (Y-branch connection part) that enables one cable to be connected to two cables.

[0002]

2. Description of the Related Art In recent years, miniaturized cable connecting portions, that is, prefabricated joints, have been developed with the aim of reducing the size of manholes, simplifying construction work, and reducing skill during assembly. FIG. 5 shows C having cross-linked polyethylene as an insulating layer.
1 shows an example of a straight joint of a power cable such as a V cable.

[0003] Reduced type prefabricated joint 1 in this example
A has an epoxy unit 3 which is an insulating unit made of an insulating material such as a normal epoxy resin in which a sleeve-like internal conductor 2 is integrally formed.

A power cable 4A such as a CV cable,
4B energized connection, ie cable connection material (male side)
100A and 100B are mounted from both sides in connection receiving holes arranged opposite to each other in the axial direction of the prefabricated joint 1A. The connection material 100A, 100B of each cable has a prefabricated structure which is well known to those skilled in the art, and connection terminals (plugs 10, 11, multi-lam band 13, and retaining device 14, etc.) formed at the end of the cable, stress, etc. It is composed of connecting parts such as a cone 44, a press fitting 43, a compression device 42, and a cable protection fitting 41, and is connected to the sleeve-like inner conductor 2.

More specifically, metal adapters 45, such as steel, having a substantially cylindrical shape are provided at both ends of the epoxy unit 3 so as to surround the metal fittings 43. The two adapters 45 are screwed with the threaded portions formed at the inner ends thereof at both ends of a cylindrical outer case 15 made of a metal such as aluminum and arranged integrally around the outer periphery of the epoxy unit 3. The inner end surface of the 45 is in contact with the end surface of the epoxy unit 3 and is fixed in place. An intermediate flange 46 is attached to the outer end surface of the adapter 45 with bolts 47, and the protective fitting 41 is fixed to the intermediate flange 46 with bolts 48.

On the outer periphery of the outer case 15 and the adapter 45, an anticorrosion layer 4 made of a heat-shrinkable tube or the like for waterproofing is provided.
9 are provided.

Further, in order to reliably prevent water from entering inside from the contact portions between the both end surfaces of the epoxy unit 3 and the adapter 45, the outer case 15 and the epoxy unit 3 are fixed.
When integrally molding the epoxy unit 3, chamfering is performed on both ends of the outer periphery of the epoxy unit 3, an annular O-ring housing groove is formed between the chamfered portion and the outer case 15, and a rubber O-ring 50 is formed in the space. It is possible to arrange.

[0008]

However, as a result of research conducted by the present inventors, in the above configuration, when the adapter 45 is screwed into the outer case 15, the rubber O-ring 50 is inserted into the O-ring housing groove. Adapter 45 because it is located
Cannot be brought into close contact with the end face of the epoxy unit 3, and a gap is formed between the end face of the epoxy unit 3 and the end face of the adapter 45, and the gap therebetween is electrically floated, that is, floated, A potential difference occurs between the two,
It has been found that the electrical characteristics deteriorate.

A similar problem also occurs in the Y-branch joint (Y-branch connection) 1. FIG. 10 shows an example of the Y-branch connection unit.

In this embodiment, the Y-branch connection portion 1 has an internal conductor (embedded electrode) 2 having a substantially Y-shape, and a Y-type epoxy unit made of epoxy resin is provided around the internal conductor 2. 3 are integrally formed.

The Y-shaped connection portion 1 has one connection receiving hole 20A formed on one side so that a connection material (connection end portion) for one power cable can be mounted thereon, and the other side has a connection receiving hole 20A. , Two connection receiving holes 20B and 20C are formed in parallel to form a connection material (connection tip) of two power cables arranged in parallel.
Can be mounted.

In order to make the surface of the epoxy unit equipotential, the surface of the epoxy unit is coated with a conductive paint (silver paint) 30 for reasons such as keeping the electric field constant.
Metal case 15 placed around the outer periphery of the epoxy unit
(15A, 15B). Although not shown, an anticorrosion layer is provided on the outer periphery of the metal case 15 for waterproofing.

Normally, an electrical connection between the metal case 15 and the surface of the epoxy unit 3 is made by connecting one end of a metal wire 200 to the surface of the epoxy unit 3 with a conductive adhesive 201 and the other end of the metal wire 200. To the metal case 15
02 and so on.

However, such a method requires skill and time and is inferior in workability. In addition, the soldering portion 202 or the connecting portion 201 made of a conductive adhesive is peeled off, and the metal wire 2
In some cases, the electrical connection due to 00 was lost.

Accordingly, an object of the present invention is to provide a compact, light-weight, low-cost, and highly-reliable, electrically connected insulating unit and metal case with a simple configuration, avoiding a decrease in electrical characteristics. It is to provide a high prefabricated joint.

Another object of the present invention is to completely prevent the invasion of water from the outside, and to electrically connect the insulation unit, the outer case, the adapter, and the like to the same potential to make the insulation unit have the same potential. An object of the present invention is to provide a small, lightweight, low-cost, and highly reliable prefabricated joint which prevents an electric floating state from occurring and prevents a decrease in electric characteristics.

[0017]

The above object is achieved by a prefabricated joint according to the present invention. In summary, the present invention comprises an inner conductor, and an insulating unit integrally formed of an insulating material around the inner conductor and having a conductive layer on an outer surface, wherein a connection hole of the inner conductor and a receiving portion of the insulating unit are provided. In a prefabricated joint for connecting a cable by attaching a cable connection material to a connection receiving hole formed by a hole, a metal case is arranged integrally on the outer periphery of the insulating unit, and the insulating unit and A prefabricated joint, wherein a conductive elastic member is disposed between the metal case and the insulating unit, and the metal case is electrically connected.

According to one embodiment of the present invention, a metal adapter for attaching the connecting material is attached to an end of the insulating unit, and the conductive elastic member is a conductive elastic ring. The conductive elastic ring is arranged between the insulating unit, the metal case, and the adapter, and the insulating unit, the metal case, and the adapter are sealed, and the insulating unit, the metal case, and the adapter are sealed. It is kept at the same potential.

According to another embodiment of the present invention, an outer peripheral portion of an end face of the insulating unit is chamfered, and an annular O-ring housing groove is formed between the chamfered portion and the metal case. The conductive elastic ring is disposed in the space of the groove. According to another embodiment, the O-ring receiving groove has a triangular cross-sectional shape.

According to another embodiment of the present invention, the prefabricated joint is a straight joint, and the connection receiving holes are formed to face each other.

According to another embodiment of the present invention, the adapter is attached to both ends of the insulating unit by screwing to both ends of the metal case projecting from an end face of the insulating unit.

According to another embodiment of the present invention, the prefabricated joint is a Y-branch joint, and the connection receiving hole is formed on one side of the insulating unit and two on the other side in parallel with each other. . Here, the insulation unit is
The metal case includes a body in which the inner conductor is arranged, and a cylinder in which a receiving hole for receiving the connection material is formed. A box-shaped case body fitted and fitted to the side surface and the outer peripheral surface, and a case lid fitted and fitted to the other side surface of the body except for the cylindrical portion of the insulating unit, The case main body and the case lid are integrally connected by a bolt, and the conductive elastic member is arranged between the outer periphery of a connection portion of the insulating unit to the body with respect to the body and the case main body. be able to. The conductive elastic member is a conductive elastic ring, seals between the insulating unit and the metal case, and holds the insulating unit and the metal case at the same potential.

According to another embodiment of the present invention, the conductive elastic member is a cushion material with a braided wire, and maintains the same potential between the insulating unit and the metal case.
According to one embodiment, the braided cushioning material comprises:
It is formed of an elastic hollow tube having a crescent or semicircular hollow cross section and a braided wire wound around the outer periphery of the elastic hollow tube.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a prefabricated joint according to the present invention will be described in more detail with reference to the drawings. The present invention
A straight joint (straight connection part) in which a cable connection material can be attached to both ends of one insulation unit facing each other, or a Y branch joint (Y branch connection) in which one cable can be connected to two cables ), But is not limited thereto.

Embodiment 1 FIG. 1 shows an embodiment of a prefabricated joint 1 to which the present invention is applied. The prefabricated joint 1 of this embodiment is a straight joint similar to that described with reference to FIG.

That is, the straight connecting portion 1 which is a prefabricated joint in this embodiment has an internal conductor (embedded electrode) 2 and is formed around the internal conductor 2 with an insulating material such as epoxy resin. The epoxy unit 3, which is an insulating unit, is integrally formed. A conductive layer is provided on the outer surface of the epoxy unit 3 by applying silver paint. The prefabricated joint 1 is formed with two connection receiving holes 20A and 20B in which power cables to be connected, for example, CV cables 4A and 4B, to which connection materials (connection tip portions) 100A and 100B can be attached, respectively. You. In FIG. 1, a connection material (connection tip portion) 100A of one cable 4A can be attached to the right connection receiving hole 20A of the prefabricated joint 1, and the other cable 4B is connected to the left connection receiving hole. Connection material (connection tip) 1
00B can be mounted.

Each of the connection receiving holes 20A and 20B has a substantially cylindrical connection hole 21 formed in the internal conductor 2 and the connection hole 2A.
1 and a tapered receiving hole 22 formed in the epoxy unit 3 in communication with the receiving unit 1.

The connecting materials 100A and 100B are formed by connecting terminals (such as plugs 10 and 11, the multi-ram band 13 and the retaining device 14) formed at the distal end of the cable, the stress cone 44, the press fitting 43, the compressing device 42, It has a prefabricated structure with connecting parts such as a cable protection fitting 41 and is connected to the sleeve-like inner conductor 2. Connection material 10
The structure of the cable end conductors of the cables 0A and 100B will be described later in detail.

According to the present invention, at both ends of the epoxy unit 3, metal adapters 45, such as steel, having a substantially cylindrical shape surrounding the metal fittings 43 are arranged. The two adapters 45 have a threaded portion formed at the inner end thereof integrally disposed around the outer periphery of the epoxy unit 3, and both ends of the cylindrical outer case 15 made of metal such as aluminum protruding from the end surface of the epoxy unit 3. Both ends are screwed into the threaded portions, and the inner end surface of each adapter 45 abuts against the end surface of the epoxy unit 3 and is fixed in place.

On the outer periphery of the outer case 15 and the adapter 45, an anticorrosion layer 4 made of a heat-shrinkable tube or the like for waterproofing or the like is provided.
9 are provided.

Further, as will be better understood with reference to FIG. 2, it is ensured that water permeates into the center inward from the contact portion between the end surface 3a of the epoxy unit 3 and the end surface 45a of the adapter 45. When the outer case 15 and the epoxy unit 3 are integrally formed for sealing, a chamfer 3b is formed on the outer peripheral portion of the end face of the epoxy unit, and the cross-sectional shape between the chamfer 3b and the outer case 15 is triangular. An annular O-ring storage groove 3c is formed, and a conductive elastic ring 51 as a conductive elastic member is disposed in a space of the O-ring storage groove 3c. Also, epoxy unit 3
A conductive paint (silver paint) 30 is applied to a portion of the outer surface indicated by a broken line in the drawing. The cross-sectional shape of the O-ring storage groove 3c is not limited to a triangular shape, but may be any shape.

Therefore, as shown in FIG.
Is screwed into the end of the outer case 15 because the conductive ring 51 is disposed in the O-ring storage groove 3c.
The epoxy unit 3, the adapter 45, and the outer case 15 are electrically contacted via the conductive ring 51, so that the epoxy unit 3, the adapter 45, and the outer case 15 can be maintained at the same potential. Therefore, the adapter 45 is connected to the outer case 1
5, the end face of the adapter 45 cannot be brought into close contact with the end face of the epoxy unit 3, and the end face 3a of the epoxy unit 3 and the end face 45a of the adapter 45, as shown in FIG. Even if a gap (g) is generated between them, the two do not become electrically floated, that is, do not float, and the electrical characteristics of the prefabricated joint 1 can be improved.

The material of the conductive elastic ring is preferably made of silicone rubber or EP rubber mixed with carbon to make it conductive. In the present embodiment, the outer diameter (D) of the epoxy unit 3 is 150 mm, and the O-ring housing groove 3c has a triangular cross-sectional shape with one side (w) of 7.8 mm. JISB2401
P140 or equivalent conductive silicone rubber was used, and the cross section was a circular cross section with a diameter of 5.7 mm.
Good results could be obtained by arranging 39.6 mm in the O-ring storage groove 3c.

Next, an embodiment of the structure of the cable tip conductor connecting portion in the cable connecting materials 100A and 100B connected to the prefabricated joint 1 will be described. According to the present embodiment, the cable connection materials 100A,
Since 00B has the same structure, only the connection material 100A of the cable 4A will be described.

Referring to FIG. 3, a plug means for making electrical contact with the inner conductor 2 is attached to the distal end conductor portion 40 of the cable 4A which has been subjected to the terminal treatment and exposed. The plug means includes an inner plug 10 fitted to the tip conductor 40,
An outer plug 11 is attached to the inner plug 10 and brought into an electrically contacting state. The inner plug 10 has a cap shape with one end opened, and a projection 16 having a sharp point from the closed end is formed upright to the opening. Inner plug 1
0 by fitting the cylindrical portion 17 into the outer periphery of the tip conductor portion 40 and simultaneously pushing the projection 16 into the tip conductor portion.
And both members are fixedly connected to make electrical contact. An annular groove is formed on the outer peripheral surface of the inner plug 10, and
A contact 12 such as a multi-ram band formed by arranging a number of ribbon-shaped leaf spring assemblies in an annular shape can also be arranged.

The outer plug 11 has a shape complementary to the outer periphery of the inner plug 10, and compresses and fixes the inner plug 10 to the tip conductor 40. An annular groove is formed on the outer peripheral surface of the outer plug 11, and a contact 13 such as a multi-lam band similar to that described above is arranged therein. When the cable 4A is connected to the prefabricated joint 1, this multi-ram band 13
Are fitted in the connection holes 21 of the inner conductor 2 and make electrical contact.

According to the present embodiment, the retaining device 14 for preventing the cable 4A from being pulled out from the connection portion 1 is provided between the outer plug 11 fixed to the inner plug 10 and the cable insulator end face 46. Is arranged.

The retaining device 14 comprises a generally cylindrical retaining device 3 arranged between the outer plug 11 and the cable insulator end face 46, as can be better understood with reference also to FIG.
One. In the present embodiment, the retaining tool 31 is movably disposed in an internal recess of the cylindrical body 11a formed on the side of the outer plug 11 facing the cable insulator end face 46.

The compression spring 18 is arranged between the fastening tool 31 and the outer plug 11, and normally urges the fastening tool 31 toward the cable insulator end surface 46. Fastener 3
An annular cam portion 32 is formed on the outer peripheral surface at the end where the one compression spring 18 is arranged, and an annular cam that abuts against an annular pusher 44a arranged on the end surface of the stress cone is formed on the other end. A stopper 33 is provided integrally.

A plurality of, for example, 4 to 8 locking holes 11b are formed at equal intervals in the cylindrical body 11a of the outer plug 11, and locking balls 34 are movably arranged.

Therefore, when the stress cone 44 is mounted in the tapered receiving hole 22 and inserted and set at a predetermined position, the stress cone end face pressing tool 44a comes into contact with the annular stopper 33 and compresses the retaining tool 31. It is pressed against the outer plug 11 against the force of the spring 18 and moved. As a result, the locking ball 34 is moved outward in the radial direction by the locking portion 32 formed on the fastener 31 as shown in FIG. 3, and is pushed into the locking hole 11 b of the outer plug 11. You.
A part of the locking ball 34 is provided in the locking hole 11b of the outer plug 11.
Also enters the annular groove 3a of the internal conductor 3 formed corresponding to the position of. This locks the cable 4A to the prefabricated joint 1 and prevents the cable connecting material from being pulled out.

On the other hand, when the stress cone 44 is moved in the pulling-out direction from the cable and in the right direction in FIG.
As shown in FIG. 4, the stress cone tip pusher 44a pressing the annular stopper 33 is eliminated, and
1 is pushed out to the cable insulator end face 46 side by the compression spring 18, abuts against a stopper ring 35 arranged on the outer plug cylinder 11 a, and is held there. Accordingly, the annular groove 3a of the inner conductor 3 and the locking hole 11b of the outer plug 11
The locking ball 34, which has protruded from the cable 4A, can be moved or moved inward in the radial direction.
The locked state of the prefabricated joint is released,
The cable connection material, that is, the cable 4A can be pulled out.

According to the present invention, the prefabricated joint 1 configured as described above is extremely small, lightweight, low in cost, and highly reliable.

The prefabricated joint 1 of the present invention is not limited to the linear joint described in the above embodiment, but can be applied to, for example, a Y-branch prefabricated joint, and the same operation and effect can be obtained.

Embodiment 2 FIGS. 6 and 7 show another embodiment of the prefabricated joint 1 to which the present invention is applied. In this embodiment, the prefabricated joint 1 is a Y-branch joint (Y-branch connection) 1, and the Y-branch connection of this embodiment is a Y-branch connection similar to that described with reference to FIG. You.

That is, in this embodiment, the Y-branch connection unit 1
An internal conductor (embedded electrode) 2 having a substantially Y-shape;
An epoxy unit (insulating unit) 3 made of epoxy resin is integrally formed around the inner conductor 2. Further, a conductive paint (silver paint) is applied to the outer periphery of the epoxy unit 3 in a region indicated by a broken line, and a conductive layer 30 is formed.

One connection receiving hole 20A is formed on one side of the Y-branch connection portion 1 so that a connection material (connection end portion) 100A of one power cable 4A can be attached thereto, and a parallel connection receiving hole 20A is formed on the other side. The connection materials (connection end portions) 100B and 100C of the two power cables 4B and 4C arranged in the two positions are arranged in parallel with each other so as to be attachable.
OC is formed. Each connection receiving hole is formed by a connection hole 21 formed in the internal conductor 2 and a reception hole 22 formed in the epoxy unit in communication with the connection hole 21.

According to the present invention, the cable connection materials 100A, 100B, 100C connected to the Y branch connection portion 1
Has the same configuration as the cable connection material described in the first embodiment.

That is, the cable connection materials 100A, 10A
0B and 100C have the same structure.
The connection material 100A will be briefly described below. The connection material 100A includes connection terminals (such as plugs 10 and 11, the multi-ram band 13 and the retaining device 14) formed at the distal end of the cable, a stress cone 44, and a press fitting 43. ,
It has a prefabricated structure with connecting parts such as a compression device 42 and a cable protection fitting 41, and is connected to the connection hole 21 of the internal conductor 2. Since the cable tip conductor connection portion of the cable connection material has the same configuration as that described in the first embodiment with reference to FIGS. 3 and 4 and the like, the description in this embodiment is omitted.

The epoxy unit 3 is Y-shaped, and has a body 3A on which the internal conductor 2 is arranged, and a cylinder 3B located on both sides of the body 3A to which the above-mentioned connection material is attached. That is, one cylindrical portion 3B is formed on one side of the body portion 3A, and two cylindrical portions are formed on the other side.

Further, a metal case 15 is attached to the outer periphery of the epoxy unit 3 so as to substantially cover both side surfaces and a central outer peripheral surface of the body 3B of the epoxy unit 3. An anticorrosion layer 49 for waterproofing is provided on the outer periphery of the metal case 15.

In this embodiment, the metal case 15 is a box-shaped case body fitted and fitted to the right side surface and the central outer peripheral surface of the body 3A except for the cylindrical portion 3B of the epoxy unit 3 in FIG. 15A and a case cover 15 fitted to the left side of the body 3A except for the cylindrical portion 3B of the epoxy unit 3.
B. Case body 15A and case lid 15B
Are integrally joined by a bolt 15C.

In the epoxy unit 3, an annular shoulder portion 3a is formed at a connecting portion where the cylindrical portion 3B is connected to the body portion 3A, and the inner surface 3b of the case body 15A and the shoulder portion 3A are formed.
a space 3c is formed between the ring-shaped space 3a and the space 3c, and a conductive elastic member, in this embodiment, a conductive elastic ring 51 which is a ring-shaped disk-shaped conductive flat packing. Is arranged.

Therefore, as shown in FIG. 6, when the metal case 15 is mounted on the outer periphery of the epoxy unit 3,
Since the conductive flat packing 51 is disposed in the space 3c as an elastic ring storage groove formed around the outside of the connection part of the B with the body 3A, the epoxy unit 3 and the metal case 15 are electrically conductive flat packing. 51, the epoxy unit 3 and the metal case 15 can be maintained at the same potential, and the two are not electrically floated, that is, in a floating state. Can be improved in electrical characteristics.

Further, in the prefabricated joint 1 having the above configuration, as described above, the conductive layer 3 on the surface of the epoxy unit 3
0 and the metal case 15 are electrically connected by a conductive flat packing 51, and the conductive flat packing 51 is
Space 3 between metal case 15 and epoxy unit 3
It is possible to effectively prevent water from entering from inside c into the inside of the epoxy unit. Therefore, the prefabricated joint 1 having the configuration of the present embodiment can be suitably used as a power cable connecting portion to be installed in a manhole or the like which is supposed to be submerged.

As the material of the conductive flat packing, as described in Embodiment 1, a material obtained by mixing carbon into silicone rubber or EP rubber to make it conductive is preferable.
In this embodiment, the conductive flat packing 51 has an outer diameter of 158.
mm, the inner diameter was 143 mm, and the wall thickness was 3 mm, and good results could be obtained by arranging them in the annular space 3c.

Embodiment 3 FIG. 8 shows another embodiment of the prefabricated joint 1 to which the present invention is applied. In this embodiment, the prefab joint 1
Are the same Y-branch joints (Y-branch connection portions) as described in the second embodiment.
In the structure and application location of Therefore, components having the same structure and operation as those described in Example 2 are denoted by the same reference numerals, and detailed description thereof will be omitted.

According to the Y-branch connection portion 1 of the present embodiment, the epoxy unit 3 is connected to the two parallel cylinder portions 3B, 3B located on the right side of FIG. The cushion member with the braided wire as the conductive elastic member 51 is disposed in a space defined by the outer surface 3a of the case body and the inner side surface 3b of the case body 15A, that is, in the storage groove 3c. Of course, a conductive paint (silver paint) is applied to the outer surface 3a of the epoxy unit 3 on which the conductive elastic member 51 is disposed, and the conductive layer 30 is formed.

Although the cushion material 51 with a braided wire can have any shape, in the present embodiment, as shown in FIG. 9, a cross section is formed by a flat plate 51A and a curved portion 51B having a radius R. It is formed by a crescent or semicircular elastic hollow tube which is a so-called kamaboko-shaped hollow body and a braided wire 51C wound around the outer periphery of the elastic hollow tube. As the elastic hollow tube, EPDM (ethylene-propylene-diene rubber) can be used. Specifically, the present invention is not limited to this, but the thickness (t) is 5 mm and the width (W). Is 19 mm, the height (H) is 21 mm, and the length (L) is 100 mm. As the braided wire, a braided copper wire formed by knitting 2816 0.1 mm copper wires into a tube shape can be used.

Therefore, as shown in FIG. 8, when the metal case 15 is mounted on the outer periphery of the epoxy unit 3, the cushion material 51 with a braided wire as a conductive elastic member is disposed in the storage groove 3c. And epoxy unit 3,
The metal case 15 is electrically contacted via the braided cushion material 51, and the epoxy unit 3, the metal case 1
5 can be kept at the same potential, and the two can be kept in an electrically floating state, that is, in a floating state, and the electrical characteristics of the prefabricated joint 1 can be improved.

Further, the cushion material 5 with a braided wire of the present embodiment
1 can be freely changed in its shape, and therefore can be easily arranged in a gap portion of any shape to be electrically connected.

Of course, as described in the second embodiment,
A conductive flat packing 51 as a conductive elastic member is provided between the cylindrical portion 3B of the epoxy unit 3 and the metal case main body 15.
The waterproofness can also be improved by providing.

[0063]

As described above, the present invention comprises an internal conductor and an insulating unit integrally formed of an insulating material around the internal conductor and having a conductive layer on the outer surface, and a connection hole for the internal conductor. In a prefabricated joint for connecting a cable by attaching a cable connecting material to a connection receiving hole formed by a receiving hole of the insulating unit and a receiving hole of the insulating unit, a metal case is disposed integrally on an outer periphery of the insulating unit. Since the conductive elastic member is arranged between the insulating unit and the metal case, and the insulating unit and the metal case are electrically connected, (1) the insulating unit and the metal case can be easily configured. Electrical connection can be made to prevent the deterioration of the electrical characteristics, and furthermore, small size, light weight, low cost, and high reliability. (2) Water can be completely prevented from entering from the outside, and the insulation unit, the outer case, the adapter and the like are electrically connected to have the same potential, and the insulation unit is in an electrically floating state. And the electrical characteristics can be prevented from deteriorating. Further, the device is small, lightweight, low-cost, and highly reliable. Such an effect can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a prefabricated joint according to the present invention.

FIG. 2 is a partially enlarged sectional view of the prefabricated joint of FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a cable tip conductor connecting portion provided with a retaining device.

FIG. 4 is a cross-sectional view illustrating a configuration of a cable tip conductor connection portion provided with a retaining device.

FIG. 5 is a sectional view of a prefabricated joint to which the present invention can be applied.

FIG. 6 is a sectional view showing another embodiment of the prefabricated joint according to the present invention.

FIG. 7 is a front view of the prefabricated joint of FIG. 6;

FIG. 8 is a sectional view showing another embodiment of the prefabricated joint according to the present invention.

FIG. 9 is a perspective view of one embodiment of a conductive elastic member.

FIG. 10 is a schematic sectional view of a conventional Y-branch connection portion.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cable connection part 2 Inner conductor (embedded electrode) 3 Insulation unit (Epoxy unit) 4A, 4B cable 10 Inner plug 11 Outer plug 13 Contact (multi-ram band) 14 Detention device 15 Outer case 20A, 20B Connection receiving hole DESCRIPTION OF SYMBOLS 21 Cylindrical connection hole 22 Tapered receiving hole 40 Tip conductor part 41 Protection fitting 42 Compressor 43 Press fitting 44 Stress cone 45 Adapter 51 Conductive elastic member 100A, 100B, 100C Cable connection material

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5G375 AA02 BA26 BB03 BB24 BB28 BB81 CA02 CA18 CB05 CB14 CB27 CB36 CB38 CB47 CB53 DB09 DB26 DB35

Claims (11)

[Claims] An internal conductor, and an insulating unit integrally formed of an insulating material around the internal conductor and having a conductive layer on an outer surface, wherein a connecting hole of the internal conductor and a receiving hole of the insulating unit are provided. In a prefabricated joint for connecting a cable by attaching a connection material of a cable to a connection receiving hole formed by forming, a metal case is disposed integrally on an outer periphery of the insulating unit, and the insulating unit and the metal case are arranged. A prefabricated joint, wherein a conductive elastic member is arranged between the prefabricated joint and the insulating unit and the metal case. 2. A metal adapter for attaching the connection material is attached to an end of the insulating unit, the conductive elastic member is a conductive elastic ring, and the insulating unit and the metal case. And disposing the conductive elastic ring between the adapter and the adapter, sealing the insulation unit, the metal case and the adapter, and maintaining the insulation unit, the metal case and the adapter at the same potential. The prefabricated joint according to claim 1, wherein: 3. An outer peripheral portion of an end surface of the insulating unit is chamfered, an annular O-ring housing groove is formed between the chamfered portion and the metal case, and the conductive portion is formed in a space of the O-ring housing groove. 3. The prefabricated joint according to claim 2, wherein an elastic ring is arranged. 4. The prefab joint according to claim 3, wherein the O-ring housing groove has a triangular cross section. 5. The prefabricated joint according to claim 1, wherein the prefabricated joint is a linear joint, and the connection receiving holes are formed to face each other. 6. The adapter according to claim 2, wherein the adapter is attached to both ends of the insulating unit by screwing to both ends of the metal case protruding from an end surface of the insulating unit. The prefabricated joint according to the item. 7. The prefabricated joint is a Y-branch joint, and one connection receiving hole is formed on one side of the insulating unit, and two connection receiving holes are formed on the other side in parallel with each other. Prefabricated joint. 8. The insulating unit includes a body in which the inner conductor is arranged, and a tubular portion in which a receiving hole for receiving the connection material is formed. A box-shaped case body fitted and fitted to one side and a central outer peripheral surface of the trunk except for the tubular part, and fitted and fitted to the other side of the trunk except for the tubular part of the insulating unit. A case lid, wherein the case body and the case lid are integrally connected by bolts, and the outer periphery of a connection portion of the insulating unit with respect to the trunk portion of the cylindrical portion and the case body. The prefabricated joint according to claim 7, wherein the conductive elastic member is arranged between the prefabricated joints. 9. The conductive elastic member is a conductive elastic ring, which seals between the insulating unit and the metal case, and holds the insulating unit and the metal case at the same potential. The prefabricated joint of claim 8, wherein 10. The prefabricated joint according to claim 8, wherein the conductive elastic member is a cushion material with a braided wire, and maintains the same potential between the insulating unit and the metal case. 11. The cushioning material with a braided wire includes an elastic hollow tube having a hollow body having a crescent or semicircular cross section, and a braided wire wound around the outer periphery of the elastic hollow tube. 11. The prefabricated joint according to claim 10, wherein the joint is formed.