JP2000350325A - Connection of electric cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate subsequent shaping treatment by forming a fixed clearance between the surface of a cable insulator to be connected and an inserting hole in a supplementary insulator in connecting an electric cable such as a CV cable with the supplementary insulator, and eliminating the clearance at the end of the supplementary insulator. SOLUTION: An inserting hole 30 in a supplementary insulator 11 is formed so as to meet a cable outer diameter R within the range of a distance A from the end thereof and so that a taper 32 may be formed within the range of a distance B. For a cable insulator, a portion 35 not to be cut is formed within the range of a distance C, and a taper having a fixed gap W is formed between the inserting hole and it over a conductor exposed part. When the front end of the cable is inserted into the inserting hole 30, the cable is assembled so that the hole diameter of the end part of the inserting hole and the outer diameter of the cable insulator may roughly meet each other, thereby facilitating the subsequent treatment for the end part 20 of the supplementary insulator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for forming an intermediate connection between power cables of different sizes, and more particularly to an apparatus for easily connecting cables inside a pre-molded reinforcing insulator.

[0002]

2. Description of the Related Art When constructing an underground high-voltage power transmission line using a rubber / plastic power cable such as a CV cable or the like, a cable is carried into a tunnel from a manhole or the like and an intermediate connection portion is formed in the manhole. Then, a long transmission line is formed. In order to form the intermediate connection portion, it has been proposed to use a resin-made pre-molded insulator prepared in advance in a factory or the like as disclosed in, for example, Japanese Patent Application Laid-Open No. 9-117029. In the conventional example, the pre-molded insulator is positioned at the cable conductor connection portion, and then externally heated and pressurized, so that the pre-molded insulator can be integrated as in the case of extrusion molding.

[0003] The prefabricated connecting portion formed as described above is configured as shown in FIG. 3. In order to form the prefabricated connecting portion 10, FIGS.
5C and the steps shown in FIGS. 5A and 5B. In the prefabricated connecting portion 10 shown in FIG. 3, the two cables 1 and 1a to be connected are such that the conductors 2 and 2a are respectively exposed at their distal ends by a predetermined length, and the cable insulator 3 and the cable outer semiconductive layer. 4, and the shielding layer 5 and the like are exposed to a predetermined length. And the cable conductors 2, 2
Conductor connectors 7 and 7a are fixedly attached to the distal end of a, respectively, and connectors 8 and 8a for directly connecting two conductor connectors are attached to the distal end of the conductor connector. Therefore, by the above operation, the conductor connector is positioned via the conductor contact 13 and the electrical conduction is set.

As an insulator corresponding to the cable connecting portion, a reinforcing insulator 11 made of rubber or plastic is arranged on an outer peripheral portion of the connecting portion. For example, as an uncrosslinked polyethylene tubular member, A reinforcing insulator is formed, and a conductor contact 13 and a high-voltage shield electrode 12 are arranged inside a central portion corresponding to a portion where the conductor connector is connected. The reinforcing insulator 11 has a cylindrical shape at the center and has tapered tapered ends at both ends. A hole is formed through the center of the cross section of the cylinder, and a cable is inserted from both sides of the through hole. Insert and position.

[0005] In the prefabricated connecting portion 10 constituted by the reinforcing insulator 11, an outer semiconductive layer 14 is formed around the prefabricated reinforcing insulator 11, and the outer semiconductive layer 14 is provided outside the cable. It is connected to the semiconductive layer 4. Further, a space between the protective tube 16 and the reinforcing insulator 11 is filled with the waterproof mixture 15, an insulating tube 17 is disposed at the center of the protective tube 16, and a cable sheath is provided at both ends of the protective tube 16. The waterproof layers 19 and 19a are disposed between the prefabricated connection portion 6 and the inside of the prefabricated connection portion 10, respectively. Further, an insulating tube 17 is disposed on the outer peripheral portion at the center of the prefabricated connecting portion 10 and the protective tube 1 is provided.
6, terminal seats 18 are arranged at arbitrary intervals to constitute a means for connecting to a ground.

[0006] In forming the prefabricated connection portion 10, the order of the processing operation on the end of the cable, the operation of forming the conductor connection portion via the reinforcement insulator 11, and integrating the connection portion with the reinforcement insulator. Will be described with reference to FIGS. First, as shown in FIG.
After correcting the bending of the end of the cable and forming it into a straight state, the corrugated sheath 6 is removed to expose the outer shielding layer 5, and the cable insulator 3 and the cable outer semiconductive layer 4 are respectively An operation of stripping each member is performed so as to expose a predetermined length. Next, as shown in FIG. 2B, the insulator 3 is stripped so that the cable conductor 2 is exposed for a predetermined length, and the end of the insulator 3 is formed into a tapered shape toward the conductor. Do.

Thereafter, as shown in FIG. 1C, the conductors 2 and 2a of the two cables 1 and 1a to be connected are
The conductor connectors 7 and 7a are attached, respectively. A conductor is inserted into a hole provided in the conductor connector, and the conductor connector and the cable conductor are compressed in a state where pressure is applied from the surroundings to crush the conductor. Then, after fixing the conductor connectors 7 and 7a to the conductors 2 and 2a, the protrusions on the surface of the conductor connectors are cut off and modified into a cylindrical shape, and can be accommodated inside the reinforcing insulator 11. State. Further, the conductor connectors 7, 7
The connecting members 8 and 8a are attached to the respective distal ends of the terminals a so that the conductor connectors 7 and 7a can be connected to each other via the connecting members while the conductor connectors 7 and 7a are abutted against each other.

As the connecting tool, for example, Japanese Unexamined Patent Publication No.
Although a connecting member such as that described in JP-A-307421 can be used, any other connecting means can be used. When the conventional connecting device is applied to the present embodiment, one of the connecting members 8 and 8a attached to the distal ends of the two cable conductors is provided with a locking member on one protruding member and the other is provided with a locking member. It is possible to provide a configuration in which a concave portion for receiving the protruding member and a locking means are provided at a distal end portion of the connection tool. Then, by using the connecting tool as described above, the two cables are inserted into the reinforcing insulator, and the ends of the conductors are automatically connected at the connecting tube portion,
Electrical conduction can be set at the same time.

As shown in FIG. 4C, after the conductor connectors 7 and 7a are attached to the ends of the two cable conductors, respectively, as shown in FIG. The distal end of the cable 1 a is inserted from one of the through holes of the body 11, and the conductor connector 7 a is positioned with respect to the conductor contact 13. Next, as shown in FIG.
By inserting another cable 1 from the other one of the through holes and positioning the two conductor connectors 7 and 7a at the center of the reinforcing insulator 11 so as to face each other,
8a is connected at the center of the conductor contact 13 so that the operation of fixing the two conductors together and the operation of establishing electrical continuity are automatically performed.

After the connection as shown in FIG. 5 (B) is made, the outer semiconductive layer of both cables and the outer semiconductive layer of the reinforcing insulator are connected to each other, not shown, to form a heating / pressurizing vessel. Is used to crosslink the rubber / plastic material of the reinforcing insulator, and to integrate the cable insulator and the reinforcing insulator. Thereafter, a prefabricated connecting portion 10 as shown in FIG. 3 is formed by arranging the connecting cylinder around the periphery thereof with a waterproof mixture. In this embodiment, the cables 1 and 1a are made of a metal corrugated sheath 6.
However, the cable may be a CV cable or the like having no corrugated sheath.

[0011]

When the cable connecting portion is formed through the steps described above, the reinforcing insulator 11 is used.
As shown in FIG. 6, the relationship between the insertion hole 11a provided in the cable and the cable 1 is set such that the cable outer diameter R has a difference of about 2 mm from the inner diameter R1 of the insertion hole of the reinforcing insulator 11. You. As described above, since the outer diameter of the cable is small, the cable can be easily inserted into the insertion hole 11a of the reinforcing insulator. A gap 23 of about 2 mm is formed outside the cable inserted into the insertion hole 11a. If the thickness of the block end 20 of the reinforcing insulator 11 is 1 mm, the reinforcing insulator Since a step of 3 mm is generated between the end of the cable and the cable surface, in order to eliminate the step, as shown in FIG. Means are used to form a gentle taper between the outer surface and the cable outer diameter.

However, as shown in FIG. 7, when the shrink tube 25 is wound in order to eliminate a step, and then a heating and compressing action is applied to the reinforcing insulator, the material of the shrink tube melts first and the gap 23 is formed. And the reinforcing insulator is compressed in a state where the biting portion 25a is formed in the gap. Therefore, even if the process of heating and compressing the reinforcing insulator is performed to reduce the inner diameter of the insertion hole and bring the cable into close contact with the outer surface of the cable, the bite portion 25a of the shrink tube may be interposed at the end of the reinforcing insulator. And the problem of impairing the characteristics of the reinforcing insulator occurs. Therefore, in order to solve the above-mentioned problem, it has been considered that the end portion 20 of the reinforcing insulator is covered with polyethylene, and a shrink tube is disposed thereon to perform heat shrinking to form the shape. Then, by pouring the same material (for example, polyethylene) as the constituent material of the reinforcing insulator into the gap, the performance of the reinforcing insulator as an insulator can be maintained. However,
Due to the need for a long working time, there remains a problem that the working efficiency for configuring the cable connecting portion is not good.

In order to solve the above-mentioned problem, the inventors of the present invention disclosed a technique disclosed in Japanese Patent Application Laid-Open No. Hei 10-234119, in which an effect of locally heating the end of a reinforcing insulator was added. Then, an end treatment method for making the end of the reinforcing insulator adhere to the outer surface of the cable was proposed. In the example shown in the above publication, as shown in FIG. 8, after the cable 1 is inserted into the hole of the reinforcing insulator 11, the end 20 of the reinforcing insulator 11 is heated using a heating means, and Part 2
The portion 21 that has been softened is brought into close contact with the surface of the cable insulator 3. After the heat treatment, the shrink tube 25 is disposed to further apply a heating effect, so that a step is not formed at the connection between the end of the reinforcing insulator and the cable insulator. Can be. However, when applying the above method,
It is necessary to separately prepare a heating device, and by arranging many devices of different types of work in a narrow work space such as a manhole, a workability problem or the like may newly occur. Therefore, at present, a method for easily processing the end portion of the reinforcing insulator and easily performing the operation of forming the cable connection portion has been sought.

The present invention solves the above-mentioned problem of processing at the end of the conventional block, and the shape of the through hole provided in the block in advance is adapted to the shape of the end of the cable. It is an object of the present invention to provide a method in which a cable can be inserted into a cable and the end of the reinforcing insulator can be easily processed.

[0015]

According to the present invention, a high-voltage shield electrode and a conductor contact are arranged at the center of an insertion hole of a block-shaped reinforcing insulator, and a tip end of a cable conductor inserted from both sides of the insertion hole. The present invention relates to an intermediate cable connecting portion formed by connecting the conductor connectors provided in the above-mentioned manner in a state where the conductor contacts are abutted on each other. The invention according to claim 1 of the present invention is characterized in that an insertion hole provided in the reinforcing insulator is formed over a predetermined range from an end of the insertion hole, and a horizontal portion having the same diameter as the outer diameter of the cable insulator to be inserted. A taper portion having a diameter gradually reduced from the end of the horizontal portion to the high-voltage shield electrode, and the cable insulator to be inserted into the insertion hole is formed from the end of the insertion hole. An uncut portion formed at a shorter interval than the horizontal portion of the insertion hole, and a tapered portion cut so as to have a fixed gap with respect to the tapered portion of the insertion hole are provided, and the insertion hole of the reinforcing insulator is provided. When a cable is inserted into a cable insulator, the surface of the portion of the cable insulator that is not cut in the final stage of insertion is brought into close contact with the insertion hole.

According to a second aspect of the present invention, in the insulator of a cable to be inserted into the insertion hole of the reinforcing insulator, the insertion hole is formed through an inclined portion cut in a tapered shape from a portion which is not cut to a tapered portion. A flat portion that forms a constant gap between the horizontal portion and the horizontal portion. The invention according to claim 3 is that, after a cable is inserted into the insertion hole of the reinforcing insulator to electrically connect the conductors, an end of the reinforcing insulator is shaved, and It is characterized in that processing is performed so as not to cause a step between the end portion and the cable insulator.

By combining the reinforcing insulator and the cable configured as described above, a gap is not formed between the end of the reinforcing insulator and the insulator on the cable surface at the time of connecting the cable. At the final stage of insertion, the cable insulator will be in close contact with the insertion hole,
Subsequent processing operations can be easily performed. Also,
By cutting the end of the reinforcing insulator after making the connection, there is no step between the reinforcing insulator and the cable insulator, so there is no need to perform a process of winding tape or the like around the end, simplifying the work. can do.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for connecting a power cable according to the present invention will be described with reference to the illustrated example. In the example shown in FIG. 1, similarly to the example shown in FIG. 5B, the cable to be connected is inserted into the insertion hole 30 of the reinforcing insulator 11 from both ends, and the inside of the conductor contact 13 is Indicates a state where the conductor connectors are connected so as to abut each other. In FIG. 1, the shape of each component is shown in a state where a cable is inserted into the reinforcing insulator, which is described before a heating / pressing action is applied to the reinforcing insulator. I have. In this embodiment, a horizontal portion 3 having an inner diameter substantially equal to the outer diameter R of the cable is provided in the insertion hole 30 provided through the center of the reinforcing insulator 11 so as to extend from the end to the interval A.
1 is provided in the range of the interval A, and a tapered portion 32 is formed over the interval B between the end of the horizontal portion and the end of the high-voltage shield electrode.

In the cable to be inserted into the insertion hole 30 of the reinforcing insulator, the conductor connector 7 is attached to the tip of the conductor 2 and the cable insulator is provided at a slight distance from the attachment portion of the conductor connector. A tapered portion 38 is formed by cutting the three surfaces to form a tapered shape. Then, a gap W having a constant interval is formed between the reinforcing insulator 11 and the tapered portion 32 of the insertion hole. Further, in a state where the cable is mounted on the reinforcing insulator, a portion 35 that is not cut is provided from the end portion 20 of the reinforcing insulator toward the inside by a distance C as a portion where the cable insulator is not cut. Further, the tapered portion 38 and the non-cut portion 3
5, a flat portion 37 having a gap W is provided in the range of the interval E in correspondence with the horizontal portion of the insertion hole, and the flat portion 37 and the non-cut portion 35 are formed at an arbitrary angle. The formed inclined portion 36 is provided over the interval D.

In a state where a cable is inserted into the insertion hole of the reinforcing insulator formed as described above to form a connection portion, the inner surface of the insertion hole of the reinforcing insulator is moved from the end of the insertion hole to the inner surface of the insertion hole. In the range of the interval C, the cable insulator 3 is in contact with the horizontal portion 31 of the insertion hole, but the cut portion 35 and the inclined portion 3 are not cut.
A constant interval W is set between the surface of the cable insulator 35 and the insertion hole with respect to the insertion hole extending from the boundary portion 6 to the high-voltage shield electrode. Therefore, when a cable obtained by cutting the high-voltage shield electrode 3 into a tapered shape with respect to the insertion distal end is inserted into the insertion hole 30 of the reinforcing insulator, a portion 35 that is not cut at the final stage of the insertion is inserted. A large sliding resistance is generated only at a portion where the sliding portion slides on the horizontal portion 31 of the insertion hole. However, for example, by performing a process such as applying a lubricant so as to reduce the sliding resistance to a portion corresponding to the portion of the cable insertion portion that is not cut, the diameter is substantially equal to the inner diameter of the insertion hole. It is possible to easily perform an operation of inserting a portion of the outer diameter (diameter R) that is not cut.

As described above, a cable is inserted into the insertion hole 30 of the reinforcing insulator 11 and the conductor connector provided at the conductor tip is connected to the other end of the cable inserted from the other via the conductor contact 13. After connecting to the conductor connector, a step is formed at the tip of the end portion 20 of the reinforcing insulator. That is, the tip 20 of the reinforcing insulator cannot be shaped into a knife edge, and it is inevitable that a step of 1 to several mm is formed. Therefore, after inserting the cable into the distal end portion of the reinforcing insulator, as shown in FIG. 2, a cutting process is performed to form a cut portion 33. When machining the cutting section 33,
A knife or any other knife, or shaving using the edge of a piece of glass, shaping the slope of the end of the reinforcing insulator, the step between the end 20 and the surface of the cable insulator Perform processing to prevent formation. And, as described above, by performing shaping processing on the end portion of the reinforcing insulator, when the insulator is thereafter configured to cover the surface of the reinforcing insulator, the work of processing the end portion can be easily performed. To be able to do.

In the above embodiment, the horizontal portion and the tapered portion provided in the insertion hole of the reinforcing insulator can be formed over an arbitrary length. Therefore, it is necessary to set an interval with the tapered portion 38 provided on the cable insulator. Further, the flat portion 37 provided on the cable insulator does not always need to be provided, and a portion corresponding to the flat portion may be formed, for example, with the interval D,
It can be formed as a portion having a constant inclination angle over E. Then, after performing the connection as shown in FIG. 1, a heating / pressing member is attached to the reinforcing insulator, and pressure is applied from the surroundings while heating at a predetermined temperature,
Cross-linking of rubber and plastic materials is performed, the cable insulator and the reinforcing insulator are integrated without gaps to form a connection, and an insulation coating or protection member is placed around the connection to complete the prefabricated connection. To do.

[0023]

According to the present invention, a gap is formed between the end of the reinforcing insulator and the insulator on the cable surface when the cable is connected by combining the reinforcing insulator and the cable configured as described above. Without being
Since the cable insulator comes into close contact with the insertion hole at the final stage of cable insertion, the subsequent processing can be easily performed. Also, after connecting the cable,
By cutting the surface of the end of the reinforced insulator, there is no step between the surface and the cable insulator, so there is no need to perform a process of winding a tape or the like around the end, and the cable connection work can be simplified. it can.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of a prefabricated connection section of the present invention.

FIG. 2 is an explanatory diagram showing processing of an end portion of a reinforcing insulator.

FIG. 3 is an explanatory diagram illustrating a configuration of a general prefabricated connection unit.

FIG. 4 is an explanatory diagram of a process of processing a cable and attaching a conductor contact.

FIG. 5 is an explanatory diagram of a step of inserting and connecting two cables to a reinforcing insulator.

FIG. 6 is an explanatory diagram of conventional edge processing.

FIG. 7 is an explanatory diagram of the problem in FIG. 6; .

FIG. 8 is an explanatory diagram of another example of the conventional edge processing.

[Explanation of symbols]

1 cable, 2 cable conductors, 7 conductor contacts, 8 connectors, 10 prefabricated connections,
11 Reinforced insulator, 12 High voltage shield electrode, 1
7 insulating cylinder, 20 insulator end, 21 shaped end, 23 gap, 25 shrink tube,
25a biting portion, 30 insertion hole, 31
Horizontal part, 32 taper part, 33 cutting part,
35 Uncut part, 36 Inclined part, 37
Flat part, 38 taper part.

Claims (3)

[Claims] 1. A high-voltage shield electrode and a conductor contact are arranged at the center of an insertion hole of a block-shaped reinforcing insulator, and a conductor connector provided at a tip of a cable conductor inserted from both sides of the insertion hole is provided. In a cable intermediate connecting portion configured to be connected in a state where the conductor contacts are in contact with each other, an insertion hole provided in the reinforcing insulator is formed over a predetermined range from an end of the insertion hole, and a cable to be inserted. A horizontal portion having the same diameter as the outer diameter of the insulator; and a tapered portion having a diameter gradually reduced from an end of the horizontal portion to a high-voltage shield electrode, and a cable insulation to be inserted into the insertion hole. The body has an uncut portion formed at an interval shorter than the horizontal portion of the insertion hole from the end of the insertion hole, and a taper cut so as to have a constant gap with respect to the tapered portion of the insertion hole. Department Only, when inserting the cable into the insertion hole of the reinforcing insulator, connection of the power cable, characterized in that adhering the surface of the cutting process and not part of the cable insulation at the final stage of insertion into the insertion hole. 2. The insulator of a cable to be inserted into the insertion hole of the reinforcing insulator, the tapered portion being cut from a portion not subjected to the cutting process to a tapered portion. The power cable connection method according to claim 1, further comprising providing a flat portion that forms a predetermined gap between the power cables. 3. After the cable is inserted into the insertion hole of the reinforcing insulator and the conductors are electrically connected, an end of the reinforcing insulator is shaved to obtain an end of the reinforcing insulator. The method for connecting a power cable according to claim 1, wherein a process is performed so that a step is not generated between the cable and the cable insulator.