JPH10145956A - Connection of power cable and method for connecting power cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pull a power cable into an underground culvert through a manhole at each connection, by making the outside diameter of the connections equal to that of the other portions and ensuring the tensile strength of the connections. SOLUTION: The outside diameter of a connecting sleeve 6a placed across a pair of conductors 3, 3 is made equal to the outside diameter of the conductors 3, 3. The tips of the outermost ones 2, 2 of a large number of strands 2, 2 comprising the conductors 3, 3, are removed. The inner circumference of the connecting sleeve 6a and the outside circumference of the conductors 3, 3 are anchored to each other in the axial direction by means of plastic deformation resulting from the connecting sleeve 6a's being pressed inward in the direction of diameter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power cable connecting portion and a connecting method, and more particularly to an improvement in a portion connecting end portions of a high-voltage power transmitting cable disposed in an underground passageway or the like.

[0002]

2. Description of the Related Art A high-voltage power transmission cable installed in an underground passageway or the like has a conductor formed by bundling a plurality of strands each made of a conductive metal into a circular cross section, and covering the periphery of the conductor. And an insulating layer. For example, FIGS.
-238411, one of the power cables 1
An example is shown. As shown in FIG. 9, a number of strands 2, 2 made of a metal material having a low resistance value, such as copper or a copper-based alloy, are arranged concentrically over a plurality of layers and spirally. The conductor 3 is bundled in a twisted state. An insulating layer 4 is provided around the conductor 3, and a cable sheath 5 is provided around the insulating layer 4. In addition, each said wire 2
An insulating film is provided on the surface to suppress an increase in power transmission loss due to a skin effect. The insulating function required of the insulating film is limited, and in the case of an actual power cable, the insulating film uses an oxide film of a metal constituting each of the wires 2.

[0003] The power cable 1 as described above is long in itself, but needs to be connected on the way. For this reason, conventionally, the conductors 3, 3 of two adjacent power cables 1, 1 have been connected to each other by a structure as shown in FIG. The ends of the two power cables 1, 1 to be connected are
The conductors 3 and 3 are exposed by peeling and removing the cable sheath 5 (FIG. 8). A connecting sleeve 6 made of metal such as copper or aluminum and having a small resistance is externally fitted to the conductors 3 and 3, and the conductors 3 and 3 are connected to each other via the connecting sleeve 6.

Prior to fitting the connection sleeve 6 outside, the insulating film on the surfaces of the wires 2 constituting the conductors 3 is peeled off. As shown in FIG. 11, this stripping work is performed by loosening the wires 2 and 2 constituting the ends of the conductor 3 exposed from the insulating layer 4 and the cable sheath 5, and then, the loosened portions are made of abrasive grains such as quartz sand. By sandblasting. After the insulating film on the surface of each of the wires 2 and 2 is peeled in this manner, the wires 2 and 2 are tightly bundled again to form the conductor 3. These series of operations are performed for both the pair of power cables 1 to be connected to each other. The wires 2, 2 from which the insulating film on the surface was peeled off in this manner
As shown in FIG. 10, the conductors 3, which are bundled with each other, have their end faces abutted with each other or are brought close to each other. At this time, the connection sleeve 6 is externally fitted so as to bridge between the conductors 3.

Further, the connection sleeve 6 is pressed toward the outer peripheral surfaces of the conductors 3 and 3. As shown in FIGS. 12 and 13, this pressing operation is performed by pressing the connecting sleeve 6 inwardly in the diametric direction a plurality of times from different directions using the tightening tools 7 and 7a. By such a pressing operation, the inner peripheral surface of the connection sleeve 6 and
A large number of strands 2, 2 (FIG. 1)
In (0), a part of the outer peripheral surfaces of the outermost wires 2 and 2 are in close contact with each other, and the outermost wires 2 and 2 and the connection sleeve 6 are electrically connected to each other. Further, the outer peripheral surfaces of these several strands 2 and 2 are in close contact with each other, and the adjacent strands 2 and 2 are electrically connected to each other. As a result, each of the plurality of strands 2, 2 constituting each of the conductors 3, 3 is electrically connected to the connection sleeve 6. After the conductors 3, 3 are connected to each other by the connection sleeve 6, a cover (not shown) for insulation is attached around the conductors 3, 3 and the connection sleeve 6.

[0006]

In the case of the connection portion of the conventional power cables 1 and 1 shown in FIG. 10, an insulating film on the surface of each of the wires 2 and 2 is applied to the ends of the conductors 3 and 3, respectively. Other than peeling, no special processing is performed, and as the connection sleeve 6,
Except for both ends, the one having a uniform thickness was used. For this reason, even after the connection operation is completed, the outer peripheral surface of the connection sleeve 6 projects diametrically outward from the outer peripheral surface of each of the conductors 3, 3. The diameter increases. For this reason, the outer diameter of the insulator or the like that covers the periphery of the connecting portion also becomes large, and the outer peripheral surface of the connecting portion protrudes radially outward from the outer peripheral surface of the cable sheath 5. As a result, a plurality of power cables 1
When connecting through the manhole while connecting on the ground surface,
There is a possibility that the connection portion of the cable may be caught on the upper and lower opening peripheral edges of the manhole. Moreover, conventionally, the outer peripheral surfaces of the conductors 3, 3 and the inner peripheral surface of the connection sleeve 6 do not or do not slightly engage with each other in the axial direction. The state was mainly frictional engagement. Therefore, when a large force acts between the conductors 3 and 3 and the connection sleeve 6 in the pulling direction, the conductors 3 and 3 may come off from the connection sleeve 6.

Therefore, conventionally, a plurality of power cables 1,
The power cables 1, 1 adjacent to each other in the manhole or the cave could not be connected to the underground cave through the manhole while connecting the power cables 1 on the ground surface. Therefore, the connection work is performed in a narrow underground space or in a place far from the entrance, and the connection work is troublesome. The connection portion and the connection method of the power cable of the present invention are designed to eliminate such a troublesome cause and reduce the labor required for the connection work.

[0008]

In the power cable connecting portion and the connecting method according to the present invention, the power cable connecting portion according to the first aspect of the present invention is formed by bundling a plurality of strands into a circular cross section. This is for electrically connecting the ends of a power cable including a conductor and an insulating layer covering the periphery of the conductor. The connection portion of the power cable according to the present invention includes a conductor exposed portion formed by exposing the end of the conductor by removing the end of the insulating layer, and an outer layer substantially at the first half of the conductor exposed portion. And a small-diameter stepped portion formed by cutting a plurality of wires constituting the power cable, and the two power cables to be connected to each other, which are externally fitted in a state of being bridged between base exposed portions of the conductor exposed portions. And a substantially cylindrical connection sleeve.
The inner peripheral surface of the connection sleeve is tightly fitted to the outer peripheral surface of the exposed conductor by pressing the connection sleeve diametrically inward toward each of the exposed conductors. Is substantially the same as the outer diameter of the conductor over its entire length. The outer diameter of the small-diameter stepped portion of the conductor exposed portion is large at the base end and the distal end of each small-diameter stepped portion, and is reduced at the intermediate portion. Based on the mating with the peripheral surface,
The displacement of the two small-diameter steps and the connection sleeve in the axial direction is prevented, and the conductors of the two power cables are electrically and physically connected via the connection sleeve.

A power cable connecting method according to a second aspect of the present invention is also directed to a power cable including a conductor formed by bundling a large number of strands in a circular cross section, and an insulating layer covering the periphery of the conductor. The ends are electrically connected to each other.
Such a method for connecting a power cable according to the present invention is characterized in that, by removing the end of the insulating layer, the end of the conductor is exposed to form a conductor exposed portion, and then the plurality of conductors constituting the conductor exposed portion are removed. In a state where the wires are loosened, the insulating film covering the surface of each of these wires is peeled off, and a plurality of wires constituting the outer layer of the first half of the exposed portion of the conductor are cut off to remove the small diameter step. Make up the part. Then 2 to be connected to each other
The conductors of the power cables are opposed to each other in a state in which the plurality of strands are returned from the loosened state to the original state. The diameter is changing in a direction to become smaller toward the edge, the outer diameter of the portion near the base end of the small diameter step is the largest,
A substantially cylindrical connection sleeve having an outer diameter at the central portion smaller than the outer diameter of the portion near the base end is externally fitted between the two conductors. Thereafter, by applying a force directed inward in the diametrical direction to the outer peripheral surface of the connection sleeve, the outer diameter of the connection sleeve is adjusted so that the outer diameter of the connection sleeve is reduced in the direction of reducing the diameter of the connection sleeve and each conductor exposed portion. The outer diameter of the small-diameter step is substantially the same as the outer diameter of the conductor over the entire length, and the outer diameter of each of the small-diameter steps is plastically deformed at the base end and the distal end so as to become smaller at the middle part. The surfaces are closely fitted to the outer peripheral surfaces of the pair of exposed conductors. Then, based on the fitting between the outer peripheral surfaces of the two small-diameter steps and the inner peripheral surface of the intermediate portion of the connection sleeve, axial displacement between the two small-diameter steps and the connection sleeve is prevented, and the two power The conductors of the cable are electrically and physically connected via the connection sleeve.

[0010]

According to the power cable connecting portion and the connecting method of the present invention configured as described above, the outer diameter of the connecting sleeve is made equal to the outer diameter of the conductor, and the outer diameter of the connecting portion is reduced. Can be equal to the outer diameter of other parts. In addition, since the outer peripheral surface of the small-diameter step portion and the inner peripheral surface of the intermediate portion of the connection sleeve are fitted in a state of being engaged with the concave and convex portions in the axial direction, based on this fitting, the two small-diameter step portions are engaged. The force for preventing displacement in the axial direction with the connecting sleeve is sufficiently large. By these,
Multiple power cables can be connected to the underground cave through the manhole while being connected at the surface.

[0011]

1 to 6 show an embodiment of the present invention. First, the connection portion of the power cable shown in FIG. 1 will be described. A power cable 1, 1 connected by the connection portion of the present invention includes a conductor 3 formed by bundling a plurality of strands 2, 2 each made of a conductive metal such as copper into a circular cross section, Insulating layer 4 covering the periphery
And In order to constitute the connecting portion of the present invention, the conductors are exposed by removing the ends of the insulating layers 4 constituting the power cables 1 and exposing the ends of the conductors 3. Sections 8 and 8. Small-diameter steps 9 are formed in approximately the first half of the exposed conductors 8 provided at the end of each of the power cables 1. The small-diameter steps 9 cut the plurality of strands 2, which constitute the outermost layer of the conductors 3, at portions near the ends of the strands 2, 2. It is constituted by removing the portions near the front end of 2, 2.

In this manner, the small-diameter stepped portions 9 are formed in the respective first half portions, and the respective conductor exposed portions 8 of the pair of conductors 3, 3 are arranged concentrically and with their leading end surfaces facing each other. , 8 between the proximal ends of the connecting sleeves 6a
Are externally fitted in a state of being bridged between the base ends of the conductor exposed portions 8. This connection sleeve 6a
It is made of a relatively soft metal, such as copper or aluminum, having a small electric resistance and being easily deformed plastically, and is formed in a substantially cylindrical shape.

The inner peripheral surface of the connection sleeve 6a is connected to the outer peripheral surface of the pair of conductor exposed portions 8, 8 by the connection sleeve 6a.
Are pressed tightly toward the conductor exposed portions 8 and 8 inward in the diametrical direction, whereby the conductors are closely fitted. In the fitted state, the outer diameter of the connection sleeve 6a is substantially the same as the outer diameter of each of the conductors 3, 3 constituting the pair of power cables 1, 1 over its entire length. Also, the pair of conductor exposed portions 8, 8
The outer diameters of the small-diameter steps 9, 9 provided in the first half of each of the small-diameter steps 9, 9 are large at the base end and the distal end of each of the small-diameter steps 9, 9, and are small at the middle. In other words, the outer peripheral surface of each of the small-diameter steps 9 is a drum-shaped concave surface. The portion of the inner peripheral surface of the connection sleeve 6a facing the inner peripheral surface of each of the small-diameter steps 9 has a convex surface whose central portion in the axial direction swells inward in the diameter direction. Therefore, the outer peripheral surfaces of the small-diameter steps 9, 9 of the conductors 3, 3 and the inner peripheral surface of the intermediate portion of the connection sleeve 6a are fitted so that the diameter in the axial direction changes. Accordingly, the displacement of the small-diameter steps 9, 9 and the connection sleeve 6a in the axial direction is prevented. Then, based on the fitting or the like, the conductors 3, 3 of the two power cables 1, 1 are electrically and physically connected to each other via the connection sleeve 6a.

Next, a method of connecting a power cable of the present invention for obtaining the above-described power cable connecting portion of the present invention will be described with reference to FIGS. First, each of the insulating layers 4 and 4 and the cable sheath 5 constituting the pair of power cables 1 and 1 to be connected to each other (FIGS.
See 1. Omitted in FIGS. ) Is removed, thereby exposing the ends of the conductors 3 and 3 to expose the conductors 8 and 8.
And Thereafter, the large number of strands 2, 2 constituting the conductor exposed portions 8, 8 of the power cables 1, 1 are brought into the state shown in FIG. 11 by the spatula 10 and the spacer 11 as shown in FIG. Unravel until Then, in this state, the insulating film covering the surface of each of the wires 2 and 2 is peeled off by sandblasting. After this peeling operation is completed, the pair of conductors 3, 3 constituting the two power cables 1, 1 to be connected to each other, are separated from the state in which the large number of strands 2, 2 are loosened, to the original dense state. Return to the bundled state.

Before and after the operation of peeling off the insulating film, small-diameter steps 9 are formed in approximately the first half of each of the exposed conductors 8. The step of forming the small-diameter step portions 9 is performed by connecting the plurality of strands 2, which constitute the outermost layer of the conductors 3, to the middle of the conductor exposed portions 8, respectively. The cutting is performed by cutting the wires 2 and 2 near the ends thereof, and further removing the portions of the wires 2 and 2 near the ends. The operation of forming the small-diameter step portions 9 is performed before unwinding the large number of strands 2 or 2 in order to perform the stripping operation, or after the stripping operation, the large number of strands 9 are formed. This is performed after returning the lines 2 and 2 to the original state.

After performing the above-described work of stripping the insulating film and forming the small-diameter step portions 9, a pair of conductors 3, 3 constituting the two power cables 1, 1 to be connected to each other.
A connecting sleeve 6a is provided between the pair of conductors 3,
3 is externally fitted in a state of being bridged between portions of the conductor exposed portions 8 near the base end. This outer fitting operation is performed after returning the plurality of strands 2, 2 from the loosened state to the original state,
This is performed by bringing the pair of conductors 3 and 3 close to each other from a state where the pair of conductors 3 and 3 are concentric with each other and the end surfaces thereof are opposed to each other.

The connection sleeve 6a has an inner diameter substantially equal over the entire length and a simple cylindrical inner peripheral surface. On the other hand, the outer diameter of the outer peripheral surface of the connection sleeve 6a changes in the axial direction. First, both end portions of the connection sleeve 6a are formed as wedge-shaped conical convex surfaces whose outer diameters change in such a manner that the outer diameter decreases toward the edge.
The two small-diameter stepped portions 9 and 9 are placed at two intermediate positions in the axial direction of the sleeve 6a and between the base-exposed portions of the conductor exposed portions 8 and 8 respectively.
The outer diameter of the portion facing the base end is the largest. The outer diameter of the sleeve 6a at the intermediate portion in the axial direction is slightly smaller than the portion of each of the small-diameter steps 9 facing the base end. Further, a small-diameter cylindrical surface is provided between the portion facing the base end of the small-diameter steps 9 and 9 and the conical convex portion.

Connection sleeve 6a having the above-mentioned shape
Is externally fitted in a state of being bridged between portions of the conductors 3, 3 near the base end of the conductor exposed portions 8, 8, and then diametrically inwardly attached to the outer peripheral surface of the connection sleeve 6 a. Gives you the power you have. Then, the connection sleeve 6a and each of the conductor exposed portions 8, 8 are plastically deformed in a direction to reduce their diameters. In this manner, the work of plastically deforming the connection sleeve 6a and the conductor exposed portions 8, 8 is performed by using the fastening tools 7, 7a to move the connection sleeve 6a from different directions as shown in FIGS. This is done by pressing strongly inward in the diameter direction. Such a pressing operation is performed until the outer diameter of the connection sleeve 6a is substantially equal to the outer diameter of each of the conductors 3, 3 over the entire length thereof, as shown in FIG. When the pressing operation is performed up to this state, as shown in FIG. 1, a part of the multiple wires 2 forming the conductors 3 Is plastically deformed from a circular shape to a hexagonal shape so as to fill the gap. As a result of this plastic deformation, the outer diameter of the small-diameter steps 9, 9 formed on the conductors 3, 3 is large at the base end and the distal end based on the difference in the thickness of the sleeve 6a, and is large at the middle. And become smaller. And
The inner peripheral surface of the connection sleeve 6a and the outer peripheral surfaces of the pair of conductor exposed portions 8, 8 fit tightly.

In the state where the inner peripheral surface of the connection sleeve 6a and the outer peripheral surfaces of the pair of conductor exposed portions 8, 8 are closely fitted in this manner, as shown in FIG. The outer peripheral surfaces of the small-diameter step portions 9 and the inner peripheral surface of the intermediate portion of the connection sleeve 6a are fitted in an uneven manner in the axial direction. Then, based on this fitting, the displacement of the two small-diameter steps 9, 9 and the connection sleeve 6a in the axial direction is prevented, and the conductors 3, 3 of the two power cables 1, 1 are connected to each other by the connection sleeve. 6a
And electrical and physical connections.

According to the power cable connecting portion and the connecting method of the present invention configured as described above, the outer diameter of the connecting sleeve 6a can be made equal to the outer diameter of the conductors 3,3. Therefore, even when the connecting portion is covered with a cover or the like for insulation, the outer diameter of the connecting portion can be made equal to the outer diameter of other portions than the connecting portion. Further, the outer peripheral surfaces of the small-diameter step portions 9, 9 and the two inner peripheral surface positions of the intermediate portion of the connection sleeve 6a are fitted to each other in a state of engaging and recessing in the axial direction. Thus, the force for preventing the displacement of these small-diameter steps 9, 9 and the connecting sleeve 6a in the axial direction becomes sufficiently large.
As a result, it becomes possible to connect a plurality of power cables to the underground cave while connecting them through the manhole.

Since the small-diameter steps 9 are formed by removing the tips of the outermost strands 2 and 2, the small-diameter steps 9 and 9 are connected to the conductors 3 and 3 constituting the power cables 1 and 1. The transfer of electric power to and from the sleeve 6a is performed in a wide range, and the electric resistance of the connecting portion is reduced. The reason will be described below.

When the insulating film covering the surface of the wires 2 is peeled off, the wires 2 are connected to each other as shown in FIG.
As shown in FIG. 1, the wires 2 and 2 cannot be bent extremely much. The reason for this is to consider returning to the original conductor 3 after the peeling operation. For this reason, the insulating layers on the surfaces of the wires 2 and 2 that are present on a part of the surface of the wires 2 and 2 existing on the center side and close to the insulating layer 4 of the wires 2 and 2 It cannot be completely removed. As a result, the insulating film remains on the surfaces of the strands 2 and 2 in the substantially conical portions indicated by the dashed oblique lattice in FIG.

On the other hand, in the conventional structure shown in FIG. 10 described above, the outermost element wire 2,
Only 2 contacts the inner peripheral surface of the connection sleeve 6. Therefore, in the case of this conventional structure, the current flowing through the outermost wires 2 and 2 is transmitted from the longitudinal end of the connection sleeve 6 and the wires 2 and 2 near the center from the substantially conical portion. It flows toward the connection sleeve 6 one after another (or from the connection sleeve 6 toward the strands 2, 2). As a result,
A large part of the current flowing through the connection portion is concentrated on the end of the connection sleeve 6 as indicated by an arrow in FIG. 7, and increases the electric resistance of the connection sleeve 6 as a whole.

On the other hand, in the case of the structure of the present invention, as shown in FIG.
In addition to contacting the inner peripheral surface of the end portion, the second-layer strands 2 and 2 existing inside the outermost layer contact the inner peripheral surface of the intermediate portion of the connection sleeve 6a. Accordingly, in the case of the structure of the present invention, the current flowing through the outermost strands 2 and 2 flows from the longitudinal end of the connection sleeve 6a to the connection sleeve 6a, and the second layer and its The current flowing through the wires 2, 2 existing inside flows from the intermediate portion of the connection sleeve 6 a toward the connection sleeve 6 a. As a result,
The electric current flowing through the connecting portion is dispersed along the length of the connecting sleeve 6a, thereby reducing the electric resistance of the connecting sleeve 6a as a whole.

In FIGS. 2 and 5, a small hole 12 provided at the center of the connection sleeve 6a is used to check whether the pair of conductors 3, 3 has been correctly inserted into the center of the connection sleeve 6a in the longitudinal direction. It is for confirming whether or not. At the time of insertion work,
Wires or the like are inserted into the small holes 12 and the conductors 3 and 3 are inserted until their respective tip surfaces abut against the wires and the like.
Into the connection sleeve 6a. However, such small holes 12 need not necessarily be provided.

[0026]

The connecting portion and the connecting method of the power cable according to the present invention are constructed and operated as described above, so that the outer diameter of the connecting portion is made equal to the outer diameter of the conductor of the other portion.
The tensile strength of this connection can be increased. As a result,
The connection part of the power cable can be handled substantially the same as the main part of the power cable, and the cost required for the work of laying the power cable can be reduced. Further, the power loss can be reduced by lowering the resistance value of the connection portion.

[Brief description of the drawings]

FIG. 1 is a partially cut-away side view showing an example of an embodiment of the present invention in a state after assembly is completed.

FIG. 2 is a partially cut-away side view showing the same in the middle of assembly.

FIG. 3 is a schematic side view showing a state in which a conductor wire is loosened.

FIG. 4 is a side view showing a state where an insulating film remains on a conductor wire.

FIG. 5 is a partially cut-away side view of a connecting sleeve used to implement the present invention.

FIG. 6 is a side view showing a state of current transmission / reception at the connection portion of the present invention.

FIG. 7 is a side view showing a state of transmitting and receiving a current in a conventional connection unit.

FIG. 8 is an end perspective view showing an example of a power cable.

FIG. 9 is a sectional view of a conductor.

FIG. 10 is a partially cut-away side view showing a conventional connecting portion.

FIG. 11 is a perspective view showing a state where strands are loosened.

FIG. 12 is an end view showing a state in which the connection sleeve is pressed in a predetermined direction so as to press the connection sleeve against the conductor.

FIG. 13 is an end view showing the same pressing state in the other direction.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Power cable 2 Element wire 3 Conductor 4 Insulating layer 5 Cable sheath 6, 6a Connection sleeve 7, 7a Tightening tool 8 Conductor exposed part 9 Small diameter step part 10 Spatula 11 Spacer 12 Small hole

Claims (2)

[Claims] 1. A power cable connection for electrically connecting ends of a power cable including a conductor formed by bundling a plurality of strands in a circular cross section and an insulating layer covering the periphery of the conductor. A conductor exposed portion formed by exposing an end of the conductor by removing an end of the insulating layer, and a plurality of strands forming an outer layer substantially in the first half of the conductor exposed portion. And a substantially cylindrical connection sleeve which is fitted over the portion near the base end of each conductor exposed portion of the two power cables to be connected to each other. The inner peripheral surface of the connection sleeve is tightly fitted to the outer peripheral surface of the conductor exposed portion by pressing the connection sleeve diametrically inward toward each of the conductor exposed portions. The outer diameter of the connection sleeve is The outer diameter of the small-diameter stepped portion of the conductor exposed portion is substantially the same as the outer diameter of the conductor, and the outer diameter of the small-diameter stepped portion is large at the base end and the distal end of each small-diameter stepped portion, and is smaller at the intermediate portion. Based on the engagement between the surface and the inner peripheral surface of the intermediate portion of the connection sleeve, the displacement of the two small-diameter steps and the connection sleeve in the axial direction is prevented, and the conductors of the two power cables are connected to each other by the connection sleeve. Power cable connection that is electrically and physically connected through. 2. A power cable connection for electrically connecting ends of a power cable including a conductor formed by bundling a large number of strands in a circular cross section and an insulating layer covering the periphery of the conductor. In the method, after removing the end of the insulating layer to expose the end of the conductor to make a conductor exposed portion,
In a state where the above-mentioned many wires constituting the conductor exposed portion are loosened, the insulating film covering the surface of each of the wires is peeled off, and a plurality of wires constituting the outermost layer of the first half of the exposed conductor portion are removed. By forming a small-diameter step by cutting off the strands of
Then, the conductors of the two power cables to be connected to each other are opposed to each other in a state where the above-mentioned many wires have been returned from the loosened state to the original state, and the inner diameters thereof are substantially equal over the entire length. The outer diameter of the both ends changes in such a direction that the outer diameter decreases toward the edge, and the outer diameter of the small-diameter stepped portion near the base end is the largest, and the outer diameter of the central portion is outside the base-closed portion. After externally fitting a substantially cylindrical connection sleeve smaller than the diameter in a state of being bridged between the two conductors, by applying a force directed inward in the diameter direction to the outer peripheral surface of the connection sleeve, The outer diameter of the connection sleeve is substantially the same as the outer diameter of the conductor over its entire length in the direction of reducing the diameter of the connection sleeve and each conductor exposed portion, and the outer diameter of each of the small diameter step portions is reduced. Until the diameter is large at the proximal and distal ends and smaller at the middle By plastically deforming, the inner peripheral surface of the connection sleeve is closely fitted to the outer peripheral surface of the pair of conductor exposed portions, and the outer peripheral surface of both small-diameter stepped portions and the inner peripheral surface of the intermediate portion of the connection sleeve are fitted. Based on the above, the displacement of the two small diameter steps and the connection sleeve in the axial direction is prevented, and the conductors of the two power cables are electrically and physically connected via the connection sleeve. Connection method.