JP2003028912A - Method and device for conducting withstand voltage test on cold shrinking insulator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method, by which the labor and time required at assembling of linear connection between a pair of test cables 9 and 9, so as to facilitate the withstand voltage test performed on a cold shrinking tube 5. SOLUTION: On the outer peripheries of the end sections of the test cables 9 and 9, conically projecting tapered surface sections 16 and 16, which become gradually smaller in the outside diameter, as going toward the front ends are provided. At assembling of the linear connection between the test cables 9 and 9, the end sections of the cables 9 and 9 are respectively inserted into the cold shrinking tube 5 from both end openings of the tube 5. Then first and second connecting terminals 12a and 12b are butted against each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room temperature shrinkable insulator used for forming a straight connecting portion between end portions of a cable conductor of a high voltage power cable such as a crosslinked polyethylene insulated power cable (CV cable). The present invention relates to an improvement in the withstand voltage test method and a withstand voltage test apparatus for implementing this withstand voltage test method.

[0002]

2. Description of the Related Art As a structure in which the connection between the ends of a high-voltage power cable can be performed relatively easily, a pair of electric power is provided by a room temperature shrinkable insulator (rubber block insulator) made of rubber which is an elastic material. 2. Description of the Related Art A structure is known that covers a connecting portion between cable conductors that form a cable. FIG. 6 shows an example of a linear connection part of a power cable using such a cold-shrink type insulator.

A pair of power cables 1 to be connected to each other,
Each of 1 is formed by covering the circumference of a cable conductor 2 with a cable insulator 3. At the end portions of the cable conductors 2 and 2 constituting the pair of power cables 1 and 1, the portions protruding from the cable insulators 3 and 3 are
They are connected by the connection sleeve 4. Then, the periphery of the connection sleeve 4 is covered with a cold shrink tube 5. The room temperature shrinkable tube 5 is made of rubber, which is a material having elasticity at room temperature, and is formed into a cylindrical shape. A conductive rubber internal electrode 7 is embedded, and the outer peripheral surface is covered with a semiconductive rubber external electrode 8.

The cold-shrinkable tube 5 as described above has the above-mentioned 1
Prior to connecting the ends of the cable conductors 2, 2 of the pair of power cables 1, 1 with the connection sleeve 4,
It is loosely fitted on one of the power cables 1. still,
On the inner diameter side of the cold-shrinkable tube 5, there is provided a cylindrical expansion holding material for holding the cold-shrinkable tube 5 in the expanded state at a factory, a connection work site or the like.
It is inserted in advance by using a diameter expanding jig or a diameter expanding machine that elastically expands the inner diameter of the. Therefore, the cold-shrinkable tube 5 is loosely fitted onto the one power cable 1 with the elasticity in the diameter-reducing direction applied. And the above 1
After connecting the ends of the cable conductors 2 and 2 of the pair of power cables 1 and 1 with the connecting sleeve 4, the cold shrink tube 5 is connected to the cable insulator 3 that constitutes the pair of power cables 1 and 1. After being moved to a position where it is stretched between the three members, the expansion holding material is pulled out from the inner diameter side of the cold shrink tube 5. In this way, as the diameter expansion holding material is pulled out from the inner diameter side of the room temperature shrinkable tube 5, the room temperature shrinkable tube 5 shrinks in diameter due to its own elasticity, and the inner peripheral surfaces of both ends of the room temperature shrinkable tube 5 become The cable insulators 3 and 3 constituting the power cables 1 and 1 elastically abut on the outer peripheral surfaces of the end portions.

On the other hand, it is necessary to carry out a pressure resistance test (corona electric test) for checking the quality before shipping the cold-shrinkable tube 5 constituting the above-mentioned linear connection portion from the factory. When performing such a pressure resistance test, the room temperature shrinkable tube 5 constitutes a linear connection portion between a pair of test cables. Then, by applying a test voltage to the cable conductors forming each of these test cables, it is checked whether or not the pressure resistance value of the cold shrink tube 5 is sufficiently secured. Then, only the room temperature shrinkable tube 5 that has passed this pressure resistance test is shipped (after the above-mentioned diameter expansion holding material is inserted therein if necessary).

[0006]

Conventionally, when performing the pressure resistance test of the cold shrink tube 5 as described above, the linear connection portion between the pair of test cables is the linear connection shown in FIG. It was assembled in the same procedure as in the section.
Therefore, at the time of assembling the straight connecting portion between the pair of test cables, a room temperature expanding tube 5 is used to expand the inner diameter of the room temperature shrinking jig or a machine to expand the room temperature. It has been necessary to perform a troublesome work such as inserting a diameter expansion holding material inside the shrinkable tube 5 and further removing the diameter expansion holding material from the inside of the room temperature shrinkable tube 5. Therefore, it has been difficult to improve the efficiency of the pressure resistance test. The pressure resistance test method and the pressure resistance test apparatus for a room-temperature shrinkable insulator of the present invention were invented in view of the above circumstances.

[0007]

In the withstand voltage test method and the withstand voltage test apparatus for a room temperature shrinkable insulator according to the present invention, the withstand voltage test method for a room temperature shrinkable insulator according to claim 1 is a cable conductor Of a pair of test cables whose periphery is covered with a cable insulator, the portions of the cable conductors protruding from the cable insulator at the ends thereof are formed into a tubular shape by a material having elasticity at room temperature. They are connected to each other inside the configured cold-shrink type insulator, and the inner peripheral surface of the end of this cold-shrink type insulator is elastic over the entire circumference to the outer peripheral surface of the end of the cable insulator that constitutes each of the above test cables. The test voltage is applied to the cable conductors constituting each of the test cables in a state of being brought into contact with each other, thereby performing the withstand voltage test of the room temperature shrinkable insulator. Particularly, in the withstand voltage test method for the room-temperature shrinkable insulator of the present invention, as the pair of test cables, the axial base end portions of the connection terminals are connected to the end portions of the cable conductors. The outer peripheral surface of the connection terminal and the outer peripheral surface of the end portion of the cable insulator are provided with a tapered surface portion that is inclined in a direction in which the outer diameter decreases toward the tip end side in the axial direction of the connection terminal. Then, the ends of the cable conductors forming each of these test cables are connected to each other inside the cold-shrinkable insulator, and the inner peripheral surface of the end of the cold-shrinkable insulator is connected to the end of each of the cable insulators. In order to contact the outer peripheral surface of the part over the entire circumference, the end portions of the test cables are placed inside the room temperature shrinkable insulator, and the taper surface parts are provided from the both end openings of the room temperature shrinkable insulator. After the inner diameter of the room temperature shrinkable insulator is elastically expanded and pushed in, the connection terminals are abutted against each other inside the room temperature shrinkable insulator and joined, and then the test voltage is applied.

A room temperature shrinkable insulator withstand voltage test apparatus according to a second aspect is for carrying out the room temperature shrinkable insulator withstand voltage test method according to the first aspect.
Each is formed by covering the circumference of the cable conductor with a cable insulator, and at the end of this cable conductor, connect the axial base end of the connection terminal to the part protruding from this cable insulator, and A pair of test cables provided with a taper surface portion on the outer peripheral surface and on the outer peripheral surface of the end portion of the cable insulator, the taper surface portion being inclined in a direction in which the outer diameter becomes smaller toward the tip end side in the axial direction of the connection terminal, and each of these test A pair of cable support tables that can support and fix the cable for use on each upper surface, and a room-temperature shrinkable insulator that is formed in a tubular shape by a material that has elasticity at room temperature on the upper surface. A table, at least two support tables of the insulator support table and the pair of cable support tables, and the end portions of the pair of test cables and the pair of test cables. By moving in the central axis direction of the heat-shrinkable insulator, the end portions of the pair of test cables are pushed into the room-temperature shrinkable insulator from the openings of both ends of the room-temperature shrinkable insulator to move in the axial direction. And means. If necessary, at least two support tables of the pair of test cable support tables and the room temperature shrinkable insulator support table may be connected to the ends of the pair of test cables and the room temperature. By moving in a direction perpendicular to the central axis of the shrinkable insulator, there is provided central axis matching means for matching the central axes of the end portions of the pair of test cables and the room temperature shrinkable insulator with each other.

[0009]

In the case of the withstand voltage test method and the withstand voltage test apparatus for the room-temperature shrinkable insulator of the present invention as described above, the work of assembling the linear connecting portion between the pair of test cables can be easily performed. That is, in the case of the present invention, when assembling the linear connecting portions of the pair of test cables, the end portions of each of the test cables are placed inside the cold-shrinkable insulator, and the cold-shrinkable insulator is respectively placed. Then, the connection terminals joined to the end portions of the cable conductors of these test cables may be butted against each other inside the room-temperature shrinkable insulator by pushing in from both end openings. Therefore, when assembling the above-mentioned linear connection part, a diameter-expanding jig or a diameter-expanding machine is used to insert a diameter-expansion holding material inside the room-temperature-shrinkable insulator, or the room-temperature-shrinkable insulator is used. There is no need to perform troublesome work such as removing the diameter expansion holding material from the inside of the. In particular, according to the withstand voltage test apparatus described in claim 2, the operation of inserting the ends of the pair of test cables into the inside of the room-temperature-shrinkable insulator through the openings at both ends of the room-temperature-shrinkable insulator, Easy and accurate. For this reason, it is possible to reduce the labor required for assembling the above-mentioned linear connection portion, and to improve the efficiency of the pressure resistance test of the room temperature shrinkable insulator.

[0010]

1 and 2 show a first example of an embodiment of the present invention corresponding to claim 1 only. still,
The feature of this example is that a pair of test cables 9 and 9 including the cold-shrinkable tube 5 are included so that the cold-shrinkable tube 5 which is a cold-shrinkable insulator can be easily subjected to a pressure resistance test. The point is that the method of assembling the straight line connection part was devised. Since the structure itself of the cold-shrinkable tube 5 is substantially the same as that shown in FIG. 6 described above, the same parts are designated by the same reference numerals and overlapping description will be omitted or simplified. The description will focus on the characteristic part of.

The pair of test cables 9 and 9 used for the pressure resistance test of the room temperature shrinkable tube 5 are respectively cable conductors 10 like the power cable 1 shown in FIG.
Is covered with a cable insulator 11. Each of these test cables 9 and the cable conductor 1 forming the 9
At the end portions of 0 and 10, the first and second connection terminals 12 are provided at the portions protruding from the cable insulators 11 and 11, respectively.
a and 12b are connected. These first and second connection terminals 12a and 12b have the cylindrical compression terminal portions 13 and 13 provided at the respective base end portions thereof and the cable conductors 10 and 10 described above.
By externally fitting the ends of the cable conductors and reducing the diameter, the ends of the cable conductors 10 and 10 are mechanically and electrically connected.

A cylindrical male-side connecting portion 14 is provided at the center of the tip surface (left end surface in FIG. 1) of the first connecting terminal 12a.
At the center of the tip surface (right end surface in FIG. 1) of the second connection terminal 12b, a female-side connection portion 15 that is a circular hole is provided. The first and second connection terminals 12a, 12
When both the connection terminals 12a and 12b are brought close to each other with the front end surfaces of b facing each other, the male side connection portion 14 and the female side connection portion 15 are fitted to each other as shown in FIG. The first and second connection terminals 12a and 12b are electrically connected to each other. In addition, both the male side and female side connecting portions 1
If necessary, elastically deformable contact terminals can be provided in the fitting portions of the four and fifteen members.

Further, the tip end side is provided on the outer peripheral surfaces of the end portions of the cable insulators 11, 11 constituting the test cables 9, 9 and the outer peripheral surfaces of the first and second connection terminals 12a, 12b, respectively. The taper surface portions 16 and 16 having a conical convex shape inclined in a direction in which the outer diameter becomes smaller toward the outer peripheral surface of the cable insulators 11 and 11 and the outer surfaces of the first and second connection terminals 12a and 12b. It is provided so that the surface and the surface are smoothly continuous.

In order to perform a pressure resistance test of the cold shrink tube 5, the pair of test cables 9 and 9 as described above are joined on the inner diameter side of the cold shrink tube 5,
The work of constructing the linear connection part having the structure as shown in
Do as follows. First, the tip portions of the first and second connection terminals 12a and 12b fixed to the end portions of the cable conductors 10 and 10 constituting the pair of test cables 9 and 9,
Each is inserted into the cold-shrinkable tube 5 through the openings at both ends.

If the tip portions of the first and second connection terminals 12a and 12b are respectively inserted into the cold-shrink tube 5 through the openings at both ends as described above, the test pieces for the above-mentioned tests are continued. The end portions of the cables 9 and 9 are pushed toward the center portion in the axial direction inside the cold-shrinkable tube 5. With such a pushing operation, the inner diameters of both ends of the room temperature shrinkable tube 5 are set to the first and second connection terminals 1 respectively.
2a, 12b outer peripheral surface and each of the above test cables 9, 9
Of the cable insulators 11 and 11 that are elastically pushed apart by the taper surface portions 16 and 16 provided on the outer peripheral surfaces of the end portions of the cable insulators 11 and 11, and the end portions of the test cables 9 and 9 inside the cold shrink tube 5 are Allows entry towards the axial center.

Then, as described above, each test cable 9,
As shown in FIG. 1, the end portions of 9 are pushed toward the central portion in the axial direction of the cold-shrinkable tube 5, so that the first and second connection terminals 12a and 12b are shrunk at the cold-shrinkable temperature. Internal electrode 7 provided at the center of tube 5 in the axial direction
Butt at the inner diameter side. As a result, the cable conductors 10 and 10 are electrically coupled to each other. In this state, the inner peripheral surface of the internal electrode 7 is the outer peripheral surface of the first and second connection terminals 12a and 12b, and the inner peripheral surfaces of both ends of the insulating tubular portion 6 are the cable insulators 11 in the same manner. Similarly, the inner peripheral surfaces of both ends of the outer electrode 8 elastically abut the outer peripheral surfaces of the outer semiconductive layers 17, 17 provided outside the cable insulators 11, 11, respectively. .
In this state, the test cables 9, 9 and the first and second test cables 9 and 9 are secured so that the contact pressure between the peripheral surfaces is sufficiently ensured so that no problem occurs in the pressure resistance test. The outer diameter dimension of each part of each of the second connection terminals 12a and 12b is regulated. For this purpose, for example, the above-mentioned test cables 9, 9
Among them, in the state shown in FIG. 1, the outer diameter dimension D of the portion pressed into the axial end edge of the room temperature shrinkable tube 5 is 30 to 40.
In the case of about mm, the outer diameter dimension D is made larger by about 7 to 8 mm than the inner diameter dimension of the cold shrink tube 5 in the free state.

In the case of this example, after assembling the pair of test cables 9 and the linear connecting portions of the 9 cables as described above, as shown in FIG. 2, both ends of the cold shrink tube 5 are The semi-conductive tapes 18 and 18 hold the outer peripheral surfaces of the test cables 9 and 9 respectively. Further, the outer peripheral surface of the room temperature shrinkable tube 5 is wrapped with a conductive metal foil 19 such as an aluminum foil so that no gap is formed between the outer peripheral surface and the metal foil 19. Along with this, a metal sheath 20 provided around the outer semiconductive layers 17, 17 constituting the test cables 9, 9 by the metal foil 19,
The ends of 20 are electrically connected to each other. The above metal foil 1
The outer peripheral surface of 9 is held down by an insulating tape such as vinyl tape 21. Further, if necessary, each of the metal sheaths 2 described above
The part near 0 and 20 (the part shown by the diagonal grid in FIG. 2)
The resistance is separated by cutting the entire circumference. Then, in this state, a test voltage is applied to the cable conductors 10 and 10 that form the test cables 9 and 9 to perform a pressure resistance test of the cold shrink tube 5.

As described above, in the case of the pressure resistance test method for the room temperature shrinkable insulator of this example, the work of assembling the pair of test cables 9 and the linear connection portion of the nine cables can be easily performed. That is, in the case of this example, when assembling the linear connection part between these pair of test cables 9 and 9, the end portions of these test cables 9 and 9 are pushed into the cold shrink tube 5 to Each test cable 9, cable conductor 1 of 9
First and second connection terminals 12 fixed to the ends of 0 and 10
The a and 12b may be butted to each other in the cold shrink tube 5. Therefore, when assembling the above-mentioned straight line connecting portion, a diameter-expansion holding material is inserted inside the cold-shrink tube 5 by using the above-described diameter-expanding jig, a diameter-expanding machine, or the cold-shrink tube. There is no need to perform troublesome work such as pulling out the diameter expansion holding material from the inside of 5. For this reason, it is possible to reduce the labor required for assembling the linear connection portion, and to improve the efficiency of the pressure resistance test of the cold shrink tube 5.

Next, FIGS. 3 to 5 show a second example of the embodiment of the present invention corresponding to claims 1 and 2. This example relates to a pressure resistance test apparatus for more efficiently performing the pressure resistance test of the cold shrink tube 5 as described above. The pressure resistance test apparatus of this example has a long rectangular fixed frame 22. An insulating support table 23 is fixed to the central portion of the fixed frame 22 in the longitudinal direction (left-right direction in FIGS. 3 to 5). Further, a pair of cable support tables 24, 24 are provided at the portions of the fixed frame 22 near both ends in the length direction so as to be movable in the length direction. For this reason, in the illustrated example, the guide rails 25, 25 in which the cable support tables 24, 24 are provided on the upper surfaces of both ends in the length direction of the fixed frame 22 in the length direction of the fixed frame 22, respectively. It is provided so that it can move freely.

Further, the supporting table 24 for each of the above cables,
A screw rod 2 in which nut pieces (not shown) fixedly provided on the lower surface of 24 are arranged in the length direction of the fixed frame 20.
6 and 26 are screwed together. Each of these screw rods 26, 26
Are rotatably supported on the fixed frame 20. Then, by rotating the screw rods 26, 26 manually or by an electric motor or the like independently of each other or in conjunction with each other, the cable support tables 24, 24 are moved in the length direction. I am trying to let you do it.
The guide rails 25, 25, the nut piece,
The screw rods 26, 26 form the axial moving means described in the claims.

Further, the supporting table 24 for each of the above cables,
On the upper surface of 24, the ends of the pair of test cables 9 and 9 described in the first example are supported and fixed. Because of this,
The outer peripheral surfaces of the outermost layers 28, 28 of the test cables 9, 9 are held by the holding jigs 27, 27 provided on the upper surfaces of the cable support tables 24, 24.
The holding jigs 27, 27 and the outermost layers 28, 2 are
By interposing an insulating material such as rubber between the two members 27 and 28, these members 27 and 28 are electrically insulated from each other. In the case of this example, the test cables 9 and 9 are
In a state where the end portions of the test cables 9 are supported and fixed on the upper surfaces of the cable support tables 24, 24, the test cables 9,
The central axes of the end portions of 9 are aligned with each other. Further, test terminals 33, 33 are provided at the base ends of these test cables 9, 9, respectively.

On the upper surface of the insulator support table 23, the room temperature shrinkable tube 5 which is a sample for a pressure resistance test is used.
Can be supported and fixed freely. To perform a pressure test,
When the cold-shrinkable tube 5 is supported and fixed on the upper surface of the insulator support table 23, the outer circumferential surface of the cold-shrinkable tube 5 is previously covered with the metal foil 19 described above. Wrap it so that there is no gap between them. Then, in this state, the cold shrink tube 5
The outer peripheral surface of the intermediate portion is held by a holding jig 29 provided on the upper surface of the insulator support table 23. An insulating material such as rubber is interposed between the holding jig 29 and the metal foil 19 wound around the outer peripheral surface of the cold-shrinkable tube 5 so that the two members 29, 19 are electrically connected to each other. Insulate. In the case of this example, the cold shrink tube 5
Is supported and fixed on the upper surface of the insulator support table 23, the shapes and dimensions of the respective parts are regulated so that the center axes of the cold-shrink tube 5 and the test cables 9, 9 coincide with each other. is doing.

In carrying out the pressure resistance test, first, as shown in FIG. 3, the pair of cable support tables 24, 2 are connected.
The room temperature shrinkable tubes 5 are supported and fixed to the upper surface of the insulator support table 23 in a state where they are retracted to both ends of the fixed frame 22. Then, FIG.
As shown in FIG. 5, by rotating the screw rods 26, 26, the pair of cable supporting tables 24, 24
Are moved toward the central portion of the fixed frame 22 in the directions in which they approach each other. As a result, the tip portions of the test cables 9 and 9 are inserted into the inside of the cold shrink tube 5 through the openings at both ends of the cold shrink tube 5, and the tip portions of the test cables 9 and 9 are inserted into the cold shrink tube 5. The provided first and second connection terminals 12a and 12b are butted against each other and electrically connected.

If a pair of test cables 9 and a linear connecting portion between the test cables 9 are constructed by using the cold shrink tube 5 as a sample as described above, then the above-mentioned metal foil 19 is formed.
Axial both ends of each of the test cables 9,
By electrically connecting to the end portions of the metal sheaths 20 and 20 that form the element 9, the metal sheaths 20 and 20 are electrically connected to each other. At the same time, the metal foil 19, which is the low voltage side electrode, is grounded to form a corona measuring circuit as shown in FIG. Then, by applying a test voltage to the cable conductors 10 and 10 forming the test cables 9 and 9, it is checked whether or not the pressure resistance of the cold shrink tube 5 is sufficiently secured. Therefore, in the illustrated example, the coupling capacitor 30 is connected in parallel with the cold shrink tube 5 which is the sample, and the detection unit 32 which constitutes the detection device 31 is provided between the coupling capacitor 30 and the ground.
Are connected. Then, when the test voltage is applied as described above, the corona generated in the cold shrink tube 5 portion is directly detected by the detection device 31. Whether or not the pressure resistant performance of the cold shrink tube 5 is sufficiently ensured is determined based on the detection of corona by the detection device 31 in this manner. The detecting unit 32 constituting the detecting device 31 is connected between the metal foil 19 and the ground, as shown by a chain line in FIG. 5, instead of being connected between the coupling capacitor 30 and the ground. You can also do things.

In the case of this example in which the pressure resistance test of the cold shrink tube 5 is performed as described above, the cold shrink tube 5 is used.
Inserting the tip portions of the above-mentioned test cables 9 and 9 inside (in addition, the work of pulling out the tip portions of these test cables 9 and 9 from the inside of the cold shrink tube 5)
Can be performed easily and accurately. For this reason, the pressure resistance test of the cold shrink tube 5 can be more efficiently performed.

In the above-mentioned second example, the insulator support table 23 is fixed and the pair of cable support tables 24, 24 is axially movable, but instead of this, for example, It is also possible to fix one cable support table 24 and move the other cable support table 24 and the insulator support table 23 in the axial direction. Even in this case, the amount of movement of the other cable support table 24 increases, and the time required to insert and remove the test cable 9 from and into the room temperature shrinkable tube 5 becomes somewhat longer, but the cable connecting portion can be easily assembled and disassembled. It can be performed accurately and the pressure resistance test can be made efficient. If necessary, the insulator support table 23
And at least two support tables of the pair of cable support tables 24, 24 in a direction perpendicular to the central axes of the pair of test cables 9, 9 and the cold shrink tube 5 (for example, , The width of the fixed frame 22 and the vertical direction). By doing so, adjustment work for making the center axes of the pair of test cables 9 and 9 and the room-temperature shrinkable insulator 5 coincide with each other can be easily performed.

[0027]

As described above, the withstand voltage test method and the withstand voltage test apparatus for the room-temperature shrinkable insulator of the present invention are constructed and operated as described above, and therefore the withstand voltage test can be easily performed. Therefore, it is possible to reduce the cost at the time of carrying out this withstand voltage test, and it is possible to shorten the time required for shipping the room temperature shrinkable insulator as a product.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is a side view showing a processing state of a linear connecting portion when performing a withstand voltage test.

FIG. 3 is a plan view of a pressure resistance test device showing a second example of the embodiment of the present invention in a state before the end portions of the pair of test cables are inserted inside the cold-shrink tube.

FIG. 4 is a plan view of the pressure resistance test apparatus, similarly showing a state in which the ends of the pair of test cables are inserted inside the cold-shrink tube.

FIG. 5 is a side view of the same.

FIG. 6 is a cross-sectional view showing an example of a linear connection part using a cold shrink tube.

[Explanation of symbols]

1 power cable 2 cable conductor 3 cable insulation 4 connection sleeve 5 Cold shrink tube 6 Insulation cylinder 7 internal electrodes 8 external electrodes 9 Test cable 10 cable conductors 11 Cable insulation 12a, 12b (first and second) connection terminals 13 Compressed terminal 14 Male side connection 15 Female side connection 16 Tapered surface 17 External semiconductive layer 18 Semi-conductive tape 19 metal foil 20 metal sheath 21 vinyl tape 22 Fixed frame 23 Insulator support table Support table for 24 cables 25 guide rails 26 screw rod 27 Holding jig 28 outermost layer 29 Holding jig 30 coupling capacitors 31 Detector 32 detector 33 Test terminal

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 2G015 AA05 AA29 AA30 BA10 CA01                 5G355 AA03 BA02 BA14                 5G375 AA02 BA26 BB43 CA02 CA14                       CB07 CB19 CB38 CB47 CB53                       DB32 EA15

Claims (2)

[Claims] 1. A pair of test cables, each of which is formed by covering a circumference of a cable conductor with a cable insulator, and portions of the pair of cable conductors which are projected from the cable insulator at ends of the respective cable conductors, While being connected to each other inside a room-temperature shrinkable insulator formed into a tubular shape by a material having elasticity at room temperature, the inner peripheral surface of the end portion of the room-temperature shrinkable insulator is used as a cable insulator for the above-mentioned test cables. Performing a withstand voltage test of the room temperature shrinkable insulator by applying a test voltage to the cable conductors forming each of these test cables in a state of elastically contacting the outer peripheral surface of the end portion over the entire circumference, In the pressure resistance test method for a room-temperature shrinkable insulator, as the pair of test cables, the axial base ends of the connection terminals are connected to the ends of the cable conductors, respectively, and the connection is made. For each of these tests, use a taper surface that is inclined in the direction in which the outer diameter becomes smaller toward the tip end in the axial direction of the connecting terminal, on the outer peripheral surface of the terminal and the end outer peripheral surface of the cable insulator. The ends of the cable conductors that compose the cable are connected to each other inside the cold-shrinkable insulator, and the inner circumferential surface of the cold-shrinkable insulator is completely surrounded by the outer circumferential surface of the end of each cable insulator. In order to make contact with each other, the end portions of the test cables are placed inside the room temperature shrinkable insulator, and both ends of the room temperature shrinkable insulator are opened through the tapered surface portions of the room temperature shrinkable insulator. The inner diameter of the room temperature shrinkable insulator is pushed in while elastically expanding, the connection terminals are butt-joined to each other inside the room temperature shrinkable insulator, and then the test voltage is applied. Pressure resistance test Method. 2. A withstand voltage test device for carrying out the withstand voltage test method for a room temperature shrinkage type insulator according to claim 1, each of which is formed by covering the circumference of a cable conductor with a cable insulator. The axial base end portion of the connection terminal is coupled to the portion of the conductor projecting from the cable insulator, and the outer peripheral surface of the connection terminal and the outer peripheral surface of the end portion of the cable insulator are connected to each other. A pair of test cables provided with tapered surface portions that are inclined in a direction in which the outer diameter becomes smaller toward the tip end side in the axial direction, and a pair of cable support tables for supporting and fixing each of these test cables on their respective upper surfaces. And a support table for an insulator capable of supporting a room temperature shrinkable insulator, which is made of a material having elasticity at room temperature, in a tubular shape on its upper surface, the support table for the insulator, and the pair of cables. By moving at least two supporting tables among the supporting tables toward the ends of the pair of test cables and the central axis direction of the cold-shrink type insulator, the ends of the pair of test cables are moved. A pressure resistance test apparatus comprising: a cold-shrinkable insulator, and axial moving means for pushing the cold-shrinkable insulator from openings at both ends of the cold-shrinkable insulator.