JPH069390Y2 - Insulation protection tube - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is an insulation provided with a resin insulating pipe for conductor coating, and a metal outer skin provided around the outer periphery of the resin insulating pipe. It concerns a protective tube.

<Prior Art> This type of conventional insulation protection tube is shown in FIGS. 9 and 10.

FIG. 9 is a vertical cross-sectional front view, and FIG. 10 is a partial cutaway vertical cross-sectional side view.

As shown in FIG. 9, the resin insulation pipe 2 made of epoxy resin surrounds the conductor 4 with the space 3 interposed therebetween.
On the outer peripheral surface of this resin-made insulating pipe 2, a metal skin 1 is attached in a pipe shape. The resin-made insulating pipe 2 and the metal jacket 1 form an insulating protective pipe B. Metal skin 1
Is grounded via a sensor 17 such as an ammeter and a voltmeter.

As shown in Fig. 10, a flange is attached to the end of the insulation protection tube B.
15 is formed and two adjacent insulation protection tubes B, B are formed.
A spacer 11 is interposed between the flanges 15 and 15, and both insulating protection tubes B and B are fixedly connected by bolts and nuts 14. O-ring at the joint 13 between the spacer 11 and the flange 15
16 is interposed to seal the space 3 inside the insulation protection tube B. A hole 12 having the same diameter as the diameter of the conductor 4 is formed in the center of the spacer 11.
Is connected to. The interior space 3 of the insulating protection tube B is filled with an inert gas.

Next, the operation of the insulation protection tube B will be described.

Since the periphery of the conductor 4 is surrounded by the insulating pipe 2 made of resin through the space 3, the conductor 4 can be electrically insulated from the outside. Further, since the metal outer skin 1 on the outer peripheral surface of the resin-made insulating pipe 2 is grounded, the resin-made insulating pipe 2 is prevented from being charged and the risk of electric shock is avoided. Further, the sensor 17 can detect the strength of charging.

<Problems to be Solved by the Invention> However, the conventional example having such a configuration has the following problems.

That is, when a current flows through the conductor 4 for a long time, the conductor 4 becomes hot due to its electric resistance. The heat is transferred to the resin-made insulating pipe 2 and the metal jacket 1, and the resin-made insulating pipe 2 and the metal jacket 1 expand.

However, the thermal expansion coefficient of the resin insulating pipe 2 is different from that of the metal jacket 1. Generally, the thermal expansion coefficient of the resin insulating pipe 2 is larger than the thermal expansion coefficient of the metal jacket 1. Due to this difference, a stress is generated between the resin-made insulating pipe 2 and the metal jacket 1, and strain is generated in the resin-made insulating pipe 2 and the metal jacket 1. When the tensile strength of the resin insulation pipe 2 is smaller than that of the metal jacket 1, the resin insulation pipe 2 is cracked,
Inert gas leaks. The above causes dielectric breakdown and causes a ground fault. Further, when the tensile strength of the metal jacket 1 is smaller than that of the resin insulation pipe 2, the metal jacket 1 is broken and a part of the insulation protection tube B cannot be grounded.

The present invention has been made in view of such circumstances, and it is an object of the present invention to prevent the resin-made insulating pipe and the metal skin from breaking.

<Means for Solving Problems> The present invention has the following configuration in order to achieve such an object.

That is, the insulation protection tube of the present invention comprises a resin insulation pipe for covering a conductor, a metal outer skin provided on the outer periphery of the resin insulation pipe, the resin insulation pipe and the metal outer skin. And an elastic body for absorbing the expansion difference interposed therebetween.

<Operation> The operation of the configuration of the present invention is as follows.

That is, the elastic body for absorbing the difference in expansion absorbs the stress due to the difference in thermal expansion between the resin-made insulating pipe and the metal jacket.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

1 and 2 relate to a first embodiment of the present invention.
The drawing is a vertical sectional front view, and FIG. 2 is a partial cutaway vertical sectional side view.

The insulation protection tube of the present embodiment has a pipe-shaped elastic body 5 interposed between a resin insulation pipe 2 and a pipe-shaped metal skin 1. Rubber is generally used as the elastic body 5.

Since other configurations are similar to those of the conventional example, only corresponding parts are designated by the same reference numerals and description thereof is omitted.

Next, the operation of the first embodiment will be described.

Since the elastic body 5 is interposed between the resin-made insulating pipe 2 and the metal jacket 1, even if the resin-made insulating pipe 2 and the metal jacket 1 expand due to the heat of the conductor 4, the elastic body 5 has its own volume. Absorb the increase.

As a result, strain due to thermal stress does not occur in the resin insulating pipe 2 and the metal jacket 1. Therefore, the metal jacket 1 and the resin-made insulating pipe 2 are not cracked, so that gas leakage, dielectric breakdown, grounding failure, ground fault, etc. do not occur.

Further, when the elastic body 5 is made of rubber, the insulation resistance value is easier to manage and the detection accuracy of the sensor 17 is higher than that when air is interposed.

Next, a second embodiment will be described with reference to FIGS. 3 and 4. FIG. 3 is a vertical sectional front view, and FIG. 4 is a partially cutaway vertical sectional side view.

In this embodiment, the configuration different from the first embodiment is
It is as follows.

There is no space 3 and the elastic body 6 is attached to the outer peripheral surface of the conductor 4 in a pipe shape, and the resin insulating pipe 2 is attached to the outer peripheral surface of the elastic body 6.
Is being worn. Rubber is generally used as the elastic body 6. Since other configurations are similar to those of the first embodiment, the same reference numerals are allotted to the corresponding portions and the description thereof will be omitted.

Next, the operation of the second embodiment will be described.

When the space 3 exists as in the first embodiment, it is difficult to manage the insulation resistance value of the space 3. However, by filling the space 3 with the elastic body 6, the insulation resistance value can be easily managed. Therefore, the detection by the sensor 17 can be performed with high accuracy.
Other operations are the same as those in the first embodiment.

Next, a third embodiment will be described with reference to FIG. FIG. 5 is a perspective view with a part cut away.

Two semi-cylindrical elastic bodies 5a, 5a are attached to the outer peripheral surface of the resin insulating pipe 2, and semi-cylindrical metal skins 1a, 1a are attached to the outer surfaces of the elastic bodies 5a, 5a. The metal skins 1a and 1a are individually grounded via the sensors 17 and 17, respectively.

Since other configurations are similar to those of the first embodiment, the same reference numerals are allotted to the corresponding portions and the description thereof will be omitted.

In the case of the present embodiment, the semi-cylindrical elastic body 5a and the metal skin 1a
There is an advantage that the attaching work is easier than the pipe-like work.

Next, a fourth embodiment will be described with reference to FIG.

FIG. 6 is a perspective view with a part cut away. A plurality of relatively short pipe-shaped elastic bodies 5b are attached to the outer peripheral surface of the resin insulating pipe 2, and each of the elastic bodies 5b is attached with a pipe-shaped metal skin 1b of the same length. 1b sensor 17
Grounded through. Since other configurations are similar to those of the first embodiment, the same reference numerals are allotted to the corresponding portions and the description thereof will be omitted.

Next, a fifth embodiment will be described with reference to FIG. FIG. 7 is a vertical sectional front view.

As shown in FIG. 7, between the resin-made insulating pipe 2 and the pipe-shaped metal outer shell 1 in a state in which four elastic bodies 5c having a central arc of about 45 degrees and having a partial arc shape are equally spaced in the circumferential direction. Is intervened in. Since other configurations are similar to those of the first embodiment, the same reference numerals are allotted to the corresponding portions and the description thereof will be omitted.

In the case of this embodiment, there are advantages that the material of the elastic body 5c is small and the weight can be reduced.

It should be noted that a combination of the concept of the configurations of the fourth embodiment (FIG. 6) and the fifth embodiment (FIG. 7) is also included in the embodiments of the present invention.

Next, a sixth embodiment will be described with reference to FIG. FIG. 8 is a vertical sectional front view.

As shown in FIG. 8, a resin insulating pipe 2a and an elastic body 5 are provided.
Each of the d and the metal skin 1c is formed in a rectangular tube shape. Since other configurations are similar to those of the first embodiment, the same reference numerals are allotted to the corresponding portions and the description thereof will be omitted.

<Effects of the Invention> According to the present invention, the following effects are exhibited.

That is, since the elastic body is interposed between the resin-made insulating pipe and the metal jacket, even if the resin-made insulating pipe and the metal jacket expand, the elastic body absorbs the increased volume of the resin-made insulating pipe and the resin-made insulating jacket. Strain due to thermal stress does not occur in the pipe and metal skin. Therefore, it is possible to prevent cracks in the metal skin and the resin-made insulating pipe, and to avoid dielectric breakdown, ground failure, and ground fault.

[Brief description of drawings]

1 and 2 relate to the first embodiment, FIG. 1 is a vertical sectional front view, and FIG. 2 is a partially cutaway vertical sectional side view. Third
FIG. 4 and FIG. 4 relate to the second embodiment, FIG. 3 is a vertical sectional front view, and FIG. 4 is a partially cutaway vertical sectional side view. FIG. 5 is a perspective view of a partial cutout according to the third embodiment. FIG. 6 is a perspective view of a partial cutout according to the fourth embodiment, FIG. 7 is a vertical sectional front view according to the fifth embodiment, and FIG. 8 is a vertical sectional front view according to the sixth embodiment. 9 and 10 relate to a conventional example, FIG. 9 is a vertical sectional front view, and FIG. 10 is a partially cutaway vertical sectional side view. 1, 1a, 1b, 1c ... Metal skin 2, 2a ... Insulation pipe made of resin 4 ... Conductor 5, 5a, 5b, 5c, 5d ... Elastic body

Claims (3)

[Scope of utility model registration request] 1. A resin-made insulating pipe for covering a conductor, a metal outer skin provided on the outer periphery of the resin-made insulating pipe, and a metal insulating skin interposed between the resin-made insulating pipe and the metal outer skin. An insulating protection tube with an elastic body for absorbing the expansion difference. 2. The insulation protection tube according to claim 1, wherein the metal shell is in the shape of a pipe. 3. The insulation protection tube according to claim (1), wherein the elastic body has a pipe shape.