JP2003031062A - Insulator and insulator device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a noise prevention measure for a type of insulator, which has a discoid-umbrella shaped section and a plurality of annular fold sections, located concentrically underneath the umbrella section with a specified length of protrusions. SOLUTION: An outermost first fold 23a is made longest and a second fold 23b located inwards next to the first fold is designed to be shorter than the first fold 23a. The length of a third fold 23c specified is so that it intersects with the extension of the line L1 connecting the tip of the first fold 23a, and the tip of the second fold 23b and then the length of the fourth fold 23d is specified, so that it intersects with the extension of the line L2 connecting the tip of the first fold 23a and the tip of the third fold 23c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator and an insulator device formed by connecting a plurality of insulators in series.

[0002]

2. Description of the Related Art As one type of insulator, there is an insulator having a disc-shaped umbrella portion and a plurality of annular pleats that are concentrically located on the lower surface side of the umbrella portion and project downward by a predetermined length. As one type of insulator device, there is an insulator device in which a plurality of stages of the insulator are connected in series. These insulators and insulator devices are
Supports power lines, etc. on steel towers and power poles. To cope with the recent ultra-high voltage transmission voltage, the insulator itself should be enlarged, and the insulator device should be connected. This is dealt with by increasing the number of insulators and making them larger.

By the way, the insulator and the insulator device of this type are
In the installed state, it is naturally exposed to the wind, but depending on the wind speed and the wind direction, a large noise may be generated. The frequency and magnitude of noise generated from insulators and insulator devices have increased with the increase in size of insulators and insulator devices.

In particular, if a large amount of noise is frequently generated at night, it will be a nuisance to local residents. Therefore, noise prevention measures have been adopted, and various noise prevention measures have been proposed. Noise prevention measures for the insulator itself have been proposed in Japanese Patent Publication No. 6-101261 (first publication) and Japanese Patent Application Laid-Open No. 5-67407 (second publication), and as noise prevention measures for the insulator device. Is Japanese Patent Laid-Open No. 2000-149686 (third publication).
And Japanese Patent Laid-Open No. 2000-311531 (fourth publication).

The noise preventive insulators disclosed in the first and second publications, in which the insulator itself is provided with noise preventive measures, are concentrically located on the lower surface side of the disc-shaped umbrella portion. It specifies the shape of the folded fold. In the noise insulating insulator disclosed in the first publication, the relationship between the outermost fold portion and the next fold portion is such that the line passing through the tips of these fold portions is at least 35 degrees with respect to the horizontal direction. The angle is set. Further, in the noise prevention insulator disclosed in the second publication, the tip end portion of the fold portion is formed in a wave shape in which peaks and valleys are continuous.

On the other hand, the noise prevention insulator devices shown in the third and fourth publications, in which the insulator device is provided with noise prevention measures, are constructed by connecting the insulators in a plurality of stages in series. In the noise prevention insulator device disclosed in the third publication, a means for inserting different kinds of insulators having different natural frequencies into the insulator string is provided. Further, in the noise prevention insulator device disclosed in the fourth publication, the intervals between the insulators forming the insulator series are set to be irregular intervals.

[0007]

These noise-preventing insulators and noise-preventing insulator devices have a noise-preventing function, but all of them have the technology of "insulator wind noise generation mechanism" described below. It was based on the intellectual thought and could not be said to have a sufficient noise prevention function. That is, in the conventional "wind insulator sound generation mechanism", a Karman vortex is generated between the folds that form the insulator due to the flow of wind, and the folds slightly vibrate. Wind noise (noise) that matches the natural frequency
Was thought to occur.

The inventors of the present invention have made intensive studies on the generation of noise due to the flow of wind in insulators and insulator devices, and have come to the following conclusions. That is, in the insulator having a disk-shaped umbrella portion and a plurality of annular fold portions that are concentrically arranged on the lower surface side thereof and project downward by a predetermined length,
When the wind without turbulence blows along the extension line connecting the tips of the outermost first fold and the second fold adjacent to each other on the inner circumference side, a Karman vortex is generated between the folds, The folds repeatedly vibrate slightly and generate a faint noise, the frequency due to the Karman vortex is determined by the wind speed and the interval between the folds, and the frequency due to the Karman vortex is when the specific wind speed continues, It was found that the acoustic natural frequency of the space formed by the adjacent insulators of the insulator device coincides with that of the insulator device, and that such a phenomenon causes a resonance sound and becomes a loud noise.

Therefore, it is an object of the present invention to provide noise countermeasures for the above-mentioned insulator and insulator device based on these findings.

[0010]

The present invention relates to an insulator and an insulator device, and more particularly, to a disk-shaped umbrella portion, which is concentrically located on the lower surface side of the umbrella portion and projects downward by a predetermined length. It is intended to apply an insulator of a type having a plurality of annular pleats, and to an insulator device of a type configured by connecting a plurality of stages of the insulator in series in series.

Therefore, in the insulator according to the present invention,
In the insulator of the type described above, the outermost first fold portion of each of the fold portions is set to be the longest, and the second fold portion adjacent to the inner circumferential side of the first fold portion is The third folds, which are set shorter than the first folds and are adjacent to each other on the inner peripheral side of the second folds, have the tip of the first folds and the second folds of the second folds. A fourth fold that is set to have a length that intersects an extension line that connects the tip and the fourth fold that is adjacent to the inner peripheral side of the third fold is the tip of the first fold and the third fold. It is characterized in that the length is set to intersect with an extension line connecting the tip of the part.

Further, in the insulator device according to the present invention,
In the insulator device of the above-mentioned type, the ratio D / H of the radius D of the umbrella portion of each insulator to the distance H between the lower ends of the insulators adjacent to each other is set to 0.7 or less. To do.

[0013]

In the insulator according to the present invention, the undisturbed wind is extended along the extension line connecting the outermost first fold portion and the tips of the second fold portions adjacent to each other on the inner circumferential side thereof. When blown, the wind collides with the tip of the third fold and is reflected,
The reflected wind disturbs the air flow that causes the Karman vortex between the first fold portion and the second fold portion to generate a turbulent flow.
Therefore, the Karman vortex is prevented from being generated between the first fold portion and the second fold portion.

Further, when the undisturbed wind blows along the extension line connecting the tip of the first fold and the tip of the third fold, the wind collides with the tip of the fourth fold. And then reflected,
The reflected wind disturbs the air flow that causes the Karman vortex between the first fold portion and the third fold portion to generate a turbulent flow.
Therefore, it is possible to prevent the Karman vortex from being generated between the first fold portion and the third fold portion.

Therefore, according to the insulator of the present invention, there is no or almost no microvibration due to the generation of the Karman vortex at the fold portion, in other words, the generation of the Karman vortex that causes noise is generated. It can be regulated, and the generation of noise from the insulator and the insulator device can be prevented.

Regarding the fifth fold portion and the insulator having the fold portion on the inner peripheral side of the fifth fold portion, these fold portions are located on the inner peripheral side at a considerable distance from the outermost first fold portion. Since they are located and the diameter is small, the Karman vortex generation between these walls is small and extremely small. Is not necessary.

In the insulator device of the type to which the present invention is applied, the ratio D / H of the radius D of the umbrella portion of each insulator to the distance H between the lower ends of the insulators adjacent to each other is usually set. It is set in the range of 0.8 to 1.3, and the acoustic natural frequency of the space formed by the two adjacent insulators of the insulator series and the fineness caused by the Karman vortex generated between the folds of each insulator The phenomenon that the frequency of vibration agrees is often seen.

On the other hand, in the insulator device according to the present invention, by setting D / H to be 0.7 or less, the acoustic natural vibration of the space formed by the two adjacent insulators of the insulator series is provided. The number is shifted out of the range corresponding to the frequency of the microvibration caused by the Karman vortex generated between the folds of each insulator.

Therefore, according to the insulator device of the present invention,
Even if a Karman vortex is generated in the folds and a minute vibration is generated, it is possible to prevent generation of a large noise due to a match between the frequency of this minute vibration and the acoustic natural frequency.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first invention according to the present invention is an insulator provided with noise countermeasures, which is a disk-shaped umbrella portion and is located concentrically on the lower surface side of the umbrella portion and has a predetermined length downward. The present invention is applied to an insulator of a type having a plurality of protruding annular folds. FIG. 1 shows a typical conventional insulator 10 of this type, and FIG. 2 shows an insulator 20 according to an example of the present invention. Each of these insulators 10 and 20 is composed of insulator main bodies 10a and 20a, cap fittings 10b and 20b, and pin fittings 10c and 20c.

The insulator main bodies 10a and 20a are made of porcelain or glass, and have disk-shaped umbrella portions 11 and 21, and an umbrella portion 1.
The annular connecting portions 12 and 22 integrally formed in the central portion on the front surface side of the reference numerals 1 and 21 and the plurality of fold portions 13a to 13e and 23a formed concentrically on the rear surface side of the umbrella portions 11 and 21.
-23e.

The cap fittings 10b and 20b have a substantially annular shape, and have a fitting recess 14 that opens downward in the center.
a and 24a, and a recess 14 for connection at the top
b, 24b. Cap fittings 10b, 20b
Is fitted to the outer peripheries of the connecting portions 12 and 22 formed on the umbrella portions 11 and 21 of the insulator bodies 10a and 20a, and is fixed to the connecting portions 12 and 22 via cements 15b and 25b.

The pin fittings 10c, 20c are provided with large-diameter mounting portions 16b, 16c, 26b, 26c at the upper and lower ends of the cylindrical rod-shaped main bodies 16a, 26a. In the pin fittings 10c, 20c, the insulator main bodies 10a, 2
Connecting portions 12 and 2 formed on the umbrella portions 11 and 21 of 0a
The two inner holes 12a, 22a are concentrically inserted from the mounting portions 16b, 26b side, and are fixed to the connecting portions 12, 22 via cements 15a, 25a.

In the pin fittings 10c and 20c, the recesses 14b and 24b of the cap fittings 10b and 20b are formed.
It is inserted concentrically from the side of the mounting portions 16c, 26c, and is connected to the cap fittings 10b, 20b by fitting with the tip edge portions of the recesses 14b, 24b.
As a result, the pin fittings 10c and 20c are attached to the insulator body 10
a and 20a are connected in series in a plurality of stages to form an insulator device.

Insulator main bodies 10a, 20 of the respective insulators 10, 20
a is five annular fold parts 13a-13e, 23a-23
e. Each fold portion 13a to 13e, 23a to 23
Both e are projected by a predetermined length from the lower surface side of the umbrella portions 11 and 21.

However, in each of the folds 13a to 13e of the porcelain main body 10a of the conventional porcelain insulator 10, the folds 13b (the folds 13b (the first folds) on the outermost circumference are sequentially located on the inner peripheral side. The second fold portion, the fold portion 13c (third fold portion), the fold portion 13d (fourth fold portion), and the fold portion 13e (fifth fold portion) are sequentially formed in a short length.

On the other hand, the insulator 2 according to the example of the present invention.
In each of the folds 23a to 23e of the insulator main body 20a constituting 0, the outermost fold 23a (first fold) is formed to be the longest and the innermost fold 23e (fifth fold). Is formed in the shortest length, but the folds 23b (second folds), folds 23c (third folds), and folds 23d (fourth folds) located between the two folds 23a and 23e are The folds 23a to 23e are formed to have substantially the same length, and the length relationships of the folds 23a to 23e are set as follows.

That is, in each of the folds 23a to 23e of the insulator main body 20a constituting the insulator 20, the outermost first fold 23a is longest and the second fold 23b adjacent to the first fold 23a is the longest. The length is shorter than the first fold portion 23a, and the length of the innermost fifth fold portion 23e is set to be the shortest. Further, the third fold portion 23c adjacent to the second fold portion 23b is set to have a length that intersects with an extension line L1 connecting the tip of the first fold portion 23a and the tip of the second fold portion 23b. Further, the fourth fold portion 23d adjacent to the third fold portion 23c has a third end and a third end portion of the first fold portion 23a.
The length is set to intersect with an extension line L2 connecting the tip of the fold portion 23c. FIG. 2 shows an insulator 20 in which the relationship of the lengths of the folds 23a to 23e is set in this way.

In an insulator of this type, for example, as shown in FIG.
In the conventional insulator 10 shown in FIG. 1, when the wind without turbulence blows along the extension line L3 connecting the tips of the outermost first fold portion 13a and the second fold portion 13b, the wind is first Fold part 13a
A Karman vortex is generated between the second fold portion 13b and the second fold portion 13b to generate a slight vibration in the insulator body 10a. When this slight vibration matches the acoustic natural frequency of the space between the adjacent insulators of the insulator device, a large noise is generated from the insulator device.

On the other hand, in the insulator 20 according to an example of the present invention shown in FIG. 2, the undisturbed wind is the first outermost circumference.
When blowing along an extension line L1 connecting the tips of the folds 23a and the second folds 23b, the wind collides with the tip of the third fold 23c and is reflected, and the reflected wind is the first fold. A turbulent flow is generated by disturbing the air flow that causes the Karman vortex between the portion 23a and the second fold portion 23b. Therefore, the first fold 23
Generation of Karman vortices between a and the second fold portion 23b is prevented.

Further, when the undisturbed wind blows along the extension line L2 connecting the tip of the first fold 23a and the tip of the third fold 23c, the wind is the tip of the fourth fold 23d. The reflected wind disturbs the air flow that causes the Karman vortex between the first fold portion 23a and the third fold portion 23b to generate a turbulent flow. Therefore, generation of Karman vortices between the first fold portion 23a and the third fold portion 23c is prevented.

Therefore, according to the insulator 20, each fold 2
There is no or almost no microvibration due to the generation of Karman vortices in 3a to 23e, in other words, the generation of Karman vortex which is the cause of noise can be regulated, and the insulator and the insulator device It is possible to prevent the generation of noise.

In addition, in the insulator 20, since the fifth fold portion 23e is located on the inner peripheral side at a considerable distance from the outermost first fold portion 23a and has a small diameter, these wall portions 23a are formed. , 23e, the generation of Karman vortices is small and extremely small.
It is not necessary to take measures to prevent the generation of Karman vortices between a and 23e.

A second aspect of the present invention is an insulator device provided with noise countermeasures, which is a disk-shaped umbrella portion and is concentrically located on the lower surface side of the umbrella portion and projects downward by a predetermined length. It is intended to apply an insulator device configured by serially connecting insulators having a plurality of annular folds in a plurality of stages. Figure 3
FIG. 4 shows a conventional typical insulator device 30A of this type, FIG. 4 shows an insulator device 30B according to an example of the present invention, and FIG. 5 shows an insulator device 30C according to another example of the present invention. Is shown. Each of these insulator devices 30A to 30C has an insulator of the same type as the insulator 10 shown in FIG. 1 as a component.

The conventional insulator device 30A shown in FIG.
A plurality of insulators 30a having the same structure as the insulator 10 shown in Fig. 10 are connected in series, and the radius of the umbrella portion of each insulator 30a is formed to a dimension D0, and the lower ends of the two insulators 30a adjacent to each other. The space therebetween is formed to have a dimension H0. In the conventional insulator device 30A, the ratio D0 / H0 is generally used.
Is set to 0.8 to 1.3.

On the other hand, an insulator device 30B according to an example of the present invention shown in FIG. 4 is constituted by connecting a plurality of insulators 30b having the same structure as the insulator 10 shown in FIG. 1 in series. Therefore, although the radius of the umbrella portion of each insulator 30b is formed to have the dimension D0, the insulators 30b adjacent to each other are both insulators 30b.
The space between the lower ends of b is formed to have a dimension H1. The dimension H1 is set to be larger than the dimension H0 of the conventional insulator device 30a, and is set by using a pin metal fitting that forms the insulator 30b that is longer than the pin metal fitting that forms the insulator 30a. . In the insulator device 30B, the ratio D0 / H1≤0.7 is set.

Further, an insulator device 30C according to another example of the present invention shown in FIG. 5 is constructed by connecting a plurality of insulators 30c having the same structure as the insulator 10 shown in FIG. 1 in series. However, the radius of the umbrella portion of each insulator 30c is formed to have a dimension D1, and the interval between the lower ends of both insulators 30b adjacent to each other is formed to have a dimension H0. The dimension D1 is
The dimension is set shorter than the dimension D0 of the conventional insulator device 30a, and in the insulator device 30C, the ratio D1 / H0≤0.
It is set to 7.

In the conventional insulator device 30A, the ratio D0 / H0 of the radius D of the umbrella portion of each insulator 30a to the distance H between the lower ends of the adjacent insulators 30a is 0.8 to.
The acoustic natural frequency which is set in the range of 1.3 and which the space portion formed by the two adjacent insulators 30a of the insulator series has,
A phenomenon is often found in which the frequencies of the minute vibrations caused by the Karman vortices generated between the folds of each insulator 30a coincide with each other, and these acoustic natural frequencies and the frequencies of the minute vibrations caused by the Karman vortices coincide. In that case, large noise is generated from the insulator device 30A.

On the other hand, in each of these insulator devices 30B, 30C according to the present invention, the radius of the umbrella portion of each insulator 30b, 30c with respect to the distance H between the lower ends of the adjacent insulators 30b, 30c. D ratio D0 / H1, D1 /
H0 is set to a value outside the range of 0.8 to 1.3 which is 0.7 or less. Therefore, each insulator device 30B, 30
In C, both insulators 30b and 30c adjacent to each other in the insulator series
The natural acoustic frequency of the space formed by the
It is shifted out of the range corresponding to the frequency of the minute vibration caused by the Karman vortex generated between the folds of 0b and 30c.
Therefore, according to each of the insulator devices 30B and 30C according to the present invention, even if the Karman vortex is generated in the folds, noise due to the coincidence between the vibration frequency of the minute vibration caused by the generation of the Karman vortex and the acoustic natural frequency is generated. Occurrence can be prevented.

[0040]

EXAMPLE In this example, an insulator having the same structure as the insulator 10 shown in FIG. 1 (Comparative Example 1), and an insulator having the same structure as the insulator shown in FIG. 1 of Japanese Patent Publication No. 6-101261 (Comparative Example 2). ),
An insulator (Example 1) having the same structure as the insulator 20 shown in FIG. 2 was prepared, and an experiment (Experiment 1) was performed in which these insulators were subjected to a wind tunnel test.

In the present embodiment, the insulator 10 shown in FIG. 1 is used.
An insulator device 30A shown in FIG. 3 employing an insulator having the same structure as that of FIG.
Insulator device (comparative example 3) having the same structure as the above, insulator device (Example 2) having the same structure as the insulator device 30B shown in FIG. 4, and insulator device having the same structure as the insulator device 30C shown in FIG. An experiment (Experiment 2) in which (Example 3) was subjected to an acoustic resonance test was conducted.

(Experiment 1) Test Insulator: The following three types of insulators were adopted as test insulators. An insulator having the same structure as the insulator 10 shown in FIG.
Insulator having a length of 0 mm and the outermost first fold portion 13a having a length of 40 mm (Comparative Example 1). FIG. 1 of Japanese Patent Publication No. 6-101261
Insulator having the same structure as the insulator shown in Fig. 3, the umbrella diameter is 300 mm, the outermost first fold portion has a length of 40 mm, and the third fold portion has a first length.
An insulator (Comparative Example 2) having a length intersecting an extension line connecting the tip of the fold portion and the tip of the second fold portion. An insulator having the same structure as the insulator 20 shown in FIG. 2, an umbrella diameter of 300 mm, and an outermost first fold portion 23.
The length a is 40 mm, and the length of the third fold portion 23c is an extension line L1 connecting the tip of the first fold portion 23a and the tip of the second fold portion 23b.
And the length of the fourth fold 23d is the length of the first fold 23
An insulator having a length intersecting an extension line L2 connecting the tip of a and the tip of the third fold portion 23c (Example 1).

Wind tunnel test: In the wind tunnel test, the wind tunnel laboratory shown in FIG. 2 of Japanese Patent Publication No. 6-101261 proposed by the present applicant was used. A series of insulators is constructed by connecting a plurality of sample insulators in series, which is hung from the ceiling of the wind tunnel laboratory, and the wind in the range of 0 to 25m / sec is sent from the side of the insulator. The sound pressure level was measured with a sound collection microphone installed at a distance. The results are shown in the graph of FIG. 6 (Comparative Example 1), the graph of FIG. 7 (Comparative Example 2), and the graph of FIG. 8 (Example 1).

Consideration: Referring to the measurement result of the sound pressure level, the sound pressure level gradually increases as the wind speed increases in each insulator, but in the insulator of Comparative Example 1, it is clear from the graph of FIG. As described above, in a wide wind speed range from low speed to high speed, there are a plurality of regions locally exhibiting high sound pressure. This suggests that noise is generated in a plurality of wind speed regions.

Further, in the insulator of Comparative Example 2, as is apparent from the graph of FIG. 7, in the low to medium wind speed range, there is no region showing locally high sound pressure, but in the high wind speed range. At, there is a region where the sound pressure is locally high. This suggests that noise is generated in the high wind speed range.

On the other hand, in the insulator of Example 1, as shown in FIG.
As you can see from the graph, the wind speed is 0 to 25 m / sec
In the wind speed region of the range, there is no region that locally shows high sound pressure. This suggests that noise does not occur in the wind speed range of 0 to 25 m / sec.

(Experiment 2) Test Insulator Device: In the following three types of insulator devices, a large number of insulator devices having different ratios D / H were adopted as test insulator devices.
An insulator having the same structure as the insulator 10 shown in FIG. 1 and having an umbrella diameter of 300 m.
m, an insulator device having the same structure as the insulator device 30A shown in FIG. 3, employing an insulator in which the outermost first fold portion 13a has a length of 40 mm. An insulator device having the same insulator and the same structure as the insulator device 30B shown in FIG. An insulator device having the same insulator and the same structure as that of the insulator device 30C shown in FIG. However, in these insulator devices, the radius D of the umbrella portion is set to 57 to 196 mm, and the interval H between the lower ends of both insulators adjacent to each other is appropriately set in the range of 100 to 320 mm to set the ratio D / H to 0. It is adjusted to the range of 0.44 to 1.41. Table 1 shows the structure and ratio D / H of the created insulator device.
And shown in Table 2.

Acoustic Resonance Test: In the acoustic resonance test, as shown in FIG.
Between the insulators that make up the speaker, a sound having the same frequency as the acoustic natural frequency is applied from the speaker 42 to acoustically excite the insulator, and the volume is measured by the microphone 43 to obtain a sound of a high level. Therefore, the level of acoustic resonance in the space formed by the adjacent insulators was measured. The results are shown in Tables 1 and 2 and the graph of FIG.

[0049]

[Table 1]

[0050]

[Table 2]

Consideration: Referring to the results of measurement of the predominant level in the acoustic resonance test, an insulator device having a ratio D / H of 0.7 or less (corresponding to the insulator devices shown in FIGS. 4 and 5). Then, the excellence level is 3 dB or less. This suggests that acoustic resonance does not occur in the insulator device having the ratio D / H of 0.7 or less. On the other hand, in the insulator device having the ratio D / H of 0.8 or more (corresponding to the insulator device shown in Comparative Example 3 ... FIG. 3), when the ratio D / H exceeds 0.8, the excellence level becomes sharp. Is increasing. This is the ratio D /
In the insulator device with H of 0.8 or more, acoustic resonance occurs,
This suggests that noise is generated from the insulator device. For these insulator devices, wind tunnel tests (wind speed 0
˜25 m / sec), but the wind tunnel test has obtained the same result as the acoustic resonance test.

[Brief description of drawings]

FIG. 1 is a side view in which a part of a conventional insulator to which the present invention is applied is longitudinally cut.

FIG. 2 is a side view in which a part of an insulator according to an example of the present invention is longitudinally cut.

FIG. 3 is a side view of a conventional insulator device to which the present invention is applied.

FIG. 4 is a side view of an insulator device according to an example of the present invention.

FIG. 5 is a side view of an insulator device according to another example of the present invention.

FIG. 6 is a graph showing the relationship between wind speed and noise level in a wind tunnel test of an insulator according to a conventional example.

FIG. 7 is a graph showing a relationship between wind speed and noise level in a wind tunnel test of an insulator according to another conventional example.

FIG. 8 is a graph showing the relationship between wind speed and noise level in a wind tunnel test for insulators according to the present invention.

FIG. 9 is an explanatory view schematically showing a method of an acoustic resonance test.

FIG. 10 is a graph showing a relationship between a ratio D / H and an excellence level in an acoustic resonance test of an insulator device.

[Explanation of symbols]

10, 20 ... Insulator, 10a, 20a ... Insulator body, 10
b, 20b ... Cap metal fittings, 10c, 20c ... Pin metal fittings, 11, 12 ... Umbrella portion, 12, 22 ... Connecting portion, 12a,
22a ... Inner hole, 13a-13e, 23a-23e ... Fold, 14a, 14b, 24a, 24b ... Recess, 15a,
25a, 15b, 25b ... Cement, 16a, 26a ...
Rod-shaped body, 16b, 16c, 26b, 26c ... Mounting portion,
30A, 30B, 30C ... Insulator device, 30a, 30b,
30c ... Insulator, 41 ... Insulator series, 42 ... Speaker, 43 ...
Microphone.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takao Nakamura             2-56 Sudacho, Mizuho-ku, Nagoya             Within the corporation F-term (reference) 5G331 AA01 BB22 BC06 DA02 EA07                       FB16

Claims (2)

[Claims] 1. An insulator having a disc-shaped umbrella portion and a plurality of annular fold portions which are concentrically located on the lower surface side of the umbrella portion and project downward by a predetermined length. Outermost 1st
Is set to be the longest, and the second folds adjacent to each other on the inner peripheral side of the first folds are set to be shorter than the first folds, and the second folds are The third folds adjacent to each other on the circumferential side are set to have a length that intersects with an extension line connecting the tip of the first fold and the tip of the second fold, and the third fold. The fourth folds adjacent to each other on the inner peripheral side are set to have a length intersecting with an extension line connecting the tip of the first fold and the tip of the third fold. insulator. 2. An insulator having a disc-shaped umbrella portion and a plurality of annular folds which are concentrically located on the lower surface side of the umbrella portion and project downward by a predetermined length are connected in series in a plurality of stages. In the insulator device configured as described above, the ratio D / of the radius D of the umbrella portion of each insulator to the distance H between the lower ends of the insulators adjacent to each other.
An insulator device in which H is set to 0.7 or less.