JPH05273116A - Defect in insulator detecting method - Google Patents

Abstract

PURPOSE:To provide the defect detecting method in an insulator capable of easily and precisely detecting the presence of a defect of the insulator while keeping the stress distribution applied to the insulator more uniform. CONSTITUTION:Porcelain granular bodies 11 are fixed on the inner periphery of the head section 2 of a suspension insulator 1, and the insulator 1 is vertically reversely arranged and supported on a carrier 3. Granular elastic bodies 13 are filled in a cavity section S formed in the head section 2, and a rubber sheet 14 is mounted on them. A pressure device 6 is arranged at the upper section of the insulator 1, and internal pressure is applied to the elastic bodies 13 from the pressure device 6 via the rubber sheet 14 by water pressure. The elastic bodies 13 are elastically deformed, the granular bodies 11 are pressed by the repulsion, and the presence of a flaw of the head section 2 is detected while the stress distribution is more unified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulator defect detecting method for detecting the presence or absence of a defect in a porcelain insulator such as a suspended insulator.

[0002]

2. Description of the Related Art Conventionally, the following method has been known as a method for detecting a defect in the head portion of a suspension insulator. That is, the insulator is turned upside down, and the surroundings of the head are supported from below by a cylindrical support stand, and water is injected into the cavity of the inner surface of the head under pressure. Since this pressure force of water is applied to the inner peripheral surface of the head, if a part of the head has a defect, the insulator will be destroyed from the defective part. In this way, it is possible to detect the presence or absence of cracks existing in the insulator and defects due to the inclusion of foreign matter.

[0003]

However, the stress due to the water pressure applied to the inner peripheral surface of the head portion of the insulator tends to be large in the corner portion and small in the cylindrical portion, resulting in an uneven and uneven distribution as a whole. There is. Therefore, when there is a minute defect in the cylindrical portion of the head, there is a problem in that the presence or absence of the defect cannot be reliably detected.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to make the stress distribution applied to the insulator more uniform and to easily and accurately detect the presence or absence of defects in the insulator. An object of the present invention is to provide a method for detecting defects in insulators.

[0005]

In order to achieve the above object, in the method of detecting defects in an insulator according to the present invention, an internal pressure is applied to a hollow portion in the head formed in a cylindrical shape with a lid of a porcelain insulator. A method for detecting a defect of an insulator, wherein a granular body made of porcelain is fixed to the inner peripheral surface of the head of the insulator,
An internal pressure is applied to the elastic body in a state where the hollow portion is filled with the granular elastic body.

[0006]

In the present invention, the hollow portion of the porcelain insulator is filled with the granular elastic body. Therefore, when an internal pressure is applied to the cavity, the pressure is transmitted to the insulator through the granular elastic body. At this time, the elastic body is interposed in the gap portion of the granular body fixed to the inner peripheral surface of the insulator and is compressed and deformed by the internal pressure. Then, each elastic body presses the contact portion with the granular body by its reaction force. Therefore, the entire inner peripheral surface of the head portion of the insulator is strongly pressed by such a force, the stress distribution becomes more uniform, and as a result, the accuracy of detecting the presence or absence of a defect is improved.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIGS. As shown in FIG. 2, the suspension insulator 1 is arranged upside down, and its head 2 is fitted and inserted into a support body 3 having a cylindrical shape with a bottom, and a rubber ring 5 is attached at the base of the cap portion 4. Supported through. A pressure device 6 for press-fitting the water L to pressurize the cavity S formed in the insulator head 2 is arranged above the insulator 1. A pressurizing body 9 having a water supply passage 8 in the center is disposed in the cylindrical main body 7 of the pressurizing device 6 so as to be vertically slidable. An O-ring 10 is provided between the tubular body 7 and the pressurizing body 9 to ensure the sealing property against the water L.

As shown in FIG. 3, a granular body 11 made of porcelain is joined to the inner peripheral surface of the insulator head 2 through a glaze layer 12. Further, as shown in FIG. 1, the cavity S formed on the inner surface of the head 2 is filled with a large number of elastic bodies 13 over the entire cavity S. The elastic body 13 is formed of an epoxy resin, and its particle size is preferably a spherical body having a particle size corresponding to the particle size of the granular body 11 in the range of 1.5 to 2.5 mm.

When the elastic body 13 receives pressure, the elastic body 13 is compressed and deformed by itself to strongly press the granular body 11 by its reaction force, so that the elastic modulus is 0.4 × 10 ^{5 to} 1.5 × 10 ⁵ kg / c.
A range of m ² is preferred. This elastic modulus is 0.4 ×
If it is less than 10 ⁵ kg / cm ^{2, the} amount of elastic deformation is too large to produce a portion that cannot contact the granular body 11 or the reaction force thereof becomes weak, which is not preferable. Conversely, 1.5 × 10 ⁵ kg
If it exceeds / cm ² , the granular body 11 may be damaged, which is not preferable.

The upper surfaces of the large number of elastic bodies 13 are covered with a rubber sheet 14, and an O-ring 15 is interposed between the rubber sheet 14 and the pressure body 9 to seal the water L. Then, the water L in the cylindrical main body 7 of the pressurizing device 6 presses the rubber sheet 14 via the water supply passage 8 of the pressurizing body 9 to pressurize the elastic body 13.

When detecting the presence or absence of a defect in the insulator 1, the water L in the pressure device 6 is pressed at a pressure of 400 to 500 kg / cm ² to press the elastic body 13 through the rubber sheet 14. To do. At this time, as shown in FIG. 3, the elastic body 13 on the inner peripheral surface of the insulator head 2 is the granular body 11 on the inner peripheral surface.
It is located between the two and is elastically deformed by itself as shown by the two-dot chain line in FIG.

Then, the granular body 11 is pressed at the portion where the reaction force (arrow in FIG. 3), that is, the elastic repulsive force contacts the granular body 11. Therefore, a pressure force due to water pressure acts effectively and strongly on the granular body 11 via the elastic body 13. The pressing force on the granular body 11 acts in almost the same manner in any part.

Therefore, a required pressure is applied to the inner peripheral surface of the insulator head 2 in both the vertical direction and the circumferential direction. As described above, in this embodiment, since the stress distribution applied to the inner peripheral surface of the insulator 1 by the water pressure can be made more uniform, it is possible to easily detect the presence or absence of defects such as fine cracks existing in the insulator 1 and the inclusion of foreign matter. , Its detection accuracy is excellent.

The present invention is not limited to the above-mentioned embodiments, but may be constructed as follows, for example, within a range not departing from the gist of the present invention. (1) In the above embodiment, the rubber sheet 14 on the elastic body 13 is omitted and water pressure is directly applied to the elastic body 13. (2) As the material forming the elastic body 13, a thermosetting resin other than the epoxy resin is used. (3) Use a liquid other than water L as a medium for applying pressure to the elastic body 13.

[0015]

As described in detail above, according to the present invention,
This has an excellent effect that the stress distribution applied to the insulator can be made more uniform, and the presence or absence of defects in the insulator can be detected easily and accurately.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of an essential part of a state in which an elastic body in a hollow portion of an insulator head is pressed according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an insulator and an entire pressurizing device.

FIG. 3 is an enlarged sectional view of an essential part showing the operation of the embodiment.

[Explanation of symbols]

1 ... Suspended insulator as a porcelain insulator, 2 ... Insulator head, 11 ...
Granular body, 13 ... Elastic body, S ... Cavity part.

Claims (1)

[Claims] 1. A method for detecting a defect in an insulator by applying internal pressure to a hollow portion in the head formed in the shape of a cylinder with a lid of a porcelain insulator, wherein the porcelain is attached to the inner peripheral surface of the head of the insulator. A method for detecting defects in an insulator, characterized in that a granular material made of silicon is fixed, and an internal pressure is applied to the elastic body in a state where the hollow portion is filled with the granular elastic body.