JPH06104135A - Manufacture of insulator - Google Patents

Abstract

PURPOSE:To enable the formation of dielectric gradient to a resin insulator by injecting resin, in a state of partitioning the inside of a molding die with meshes for limiting the passage of minute granular insulating materials. CONSTITUTION:A resin molded layer 3 composed of three layers is formed; the three layers are an outer layer 6 having large-diameter hollow minute granular insulators 11 scattered in resin, an intermediate layer 5 having intermediate- diameter hollow minute granular insulators 12 and solid minute granular insulators 14 scattered in the resin, and an inner layer 4 having small-diameter solid minute granular insulators 14 scattered in the resin. Hereupon, apparent permittivities of the resin molded layer 3 have a gradient in the order of the outer layer 6 < the intermediate layer 5 < the inner layer 4, and the permittivity of the outer layer 6 being outside has a value close to 1.0 being the relative permittivity of air. Consequently, it becomes possible to equalize the voltage burdens at the time of voltage application, suppress the electric field concentration at the edge part of an apparatus. As the result, it becomes possible to make the voltage of a transformer higher, and reduce the size.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an insulating material such as a resin insulating layer of a resin molding device.

[0002]

2. Description of the Related Art For example, a mold transformer or a mold PT,
In a molded electric device such as a CT, a resin insulation covering the winding body is obtained by injecting a resin such as an epoxy resin into the molding die and curing the resin while the winding body is arranged in the molding die. I am trying to form a layer. Thus, as this type of resin, a resin in which a solid fine granular insulating material such as silica or glass is mixed is used, whereby an insulating layer in which the fine granular insulating material is dispersed is formed. It is like this.

[0003]

By the way, when the fine granular insulating material is mixed in the resin as described above, the relative dielectric constant of the insulating layer is apparently higher than that of the resin alone. The value is about 7 to 4. Generally, the insulation structure of electric power equipment is composite insulation, but in the case of the above-mentioned molded equipment, the insulation insulation is a main insulation and the outside insulation is a composite insulation structure. In composite insulation, the voltage applied to the equipment is shared by each insulator with a voltage proportional to the reciprocal of the dielectric constant, so in the case of mold insulation, the relative dielectric constant is 1.0.
That is, a high voltage is shared by the outside air side, and in an actual device, a high electric field is concentrated at the end with many sharp edges.

Therefore, in order to ensure a proper creeping insulation strength, it is necessary to suppress the electric field strength at the end of the above-mentioned equipment. In order to reduce the electric field strength, it is sufficient to form a dielectric gradient in the insulating resin layer so that the relative dielectric constant of the outer portion approaches 1.0. There was no suitable way to create a dielectric gradient.

Therefore, it is an object of the present invention to provide a method of manufacturing an insulating material, which makes it possible to form a dielectric gradient in the resin insulating material.

[0006]

According to the method for producing an insulating material of the present invention, a resin mixed with a hollow or solid fine granular insulating material is injected into a molding die and cured to form the fine granular material inside. A method for producing an insulating material in which an insulating material is dispersed, wherein the molding die is partitioned by a mesh for limiting passage of the fine granular insulating material, and the resin is injected. It has characteristics.

[0007]

According to the above means, since the inside of the molding die is partitioned by the mesh, the passage of the fine granular insulating material mixed with the resin injected into the molding die is restricted by the mesh, The distribution state between the resin layers separated by the mesh becomes different. Here, the dielectric constant of the resin layer containing the hollow fine granular insulating material is apparently smaller than the relative dielectric constant of the resin, while the dielectric constant of the resin layer containing the solid fine granular insulating material is Apparently, the relative permittivity becomes larger than the original relative permittivity of the resin.

Therefore, by appropriately setting the particle size of the fine granular insulating material to be mixed with the resin, the hollow or solid selection of the fine granular insulating material, the hole diameter of the mesh, the partition position, the resin injection position, etc. It is possible to form an arbitrary dielectric gradient in the resin insulator.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a resin mold transformer will be described below with reference to the drawings. First,
In FIG. 2, the winding 1 of the resin-molded transformer is formed by winding a conductor 2 having an insulating coating (not shown) many times. The winding 1 is molded with a resin mold layer 3 as an insulator.

The resin mold layer 3 is made by dispersing four kinds of fine granular insulators, which will be described later, in a resin such as an epoxy resin. In this case, the inner layer 4, which is closer to the winding 1, is arranged in this order. It is composed of three layers, an intermediate layer 5 and an outer layer 6. A first mesh 7 is provided at the boundary between the outer layer 6 and the intermediate layer 5, and a second mesh 8 is provided at the boundary between the intermediate layer 5 and the inner layer 4. This resin mold layer 3 is manufactured by a method described in detail below, and by making the distribution state of the fine granular insulating material different between the layers 4, 5, 6 so that the layers 4, 5, 6 have different dielectric constants. Is configured to be.

Next, the procedure for forming the resin mold layer 3 will be described with reference to FIG. FIG. 1 schematically shows how the resin mold layer 3 is formed. Here, a resin material 10 is housed in the resin injecting device 9, and the resin material 10 contains four kinds of bead-shaped minute granular insulators 11 made of, for example, silica or glass.
~ 14 are mixed.

Specifically, fine granular insulators 11 and 12
Are formed in a hollow shape (indicated by white circles for convenience in the drawing), of which the fine granular insulating material 11 has a center particle diameter of 100 μm and a large diameter (large white circle), and the fine granular insulating material 12 has a center particle diameter of 50 μm. It is said to have an intermediate diameter (medium white circle). Then, the fine granular insulators 13 and 14 are formed in a solid shape (indicated by black circles for convenience in the drawing), of which the fine granular insulator 13 has a central particle diameter of 50 μm and an intermediate diameter (medium black circle), The fine granular insulator 14 has a central diameter of 10 μm and a small diameter (small black circle).

When carrying out resin molding, the winding 1 is placed in a molding die (not shown) having a cavity corresponding to the outer shape of the resin molding layer 3, and the first mesh 7 and the second mesh are formed. 8 is arranged at a predetermined position (a position which should be a boundary between the layers 4, 5 and 6). Here, the first mesh 7 has a hole diameter of 80 μm, and the second mesh 8 has a hole diameter of 30 μm.

In this state, the resin material 10 is injected from the outer layer 6 side into the mold by the resin injection device 9.
The resin mold layer 3 is formed by heating and curing the resin material 10 filled in the molding die. At this time, the molding die is partitioned by the first and second meshes 7 and 8. Therefore, passage of the fine granular insulating materials 11 to 14 mixed with the resin material 10 is restricted by the meshes 7 and 8.

That is, the first mesh 7 has a hole diameter of 80 μm.
Therefore, the intermediate and small diameter fine granular insulating material 1
2, 13, and 14 pass through, but the large-diameter fine granular insulating material 11 cannot pass through the first mesh 7 and remains in the outer layer 6 portion. Since the second mesh 8 has a hole diameter of 30 μm, the small-diameter fine granular insulating material 1
4 only passes through and has a medium-diameter fine granular insulating material 12 and 13
Will not be able to pass through and will remain in the mid layer 5.

As a result, as shown in FIG. 1, the outer layer 6 in which the large-diameter hollow minute granular insulator 11 is dispersed in the resin,
An intermediate layer 5 in which a hollow fine granular insulator 12 and a solid fine granular insulator 13 having a medium diameter are dispersed in a resin, and an inner layer 4 in which a solid fine granular insulator 14 having a small diameter is dispersed in a resin. Thus, the resin mold layer 3 including the three layers is formed.

Here, the fine granular insulating material 1 hollow in the resin 1
When 1 and 12 are included, bubbles having a relative dielectric constant of about 1.0 are dispersed in the resin, so that the dielectric constant of the resin layer is apparently lower than that of the resin. Get smaller. On the other hand, when the resin contains solid fine granular insulators 13 and 14, an insulator having a relative dielectric constant of about 5.0 is dispersed in the resin, so that the dielectric constant of the resin layer is Apparently, the relative permittivity becomes larger than the original relative permittivity of the resin.

Therefore, in the resin mold layer 3, the apparent dielectric constant has a gradient in the order of outer layer 6 <intermediate layer 5 <inner layer 4, and the outer layer 6 located outside has a dielectric constant of The relative permittivity of air is close to 1.0. As a result, it is possible to equalize the sharing of the voltage when the voltage is applied, and suppress the electric field concentration at the device end,
As a result, it is possible to increase the voltage and size of the transformer.

As described above, according to the present embodiment, it is possible to easily form the dielectric gradient with respect to the resin mold layer 3 which has not been available by the conventional method. As a result, the relative permittivity of the resin mold layer 3 can be arbitrarily adjusted, electric field concentration and the like at the end of the resin mold device can be suppressed, and the insulation performance of the device can be improved. It is possible.

In the above embodiment, four kinds of fine granular insulators 11 to 14 and two kinds of meshes 7 and 8 are used to form three resin layers. The number of holes, the hole diameter of the mesh, the number of holes, and the like can be arbitrarily changed according to the application. For example, the dielectric gradient can be formed by using one kind of fine granular insulator having a wide particle size distribution. Besides, the present invention is not limited to resin-molded transformers, but can be applied to other molding equipment such as molds PT and CT in general, and the present invention can be appropriately modified and implemented without departing from the scope of the invention. .

[0021]

As is apparent from the above description, according to the method for producing an insulator of the present invention, a resin mixed with a hollow or solid fine particulate insulating material is injected into a molding die and cured. A method of manufacturing an insulator in which the fine granular insulating material is dispersed by injecting a resin in a state in which the molding die is partitioned by a mesh for limiting passage of the fine granular insulating material. As a result, the excellent practical effect that the dielectric gradient can be easily formed in the resin insulator is exhibited.

[Brief description of drawings]

FIG. 1 is a view schematically showing an embodiment of the present invention, showing a state during molding.

FIG. 2 is a diagram showing a winding structure of a resin mold transformer.

[Explanation of symbols]

In the drawing, 1 is a winding wire, 3 is a resin mold layer (insulator), 4
Is an inner layer, 5 is an intermediate layer, 6 is an outer layer, 7 is a first mesh,
Reference numeral 8 is a second mesh, 10 is a resin material, 11 and 12 are hollow fine granular insulating materials, and 13 and 14 are solid fine granular insulating materials.

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Claims (1)

[Claims] 1. A method for producing an insulating material in which the fine granular insulating material is dispersed by injecting a resin in which a hollow or solid fine granular insulating material is mixed into a molding die and curing the resin. A method for manufacturing an insulator, wherein the resin is injected in a state in which the molding die is partitioned by a mesh for restricting passage of the fine granular insulating material.