JPH07161252A - Resin molded product and its manufacture - Google Patents

Abstract

PURPOSE:To provide a resin molded product excellent in an insulation characteristic and mechanical strength. CONSTITUTION:In a metal mold 1 for manufacturing a resin molded product, partitioning plates 2 are arranged with a prescribed space provided. Further, these partitioning plates 2 are constituted of material melted when heated, for instance, olefin material or the like having a low melting temperature. After resins A, B,...N having a different characteristic are injected into each region divided by the partitioning plates 2, by heating the resins, the partitioning plate 2 is melted, and also hardening the injected resin. Here, the resins from A to N are suitably selected so as to continuously change the characteristic of the resin injected to each divided region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded product used in electric equipment to which a high voltage is applied and a method for manufacturing the same.

[0002]

2. Description of the Related Art Generally, in an electric device to which a high voltage is applied, a portion to which a high voltage is applied, for example, a high voltage conductor is
You can mechanically support it with a solid insulator such as an insulating spacer,
Many structures have been used such as contacting with a solid insulator or filling a high voltage portion with the solid insulator. In addition, high-voltage electrical equipment is designed so that the main body of the equipment is immersed in air or an insulating medium having a better insulating performance than air, for example, an insulating gas such as SF ₆ gas, insulating oil, or an insulating liquid such as fluorinate. Insulated by storing.

[0003]

However, since the dielectric constant of a solid insulating material is usually higher than that of a liquid or gas insulating medium, the solid insulating material used as a support or the like is used in the above-mentioned insulating method. If the high voltage part of the electric device is not brought into complete contact with the object, a small wedge-shaped gap will be formed between the solid insulator and the high voltage part. In general, the dielectric constant of a liquid / gas insulator is 1/2 to 1/4 that of a solid insulator, and is about 1/4 in the case of an insulating gas such as SF ₆ gas. A large electric field concentration due to the dielectric constant ratio occurs in the portion, and the wedge-shaped gap portion becomes a weak point in the insulation strength, which is a big obstacle in reducing the insulation dimension. Therefore, conventionally, an electric field shield is attached so that an electric field is not applied to this wedge-shaped gap portion, a recess is provided in the high-voltage portion of an electric device, and a contact portion with an insulator is arranged therein. Was taken, but the production was very troublesome.

Further, among high-voltage electric equipment, in oil-filled transformers and gas-insulated transformers having a composite dielectric insulation structure such as transformers, for example, between insulators arranged in windings or , Around the electrostatic shield for mitigating the electric field at the end of the winding, and when a minute gap occurs between the coated conductors, the dielectric constant of the insulating medium in the gap is the dielectric constant of the solid insulator. Since it is smaller, the electric field is concentrated in this gap portion, which causes dielectric breakdown.

As one of the means for reducing the concentration of electric field in such a minute gap, for example, Japanese Patent Laid-Open No. 53-743
As disclosed in Japanese Patent Laid-Open No. 21 and Japanese Patent Laid-Open No. 63-66910, it has been proposed to reduce the concentration of an electric field by using a solid insulator having a low dielectric constant as the insulator. However, in general, an insulator having a low dielectric constant is twice or more expensive as compared with an ordinary insulator, so that there is a drawback that the price of a high-voltage electric device using the same is increased.

Alternatively, as disclosed in Japanese Examined Patent Publication No. 3-34644, the insulating layer portion of the electrostatic shield ring for electrostatic shielding of the static induction device is molded and the insulating ring disposed at the end. Means for avoiding the formation of wedge-shaped gaps have also been proposed. However, it is very difficult in manufacturing to completely mold and avoid the wedge-shaped gap, and there is a drawback that the number of steps for molding is significantly increased.

Further, since the dielectric constant of a solid insulator is usually higher than that of a gas or a liquid, it is possible to reduce the electric field on the conductor surface by thickly coating the high-voltage conductor with the solid insulator. However, the electric field applied to the insulating medium becomes large. Furthermore, the breakdown strength of gas or liquid is usually lower than the breakdown strength of solid insulators, so that breakdown occurs from the insulating medium portion of gas or liquid. Further, as described above, since the insulating coating portion of the conductor is supported by the solid insulator such as the insulating spacer, a minute gap is generated between both solid insulators, and electric field concentration occurs in this gap. Is also as described above.

As described above, the greatest technical problem in the resin molded product used for various electric devices having a high voltage portion is how to maintain the dielectric strength of these electric devices.

The present invention has been proposed in order to solve the above-mentioned problems of the prior art. The first object of the present invention is to obtain various characteristics of a resin molded product used for electric equipment at a predetermined portion. The purpose of the present invention is to provide a resin molded product having excellent mechanical strength by enhancing the insulation characteristics of the high-voltage conductor by changing it substantially continuously for each. A second object of the present invention is to provide a method for manufacturing the above resin molded product.

[0010]

A method for manufacturing a resin molded product according to claim 1 is to meet the second object.
By injecting a resin having different electrical characteristics or at least one of mechanical characteristics into each region partitioned by the partitioning plate arranged at a desired interval in the mold, and then heating, While melting the partition board,
It is characterized in that the injected resin is cured.

The method for manufacturing a resin molded product according to a second aspect of the present invention also corresponds to the second object, and is divided by the dividing plates arranged at desired intervals in the mold. By injecting the same resin into the region, adding different fillers to this resin for each region, and then heating,
It is characterized by melting the partition plate and curing the injected resin.

Next, the resin molded product according to the third aspect corresponds to the first object, in which two or more kinds of resins having different relative permittivities are gradually changed in relative permittivity. It is characterized by being continuously layered.

The resin molded product according to the fourth aspect of the invention also corresponds to the first object, and two or more kinds of resins having different electric conductivity are continuously formed so that the electric conductivity gradually changes. It is characterized by being layered on.

Furthermore, the resin molded product according to claim 5 is also
It corresponds to the first object, and is characterized in that two or more kinds of resins having different filler mixing ratios are continuously layered so that the mixing ratio gradually changes. .

[0015]

According to the invention described in claim 1 or 2,
It is possible to easily obtain a resin molded product in which various characteristics such as mechanical and electrical characteristics are gradually changed.

When the resin molded product according to claim 3 is used as an insulating member for various electric devices, the relative permittivity thereof gradually changes, so that a gap formed between the insulating member and the insulating medium. The concentration of the electric field on the

Further, when the resin molded product according to claim 4 is used as an insulating member of various electric devices, the electric conductivity thereof is gradually changed, so that the current flowing through the place where the insulating member is arranged is reduced. In addition, it is possible to reduce loss and heat generation due to current.

Further, when the resin molded product according to claim 5 is used as an insulating member for various electric devices, it is suitable to arrange a portion having a high mixing ratio of the filler in a portion requiring a large strength. An insulating support structure can be taken.

[0019]

【Example】

(Method for Manufacturing Resin Molded Product) An embodiment of the present invention will be specifically described below with reference to the drawings. That is, as shown in FIG. 1, a partition plate 2 is arranged at a predetermined interval in a mold 1 for producing a resin molded product. In addition, this division board 2
Is composed of a material that melts when heated, such as an olefinic material having a low melting temperature. Then, after injecting resins A, B, ... N having different characteristics into the respective regions divided by the partition plate 2, by heating, the partition plate 2 is melted and the injected resin is cured. Let In this case, in order to continuously change the characteristics of the resin injected into each of the divided areas, A
Resins from N to N are appropriately selected.

When the injected resin is a thermosetting resin, a partition plate that melts at a temperature lower than the curing temperature is used, and the temperature is raised to the curing temperature of the resin to melt the partition plate. , Cure the injected resin. When the injected resin is a thermoplastic resin, the temperature is raised to a temperature higher than the melting temperature of the partition plate to melt the partition plate, and then the injected resin is cured.

As the resin to be injected, for example,
Use resins with different electrical properties such as permittivity and resistivity, or use resins with different mechanical properties such as elastic modulus, or resins with two or more different properties such as electrical properties and mechanical properties. Can be used. Further, in changing the characteristics, resins having different properties may be used, or as shown in FIG. 2, the additive 3 is added to the resin having the same characteristics and the additive 3 is added to each divided area. It is also possible to change various characteristics for each divided area by changing the material or the addition amount of. Further, the shape or size of the material may be changed to a hollow material or a solid material by using the additive made of the same material.

It should be noted that after sorting by a material that melts when heated, a resin may be injected to construct an electric device, and then the sorting board may be melted by heating to manufacture a desired resin molded product. Alternatively, the resin premolded by the above manufacturing method may be used in a predetermined part of the electric device.

According to such a method for producing a resin molded product,
The resin molding die is equipped with a partitioning plate made of a material that melts when heated, and a prescribed resin is injected into each partitioned area for heat treatment by a simple means. It is possible to easily manufacture a resin molded product in which a plurality of characteristics such as physical, mechanical and thermal characteristics are changed according to the location where the resin molding is arranged.

(Resin Molded Product) By using the resin molded product obtained by the above-mentioned manufacturing method as an insulator of high-voltage electric equipment, the following operational effects can be obtained.

First, a case will be described in which, of the electric characteristics, a resin molded product constructed so that the relative permittivity gradually changes is used as an insulator in an electric device. That is, as shown in FIG. 3, the insulator 12 covering the conductor 10 is
The relative permittivity ε ₁ on the side in contact with is the highest, and the relative permittivity ε ₂ ... ε _n gradually decreases as the distance from the conductor 10 increases. As a result, the interface between the insulating material 12 covering the conductor 10 and the insulating medium, especially the outermost layer 1 of the insulating material.
The electric field concentration on the wedge-shaped gap generated at the contact portion between 2c and the supporting insulator 11 such as the insulating spacer is relaxed. Moreover, since the surface of the conductor 10 is covered with the insulator 12a having a high relative dielectric constant, the electric field on the surface of the conductor 10 is greatly reduced, and the insulating characteristic is significantly improved.

The conductivity of the insulator covering the conductor is
By making it gradually smaller from the inside to the outside, due to the skin effect when current flows through the conductor,
The effect of reducing a large current flowing on the surface of the conductor is exerted, the loss is reduced, and the heat generation due to the current is also reduced.

Further, when the conductor is covered with a resin mixed with a conductive material such as metal, the adhesiveness with the conductor and the heat transfer characteristic are improved. That is, the farther away from the conductor, the less the amount of conductive contaminants such as metal powder mixed, by coating the conductor with a material having excellent electrical insulation characteristics,
Insulation characteristics can be improved. Further, since the thermal conductivity gradually changes, heat is continuously dissipated from the conductor, improving the thermal characteristics as well as the mechanical characteristics.

The resin molded product of the present invention is not limited to the above-mentioned embodiment, and may be manufactured without the manufacturing method according to the present invention.

[0029]

As described above, according to the present invention, the electric characteristics or the mechanical characteristics are different in each region divided by the dividing plate arranged at a desired interval in the mold. (EN) Provided is a method for producing a resin molded product, which is capable of easily obtaining a desired resin molded product by injecting a resin and then heating the resin to melt the partition plate and cure the injected resin. it can.

Further, various characteristics of the resin molded product are changed substantially continuously for each predetermined portion to enhance the insulating property in the high-voltage conductor and to provide a resin molded product excellent in mechanical strength. You can

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a method for manufacturing a resin molded product according to the present invention.

FIG. 2 is a sectional view showing an embodiment of a method for manufacturing a resin molded product according to the present invention.

FIG. 3 is a sectional view showing an embodiment in which a resin molded product according to the present invention is applied to a conductor of an electric device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mold 2 ... Separation board 3 ... Additives A to N ... Injected resin 10 ... Conductor 11 ... Support insulator 12 ... Insulator

Claims (5)

[Claims] 1. A resin having different electrical characteristics and / or mechanical characteristics is injected into each region divided by a dividing plate arranged at a desired interval in a mold and then heated. By so doing, the divided plate is melted and the injected resin is cured, and the method for producing a resin molded product. 2. The same resin is injected into each region divided by a dividing plate arranged at a desired interval in the mold, and a different filler is added to each region of the resin. A method for producing a resin molded product, characterized in that the divided resin is melted by heating and the injected resin is cured. 3. A resin molded product, characterized in that two or more kinds of resins having different relative dielectric constants are continuously layered so that the relative dielectric constants thereof gradually change. 4. A resin molded product, characterized in that two or more kinds of resins having different electric conductivities are continuously layered so that the electric conductivities gradually change. 5. A resin molded article, wherein two or more kinds of resins having different mixing ratios of fillers are continuously layered so that the mixing ratio gradually changes.