JPS58175816A - Manufacture of molded coil - Google Patents

Abstract

PURPOSE:To eliminate the need for painting work and working hours and drying time required for said painting work by winding an insulating material previously dyed on the outer circumference of the coil and impregnating ultraviolet- curing resin into the coil. CONSTITUTION:The coil 2 is formed by alternately winding a conductor and a base material on a winding core 1. An outer-circumferential insulting layer 3 is formed by winding the insulting material consisting of a material, such as polyethylene terephthalate non-woven fabric, aromatic polyamide paper, etc. on the outer circumference of the coil 2. The end surface 4 of the coil is sealed. The outer-circumferential insulating layer 3 is dyed previously when the coil is wound. Insulating resin for impregnation cntaining ultraviolet-curing resin is impregnated into the coil after preparatory drying. The surface of the outer- circumferenctial insulating layer is cured through the irradiation of ultraviolet rays, the leakage of insulting resin for impregnation is prevented, the coil is entered into a drying furnace and heated and cured and cooled slowly, and the winding core is pulled out from the coil.

Description

Detailed Description of the Invention The present invention relates to a method for manufacturing a resin molded coil, and particularly to a method for manufacturing a resin molded coil in which the resin molded coil is impregnated with a resin composition without using a mold. be.

Conventionally, the method of manufacturing resin molded coils used in dry-type transformers, etc. is to place a bare coil in a mold, pour a resin composition such as epoxy resin around and inside the bare coil, and then harden it. It is being However, this conventional manufacturing method has the drawback that a large amount of labor and expense is required for mold release processing 9 assembly, mold disassembly after resin hardening, and maintenance of the mold. For this reason, after impregnating the coil with a resin that has the same performance as a coil made using a manufacturing method that uses a mold without using a mold, the coil is irradiated with ultraviolet rays to form a hardened film on the coil surface. A method has been devised in which a molded coil is obtained by completely curing the inside of the coil in a drying oven.

This method will be explained using drawings.

The figure is a partial side sectional view showing a resin molded coil.

In the figure, (1) is a metal winding core.

The coil (2) is formed by alternately winding a conductor and a base material (both not shown) around a winding core 111.

The outer insulating layer +31 #- is formed by winding an insulating material made of polyethylene terephthalate nonwoven fabric, aromatic polyamide paper, etc. around the outer periphery of a coil, and has a width wider than the width of the coil.

The end face of the coil (41) is sealed by an appropriate method. After preliminary drying, the bare coil constructed as described above is placed in an impregnating tank (not shown) of a vacuum pressurized tank and coated with ultraviolet curable resin. The insulating resin for impregnation is injected into the impregnation tank and impregnated under pressure.

After this pressure impregnation, the purple coil consisting of the winding core 11] and the coil 1 was taken out, and the coil outer insulating layer (31) was irradiated with ultraviolet rays from an ultraviolet irradiation device (not shown).
! 4. Harden the surface of 4+31 to prevent leakage of the insulating resin for impregnation. 6. Next, put it in a drying oven to heat and harden it. After cooling, take out the winding core 111 from the coil (2) and apply it to the surface of the coil (2). Paint and complete the molded coil.

However, when the coil is manufactured by such a method, it takes time for the painting work, and it also takes a long time to dry the paint after finishing. Furthermore, while it is drying, it is not possible to proceed to the next step, and there are also disadvantages in that, for example, during post-painting steps such as assembly work, the surface may be scratched and the paint may peel off.

This invention was made with the purpose of eliminating the above-mentioned drawbacks, and it is possible to dye insulating paper such as polyethylene terephthalate nonwoven fabric or aromatic polyamide paper in advance to be used as the outer insulating layer at the same time as coil winding. An embodiment of the present invention will be described below based on its characteristics.

First, before winding the coil, the insulating material used for the outer insulating layer is dyed. In this example, the dyes A3001 and Asogg, manufactured by Hysol Japan Co., Ltd., were used. They were mixed in a ratio of 6 parts (1 part) to 100 parts acetone, and the solution was passed through an insulating material at a speed of 1 m 7 minutes, followed by drying. I used what I had prepared.

Next, construct a bare coil using this dyed insulating material in the same manner as explained using the above figure, and after pre-drying, the coil is impregnated with an insulating resin for impregnation, including an ultraviolet curable resin. Then, the surface of the outer insulating layer is cured by ultraviolet irradiation to prevent leakage of the insulating resin for impregnation, and this is placed in a drying oven to be heated and cured, and after cooling slowly, the core is extracted from the coil to complete the molded coil.

Here, the viscosity of the insulating resin for impregnation containing the ultraviolet curable resin will be explained. In general, it is best to use a low-viscosity resin for impregnation in order to shorten the impregnation time, but in the method for manufacturing molded coils described in this invention, ultraviolet rays are irradiated after resin impregnation. to form an outer skin between the outsides of the coil, and 'F' impregnated inside the coil.
This results in contradictory results in terms of preventing leakage of fat A. Therefore, impregnating the resin with a high viscosity will result in a dark brown color (although this also has drawbacks).

This is because the impregnation time becomes longer when a high viscosity resin is impregnated, and the stick glaze attached to the coil surface becomes thicker, resulting in a weakening of the external insulation dyeing effect according to the present invention. The inventors of the present invention were concerned about this point, and as a result of many experiments, found that if the porosity of the insulating material used for the outer insulating layer is 15 to 4b%, the viscosity of the insulating resin for impregnation, including the ultraviolet curable resin, It has been found that it is optimal to set the range to 500 CPS to 1200 Cps if the porosity is 45% or more.

As a result, the thickness of the resin attached to the outer circumference of the coil is O, S ~ 0.
60 and maintains this thickness even after UV irradiation. Therefore, after manufacturing the coil 0. The dyeing of the outer insulating layer is clearly visible through the nine coats adjusted to -0.6 fl, and the coil surface has a higher luster than the conventional coil coated after manufacturing, making it a mold with high aesthetic product value. You can get a coil.

As explained in detail above, according to the present invention, the finishing work becomes unnecessary, and the working time and drying time required for this work become unnecessary. In addition, since the color tone of the coil can be seen through the coating, a molded coil with good gloss and high product value can be obtained.

In the examples, a dye manufactured by Hysol Japan Co., Ltd. was used, but it goes without saying that the dye is not limited to this.

Further, the insulating material such as insulating paper, impregnated resin, etc. to be used are not limited to specific ones, and known ones can be appropriately used as desired.

[Brief explanation of the drawing]

The figure is a partial side sectional view showing an example of a resin molded coil. Il+ ---one-turn core, f! +---Coil, 131--
One outer insulating layer, +41-7- coil end face. Agent Shin Kuzuno −

Claims (2)

[Claims] (1) A method for manufacturing a molded coil, which includes the step of winding a pre-dyed insulating material around the outer periphery of the coil and then impregnating it with an ultraviolet curable resin. (2) If the insulating material to be dyed has a porosity of 15 to 4%, the viscosity of the impregnating resin is WOO to 5OOCC.
P8. The method for producing a molded coil according to claim 1, wherein a molded coil having a viscosity of SOO to 1100CP8 is used for a molded coil having a porosity of 41% or more.