JPS6199311A - resin mold coil - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a resin molded coil used in transformers, transformers, etc., and a method for manufacturing the same.

[Background of the invention]

Conventionally, as one method for manufacturing resin-molded coils, as disclosed in Japanese Patent Publication No. 47-16219, etc., a fibrous base material such as glass cloth is impregnated with resin and made into a semi-cured thin sheet insulator. (hereinafter referred to as prepreg) is wound around a core, and a conductive coil is wound on top of the winding core, and then a molding material mainly composed of resin is injected into the core as part of a mold die and hardened to form the prepreg. There is a method of integrally molding the conductive coil and the conductive coil.

In this method, a prepreg that has been pre-impregnated with resin is used as the inner circumferential insulation member of the coil, so it is possible to reduce the thickness of the resin layer on the inner circumferential side of the coil and make the entire resin molded coil smaller and lighter. However, no consideration was given to the adhesion between the prepreg and the molding material that is injected later. In other words, prepreg is generally a thin sheet insulator with a smooth surface made of a fine fibrous base material filled with resin without leaving any gaps, and the prepreg placed on the inner periphery of the coil is Because it is completely cured during the heating and drying process of the coil, it has poor adhesion with the molding material that is injected later, and peeling occurs between the molding material and the prepreg due to temperature changes after molding, resulting in poor insulation performance and mechanical properties. It is easy to cause a decrease in the strength of the target.

In order to improve the adhesion between the prepreg and the molding material that is injected later, the prepreg is wound around the core as disclosed in Japanese Patent Application Laid-Open No. 17921/1983.
Furthermore, attempts have been made to wind a fibrous layer material such as glass cloth or glass tape that is not impregnated with resin on top of the fibrous material, and then wind a conductive coil on top of the fibrous material, but some results have not been achieved. However, even with this method, the prepreg itself is impermeable to the molding material that is injected later, and the fibrous material wound on top of the prepreg is crushed by the electric wire during coil winding, causing the molding material to leak. Since the prepreg was difficult to penetrate, the adhesion between the prepreg and the molding material that was injected later was not sufficient.

[Purpose of the invention]

The purpose of the present invention is to sufficiently improve the adhesion between the coil inner circumferential insulating member and the molding material injected later, thereby achieving high reliability in terms of insulation performance and mechanical strength, and a compact and lightweight structure. Our objective is to provide resin molded coils.

[Summary of the invention]

The first invention of the present application is a resin mold formed by integrally molding a conductive coil and a coil inner peripheral insulating member disposed on the inner peripheral side of the conductive coil with a resin-based resin material. In the coil, the coil inner circumferential insulating member is a thin sheet insulator having a network structure having many through holes and an uneven surface, and the molding material is formed in the many through holes and the recesses on the surface. This is a resin molded coil characterized by being filled.

Further, the second invention provides a fibrous base material having a large number of pores and an uneven surface, and a fibrous base material that is impregnated with the pores and the surface unevenness and hardened. A thin sheet insulator with a network structure made of resin is used as the coil inner circumferential insulating member, and the coil inner circumferential insulating member is wound on the winding core, and a conductive coil is wound thereon. This method of manufacturing a resin-molded coil is characterized in that the coil inner peripheral insulating member and the conductive coil are integrally molded using a molding material mainly made of resin as part of a mold.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a diagram showing an embodiment of the resin molded coil of the present invention.

As schematically illustrated in FIGS. 1(a) and 1(b), the resin molded coil 1 of this embodiment includes a conductive coil 2 divided into two in the coil axial direction and a coil arranged on the inner circumferential side of the conductive coil. The inner peripheral insulating member 3 is integrally molded with a molding material 4 made of a resin such as epoxy resin mixed with an inorganic filler.

To explain in more detail, each conductive coil 2 is
As shown in FIG. 1(c), the electric wire 5 is wound in multiple layers with an interlayer insulating material 6 interposed therebetween, and the coil inner peripheral insulating member 3 has a large number of through holes and has an uneven surface. The thin insulating material has a network structure, and FIG. 1(c) shows the thin insulating material embedded in the molding material 4.

Figures 2 and 3 are diagrams showing the coil inner circumferential insulating member 3 in Figure 1. In Figure 6, 7 is woven in a coarse plain weave pattern with a plurality of warps and wefts lined up each. The fibrous base material is selected from inorganic fibers such as glass fibers or synthetic fibers such as polyester fibers that are compatible with the heat resistance category of the molded coil. This fibrous base material 7 is impregnated in advance with a low-viscosity resin that does not contain a filler, and a large number of through holes 9 corresponding to the mesh of the base material 7 are formed as shown with diagonal lines 8 in FIG. and surface wavy irregularities lOa, 10b
By coating only the surface of the fibers with a thin layer of resin, leaving the fibers intact, and then heat-treating until the resin is completely cured, the intersections of the mesh are fixed with the resin.

As shown in FIG. 1(c), a thin sheet insulator having a strong network structure that can maintain the original shape of the base material 7 even when embedded in the mold material 4 is produced. This thin insulator is used in the form of a sheet or tape.

The size of the mesh of the thin insulator, that is, the size of the through holes 9, is such that the molding material 4 can easily penetrate (in the illustrated example, about 0.5
+ m x 3.5 cm), and if it is too thick, it will easily break when wound around the core, so a thickness of about 0.2 to 0.5 mm is appropriate.

The resin impregnated into the fibrous base material 7 may be an epoxy resin of the same type as the molding material 4, or may be a different type of resin such as a polyester resin or a phenol resin.

When the thin sheet insulator with the network structure shown in Figures 2 and 3 is used as the inner circumferential insulation member of the coil, it has good adhesion with the molding material that is injected later, and can be manufactured at low cost with fewer man-hours. This material is suitable for use as a coil inner circumferential insulating member.

FIG. 4 shows another example of a thin sheet insulator with a network structure suitable for use as an insulating member for the inner periphery of a coil. A large number of through holes 12 are provided by punching, and convex portions 13b and concave portions 13a are formed by cutting and raising the surface.
is formed, and the impregnated resin is completely cured in this state. In order to improve the adhesion with the molding material, it is preferable to form the convex portions 13b and the concave portions 13a alternately on both surfaces.

Next, a manufacturing process of a resin molded coil using a thin sheet insulator having a network structure shown in FIG. 2, FIG. 3, or FIG. 4 as a coil inner peripheral insulating member will be described.

First, as shown in FIG. 5, a coil inner circumferential insulating member 3 made of a thin sheet insulator with a network structure is wound on a winding core 15 attached to a rotating shaft 14 of a winding machine, and a conductive coil 2 to form a winding.

After the winding work is completed, conductive coil 2 and coil inner circumferential insulating member 3
The core 15 is removed from the winding machine together with the core 15, and the core 15 is used as a part of the mold (inner body plate) as shown in FIG. After assembling the mold and performing a predetermined drying process, a molding material 4 is vacuum injected into the mold, and after hardening, the mold is released from the mold to form a resin molded coil 1 as shown in FIG.

Here, when looking at the adhesion state between the coil inner circumferential insulating member 3 and the molding material 4, as shown in FIGS. 2 and 3, a network structure is formed by impregnating a coarse fibrous base material 7 with resin and curing it. When using a thin leaf insulator as the coil inner insulating member, the coil inner insulating member 3 retains its original shape without being crushed even if it is strongly pushed by the outer wire 5 during coil winding, and the above-mentioned Since a gap communicating with the through hole 9 of the insulating member 3 is ensured between the uneven surface of the insulating member 3 and the conductive coil 2 and the winding core 15, the molding material 4 injected later is As shown in FIG. 1(C), the numerous through holes 9 and the recesses 10a on the surface of the insulating member 3 are completely filled with the insulating member 3, thereby ensuring strong adhesion between the insulating member 3 and the molding material 4. .

As shown in FIG. 4, after punching a prepreg 11 to form through holes 12 and unevenness 13a, 13b, a thin sheet insulator with a network structure made by curing impregnated resin may be used as the coil inner circumferential insulating member. Similarly, the molding material 4 injected later passes through the gap secured by the convex portion 13b of the coil inner circumferential insulating member 3 and into the numerous through holes 1 of the insulating member 3.
2 and the recess 13a on the surface thereof, the coil inner peripheral insulating member 3 and the molding material 4 can be firmly bonded together.

The present inventors investigated the adhesion with the molding material of coarse fibrous base materials that were not impregnated with resin or those that were impregnated with resin but remained in a semi-cured state, but they were not impregnated with resin. In cases where there is no such thing, the fibrous base material is crushed during coil winding, and in cases where the impregnated resin remains in a semi-hardened state,
During heating and drying after coil winding, the fibrous base material is deformed once it becomes soft during the hardening process of the impregnated resin, making it difficult for the molding material injected later to penetrate. It was found that sufficient adhesion could not be obtained unless the fibrous base material, which had a large number of through holes and an uneven surface, was impregnated with resin and hardened in advance, as in the example. If necessary, the insulation performance and mechanical strength can be further improved by winding the coil inner circumferential insulating member 3 made of the above-mentioned network-structured thin-sheet insulator in two or more layers.

In this case, in order to facilitate penetration of the molding material, it is preferable that the upper coil inner circumferential insulating member has a rougher mesh than the lower coil inner circumferential insulating member, that is, one with a larger diameter through-hole.

In Fig. 7, 3a is an upper coil inner circumference insulating member with a relatively coarse mesh, and 3b is a lower coil inner circumferential insulating member with a relatively fine mesh, and these two layers of coil inner circumferential insulating members are overlapped and wound. They can be wound simultaneously on the core 15.

Next, another embodiment of the present invention will be described with reference to FIGS. 8 and 9.

In this embodiment, as shown in FIG. 8, a coil outer insulating member 21 made of a thin sheet insulator having a network structure similar to the coil inner insulating member 3 is arranged on the outer circumferential side of the conductive coil 2, and The insulating members 3° 21 on the inner and outer peripheries are integrally molded with a molding material 4 mainly made of resin.

In the manufacturing process, as shown in FIG. 9, a coil inner circumferential insulating member 3,
Winding the conductive coil 2 and the coil outer insulating member 21 in this order,
A tape or sheet 22 made of an impermeable material such as a polyester film is wound and fixed around the outermost periphery. after that,
A tape or sheet 2 consisting of a winding core 15 that becomes the inner body plate of the mold type and an impermeable material on the outermost periphery that replaces the outer body plate.
One end of 2 is fixed with putty or the like on a mirror plate (not shown), and after a prescribed drying process, a molding material is injected into the mold, and after hardening, the mold is released to form a resin molded coil as shown in Fig. 8. 1
′ is formed. In this process, the molding material 4 sufficiently penetrates into the coil inner circumferential insulating member 3 and the coil outer circumferential insulating member 21, and they are firmly bonded.

According to this embodiment, the resin layers on the inner and outer circumferences of the coil are both zero.
．． Since the wall can be made as thin as approximately 5 to 2 m, the entire molded coil can be made smaller and lighter than the example shown in Figure 1, and the thinner resin layer improves heat dissipation from the coil, reducing temperature rise. Therefore, the thermal stress in the resin layer is also reduced, and the occurrence of cracks can be prevented.

In addition, if corona characteristics are a problem with high-voltage coils,
The electrostatic shielding layer placed on the inner or outer side of the coil is made of a coarse fibrous base material made of carbon fiber that has a network structure impregnated with resin and cured, thereby achieving adhesion to the molding material. It can improve sex.

〔Effect of the invention〕

According to the present invention, compared to conventional resin molded coils that use prepreg as the coil inner circumference insulating member, the adhesiveness between the coil inner circumferential insulating member and the molding material injected later is significantly improved, and after molding, Since peeling between the coil inner insulating member and the molding material due to temperature changes can be prevented, the reliability of the insulation performance and mechanical strength of the resin molded coil is improved, and the coil inner insulating member and the molding material are separated. The strong adhesion of the coil can increase the mechanical strength of the coil against electromagnetic force during a short circuit, and furthermore, the resin molded coil can be made smaller and lighter by thinning the inner peripheral resin layer of the coil.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the resin molded coil of the present invention, (A) is an external perspective view, (B) is a partially cut side view, (C) is a partially enlarged sectional view, and FIG. 3 is a schematic perspective view of the coil inner circumferential insulating member used in this embodiment, FIG. 3 is a detailed view of the same, and (A) is a plan view. (B) is an enlarged view of part A, (C) is a partially enlarged side view, and FIG.
(a) is a perspective view, (b) is a sectional view, Fig. 5 is a partially cut side view to explain the winding process of the resin molded coil shown in Fig. 1, and Fig. 6 is a side view showing the same molding process. Fig. 7 is a partially cutaway side view for explanation;
The figure is a partially cutaway side view showing another embodiment of the resin molded coil of the present invention, and FIG. 9 is a partially cutaway side view for explaining the winding process. 1.1'... Resin molded coil 2... Conductive coils 3.3a, 3b... Coil inner peripheral insulating member 4... Mold material 7.11... Fibrous base material 9 impregnated with resin .12...
・Through holes 10a, 10b, 13a, 13b--surface irregularities 15
... core

Claims (2)

[Claims] (1) In a resin molded coil formed by integrally molding a conductive coil and a coil inner circumferential insulating member disposed on the inner circumferential side of the conductive coil with a molding material mainly made of resin, the coil inner circumferential insulating member has many through holes,
A resin molded coil characterized in that it is a thin sheet insulator having a network structure with unevenness formed on its surface, and its many through holes and recesses on its surface are filled with the molding material. (2) A fibrous base material that has many through holes and an uneven surface, and a network made of a resin that is impregnated into the base material and hardened while leaving the through holes and surface unevenness. A thin sheet insulator of this structure is used as a coil inner circumferential insulating member, the coil inner circumferential insulating member is wound on a winding core, a conductive coil is wound thereon, and then a part of the said winding core is molded. A method for manufacturing a resin-molded coil, characterized in that the coil inner peripheral insulating member and the conductive coil are integrally molded using a molding material mainly composed of resin.