JPH0690983B2 - Resin molded coil - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a resin mold coil used in transformers, transformers and the like.

[Background of the Invention]

Conventionally, as one of the methods for producing a resin mold coil, as disclosed in Japanese Patent Publication No. 47-16219, etc., a thin insulating material in which a fibrous base material such as glass cloth is impregnated with a resin and is in a semi-cured state. (Hereinafter referred to as a prepreg) is wound around a core, a conductive coil is formed on the core, and a molding material mainly made of a resin is injected and cured by using the core as a part of a mold to cure the prepreg. There is a method of integrally molding and the conductive coil.

In this method, since the prepreg impregnated with the resin is used as the coil inner circumference insulating member in advance, there is a possibility that the resin mold coil can be made smaller and lighter by reducing the thickness of the coil inner circumference resin layer. The adhesiveness between the prepreg and the molding material injected later was not considered. That is, generally, a prepreg is a thin-walled insulating material having a smooth surface formed by filling a resin into a fine-grained fibrous base material without leaving a gap, and the prepreg arranged on the inner peripheral portion of the coil is molded before molding. Since it is completely cured during the heating and drying process of the coil, the adhesiveness with the molding material injected later is poor, and peeling occurs between the molding material and the prepreg due to the temperature change after molding, resulting in insulation performance and mechanical It is easy to cause a decrease in strength.

In order to improve the adhesiveness between the prepreg and the molding material injected later, as disclosed in JP-A-57-187921, the prepreg is wound on the core, and the resin thereon is Attempts have also been made to wind a fibrous base material such as glass cloth or glass tape that has not been impregnated, and then to wind a conductive coil on top of it. The material itself is impermeable to the molding material that is injected later, and the fibrous material wound on the prepreg is crushed by the electric wire during coil winding and the molding material penetrates into a difficult state. Therefore, the adhesiveness between the prepreg and the molding material injected later was not sufficient.

[Object of the Invention]

An object of the present invention is to improve adhesiveness between a coil inner circumference insulating member and a molding material to be injected later, so that the resin has high reliability in terms of insulation performance and mechanical strength, and is small and lightweight. It is to provide a mold coil.

[Outline of Invention]

A first invention of the present application is a resin-molded coil obtained by integrally molding a conductive coil and a coil inner peripheral insulating member arranged on the inner peripheral side of the conductive coil with a molding material mainly composed of a resin. The coil inner circumference insulating member is a fibrous base material having a large number of gaps or through holes formed in a texture formed by alternately crossing a plurality of warps and wefts having a larger number than the warps, and is formed on the surface thereof. A thin leaf insulator having a net-like structure which is impregnated with a resin and cured while leaving the unevenness left and filled with the through holes and the recesses on the surface by the molding material, and the coil inner circumference insulating member. A resin molded coil characterized by being integrally molded with the conductive coil.

A second aspect of the present invention is a resin molded coil in which a conductive coil and a coil inner peripheral insulating member disposed on the inner peripheral side of the conductive coil are integrally molded with a molding material mainly composed of a resin. The inner peripheral insulating member is a net-like insulating material having a net-like structure in which a large number of through holes are formed in a fibrous base material impregnated with a resin and semi-cured to form convex portions and concave portions. The resin molded coil is characterized in that the through hole and the recessed portion on the surface are filled and the coil inner peripheral insulating member and the conductive coil are integrally molded.

Example of 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 mold coil of the present invention.

As schematically shown 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 width direction and a coil arranged on the inner peripheral side of the conductive coil. The inner peripheral insulating member 3 and the inner peripheral insulating member 3 are integrally molded with a molding material 4 made of a resin such as an epoxy resin and an inorganic material mixed with a filler or the like.

More specifically, each conductive coil 2 is
As shown in FIG. 1 (c), the electric wire 5 is wound in multiple layers with the interlayer insulator 6 interposed therebetween, and the coil inner peripheral insulating member 3 has a large number of through holes, and the surface has irregularities. FIG. 1C shows a thin insulator having a net-like structure, which is embedded in the molding material 4.

2 and 3 are views showing the coil inner circumference insulating member 3 in FIG. 1 taken out. In the figure, 7 is a fibrous base material having a large number of gaps, that is, through holes, formed by weaving a plurality of weft yarns and weft yarns having a larger number than the warp yarns. It is selected from suitable inorganic fibers such as glass fibers or synthetic fibers such as polyester fibers. This fibrous base material 7 is impregnated beforehand with a low-viscosity resin containing no filler, and a diagonal line 8 is shown in FIG.
As shown by the symbol, only the surface of the fiber is thinly coated with the resin while leaving a large number of through holes 9 corresponding to the mesh of the base material 7 and the wavy irregularities 10a and 10b on the surface, and then the resin is completely cured. By the heat treatment, the intersections of the mesh are fixed by the resin, and the thin leaf having a strong mesh structure capable of retaining the original shape of the base material 7 even in the state of being embedded in the molding material 4 as shown in FIG. Insulation is made. This thin leaf insulator is used as a sheet or tape.

The mesh of the thin insulating material, that is, the size of the through hole 9 is such that the molding material 4 can easily penetrate (about 0.5 mm in the illustrated example).
X 3.5 mm), and if the thickness is too thick, it easily breaks when wound on the core, so about 0.2 to 0.5 mm is suitable.

The resin with which the fibrous base material 7 is impregnated may be the same epoxy resin as the molding material 4, or different resins such as polyester resin and phenol resin.

When used as the coil inner circumference insulating member, the thin leaf insulator having the reticulated structure shown in FIGS. 2 and 3 has good adhesiveness to the molding material to be injected later, and can be manufactured inexpensively with a small number of work steps. Therefore, it is a suitable material for the coil inner circumference insulating member.

FIG. 4 shows another example of a thin-walled insulator having a net-like structure suitable for use as a coil inner circumference insulating member. This is to form a large number of through holes 12 by punching in a prepreg 11 that is a semi-cured state by impregnating a fine fibrous base material with a resin, and form convex portions 13b and concave portions 13a by cutting and raising on the surface, In this state, the impregnated resin is completely cured, and in order to improve the adhesiveness with the molding material, it is preferable that the convex portions 13b and the concave portions 13a are alternately formed on both surfaces.

Next, a description will be given of a process for manufacturing a resin mold coil using the thin-wall insulation having the mesh structure shown in FIG. 2, FIG. 3 or FIG. 4 as the coil inner circumference insulating member.

First, as shown in FIG. 5, a coil inner circumference insulating member 3 made of a net-like thin-film insulator is wound around a winding core 15 attached to a rotary shaft 14 of a winding machine, and a conductive coil 2 is formed thereon. Is formed by winding.

After finishing the winding work, the conductive coil 2 and the coil inner circumference insulating member 3
The core 15 together with the core 15 from the winding machine, and as shown in FIG. 6, the core 15 remains as it is as a part of the mold (inner shell plate).
As shown in FIG. 1, the outer body plate 16, the end plates 17 and 18, and the packings 19 and 20 are assembled into a mold, and after a predetermined drying process, the molding material 4 is vacuum-injected into the mold, cured, and released. The resin mold coil 1 is formed as shown.

Here, looking at the bonding state of the coil inner peripheral insulating member 3 and the molding material 4, as shown in FIGS. 2 and 3, a net-like structure formed by impregnating a resin into the fibrous base material 7 having rough mesh and curing the resin. When the thin-walled insulation material of No. 3 is used as the coil inner circumference insulating member, the coil inner circumference insulating member 3 does not get crushed even if it is strongly pressed by the electric wire 5 wound outside during coil winding. Since a clearance 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 core 15, the molding material 4 injected later is As shown in FIG. 1 (c), the large number of through holes 9 and the recesses 10a on the surface of the insulating member 3 are completely filled, so that a strong adhesion between the insulating member 3 and the molding material 4 is guaranteed. .

As shown in FIG. 4, when the through hole 12 and the concavities and convexities 13a and 13b are provided on the prepreg 11 by punching, and then the thin leaf insulator of the net structure formed by curing the impregnating resin is used as the coil inner circumference insulating member. Similarly, the molding material 4 injected afterwards passes through the gaps secured by the projections 13b of the coil inner circumference insulating member 3 and the large number of through holes 12 of the insulating member 3 and the recesses on the surface.
Since it is completely filled in 13a, the coil inner circumference insulating member 3 and the molding material 4 can be firmly adhered.

The present inventors have investigated the adhesiveness with the molding material for the one in which the fibrous base material having rough mesh is not impregnated with the resin and the one in which the impregnated resin is kept in a semi-cured state, but the resin is impregnated with the resin. For those that do not have, the fibrous base material is crushed during coil winding, and for those that keep the impregnated resin in a semi-cured state,
Since the fibrous base material is deformed once it is in a softened state in the process of hardening the impregnated resin during heating and drying after winding the coil, it is difficult for the injected mold to permeate afterwards. It was found that sufficient adhesiveness cannot be obtained unless the fibrous base material that has a large number of through holes as in the example and has irregularities on the surface is impregnated with resin in advance and cured. .

If necessary, the insulation performance and the mechanical strength can be further improved by winding two or more layers of the coil inner peripheral insulating member 3 made of the above-mentioned thin-walled insulating material having a net-like structure and winding the layers.

In this case, in order to facilitate the penetration of the molding material, it is preferable to use, as the upper coil inner peripheral insulating member, one having a coarser mesh than the lower coil inner peripheral insulating member, that is, one having a larger diameter of the through hole.

In FIG. 7, 3a is an upper coil inner peripheral insulating member having a relatively coarse mesh, and 3b is a lower coil inner peripheral insulating member having a relatively fine mesh. heart
Can be wound on 15 at the same time.

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

In this embodiment, as shown in FIG. 8, a coil outer peripheral insulating member 21 made of a thin leaf insulator having a mesh structure similar to that of the coil inner peripheral insulating member 3 is arranged also on the outer peripheral side of the conductive coil 2 and The insulating members 3 and 21 on the inner and outer circumferences are integrally molded with a molding material 4 mainly composed of resin.

As the manufacturing process, as shown in FIG.
A coil inner circumference insulating member 3, a conductive coil 2, and a coil outer circumference insulating member 21 are wound in this order on a winding core 15 attached to 14, and a tape or sheet 22 made of an impermeable material such as a polyester film is wound around the outermost circumference. Fix it. After that, one end of a tape or sheet 22 made of an impermeable material at the outermost periphery, which replaces the core 15 and the outer shell, which is the inner shell of the mold, is fixed with putty or the like on an end plate (not shown), After a drying process, a molding material is injected into the mold, and after curing, the mold is released to form a resin mold coil 1'as shown in FIG. In this process, the molding material 4 sufficiently penetrates into the coil inner circumference insulating member 3 and the coil outer circumference insulating member 21 and firmly adheres thereto.

According to this embodiment, the resin layers on the inner and outer circumferences of the coil are both 0.
Since it can be thinned to about 5 to 2 mm, the entire molded coil can be made smaller and lighter than that of the embodiment shown in FIG. 1, and the resin layer can be thinned to improve heat dissipation of the coil and reduce temperature rise. Therefore, the thermal stress of the resin layer is also reduced, and the occurrence of cracks can be prevented.

If corona characteristics are a problem for high voltage coils,
Adhesion to the molding material by using a mesh-like structure in which a resin is impregnated and cured in a coarse fibrous base material using carbon fiber as the electrostatic shield layer placed on the inner or outer circumference of the coil. You can improve your sex.

〔The invention's effect〕

According to the present invention, as compared with the conventional resin molded coil using the prepreg as the coil inner circumference insulating member, the adhesiveness between the coil inner circumference insulating member and the molding material injected later is significantly improved, and after molding. Since it is possible to prevent peeling between the coil inner circumference insulating member and the molding material due to the temperature change, the insulation performance of the resin molded coil and the reliability of mechanical drop strength are improved, and the coil inner circumference insulating member and the mold are separated. The strong adhesion can increase the mechanical strength of the coil against electromagnetic force at the time of short circuit, and the resin mold coil can be reduced in size and weight by thinning the resin layer on the inner circumference of the coil.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of a resin mold coil of the present invention, (a) is an external perspective view, (b) is a partially cut-away side view, (c) is a partially enlarged sectional view, and FIG. Is a schematic perspective view of the coil inner circumference insulating member used in this embodiment, FIG. 3 is a detailed view of the same, (a) is a plan view, (b) is an enlarged view of part A thereof, (c).
FIG. 4 is a partially enlarged side view, FIG. 4 is a view showing another configuration example of the coil inner circumference insulating member, (a) is a perspective view, (b) is a sectional view,
5 is a partially cut side view for explaining the winding step of the resin mold coil shown in FIG. 1, FIG. 6 is a partially cut side view for explaining the molding step, and FIG.
FIG. 8 is an explanatory view of the work of overlappingly winding coil inner peripheral insulating members having different roughness of the eyes, FIG. 8 is a partially cut side view showing another embodiment of the resin mold coil of the present invention, and FIG. It is a partially cut side view for explaining a winding step. 1, 1 '... Resin molded coil 2 ... Conductive coil 3, 3a, 3b ... Coil inner circumference insulating member 4 ... Mold material 7, 11 ... Resin impregnated fibrous base material 9, 12 ... Transparent Holes 10a, 10b, 13a, 13b …… Surface irregularities 15 …… Core

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-57-187921 (JP, A) JP-A-54-105766 (JP, A) JP-A-60-80210 (JP, A) Actual development Sho-55- 77821 (JP, U) Actual development Sho 56-164526 (JP, U) Japanese patent 47-17219 (JP, B1) Japanese public 59-42543 (JP, B2)

Claims (2)

[Claims] 1. A resin molded coil comprising a conductive coil and a coil inner peripheral insulating member arranged on the inner peripheral side of the conductive coil integrally molded with a molding material mainly composed of a resin. The insulating member is a fibrous base material having a large number of gaps, that is, through holes formed in a texture formed by alternately crossing a plurality of warps and wefts having a larger number than the warps, and the unevenness formed on the surface thereof. A thin leaf insulator having a net-like structure that is impregnated with resin and cured while leaving the above. The molding material fills the many through holes and the recesses on the surface, and the coil inner circumference insulating member and the conductive coil. A resin molded coil, characterized in that and are integrally molded. 2. A resin molded coil formed by integrally molding a conductive coil and a coil inner peripheral insulating member arranged on the inner peripheral side of the conductive coil with a molding material mainly composed of a resin. The insulating member is a thin-walled insulating material having a net-like structure in which a large number of through holes are formed in a fibrous base material impregnated with a resin and semi-cured to form convex and concave portions. A resin molded coil, characterized in that it fills a hole and a recess on the surface, and is formed by integrally molding the coil inner peripheral insulating member and the conductive coil.