JPH0817134B2 - Molded coil manufacturing method - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a mold coil used in a power distribution mold transformer or the like.

Conventional technology Molded coils, which are formed by forming a resin layer such as epoxy resin around the coil, have excellent insulating properties and ease of maintenance, and their applications are expanding.

A conventional method of manufacturing a mold coil, in particular, a method of manufacturing a mold coil used for low voltage is to dispose a sheet-shaped insulating material that also serves as a part of the mold on the inner peripheral portion and the outer peripheral portion of the element coil, After the rising end from this element coil has the upper end face downward and the lower end face upward, the mold resin is filled between the inner peripheral portion and the outer peripheral portion and cured, and then the upper end face is directed upward. A resin molding method is generally used.

FIG. 4 shows a molded coil manufactured by a conventional method, FIG. 5 is a sectional view taken along line VV of FIG. 4, and FIG. 6 is a partially enlarged sectional view of FIG. In FIGS. 4 to 6, 1 and 2 are rising lead portions, which are made of an aluminum plate or a copper plate. Reference numeral 3 is a coil main body, and 4 is an inner peripheral member made of a sheet-shaped insulating material disposed on the inner peripheral portion of the coil main body 3, and the material is an epoxy resin-impregnated glass cloth simple substance or a polyethylene terephthalate film bonded together. Etc. are used. Reference numeral 5 is an element coil, which is composed of conductors 6 and interlayer insulating material 7 that are alternately stacked. Reference numeral 8 denotes an outer peripheral member made of a sheet-shaped insulating material disposed on the outer peripheral portion of the coil main body 3, and the material thereof is the same as the inner peripheral member 4. Reference numeral 9 is a molding resin injected between the element coil 5 and the inner peripheral member 4 and outer peripheral member 8 and the upper end surface of the element coil 5, and 10 is a molding resin injected into the bottom end surface of the element coil 5. The mold resin 10 is usually filled before the mold resin 9 to form a portion corresponding to the mold of the mold resin on the outer peripheral portion of the element coil 5, and then the resin is injected from the upper end surface to form the resin mold 9. To do. The upper end surface of the resin mold 9 is formed flush with the inner peripheral member 4 and the outer peripheral member 8.

However, in such a conventional mold coil manufacturing method, since the upper end surface is lowered by impregnation of the molding resin 9 injected from the upper end surface of the element coil 5 into the element coil 5 and curing shrinkage, The injection of the mold resin 9 has to be repeated several times, and there is a problem that extra time and mold resin are required.

The present invention solves such a conventional problem, and an object of the present invention is to provide an excellent method for producing a molded coil that can reduce the production time and the amount of resin used. .

Means for Solving the Problems In order to achieve the above object, the present invention provides an element coil in which a conductor and an interlayer insulating material are alternately wound between an inner peripheral member and an outer peripheral member made of a sheet-shaped insulating material. Then, after the bottom end face is directed upwards and the bottom end face is stitched, mold resin is injected between the inner peripheral material and the outer peripheral material, and the bottom bottom surface of the mold resin has excellent releasability from the mold resin. Cover with the lid member, and then, conversely, with the bottom end face down, fill the filler from the upper end face of the coil to the inner and outer peripheral members, and then heat to remove the mold resin on the bottom end face. It includes a step of curing and further filling the upper end surface with a mold resin and curing.

Effect Therefore, according to the present invention, since the filler is filled from the upper end surface of the element coil and then the mold resin is filled,
Since the filling and impregnation of the mold resin into the voids of the coil etc. are rarely performed, the impregnation of the mold resin into the filler filled in the voids of the coil etc. is done only at the minute parts in contact with the mold resin. Since it is performed only once, there is almost no decrease in the upper end face due to curing after the filling of the mold resin, and the manufacturing time is shortened and the amount of the mold resin to be filled is small.

EXAMPLE FIG. 1 is a perspective view of a mold coil manufactured by the mold coil manufacturing method of the present invention, and FIG. 2 is II- of FIG.
A sectional view taken along line II and FIG. 3 are partially enlarged sectional views of FIG.
In FIGS. 1 to 3, 11 and 12 are rising leads, which are made of an aluminum plate or a copper plate. 13
Is a coil main body, 14 is an inner peripheral member made of a sheet-shaped insulating material disposed on the inner peripheral portion of the coil main body 13, and the material is an epoxy resin-impregnated glass cloth simple substance or a polyethylene terephthalate film stuck together, etc. Is used. Reference numeral 15 is an elementary coil, and conductors alternately stacked
16 and an interlayer insulating material 17. Reference numeral 18 denotes an outer peripheral member made of a sheet-shaped insulating material disposed on the outer peripheral portion of the coil body 3, and the material is the same as the inner peripheral member 14. Reference numeral 19 denotes a mold resin injected between the element coil 15 and the inner and outer peripheral members 14, 18 and the upper end surface of the element coil 15, and 20 denotes a mold resin injected to the bottom end surface of the element coil 15. Reference numeral 21 is a seal for preventing the mold resin 20 from leaking to the element coil 15 when the mold resin is injected into the bottom end surface. Reference numeral 22 is a filling material filled from the upper end surface of the element coil 15.

Next, a method of manufacturing this mold coil will be described. First, after mounting the inner peripheral member 14 made of a sheet-shaped insulating material on a core (not shown), the rising lead portion 12 attached by welding or the like is fixed to the winding start portion, and the conductors 16 and the interlayer insulating material 17 are alternately arranged. After both are wound a specified number of times, another rising lead portion 11 is attached and fixed to the end portion of the last conductor 16. Then, the outer peripheral member 18 made of a sheet-shaped insulating material is attached to the outer periphery thereof. It is preferable that the inner peripheral member 14 and the outer peripheral member 18 have a certain degree of rigidity, for example, a B-stage epoxy resin impregnated glass cloth having a thickness of 0.2 mm to 0.25 mm and a polyethylene terephthalate film (PET film) having a thickness of 0.25 mm. It is preferable that they are laminated.

Then, in this manner, the inner and outer peripheral members 14 and 18 are provided on both sides in this manner.
After the bottom end face of the element coil 15 provided with the upward, the bottom end face is covered with a seal 21 formed of glass wool, polyester wool, ceramic wool, or the like,
Mold resin 20 (Epoxy resin with an inorganic filler mixing ratio of 60
~ 70% by weight). Next, the lid member 23 whose surface that contacts the bottom end surface of the mold resin is made of a releasable material
Then, with the bottom end face downward and the upper end face upward, the inner peripheral member 14 and the outer peripheral member 18 are inserted from the upper end face.
After the filler 22 is filled in the gap between the coil interlayer resin and the like between them, the mold resin 20 at the bottom is hardened by heating, and the mold resin 19 is filled from the end face of the coil and hardened.

As the filler 22 to be filled from the upper end face, the filling effect can be seen only with an inorganic substance such as silicon dioxide, but in order to improve the mechanical characteristics of the coil interlayer resin, an inorganic powder and a binder such as a resin were mixed. Things are more suitable. However,
When mixing powders that cause volume changes such as resins, the mixing ratio becomes a problem, and in order to impart adhesiveness,
Since it is necessary to increase the amount of resin, it is important to determine the optimum compounding ratio. The following table shows an example of the results of comparative examination of the mixing ratios.

As is clear from this table, the best results are obtained when the ratio of the epoxy powder and the silica powder is 20-40% by weight: 60-80% by weight. Here, although silica powder is used as the inorganic powder, it is not limited to this.
Insulating inorganic powders such as alumina powders and magnesium oxide powders can be sufficiently put to practical use.

EFFECTS OF THE INVENTION As described above, according to the method for producing a molded coil of the present invention, the gap between the coils is filled with the filler and then the final mold resin is filled. There is no deterioration of the resin surface after filling with the mold resin, so the number of injections of the mold resin is reduced, the manufacturing time is shortened and the amount of resin used is reduced, and the workability in mold coil manufacturing is significantly improved. effective.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a mold coil manufactured by the method for manufacturing a mold coil of the present invention, FIG. 2 is a sectional view taken along line II-II of FIG. 1, and FIG. 3 is a partially enlarged view of FIG. A sectional view, FIG. 4 is a perspective view of a mold coil showing an example of a mold coil manufactured by a conventional method for manufacturing a mold coil, FIG. 5 is a sectional view taken along line VV of FIG. 4, and FIG. It is a partial expanded sectional view of FIG. 11, 12 …… Standing lead part, 12 …… Coil body part,
14 …… Inner peripheral material, 15 …… Element coil, 16 …… Conductor, 17 …… Interlayer resin, 18 …… Outer peripheral material, 19,20 …… Mold resin, 21…
… Sticks, 22 …… filling material, 23 …… cover member.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Shigeru Hirano 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hiromitsu Hara, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Katsuhiko Iho 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-58-35912 (JP, A) JP-A-59-6512 (JP, A) JP-A-SHO 58-42215 (JP, A) JP-A-55-146923 (JP, A) Actually developed Sho-56-121214 (JP, U)

Claims (2)

[Claims] 1. An element coil, in which a conductor and an interlayer insulating material are alternately wound, is disposed between an inner peripheral member and an outer peripheral member made of a sheet-shaped insulating material, and the bottom end surface of the element coil is directed upward. After sealing the bottom end face, inject a mold resin between the inner peripheral material and the outer peripheral material, and cover the bottom bottom surface with a lid member having excellent releasability with respect to the mold resin. Conversely, after filling the filler between the inner peripheral material and the outer peripheral material from the upper end surface of the element coil with the bottom end surface facing downward, it is heated to cure the mold resin on the bottom end surface, A method of manufacturing a molded coil, comprising a step of filling a mold resin into an end surface and curing the resin. 2. The filler filled from the upper end surface of the elementary coil is a mixture of 20 to 40% by weight of B-staged epoxy powder resin and 60 to 80% by weight of inorganic powder. Method for manufacturing molded coil of.