JPS6080210A - Manufacture of molded winding - Google Patents

Abstract

PURPOSE:To enable the manufacture of molded windings without a mold by winding fibrous material being applied impregnation resin on the predetermined part around a winding core subjected to a mold-release treatment on the surface and winding an electric wire around the periphery of said fibrous material and further the similar fibrous material around that. CONSTITUTION:A winding core 1 is attached to a winding machine. Next, a fibrous material 2 is wound around the winding core 1. In this case, impregnation resin is applied for a few turns from the winding core so as to form a tight laminar insulation 2'. After winding the predetermined turns, a primary winding 3 is wound. After a secondary winding 4 is similarly wound, a fiburous material 2 is wound and the impregnation resin is applied only for the several turns of ending so as to form a tight insulating layer 2'. Next, a metrallic plate 5 subjected to a mold-release treatment is wound on the periphery of said layer 2' and it is fixed by a band tape 6. Next, this is placed on a soft rubber-form sheet 7 and a ring-shaped plate 8 and the resin is impregnated into the windings and the fiburous material in a vacuum. Next, this is cured by heating and is disassembled thereby completing a molded winding. By this manufacturing method, the molded windings having good crack-resistance can be obtained without using a mold.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing molded windings used for transformer windings and the like.

[Technical background of the invention and its problems]

A transformer is a device in which the transformer windings are placed in a mold and impregnated with synthetic resin under vacuum. Therefore, it has a very good appearance and is well-received for its ease of maintenance, as it can be washed with water even in extreme cases, even against dust and dirt from the outside. However, compared to other dry type transformers, all of the windings are wrapped in impregnated resin, and because the difference in thermal expansion between the windings and the impregnated resin is different, cp and cracks may occur during the heat cycle when the lance stops operating. It has the disadvantage of being easy to remove. Naturally, if a crack occurs, moisture, dust, etc. will enter the crack, causing the transformer to lose its insulation performance and no longer function as a transformer. Therefore, the impregnating resin can be impregnated by mixing powder such as silica (S1o=) as a filler to minimize the difference in thermal expansion between the winding wire and the impregnating resin, or by inserting glass fibers or glass chips around the winding wire. This prevents cracks from forming in the resin. Another drawback is the need for a mold. That is, by using a mold, the impregnated resin can be molded into a product that conforms to the shape of the mold, so it has the advantage of having a very good appearance, but on the other hand, the manufacturing process is entirely determined by the mold. In other words, it has the disadvantage that if mass production is considered, the same mold must be made, and if multi-species production is considered, various molds must be made. The mold, of course, varies depending on the capacity of the transformer, but it must be strong enough to be moved even when the transformer windings and impregnated resin are in it, so the weight is also the same. Become. In addition, molds are often divided into two or three parts or more, but the appearance of the transformer is determined by the degree of finish on the inside of the mold.
Requires accuracy of D. Furthermore, even if the impregnating resin is impregnated, extreme care must be taken to ensure that it does not leak from the joints of the mold. Therefore, the manufacturing cost of the mold is considerable, and it is not a good idea to manufacture a large number of molds.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for manufacturing a molded winding wire, which allows a molded winding wire with excellent crack resistance to be obtained without using a mold.

[Summary of the invention]

The method for manufacturing a molded winding wire according to the present invention includes the steps of winding a fiber material coated with impregnated resin in at least the first few windings to a specified insulation thickness around a winding core whose surface has been subjected to mold release treatment, and a step of winding an electric wire around the outer periphery of the fibrous material a predetermined number of times, and a step of wrapping a fibrous material coated with an impregnated resin at least several times at the end of the winding to a predetermined insulating thickness to cover the wound electric wire; A step of wrapping jFE, which has been subjected to a release treatment on one side, around the outer periphery of the wrapped fiber material so that the release treatment surface is in contact with the outer periphery and binding, and heating the wrapped body made in each of the above steps. fiber material i
: A step of hardening the impregnated resin that has been wrapped, a step of placing one end surface of the wrapped body on a release-treated plate and impregnating it with the impregnating resin in a vacuum state, and a step of curing the wrapped body with the impregnated resin. By heating the mounting body and curing the impregnated resin, a molded winding with excellent crack resistance and no leakage of the impregnated resin is formed without using a mold.

The details of the present invention will be explained below in the order of steps.

(1) First, the winding core is attached to the winding machine. The material of the winding core used here may be of any material, but it must be sufficiently durable for the winding work to be performed in the subsequent process. The surface of the winding core is preferably coated with or baked with a PII type agent (so-called mold release treatment).

(2) Wrap the glass cloth sheet or other fibrous material several times while coating it with impregnated resin until the specified insulation thickness is achieved. The reason why the impregnating resin is applied only a few times when wrapping the fiber material is as follows:
In the post-process, this is cured by heating, and then impregnated with resin. At this time, a dense laminated insulation is obtained to the extent that the impregnated resin does not leak inside. Therefore, if one side of the fiber material is soaked in the impregnating resin in advance to semi-cure it, there is no need to apply the impregnating resin and workability is also good.

3) Wrap the fiber material until the specified insulation thickness is reached, and then wrap the insulated wire a specified number of times to form a winding.

Naturally, when the primary and secondary windings are molded as one unit, after the primary winding is wound, a fiber material is rolled in to ensure the specified insulation thickness, and the secondary winding is wound on top of that. Turn.

4) A fiber material is further wound on top of the winding to ensure a specified insulation thickness, but the winding is continued while applying the impregnated resin only a few times to the final number of turns. The reason why the impregnated resin is applied here is the same as in step (2). Tighten the stator.

If a heat-shrinkable tape is used to cover the bind tape, sufficient shrinkage can be obtained by heating in a subsequent process, and there is no need to worry about loosening of the bind tape or the like.

(6) Next, L for heating! l Harden the impregnated resin applied to the fiber material. Here, the hardening of the impregnating resin is to prevent the impregnating resin from leaking to the side surfaces, that is, the inner circumferential direction and the outer circumferential direction when impregnating with the impregnating resin in a subsequent step, and it is not necessary to completely cure the impregnating resin. Furthermore, if heat-shrinkable tape is used as the binding tape in step (5), the outer peripheral surface of the mold transformer can be finished neatly by applying sufficient tightening force in this step.

(7) Remove it from the winding machine, place it on top of a ring-shaped disc that has been subjected to release treatment and a flexible rubber sheet on the bottom, and leave it in an impregnating tank.

(8) Impregnating with impregnating resin under vacuum. The impregnating resin is applied in steps (2) and (5), followed by step (6) to prevent the impregnating resin from leaking to the side surface, and By resting on the flexible rubber sheet carried out in step (7), leakage of the impregnated resin from the bottom is also prevented, and as a result, the winding can be impregnated with the impregnated resin as a single container. .

(9) After the impregnation is completed, transfer to a heating furnace to harden the applied impregnated resin and the impregnated impregnated resin. The molded winding is completed.

The molded winding wire made in this manner does not require mixing a filler such as silica (StO,) into the impregnated resin during manufacture, and has a very low viscosity and good impregnability. In addition, since it contains enough fiber material such as glass, it is possible to achieve the same thermal expansion as when silica (StO, ) is added, and there is no need to worry about the occurrence of cracks or the like due to the fiber material being mixed in. Furthermore, expensive molds are no longer required. The winding core used here, the metal plate wound on the outside, the ring-shaped disk used at the bottom, and the flexible rubber sheet can be reused.

The above steps will be explained using figures as follows. First, in step (1), the winding core is placed in a winding machine. If the winding core 1 has a taper, there is no need to divide it, but if there is no taper, it is preferable to divide it into two. In step (2), a fiber material 2 such as glass cloth is wound, and impregnated resin is applied several times from the winding core 1 to form a dense laminated insulation 2'. After winding the specified number of times, the next winding 3 is wound. Incidentally, fiber material 2 such as glass cloth is also wound around the upper and lower ends of the next winding 3. After winding the secondary winding 4 in the same way, the fiber material 2 such as glass cloth is wound, and the impregnated resin is applied only the last few times to form a dense insulating layer 2.
′ is formed. A metal plate 5 subjected to mold release treatment is wound around its outer periphery and fixed with bind tape 6. This is placed on a flexible rubber sheet 2 and a ring-shaped disk 8, and the winding wire and fiber material are impregnated with the impregnating resin under vacuum. By heating and curing this and decomposing it in the OI process, a molded winding wire is completed.

[Effect of the invention] ゛As described above, according to the present invention, without using a mold,
A molded winding with excellent crack resistance can be obtained.

[Brief explanation of the drawing]

The drawing is a partial cross-sectional view of a molded transformer before the impregnation step in an embodiment of the molded winding manufacturing method according to the present invention. DESCRIPTION OF SYMBOLS 1... Winding core, 2... Fiber material, 3...-Next winding, 4
... Secondary winding, 5 ... Plate material, 6 ... Bind tape, 7 ... Flexible rubber sheet, 8 ... Ring-shaped disk.

Claims (1)

[Claims] A process of winding a fiber material coated with impregnated resin at least in the first few windings around a winding core whose surface has been subjected to mold release treatment, to a specified insulation thickness, and then wrapping an electric wire around the outer periphery of this wrapped fiber material a specified number of times. A process of winding, a process of winding a fiber material coated with impregnated resin at least several times at the end of the winding to a specified insulation thickness to cover the wrapped electric wire, and a handle material that has been subjected to a release treatment on one side. Wrapping and binding the above-mentioned wrapped fibrous material so that the release-treated surface is in contact with the outer periphery of the above-mentioned fibrous material, and heating the wrapped body made in each of the above-mentioned steps to form an impregnated resin applied to the fibrous material. a step of curing one end surface of the wrapped body, and a step of impregnating the wrapped body with the impregnated resin in a vacuum state after placing it, and heating the wrapped body impregnated with the resin to release the impregnated resin. A method for manufacturing a molded winding wire, comprising: a step of curing the wire.