JP2019192766A - Mold transformer - Google Patents

Abstract

To solve such a problem that weight reduction of the entire mold transformer including a primary coil and a secondary coil integrally coupled therein is not considered.SOLUTION: According to an example of the present invention, there is provided a mold transformer including an iron core wound with a primary coil covered with a first mold resin and a secondary coil covered with a second mold resin. A third mold resin connecting between the first mold resin and the second mold resin is also provided. The third mold resin has a duct passing through from an upper face to a lower face in a part of a region between the primary coil and the secondary coil, and has a face connected to the duct and the lower face or the upper face, the face being different from the lower face, the upper face or the duct. The cross section of the duct on an upper face side of the third mold resin is larger or smaller than the cross section on a lower face side.SELECTED DRAWING: Figure 2

Description

  It relates to a mold transformer.

  Patent Document 1 states that “a resin molded coil used for a mold transformer, and a primary side coil and a secondary side coil provided concentrically inside the primary side coil are integrally formed by a mold resin. Resin having a configuration in which a cooling duct having a substantially constant cross-sectional shape and area is provided in a mold resin that is coupled or separated and is disposed at least inside the outer position of the primary coil. A molded coil "is disclosed (see claim 1).

JP 2005-191360 A

  In Patent Document 1, a primary side coil and a secondary side coil provided concentrically on the inner side of the primary side coil are integrally joined by a mold resin, and the cross-sectional shape and area are substantially constant. A duct is disclosed.

  However, this configuration is a technique for reducing the cost, and does not consider the weight reduction of the entire molded transformer in which the primary side coil and the secondary side coil are integrally coupled.

  According to an example of the present invention, there is provided a mold transformer having an iron core around which a primary coil covered with a first mold resin and a secondary coil covered with a second mold resin are wound. A third mold resin is provided to connect between the mold resin and the second mold resin, and the third mold resin is provided in a partial region between the primary coil and the secondary coil from the upper surface to the lower surface. A lower surface or an upper surface connected to the duct and the lower surface or the upper surface, or a surface different from the duct, and the cross-sectional area of the upper surface side of the third mold resin in the duct is the lower surface side The present invention provides a molded transformer characterized in that it is larger or smaller than the cross sectional area.

  According to the molded transformer of the present invention, it is possible to reduce the weight of the molded transformer in which the primary side coil and the secondary side coil are integrally cast.

It is a figure which shows the external appearance of the three-phase tripod mold transformer. It is a figure which shows the external appearance of the integral mold coil which shows Example 1 of this invention. It is a figure which shows the external appearance of the integral mold coil which shows Example 2 of this invention. It is a figure which shows the external appearance of the integral mold coil which shows Example 3 of this invention. It is a figure which shows the external appearance of the integral mold coil which shows Example 4 of this invention, and the cross section of a duct. It is a figure which shows the cross section of the duct of Example 5 of this invention. It is a figure which shows the cross section of the duct of Example 6 of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiments, and the repetitive description thereof will be omitted.

Further, in the following embodiment, when it is necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments, but they are not irrelevant to each other unless otherwise specified. The other part or all of the modifications, details, supplementary explanations, and the like are related.

  FIG. 1 shows a three-phase tripod mold transformer 100. The molded transformer 100 has three primary coils 10 and three secondary coils 20. Further, the inner cores 40a and 40b and the outer core 40c are wound around the coils 10 and 20, respectively.

  A first embodiment of the present invention will be described with reference to FIG. FIG. 2 shows an integrated mold coil 50 in which the mold resin of the pair of primary coil 10 and secondary coil 20 included in the mold transformer 100 shown in FIG. 1 is integrated.

  Here, the term “integrated” refers to a mold resin that is not cast separately when casting a mold resin, and a mold resin that covers the primary side coil 10 and the secondary side coil 20 is cast at once, and is cured. It means that there is. That is, it has the mold resin part to which the mold resin which covers the primary side coil 10 and the mold resin which covers the secondary side coil 20 are connected without having an interface.

  That is, the third mold resin that has the first mold resin that covers the primary coil 10 and the second mold resin that covers the secondary coil 20 and connects between the first mold resin and the second mold resin. Are connected by a mold resin. The first mold resin, the second mold resin, and the third mold resin are cast integrally and then cured.

  For this reason, the first mold resin, the second mold resin, and the third mold resin are connected without having a connection surface or an interface provided when the mold resin is cast separately. That is, the first mold resin and the third mold resin or the second mold resin and the third mold resin are directly connected without an interface. The two resin members are not bonded to the surface after one resin member is cured, or the interfaces between the two cured resin members are bonded with an adhesive or the like. Since each resin member is connected when cured, the connectivity is high.

  Moreover, since the connection area | region of two resin members is connected without interposing an interface by carrying out integral casting, peeling of members centering on an interface becomes difficult to occur. As a result, the reliability of the entire molded transformer is improved.

  The third mold resin that connects the first mold resin covering the primary coil 10 and the second mold resin covering the secondary coil 20 is molded in a partial region between the primary coil and the secondary coil. It has a duct 70a that passes from the upper surface to the lower surface of the resin.

  In the molded coil 50, the primary side 60p and the secondary side 60s are connected by a molding resin, and a duct 70a is provided in a part between the connecting portions. The duct 70 a is a hole that penetrates from the top surface to the bottom surface of the molded coil 50. By providing the duct 70a, an air passage can be formed between the primary side 60p and the secondary side 60s of the molded coil 50, so that the air heated by the energized coil escapes upward. This contributes to cooling of the mold coil 50.

  A second embodiment of the present invention will be described with reference to FIG. The difference from the first embodiment is that a duct 70b provided at a connection portion between the primary side 60p and the secondary side 60s is widely provided at corner portions of the primary coil and the secondary coil. Since the duct portion is widely provided, the weight of the coil can be reduced.

  By providing the duct 70b in more than half of the circumference between the primary side 60p and the secondary side 60s, the weight of the molded coil 50 can be reduced. Moreover, since the duct 70b is more than half of the circumference, the heat dissipation characteristics of the energized mold coil 50 are improved.

  Further, by providing the duct 70b at the corner portion between the primary side 60p and the secondary side 60s, it becomes easy to absorb the vibration in the oblique direction.

  Furthermore, by providing the connecting part 75a in the front-rear direction or the connecting part 75b in the left-right direction between the primary side 60p and the secondary side 60s of the mold coil 50, the mold coil 50 vibrates in the front-rear left-right direction due to an earthquake. In some cases, the shock is easily absorbed. That is, since the primary coil 10 and the secondary coil 20 do not vibrate separately, the coils do not collide with each other and the vibration is easily absorbed. Therefore, the molded transformer 100 having excellent earthquake resistance can be provided.

  A third embodiment of the present invention will be described with reference to FIG. The difference from the first embodiment is that a duct 70c provided at a connection portion between the primary side 60p and the secondary side 60s is widely provided in a linear portion of the primary coil secondary coil.

  By providing the duct 70c in the straight portion, the work of pulling out the punching die from the cast and hardened mold resin becomes easy. Compared with the first embodiment, since the straight portion other than the corner portion can be the duct 70c, the cooling performance is improved. In addition, the straight line portion other than the corner portion occupies most of the circumference as compared with the first embodiment, but by using this as the duct 70c, it is possible to contribute to weight reduction of the molded transformer 100.

  A fourth embodiment, which is a modification of the first embodiment, will be described with reference to FIG. FIG. 5A shows a state in which the duct 70d is provided in the molded transformer 100. FIG. FIG. 5B shows a cross-sectional view taken along line AB of FIG.

  The difference from the first embodiment is that the upper surface and the lower surface of the duct 70d are chamfered. By chamfering, partial discharge is less likely to occur at the upper or lower surface of the duct 70d of the molded coil 50. As a result, the reliability of the mold transformer 100 can be improved. Note that the chamfering may be only one of the upper surface portion and the lower surface portion.

  The chamfering is to provide a surface 75 d different from the upper surface or the lower surface connected to the upper surface or the lower surface of the duct 70 d and the molded coil 50. The different surfaces 75d are surfaces having different angles or curvatures from the upper surface and the lower surface of the duct 70d and the molded coil 50.

  That is, the different surface 75d is a surface connected to the surface of the duct 70d and the upper surface or the lower surface of the molded coil. By providing different surfaces, it is possible to reduce the weight of the molded coil 50 as compared with the first embodiment, and it is possible to provide the molded transformer 100 that is reduced in weight.

  In addition, although the different surface 75d which is a chamfering part is expressed linearly in FIG.5 (b), it may be a situation. By adopting the aspect, the connecting portion between the upper surface or the lower surface of the molded coil 50 and the duct 70d does not have a convex portion, so that partial discharge is less likely to occur.

  Moreover, since a convex part is not formed in the connection part of the different surface 75d and the duct 70d, it becomes difficult to produce partial discharge. Thereby, it becomes possible to provide the mold transformer 100 with high reliability.

  A fifth embodiment, which is a modification of the fourth embodiment, will be described with reference to FIG. The difference from the fourth embodiment is that the duct 70d of the fourth embodiment is changed to a duct 70e having a different width in the vertical direction of the molded coil 50.

  The duct 70e has a different surface 75e at the connecting portion between the duct 70e and the upper surface of the molded coil 50. Similarly, the connecting portion with the lower surface also has a different surface 75e. If the different surface 75e is curved as in the fourth embodiment, partial discharge is less likely to occur, which is effective.

  A taper is provided from the lower surface 75e of the duct 70e toward the upper surface 75e. That is, the width w2 of the duct section on the lower side is larger than the width w1 of the duct section on the upper side.

  In this case, the width w2 has the largest cross-sectional area between the different upper surface 75e and the lower different surface 75e of the duct 70e. In consideration of manufacturing work, the cross-sectional area of the width w1 may be larger than the width w2.

  This facilitates the drawing operation when the drawing die is drawn from the cast and hardened mold resin. The reliability of the mold transformer 100 can be improved by having the different surface 75e which is a chamfer. In addition, it is possible to reduce the weight of the mold resin by increasing the cross-sectional area of the duct 70e. In addition, since the cross-sectional area of the duct 70e is larger than that of the fourth embodiment, the air permeability in the vertical direction is improved, so that the heat dissipation characteristics can be improved.

  A fifth embodiment, which is a modification of the fourth embodiment, will be described with reference to FIG. The difference from the fourth embodiment is that the members 200s and 200p are arranged around the duct 70f. The different surface 75f may have the same configuration as the different surface 75e.

  The members 200s and 200p are provided with insulating paper, insulating film, or glass cloth. It is also possible to arrange a plurality of these members in combination, and it is also possible to arrange them as a single member.

  In addition to these members, a member different from the mold resin can be arranged. For example, other members having excellent insulation, fire resistance, or heat resistance can be used. The member 200s and the member 200p are preferably arranged on the surface facing the duct 70f. The members 200s and 200p are arranged in the mold resin so as to cover the duct 70f.

  That is, the duct 70f is disposed between a different upper surface 75f and a lower lower surface 75f. Thus, when chamfering the cast resin that has been cast and cured, the member 200s and the member 200p do not interfere with each other during the chamfering, so that the chamfering operation is facilitated. Further, by disposing the member 200s and the member 200p, the resin surface becomes smooth, the aesthetic appearance is improved, and partial discharge hardly occurs.

  By disposing these members 200s and 200p in the opposing region of the duct 70f, the insulation performance can be improved more than in the fourth embodiment. As a result, the mold transformer 100 with improved reliability can be provided.

  Although the invention made by the present inventor has been specifically described based on the embodiments of the invention, the present invention is not limited to the embodiments of the invention, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.

  Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. .

DESCRIPTION OF SYMBOLS 100 ... Mold transformer 10 ... Primary coil 20 ... Secondary coil 50 ... Integrated mold coil 60p which integrated mold resin ... Primary side 60s ... Secondary side 70a, 70b, 70c, 70d, 70e, 70f ... Ducts 75d, 75e, 75f ... different surfaces

Claims (9)

A mold transformer having an iron core around which a primary coil covered with a first mold resin and a secondary coil covered with a second mold resin are wound,
A third mold resin is provided for connecting between the first mold resin and the second mold resin;
The third mold resin has a duct that passes from the upper surface to the lower surface in a partial region between the primary coil and the secondary coil,
The lower surface connected to the duct and the lower surface or the upper surface or a surface different from the upper surface or the duct,
The mold transformer characterized in that the cross-sectional area on the upper surface side of the third mold resin in the duct is larger or smaller than the cross-sectional area on the lower surface side. The molded transformer according to claim 1,
The mold transformer, wherein the first mold resin, the second mold resin, and the third mold resin are cast integrally. The molded transformer according to claim 2,
A connection region between the first mold resin and the third mold resin or a connection region between the second mold resin and the third mold resin is directly connected without an interface. Mold transformer. The molded transformer according to claim 1,
The mold transformer is characterized in that the different surface is a curved surface. The molded transformer according to claim 1,
The mold transformer according to claim 1, wherein a cross-sectional area of a region between the different upper surface and the lower different surface of the duct is tapered toward an upper portion or a lower portion. The molded transformer according to claim 5,
The molded transformer according to claim 1, wherein a cross-sectional area of a portion of the duct connected to the different surface is the largest or the smallest of the cross-sectional areas. The molded transformer according to claim 1,
The mold transformer is characterized in that the different surface is a chamfered surface between the duct and the upper surface or the lower surface. The molded transformer according to claim 1,
The third mold resin is characterized in that a member different from the mold resin is disposed so as to cover a region between the different surface disposed above the duct and the different surface below. Mold transformer. The molded transformer according to claim 8,
The different member is an insulating paper, an insulating film, or a glass cloth.

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