JPH02890Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a coil spacing device for maintaining a predetermined spacing between an inner coil and an outer coil in a molded transformer.

[Prior art]

Generally, the coil of a molded transformer has an inner coil 1 and an outer coil 2 molded with resin arranged concentrically around an iron core 3, as shown in FIG. An E-shaped coil spacing holding device 5 which also serves as a coil holder is inserted between the coils 1 and 4, and the coil holder 5 is tightened to support both the coils 1 and 2 on the iron core 3. However, since both the coils 1 and 2 have a space 6 between them for ventilation of cold air, and only their axial ends are supported by a coil spacing device 5 which also serves as a coil holder, short circuits may occur. When a large electromagnetic mechanical force is generated in the radial direction of the coil due to an overcurrent flowing through the coil, the inner coil 1 moves radially inward,
In addition, the outer coils 2 each receive a force directed outward in the radial direction, and if this force is excessive, the coils 1,
In some cases, cracks were generated in the second resin layer. For this reason, recently, as shown in FIG. 3, a coil conductor is placed on an insulating layer 9 formed by winding a glass roving material impregnated with thermosetting resin on the outer peripheral surface of an insulating cylinder 8 in parallel. The wound conductor layer 10 is formed by winding one layer, and then the end of the winding is cut once, and the resin-impregnated glass roving material is placed on the wound conductor layer 10 again. 10 is wound two to three times to form an interlayer insulating layer 11, and a coil conductor and a glass roving material are alternately wound in sequence on this interlayer insulating layer 11 in the same manner as described above to form an inner coil 12. Then,
On the outer peripheral surface of the coil 12, a band-shaped insulating plate 13 made of, for example, a fiber-reinforced plastic plate, having a width approximately equal to the height of the inner coil 12, is provided.
Wide plate-shaped duct pieces 14 made of the same material as the insulating plate 11 and processed to have a longitudinal dimension approximately equivalent to the width dimension of the insulating plate 13 are placed at equal intervals in the length direction of the insulating plate 11 using an adhesive. The coil spacing maintaining device 15 is formed by disposing the coil spacing maintaining device 1.
5 is the same as when the duct piece 14 is wound while being pressed against the outer peripheral surface of the inner coil 12 so that it is arranged concentrically around the outer periphery of the inner coil 12, and then the inner coil 12 is wound from the outside of the coil spacing maintaining device 15. After that, the inner and outer coils 12 and 16 are mounted on a rotating device (not shown), and the interlayer insulating layer 11 of each coil 12 and 16 is rotated at a low speed. Coil A for a molded transformer was manufactured by heating and curing the impregnated resin. As described above, this coil A is wound with the coil conductor layer 10 wrapped in a glass roving material, so that the low-voltage and high-voltage coils 12,
16, it is not significantly influenced by electromagnetic mechanical forces. That is, cracks are prevented from occurring in the resin layer of the coil A due to the wound conductor layers 10 being displaced in the axial direction of the coil A or being pushed in the radial direction. However, when the inner coil 12 is wound, each time the coil conductor is wound to form the wound conductor layer 10, a roving material wraps around both ends of the wound conductor layer 10. Since the interlayer insulating layer 11 is formed by winding the inner coil 12 while folding it back at both ends, when the inner coil 12 is completed, both ends of the outer circumferential surface of the inner coil 12 are wound as shown in FIG. coil 1
It is in a bulged state compared to the central portion of 2, that is, a bulged portion is formed. Therefore, when the coil spacing maintaining device 15 is arranged on the outer circumferential surface of the inner coil 12, as shown in FIG. , there is almost no contact with the recessed part in the center, that is, the duct piece 14 can only come into contact with the outer circumferential surface of the inner coil 12 with a small contact area, so the electromagnetic force is small enough to not adversely affect the coil A. Even if a mechanical force is generated, the inner coil 12 and outer coil 16
There was a risk that they would shift in opposite directions in the axial direction. For this reason, the inner coil 12
The lead wire connected to the lead wire may be pulled, causing a crack in the resin layer at its base, or the coil A may swing due to the vibration of the iron core during operation, causing noise. Furthermore, there were other drawbacks such as damage to the coil holder.

[Purpose of invention]

The present invention solves the conventional drawbacks and provides a coil spacing maintaining device for a molded transformer that suppresses displacement of the inner coil and outer coil in the axial direction of the coil due to electromagnetic mechanical force. .

[Summary of the idea]

In the present invention, a duct piece for maintaining the distance between the inner coil and the outer coil at a predetermined distance is formed with a stepped portion on the end surface side that contacts the outer circumferential surface of the inner coil. The purpose is to prevent the inner coil and the outer coil from shifting in opposite directions along their axial directions due to electromagnetic mechanical force.

[Example of idea]

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

In FIG. 1 and FIG. 5, the same parts as in the conventional example are given the same reference numerals and explained.

As shown in FIG. 5, the coil spacing maintaining device 15a of the present invention includes
On the end surface side that comes into contact with the outer circumferential surface, the upper part of the duct piece 17 corresponding to the bulge on the outer circumferential surface of the inner coil 12,
As shown in FIG. 1, a notch 17a for accommodating the bulge is formed in the lower part in the vertical direction, and a vertically elongated convex strip 17b is formed in the center that comes into contact with the recessed part of the outer peripheral surface of the inner coil 12. The coil spacing is maintained by integrally forming the duct piece 17 and disposing the opposite end surface of the duct piece 17, which does not have the protruding stripes 17b, etc., on the strip-shaped insulating plate 13 using adhesive at equal intervals as in the past. This constitutes a device 15a. When installing this coil spacing retaining device 15a, after winding the inner coil 12 in the same manner as before, the end surface of the duct piece 17 having the notch 17a and the convex strip 17b is attached to the outer peripheral surface of the inner coil 12. When the coil spacing maintaining device 15a is wound by pressing the coil spacing device 15a, as shown in FIG. The bulges formed on both sides of the surface are accommodated in the notches 17a of the duct piece 17, and conversely, the bulges formed in the center of the outer peripheral surface of the inner coil 12 are accommodated in the notches 17a of the duct piece 17. The vertically elongated convex portion 17b at the center of the duct piece 17 is accommodated. That is, most of the end surface of the duct piece 17 having the notch 17a and the protruding strip 17b comes into contact with the outer circumferential surface of the inner coil 12. When the outer coil 16 is wound from the outside of the coil spacing retaining device 15a in this state, the edge _17b1 of the convex portion 17b of the duct piece 17 is tightened by the winding force of the outer coil 16 as shown in FIG. As in, inner coil 1
It is held in a state in which it is bitten into an insulating layer 12a formed by winding a glass roving material two to three times around the outer circumferential surface of 2. In this way, the coil spacing device 15a of the present invention is inserted between the inner coil 12 and the outer coil 16, and the coil B for the molded transformer is
When the resin impregnating the interlayer insulating layer 11 and the insulating layer 12a of each coil 12, 16 is heated and hardened, the duct piece 17 of the coil spacing device 15a is The coil 12 can be fixed and held in close contact with the insulating layer 12a on the outer peripheral surface of the coil 12 with almost no gaps.

Therefore, when a short circuit current flows in the coil B and an electromagnetic mechanical force is generated, the force acting in the radial direction of the coil B is caused by the interlayers formed by winding the glass roving material between each winding conductor layer 10 of the coil B. The force acting in the axial direction of the coil B can be absorbed by being wrapped in the insulating layer 11 and by solidifying the resin impregnated in the interlayer insulating layer 11 and the insulating layer 12a. The duct piece 17 of the coil spacing device 15a is in close contact with the outer peripheral surface of the inner coil 12, and the duct piece 1
The edge 17b ₁ of the protruding portion 17b of No. 7 is the inner coil 12
Since the coil B can be received by being attached by biting into the insulating layer 12a of the coil B, it becomes possible to significantly reduce the adverse effects caused by the electromagnetic mechanical force.

Incidentally, the cutout portion 17a and the protrusion portion 17b of the duct piece 17 are provided with saw blade-like portions with dimensions slightly smaller than the thickness of the insulating layer 12a formed by winding the glass roping material two to three times as shown in FIG. a, and this sawtooth part a is connected to the insulating layer 12 on the outer surface of the inner coil 12.
a, the inner coil 12 and outer coil 13 are moved to coil B by electromagnetic mechanical force.
The present invention can also be achieved by preventing displacement in the axial direction.

[Effect of idea]

As explained above, in the coil spacing maintaining device of the present invention, the duct piece that brings the inner coil into contact with the outer circumferential surface is formed in an uneven shape to match the shape of the outer circumferential surface of the inner coil in the axial direction. By using this duct piece, the present invention has the following effects.

In the present invention, one end surface of the duct piece that faces the outer peripheral surface of the inner coil faces the bulge of the insulating layer that is created by folding and winding the glass roving material at both ends of the inner coil multiple times. a notch for accommodating the bulge,
In addition, a convex portion protruding toward the recess is formed at a portion facing the recess in the central portion of the inner coil, and has a step with the notch. Since it is provided in accordance with the shape of the coil, it is possible to quickly and reliably attach the inner coil and the outer coil in close contact without creating a gap on the outer peripheral surface of the inner coil.

In the present invention, since the end surface side of the duct piece facing the outer circumferential surface of the inner coil is formed to match the shape of the outer circumferential surface of the inner coil, the duct piece is attached to the insulating layer of the inner coil when the outer coil is wound. The resulting tightening force allows the duct piece to be firmly attached under pressure, allowing the resin impregnated in the insulating layer to penetrate between the insulating layer and the duct piece, thereby insulating the duct piece. It can be firmly attached to the layer.

Furthermore, according to the present invention, the end surface of the duct piece facing the insulating layer is formed in an uneven shape to match the shape of the insulating layer on the outer peripheral surface of the inner coil, so that when the duct piece is attached to the insulating layer of the inner coil, , the end edge portion having the step that forms the boundary between the convex portion and the notch portion of the duct piece is wrapped with glass roving material for two to two minutes by the winding force of the outer coil.
Since the duct piece can be inserted between the inner coil and the outer coil while being reliably bitten into the insulating layer formed by triple winding, the duct piece can be attached in close contact with the inner coil. ,
Coupled with the fact that the insulating layer is constructed by winding glass roving material multiple times to wrap around the coil, when a short circuit current flows in the molded coil and electromagnetic mechanical force is generated, the coil radially and axially Reliably absorbs the force acting on the
It is possible to significantly reduce adverse effects such as misalignment or deformation of the inner coil and outer coil due to electromagnetic mechanical force.

In addition, the present invention allows the convex portion and notch provided on the duct piece to conform to the outer peripheral surface of the inner coil, so that it can be inserted between the outer coil and the outer coil without creating a gap. Since the molded coil itself is provided with a small diameter, there is an advantage that the molded coil itself can be manufactured with a smaller diameter.

Moreover, since the duct piece that forms the spacing device between the inner and outer coils has a simple shape with only a convex part and a cutout on the end face side facing the inner coil, an insulating plate is used. When manufacturing a duct piece, no special effort or labor is required, so it can be manufactured at low cost with excellent mass productivity.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the main parts of a molded coil using the coil spacing device of the present invention, and FIG. 2 is a vertical sectional view showing the main parts of a molded transformer equipped with the conventional coil spacing device. Fig. 3 is an explanatory diagram showing the winding state of the inner coil, and Fig. 4 is an explanatory diagram showing the winding state of the inner coil. Fig. 4 shows an outer coil manufactured by winding the inner coil in the same manner as the inner coil shown in Fig. 3, and a space between the outer coil and the inner coil. FIG. 5 is a perspective view of the coil spacing device of the present invention; FIG. 6 is an enlarged view of portion P in FIG. 1; FIG. FIG. 3 is a front view showing another embodiment of the present invention. 11... Interlayer insulation layer, 12... Inner coil, 1
5a... Coil spacing maintaining device, 16... Outer coil, 17... Duct piece, 17a... Notch,
17b... Convex portion, B... Molded coil.

Claims (1)

[Scope of utility model registration request] Each time the coil conductor is wound a predetermined number of times to form one layer of the wound conductor layer 10, the wound conductor layer 10 is
A glass roving material impregnated with resin is placed between the wound conductor layer 10 of the previous layer and the wound conductor layer 10 of the previous layer.
In a molded transformer coil in which an inner coil 12 and an outer coil 16 are concentrically wound, the coil is provided with an interlayer insulating layer 11 formed by winding a plurality of times while surrounding both ends of the coil. A resin-impregnated glass roving material is wound around the outer peripheral surface of the inner coil 12 to surround both axial ends of the inner coil 12 between the inner coil 12 and the outer coil 16. Insulating layer 12a
A notch 17a is formed at both ends of the inner coil 12 to accommodate the bulge formed by winding the glass roving material, and a notch 17a is formed at the center of the outer peripheral surface of the inner coil 12 to accommodate the bulge. A duct piece 17, which is formed vertically with a convex portion 17b projecting toward the concave portion and having a step with the notch portion 17a, is placed in a portion corresponding to the concave portion of 1. A coil spacing maintaining device for a molded transformer, characterized in that the end face side having the above is inserted in close contact with an insulating layer 12a on the outer peripheral surface of an inner coil 12.