JPH06196340A - Resin-molded winding - Google Patents

Abstract

PURPOSE:To obtain a product having a small size and high reliability by effectively introducing synthetic resin between layers of a winding part even if a thickness of a sheetlike spacer is reduced. CONSTITUTION:A winding is formed by so inserting a sheetlike spacer 4 provided with a cutout 4a between layers that one or both sides of a lateral direction are pectinated, impregnated or cast with synthetic resin. A cutout depth size D of the cutout 4a is so decided by calculating that a voltage between the layers in a deepest part of the cutout 4a becomes about 235V of a spark voltage of substantially Paschen's law.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-molded winding in which a winding portion is molded with a synthetic resin such as an epoxy resin, such as a resin-molded transformer. It is about.

[0002]

2. Description of the Related Art FIG. 6 is a perspective view showing a laminated material for interlayer insulation disclosed in, for example, Japanese Patent Application Laid-Open No. 3-48410, and FIG. It shows an example of a container. In the figure, 1 is a secondary winding (low-voltage side coil), 2 is a primary winding (high-voltage side coil)
In this case, each magnet wire is wound.
Reference numeral 3 is an insulating sheet, and 4 is a sheet-like spacing material having notches 4a symmetrically provided on both sides, both of which are made of craft insulating paper or polyethylene terephthalate film. As shown in FIG. The sheet-shaped spacing member 4 is attached to both surfaces of the above to form the overlapping material 10. The laminated material 10 is interposed between the layers of the primary winding 2. Reference numeral 5 denotes a main insulating layer interposed between the secondary winding 1 and the primary winding 2, which is formed by winding a synthetic resin film such as a polyethylene terephthalate film or winding a superposing material 10. To be done. 6 is a casting resin layer, which is formed by setting the winding portion formed by the secondary winding 1 and the primary winding 2 in a casting mold, casting the casting resin, and heat-curing it. is there. Reference numeral 7 is a spacer used when setting the winding part in the casting mold.

A transformer is constructed by providing a terminal device, an iron core, mounting metal fittings, etc. on a resin mold winding formed as shown in FIG.

[0004]

Although the conventional resin-molded winding is constructed as described above, in order to inject the casting resin into the inside of the primary winding 2, the notch of the sheet-like spacing member 4 is formed. The portion 4a is a notch from both sides in the width direction to a depth leaving about 10% to 30% of the width W in the central portion. In this configuration, it is necessary for the casting resin to pass through the cutout portion 4a of the sheet-shaped spacing member 4 and be cast in the void portion between the layers of the primary winding 2.

Since a casting resin usually contains a filler, the viscosity becomes high, and generally 1000 cps to 500 cps.
It is 0 cps. Therefore, the thickness of the sheet-shaped spacing member 4 needs to be 0.3 mm or more in order to pass the casting resin into the depth of the cutout portion 4a. However, if the thickness of the sheet-shaped spacing member 4 is increased, the mold winding becomes large, which becomes an obstacle in downsizing the transformer. Although it is suitable for downsizing if the thickness of the sheet-shaped spacing member 4 is reduced,
In the case of the thickness of about 2 mm, in the configuration of the cutout portion 4a leaving about 10% to 30% of the width from both sides in the width direction of the sheet-like spacing member 4 in the central portion, the filler powder is poured. In some cases, the mold pillar does not impregnate the inside of the primary winding 2. That is, since the sheet-shaped spacing member 4 has a small thickness, the casting resin may be difficult to pass through the notch 4 and air bubbles may remain between the layers of the secondary winding 2. Bubbles between layers were often the cause of partial discharge.

The present invention has been made to solve the above problems. Even if the thickness of the sheet-shaped spacing member 4 is reduced, partial discharge is prevented by proper interlayer insulation, and the size and size are reduced. The purpose is to obtain a reliable resin-molded winding.

[0007]

A resin-molded winding according to the present invention has a notch formed between layers of a winding in which a magnet wire is wound in a plurality of layers so that one side or both sides in the width direction have a comb tooth shape. In the resin-molded winding formed by impregnating or casting a synthetic resin in the winding part where the sheet-shaped spacer is inserted, the cutout depth of the sheet-shaped spacer is the maximum depth of the cutout. The notch depth dimension is determined so that the inter-layer voltage in the portion becomes approximately 235 volts of the spark voltage according to the Paschen's law.

[0008]

In the resin-molded winding according to the present invention, the cutout depth dimension is determined by calculating so that the interlayer voltage at the deepest part of the cutout portion of the sheet-like spacing material becomes about 235 volts of spark voltage according to Paschen's law. As a result, the depth dimension of the cutout portion is reduced. Therefore, even if the thickness of the sheet-shaped spacing member is reduced, the synthetic resin surely enters the deepest portion of the cutout portion.

[0009]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a laminated material 10, which is formed of an insulating sheet 3 and a sheet-like spacing member 4 attached to the insulating sheet 3. The sheet-like spacing member 4 is formed in a comb-tooth shape by providing cutout portions 4a on both sides as in the conventional one shown in FIG. However,
The notch depth dimension D of the notch portion 4a is calculated and set as described later. 2 and 3 show an example in which the laminated material 10 is applied to interlayer insulation of a resin mold type transformer, 5 is a main insulating layer, 6 is a synthetic resin layer, and the secondary winding 1 and the primary winding are shown. It is formed by impregnating or casting the winding portion formed by the wire 2. 8 is an iron core. In the primary winding 2, the magnet wires are sequentially wound side by side in the axial direction from one end side to the other end side, and the next layer is sequentially wound from the other end side to one end side and repeated. Is formed in a plurality of layers. FIG. 3 is a half sectional view showing the winding portion of FIG. 2 in an enlarged manner.

In the resin-molded transformer having the above structure, a high voltage is applied to the primary winding 2, but the interlayer voltage also increases in proportion to the applied voltage. For example, if the primary voltage is 6600 volts, the number of layers is generally 4
It is often designed with 0 or more layers. Therefore, when the number of layers is 40, the interlayer voltage is 6600 volts × 2/40 = 33.
The voltage is 0 volt, and this voltage is alternately generated on the left and right sides at the end portions, such as between points a and d and between points c and f shown in FIG. The potentials are almost the same between points b and c and between points d and e. It is known as the spark voltage of Paschen's law that when the interlayer voltage is 235 V or less, partial discharge does not occur even if a void exists.

In the primary winding 2 of the resin mold type transformer, in order to eliminate the partial discharge between the layers, it is sufficient to provide an appropriate interlayer insulation at the portion where the interlayer voltage becomes the spark voltage of 235 V or more according to Paschen's law. . The present invention focuses on this point, and determines the cutout depth dimension D of the cutout portion 4a of the sheet-shaped spacing member 4 by the spark voltage 23 of Paschen's law.
It was set based on 5 volts.

That is, the notch depth dimension D of the notch portion 4a is D when the width of the sheet-like spacing member 4 (correctly, the width of the winding portion) W and the interlayer voltage of the winding portion are V = W- (W × 235 / V) is determined based on the value calculated by the calculation formula. According to this calculation formula, for example, in the transformer of 6600 volts as described above, the notch depth D when the interlayer voltage is 330 volts is 28.8% of the width of the sheet-shaped spacing member 4. According to the experimental result, the notch depth D is the sheet-like spacing member 4
If the width is less than about 30%, the synthetic resin sufficiently penetrates to the deepest portion of the cutout portion 4a even if the sheet-shaped spacing member is thin. Even in the case of a casting synthetic resin containing a filler powder used in this type of mold, it is sufficiently incorporated. In this case, the material of the sheet-like spacing member 4 is a polyethylene terephthalate film, and the thickness is 0.2 mm and the width is 7 mm.
Although 0 mm was used, almost the same result can be obtained if the material is an insulating film such as a polyethylene terephthalate film. The cut depth dimension D is 20 mm from the above calculation formula. The width dimension L of the cutout portion 4a and the width dimension S of the comb tooth portion are also related in terms of the ease with which the synthetic resin can enter, but in this case, L is 3 mm to 4 mm and S is 1.5.
The suitable range is about mm to 2.5 mm. However, these dimensions L and S are required to be appropriate dimensions from the size of the transformer and the wire diameter of the magnet wire, and are not related to the calculation of the spark voltage according to the Paschen's law in the present invention.

As shown in FIG. 6, the prior art overlapping member 10 is provided with the spacing members 4 on both sides of the insulating sheet 3. However, in the present invention, as shown in FIG. The spacing member 4 is provided. Since the notch depth dimension D is shallow, the synthetic resin sufficiently enters the necessary portion even if it is provided only on one side. In the case of the above-mentioned embodiment, the insulating sheet 3 is made of the same material as the sheet-like spacing member 4 and has a thickness of about 0.2 mm, but may be a different material as long as it has the same physical properties as the polyethylene terephthalate film. Absent.

Example 2. In the first embodiment described above, the sheet-like spacing member 4 has the notches 4a provided symmetrically on both sides, but as shown in FIG. 5, the notches 4a are provided on only one side.
It may be provided with a. That is, the interlayer voltage is generated between the points a and d shown in FIG. 4 as described above, but the lower layer and the upper layer are different between the points b and c or the points d and e. Almost no interlayer potential is generated on the connected side. That is, the points b and c and the points d and e are
According to Paschen's law, partial discharge does not occur without special interlayer insulation. Therefore, the points a and d, and c
The notch 4a may be arranged only on the side of the point and the point F.

[0015]

As described above, according to the present invention, the notch depth dimension of the notch portion of the sheet-like spacing member is set by calculation based on Paschen's law. This depth dimension is
Since the depth dimension is smaller than that of the conventional one, even if the thickness of the sheet-shaped spacing member is reduced, the synthetic resin surely enters the deepest portion of the cutout portion. Therefore, the size of the winding portion is reduced, and an inexpensive and highly reliable product can be obtained.

Although the embodiment of the resin-molded transformer has been described above, the same effect can be obtained by implementing it in an electromagnetic coil such as a reactor.

[Brief description of drawings]

FIG. 1 is a perspective view of a laminated material used in Example 1 of the present invention.

FIG. 2 is a sectional view showing a resin mold type transformer according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a winding portion according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of windings for explaining Paschen's law in the present invention.

FIG. 5 is a perspective view of a laminated material used in Example 2 of the present invention.

FIG. 6 is a perspective view showing a laminated material for interlayer insulation used in a conventional resin mold winding.

FIG. 7 is a half sectional view of a conventional resin mold winding.

[Explanation of symbols]

 3 Insulating sheet 4 Sheet-like spacing material 4a Notch 6 Synthetic resin layer 10 Laminating material

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[Procedure amendment]

[Submission date] October 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

Since a casting resin usually contains a filler, the viscosity becomes high, and generally 1000 cps to 500 cps.
It is 0 cps. Therefore, the thickness of the sheet-shaped spacing member 4 needs to be 0.3 mm or more in order to pass the casting resin into the depth of the cutout portion 4a. However, if the thickness of the sheet-shaped spacing member 4 is increased, the mold winding becomes large, which becomes an obstacle in downsizing the transformer. Although it is suitable for downsizing if the thickness of the sheet-shaped spacing member 4 is reduced,
In the case of the thickness of about 2 mm, in the configuration of the cutout portion 4a leaving about 10% to 30% of the width from both sides in the width direction of the sheet-like spacing member 4 in the central portion, the filler powder is poured. In some cases, the mold pillar does not impregnate the inside of the primary winding 2. That is, since the thickness of the sheet-like spacer 4 is thin, is towards the back of the notch 4 may leave bubbles between the layers of cast resin passes difficult one winding 2. Bubbles between layers were often the cause of partial discharge.

Claims (1)

[Claims] 1. A sheet-like spacing member having notches formed so that one or both sides in the width direction has a comb tooth shape is inserted between layers of a winding for winding a magnet wire in a plurality of layers and then wound. In the resin-molded winding formed by impregnating or casting a synthetic resin in the wound portion, the cutout depth of the cutout portion of the sheet-like spacing material is defined as the interlayer voltage at the deepest portion of the cutout portion. A resin-molded winding having a voltage of about 235 volts.