WO1996027200A1

WO1996027200A1 - Coil winding, transformer using it, and method of manufacturing coil winding

Info

Publication number: WO1996027200A1
Application number: PCT/JP1995/000296
Authority: WO
Inventors: Keiji Fukushi; Ryozo Takeuchi; Toshio Shimizu; Syuuya Hagiwara; Tomomi Izuna
Original assignee: Hitachi, Ltd.
Priority date: 1995-02-27
Filing date: 1995-02-27
Publication date: 1996-09-06
Also published as: JP3441734B2

Abstract

A coil for a transformer which is remarkably improved in heat radiating characteristic without increasing the eddy current loss which is generated when the coil is interlinked with leakage fluxes caused by the load current of the winding constituting the coil. A belt-like conductor (1) in which prepreg tapes (2) are interposed is spirally wound and, the conductor (1) is inclined so that the width direction of the cross section of the conductor (1) is approximately parallel with the direction of the leakage fluxes at the end of the coil. Since the leakage fluxes generated between low- and high-voltage coils are almost parallel with the conductor (1), the eddy current loss generated in the winding conductor can be reduced.

Description

Specification

Coil winding and transformer using it

And manufacturing method of coil winding

The present invention relates to a coil winding, a transformer using the same, and a method of manufacturing the coil winding. In particular, the present invention relates to a coil winding that facilitates heat dissipation, can be cooled well, can be used up to a high voltage, and uses the same. Transformers and methods for manufacturing coil windings. Background art

Molded coils made by molding conductor windings with epoxy resin, etc., are excellent in mechanical strength, insulation performance and moisture resistance, and have many disaster prevention advantages such as flame retardancy. It has increased. Recently, a molded transformer using this molded coil has also been required to be smaller and cheaper. To meet this demand, a structure with better ripening characteristics is indispensable.

The winding structure of a conventional molded coil is roughly divided into the following structures. One is that, as described in, for example, Japanese Patent Application Laid-Open No. 63-72106 (hereinafter referred to as well-known example I), a round wire or a flat wire is wound in a cylindrical shape in the axial direction, and the outer circumferential side is formed. An insulating material is wound around the wire, and a winding conductor is wound thereon. This process is repeated a predetermined number of times to form a winding unit. A required number of these winding units are connected in series in the axial direction to form a coil winding.

The other is, as described in, for example, Japanese Patent Application Laid-Open No. 54-104529 (hereinafter referred to as "known example 1"), in which a strip-shaped conductor is wound in a tubular shape with an insulating material interposed therebetween to form a winding unit. And the required number of them are arranged in the axial direction and connected in series. As a result, a coil winding is formed.

The heat generated in the coil (Joule heat mainly generated by the resistance of the windings) is eventually dissipated from the outer surface of the coil, that is, the inner and outer peripheral surfaces, and the ends in the axial direction. Is a cylindrical shape that is long in the axial direction, as can be seen in the well-known examples (1) and (2). You.

For this reason, the heat generated inside the coil will flow mainly in the radial direction. However, in the conventional coil structure as described above, an insulator with small mature conduction (three digits in comparison with the heat conduction of the conductor) Are arranged so as to divide many radial directions. Therefore, in these coil structures, the flow of heat in the radial direction is blocked, and the temperature difference between the inside of the coil and the temperature of the coil surface is large, resulting in a coil having poor heat dissipation characteristics.

As a proposal for improving the heat dissipation characteristics of such a conventional coil structure, there is Japanese Utility Model Publication No. 56-63030 (hereinafter referred to as known example ③).

In this method, the strip conductor is wound while being stacked in the axial direction with an insulator interposed therebetween.Since the strip conductor is continuous from the inner peripheral side to the outer peripheral side without interposing an insulator that divides the radial direction, It has the advantage of efficiently transmitting the heat generated inside the coil to the inner and outer peripheral surfaces. As a result, a coil with excellent heat radiation characteristics can be obtained.

In addition, regarding the above-described method for manufacturing a molded coil, for example, as described in Known Example 3 and Japanese Patent Application Laid-Open No. 56-161625 (hereinafter referred to as Known Example 2), After fixing the coil winding thus formed at a predetermined position in the mold, a method of injecting a thermosetting resin and heat-curing the same to form a mold coil has been used as an effective molding method. Was.

However, in the known example (3), the eddy current at the coil end is linked to the leakage flux generated between the low-voltage coil and the high-voltage coil due to the winding structure. There is a disadvantage that the flow loss increases.

In each of these known examples (1), (2), (3) and (4), the conductor winding is molded with epoxy resin or the like, so that the entire apparatus becomes large and, of course, work such as resin injection is required. The production of coils is time-consuming and cumbersome, and a new mold is required for each coil with a different shape or size, increasing the number of molds and requiring more time for storage and maintenance. was there.

The present invention has been made in view of the above points, and a first object of the present invention is to provide not only excellent heat dissipation characteristics, but also simple and compact coil windings, and And a method for producing a coil winding.

A second object of the present invention is to provide a coil winding having excellent heat dissipation characteristics and capable of reducing eddy current loss at a coil end, and a transformer using the same. It is in. Disclosure of the invention

The first object is to perform insulation treatment on the strip-shaped conductors, or to use a prepreg tape as an insulator interposed between the strip-shaped conductors to insulate the strip-shaped conductors from each other. Coil winding,

A low-voltage coil disposed around the iron core, or a high-voltage coil attached around the low-voltage coil, is wound a predetermined number of times while the strip conductor and the prepreg tape are stacked in the axial direction, and the prepreg tape is interposed therebetween. A transformer in which the strip-shaped conductors are fixed and integrally formed,

After fitting the first end insulator into the insulating cylinder, the band-shaped conductor wrapped with prepreg tape is processed into a wavy shape, which is wrapped around the insulating cylinder, and is wound in the axial direction. The intermediate insulator is provided at the time of winding to the center, and thereafter, the projecting direction of the wavy convex portion of the band-shaped conductor is changed and further wound up by a predetermined number, and the second end is opposite to the first end insulator. This is achieved by providing a method for manufacturing a coil winding in which the outer layer is insulated after the partial insulator is attached, and then the whole is heated and cured while being pressed from above and below.

The second object is that, at each of the coil axial ends, the cross-sectional inner diameter side end of the belt-shaped conductor is inclined toward the center in the axial direction as compared with the outer diameter side end, or at each end in the coil axial direction. The cross section of the strip conductor is inclined so that it is substantially parallel to the direction of the leakage magnetic flux at both ends in the coil axis direction, or the bent projections of the strip conductor are axially centered at both ends in the coil axis direction. A coil winding characterized by being configured to be:

At each of the coil axial ends, the force at which the cross-sectional inner end of the high-voltage coil strip conductor is inclined so that it is closer to the center in the axial direction than the outer end, the axial ends of the high-voltage coil The cross section of the strip conductor is tilted so that it is almost parallel to the direction of the leakage magnetic flux at both ends in the axial direction of the coil generated between the low-voltage coil and the high-voltage coil. ^ Either the end of the coil in the axial direction is located on the center side in the axial direction, or the end of the coil in the axial direction is compared to the cross-sectional outer diameter end force and inner diameter end of the low-voltage coil band conductor. It is inclined so that it is on the center side in the axial direction, or the cross section of the band-shaped conductor at both ends in the axial direction of the low-voltage coil is almost parallel to the direction of the leakage magnetic flux at both ends in the axial direction of the coil generated between the low-voltage coil and the high-voltage coil. It is accomplished by a transformer that is inclined to so that. In the present invention, the band-shaped conductor is stacked and wound in the axial direction with the prepreg tape interposed therebetween, so that the band-shaped conductor is continuous without any intervening insulator separating the radial direction from the inner peripheral side to the outer peripheral side. The heat generated inside the coil is efficiently transmitted to the inner and outer peripheral surfaces, so the heat dissipation characteristics are excellent. Needless to say, since prepreg tape is used, it is not necessary to perform the filling and curing of the thermosetting resin as in the conventional case, and it is needless to say that the strip-shaped conductors are formed of the resin flowing from the prepreg tape. However, the first object can be achieved because other insulators can be bonded and integrated.

Further, according to the present invention, not only the heat dissipation characteristics are excellent for the same reason as described above, but also the leakage magnetic flux generated between the low-voltage coil and the high-voltage coil and the strip-shaped conductor are in a state close to parallel, Since the eddy current loss generated inside the wire conductor can be reduced, the second object is achieved. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a sectional view showing an embodiment of the coil winding of the present invention, FIG. 2 is a partial perspective view showing a strip-shaped conductor used in FIG. 1, and FIG. 3 is a view of the strip-shaped conductor used in the present invention. FIG. 4 is a cross-sectional view taken along line AA ′ in FIG. 3, FIG. 5 is a cross-sectional view taken along line BB ′ in FIG. 3, and FIG. 6 is the present invention. FIG. 7 is a cross-sectional view showing another embodiment of the coil winding of FIG. 7, FIG. 7 is a schematic perspective view showing a method of manufacturing the coil winding of the present invention, and FIG. 8 shows a pressed state of the coil winding of the present invention. FIG. 9 is a sectional view showing still another embodiment of the coil winding of the present invention, FIG. 10 is a partial perspective view showing another example of the strip conductor used in the present invention, and FIG. FIG. 12 is a partial plan view showing a bent state of another example of the strip conductor used in the present invention; FIG. 12 is a partial plan view showing a bent state of still another example of the strip conductor used in the present invention; Fig. 13 is a plan view showing how the strip conductor is bent when the present invention is applied to a rectangular coil, and Fig. 14 is a transformer showing the distribution of leakage magnetic flux in the low-voltage and high-voltage coils of the transformer of the present invention. FIG. 15 is an explanatory diagram showing an example of a method of interlinking a strip conductor and a leakage magnetic flux in the present invention, and FIG. 16 is an explanatory diagram showing a flow of an eddy current in FIG. Fig. 17 shows an example of the conventional way of interlinking a strip conductor with leakage flux. FIG. 18 is an explanatory diagram showing how eddy currents flow in FIG. 17. FIG. 19 is a partial perspective view showing a conductor shape used in another embodiment of the coil winding of the present invention. FIG. 20 is a cross-sectional view showing another embodiment of the coil winding of the present invention. FIG. 21 is a partial perspective view showing an example in which a slit is provided in a strip conductor employed in the present invention. FIG. 2 is a sectional view showing an example of a coil winding constituted by using the prepreg tape of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows an embodiment of a coil winding according to the present invention, which is an example in which the present invention is applied to a high-voltage coil 22 having a transformer configuration shown in FIG.

As shown in FIG. 14, the transformer is schematically configured by disposing a low-voltage coil 21 around an iron core 23 and a high-voltage coil 22 around the core. The low-voltage coil 21 and the high-voltage coil 22 are formed by winding a band-shaped conductor such as a metal strip such as copper or aluminum or a metal foil with an insulating material interposed therebetween, and electrically connecting them in series. Have been.

As shown in FIG. 1, as the conductor in the coil winding of this embodiment, for example, as shown in FIG. 2, a conductor obtained by winding a prepreg tape 2 as an insulator on a strip conductor 1 is used. The prepreg tape 2 is, for example, a glass tape base material impregnated with a thermosetting resin such as an epoxy resin, and a curing reaction is advanced to some extent to form a semi-cured state. As the prepreg tape, use a glass tape as a base material and a piece of mica bonded to the base material to improve insulation properties, or to improve thermal conductivity by adding inorganic powder to the impregnated resin. Can also. It is also a promising means to use a prepreg tape containing a large amount of resin using a porous base material such as a glass nonwoven fabric to fill a gap formed near the conductor as described later. In short, a prepreg tape made of glass fiber, polymer fiber, or natural fiber woven fabric, which is impregnated with a thermosetting resin and which has been cured to some extent to make it semi-cured, glass fiber, polymer Using a non-woven fabric of fiber or natural fiber as a base material, impregnating it with a thermosetting resin, performing a curing reaction to some extent, and using a semi-cured prepreg tape or film material as a base material, and using a thermosetting resin on the surface A prepreg tape may be formed by applying a resin and proceeding a curing reaction to some extent to make it semi-cured.

As one method for winding such a band-shaped conductor 1 in a disk shape, there is a method described in the above-mentioned known example ③, which is shown in FIG. As shown in FIG. 3, this is a method in which the strip-shaped conductor 1 is folded at a fold line 7 to form a convex portion 8 (to make a business trip perpendicular to the paper surface or to be dented) and to wind it up. In this case, the cross section of A-A 'in Fig. 3 is as shown in Fig. 4, and the cross-section of B-Β' is as shown in Fig. 5, and each turn of the winding is bent. By making the ώ section 8 overlap tightly, a compact winding in the axial direction becomes possible.

In FIG. 1 showing an embodiment of the present invention, a cross section on the right side shows a section taken along a line ΑA ′, and a left side shows a section taken on a line BB ′. As can be seen from the cross-sectional view on the left side of FIG. 1, in the present invention, the bent convex portion 8 generated by bending is configured so that both ends thereof are on the axial center side.

Fig. 6 is a special case of Fig. 1, where Fig. 4 showing the section A-A 'in Fig. 3 is horizontal (Fig. 1 is inclined so that the inner circumference side is recessed). It is.

With this configuration, the direction of the leakage magnetic flux generated by the load current of the winding becomes almost parallel to the width direction of the strip-shaped conductor 1, so that the eddy current loss generated in the strip-shaped conductor 1 can be reduced.

This effect will be described with reference to the drawings. FIG. 14 shows a transformer according to the present invention. The layout of the iron core 23, the low-voltage coil 21 and the high-voltage coil 22 and the general directions of the leakage flux 24 are shown. As is clear from FIG. 14, at the axial end of the high voltage coil 22, the high voltage coil 22 and the leakage magnetic flux 24 intersect obliquely. .

Now, consider the case of Fig. 15 and Fig. 17 assuming that the leakage magnetic flux 24 interlinks with the band-shaped conductor that constitutes the high-voltage coil 22 with a width that is considerably wider than the thickness, and consider the eddy current loss. Compare. FIG. 16 shows a conductor cross section in a plane perpendicular to the magnetic flux leakage 24 of FIG.

As shown in Fig. 15, when the leakage magnetic flux 24 and the strip-shaped conductor 1 are almost parallel, the eddy current 25 flows as shown in Fig. 16 due to the thin conductor thickness. Is restricted and flows in a limited cross section. On the other hand, as shown in Fig. 17, when the leakage magnetic flux 24 intersects at a right angle to the surface of the strip-shaped conductor 1, the cross section of the conductor perpendicular to the leakage magnetic flux 24 is As shown in FIG. 18, the eddy current 25 flows over the entire surface of the strip-shaped conductor 1 due to the large eddy current loss, and the eddy current loss increases. Now, when comparing the eddy current loss with the thickness of the strip-shaped conductor 1 being 0.5 ram and the width being 40 hidden, Fig. 15 shows that the eddy current loss is as small as about 150 to 110 in the case of Fig. 17. Become.

That is, in the present invention, utilizing this relationship, the coil winding is formed by inclining the strip-shaped conductor cross sections at both ends in the coil axial direction so as to be nearly parallel to the direction of the leakage magnetic flux 24. It is. Since this corresponds to FIG. 15 described above, a significant effect of reducing eddy current loss can be obtained as in the above description.

Also, as shown in the right-hand cross section of FIG. 6, in a portion where the strip-shaped conductor 1 is horizontal, the leakage magnetic flux 24 intersects the strip-shaped conductor 1 obliquely. Although the value is in the middle of the figure, the shape of the bent portion is close to the direction of the leakage magnetic flux 24 shown on the left side of FIG. Therefore, what kind of consideration The value of the eddy current loss can be made smaller as compared with the case where no eddy current loss occurs.

In addition, as shown in Fig. 1, the entire winding is tilted (the right and left tilt angles are different due to bending) to reduce the deviation between the width direction of the strip-shaped conductor 1 and the direction of the leakage magnetic flux. Therefore, there is an effect that eddy current loss can be further reduced.

Next, a method of forming a coil using a prepreg tape, which is a main forming means in the present invention, will be described with reference to FIG.

As shown in FIG. 22, a band-shaped conductor 1 on which a prepreg tape 2 is wound around an insulating tube 3 is wound up in the axial direction as shown in the figure, and an end insulating ring 5 is attached to the axial end. Wind the outer insulating layer 4. After winding the strip-shaped conductor 1, the insulating tube 3 may be inserted into the inner peripheral side thereof. The prepreg tip 2 may be wound up while being sandwiched between the strip-shaped conductors 1 instead of being wound. As the outer insulating layer 4, a prepreg tape may be used.

The coil winding thus wound is heated and pressurized with pressure P from above and below as shown. In prepreg molding, heat is applied to the prepreg tape 2 while heating, and the resin in the prepreg tape 2 is caused to flow to push out defects such as an air layer remaining around the conductor, thereby obtaining an insulating layer with few defects. Things. In addition, since the prepreg material and the conductor are brought into close contact with each other, the adhesion between them can be improved. If the pressing force is not sufficiently transmitted to the prepreg tape 2, there is a concern that defects may occur in the insulating layer.

However, the structure of the present invention as shown in FIG. 22 is such that the strip-shaped conductor 1 on which the prepreg tape 2 is applied is only spirally wound in the axial direction. Transmission is easy, and the pressurized power from above and below is sufficiently transmitted to the inside of the coil. Resin extruded by pressure Fills the gap between the strip-shaped conductors 1 and penetrates between the inner circumferential insulating cylinder 3 and the end insulating ring 5 and hardens, so that they are integrally fixed.

Thus, in the structure of the present invention, it is possible to form an insulating layer having few defects and a mechanically strong coil using the prepreg tape 2.

Next, a method of manufacturing the coil winding of the present invention will be specifically described. The coil winding of the present invention is manufactured, for example, by a procedure schematically shown in FIG. That is, after the end insulating ring 5 which is an insulating material at the end is fitted into the insulating cylinder 3, the band-shaped conductor 1 wrapped with the prepreg tape 2 is processed into a wave shape, so that the band-shaped conductor 1 is passed between the gears 9 and 10. 1 is deformed (forming a bent convex portion 8 shown in FIG. 3) and wound around the insulating tube 3 set on the turntable 1 1. as shown in FIG. After winding up to the center in the axial direction (it does not have to be the center), the intermediate insulating ring 6 is provided, and the projecting direction of the bending projection 8 is changed here (winding so as to project toward the axial end). ) Wind up a predetermined number of times, and then attach the opposite end insulating ring 5. After winding the winding while attaching a plurality of insulating rings in this way, the outer insulating layer 4 is wound. The insulating cylinder 3 may be prepared by winding a prepreg around a separately prepared mandrel (winding frame) and heat-curing. The insulating cylinder 3 is manufactured by casting separately using an epoxy resin containing a filler, and has a shot blasted outer surface. You may. In addition, in FIG. 1, FIG. 6, or FIG. 7, a separate mandrel may be prepared, a prepreg may be wound thereon, and the curing may be performed simultaneously with a curing process of a winding portion described later.

One side (axial side) of the end insulating ring 5 and both sides of the intermediate insulating ring 6 in the axial direction need to have a shape corresponding to the bent part 8 of the winding. For this purpose, using a gear device or the like shown in Fig. 7, a material having an appropriate thickness is bent into the same shape and pitch as the windings, for example, into a filler. It can be made by casting epoxy resin. In this case, the surface is preferably subjected to a shot blast treatment or the like to improve the adhesive strength. Of course, it may be manufactured by other methods, for example, machining.

As the outer insulating layer 4, a prepreg material similar to that used for the interlayer insulating material of the wound wire may be used, or a film material provided with an adhesive may be wound. Alternatively, a glass tape or the like not impregnated with a resin may be wound thereon to absorb the resin flowing out of the prepreg in a curing process described later into this portion, thereby forming an insulating layer. In this case, it is necessary to sufficiently understand the amount of resin flowing out of the prepreg and the amount absorbed by the outer insulating layer 4 before performing the operation.

As shown in FIG. 1, the winding thus wound is heated as a whole while being pressed from above and below by a pressing force P to cure the winding. During this temperature-raising process, the semi-cured resin of the prepreg material is again in a fluid state, and since a pressing force is applied from above and below, it flows out of the prepreg material, the upper and lower windings, the windings and the end insulating ring 5, Fill the gaps remaining between the windings and the insulating cylinder 3 and between the windings and the outer insulating layer 4.

Fig. 8 shows the simplest method for achieving this state. Bolts 13 and nuts 14 shown in the external view are for applying pressure from above and below, and when tightened, pressure is applied to the windings via the end holding plate 12. The pressure is applied when the temperature is raised to an appropriate temperature at which the prepreg softens (Nut

(Tighten 14), compress to the specified dimensions (design coil height) (decrease the coil height), and hold in that state until the end of curing. In actual mass production of coils, a device having a press mechanism that can control the applied pressure and the amount of coil deformation can be used. When a prepreg material is also used for the outer insulating layer 4, it is necessary to provide an outer mold from the outer peripheral side and pressurize, or to apply pressure by winding a heat-shrinkable tape. In such a molding method, the resin that has flowed out of the pre-predder is used to adhere to the end insulating ring 5, the insulating tube 3 on the inner peripheral side, etc., and to fill the gap generated in the winding portion. Therefore, it may be appropriate that the amount of resin contained in the prepreg is larger than usual. In that case, as mentioned earlier, the prepreg may be formed using a porous base material such as a glass nonwoven fabric. When it is desired to obtain a resin having an intermediate resin content, a base material such as a glass nonwoven fabric or a glass woven fabric may be used in appropriate combination. Furthermore, by adding an inorganic filler to the resin impregnating the pre-breg material, the thermal conductivity of this portion can be increased.

By doing so, the winding conductor (band-shaped conductor 1), the end insulating ring 5, the insulating cylinder 1, and the outer insulating layer 4 are integrated, so that a robust and compact coil winding is obtained. be able to. Further, in the coil winding having this structure, since the band-shaped conductor 1 having high thermal conductivity is continuous from the inner peripheral side to the outer peripheral side, extremely excellent heat dissipation characteristics can be obtained.

Further, as described above, the eddy current loss caused by interlinking with the leakage magnetic flux can be significantly reduced by inclining the strip-shaped conductor 1 at both ends in the coil axial direction. In addition, this manufacturing method has an effect of facilitating coil manufacturing such that only a winding step and a heating and pressing step for curing the resin do not require a step of resin injection or the like.

Up to now, the manufacturing method has been described in which the prepreg tape 2 is used for the interlayer insulating layer and the temperature is raised while applying pressure to cure the material. However, as shown in FIG. 6, and the bottom plate 17 constitute a container, into which the winding block described in Fig. 1 is put, and the surroundings are filled with epoxy resin 18 mixed with inorganic powder such as ferrer, and heat-cured. Is also good.

In this case, the end insulating ring is not always necessary, and the winding may be floated at a predetermined position with an appropriate spacer. Fig. 9 shows the first As shown in the figure, the structure is such that the interlayer insulating material is wound around the winding, but as shown in Fig. 10, the insulating material (prepreg tape 2), which is wider than the strip-shaped conductor 1, is overlaid. A thing may be used. However, in this case, in order to facilitate the bending process of the strip-shaped conductor 1 described above, it is preferable that the insulating agent and the strip-shaped conductor 1 be integrated in advance using an adhesive or an adhesive. good.

In these methods, the method described in FIG. 3 is used as a method of bending the strip-shaped conductor when the strip-shaped conductor is wound in a spiral shape while being bent, but the vertex of the fold of the bent protrusion 8 as shown in FIG. 3 is not necessarily required. It may be bent as shown in Fig. 11 or Fig. 12 without focusing on one point.

For the coil winding, a rectangular coil that matches the cross-sectional shape of the iron core is often used. In this case, as shown in Fig. 13, the band-shaped conductor is bent at the bent part. What is necessary is just to process so that may be located.

FIG. 20 shows another embodiment of the present invention, in which the strip-shaped conductor 1 is spirally wound while the strip-shaped conductor 1 is formed to form a coil winding. FIG. 19 shows a strip-shaped conductor 1 provided with insulation (prepreg tape 2) for use in this.

This embodiment shows an example in which the strip-shaped conductor 1 is used in a state of being bent edgewise (while extending the outer peripheral side) to some extent. Normally, when winding a strip-shaped conductor edgewise, it is bent while extending the outer circumference, and is bent into a flat disk shape until the inner circumference radius of the strip-shaped conductor is equal to the radius of the winding. In the case of FIG. 20, the inner radius of the band-shaped conductor 1 after bending is set to be larger than the radius of the coil winding. As shown in FIG. 20, this is wound while the cross section of the strip-shaped conductor 1 is inclined to obtain a coil winding having a predetermined radius.

Even with such a winding method, the reasoning described with reference to FIGS. Therefore, it goes without saying that eddy current loss caused by linkage with the leakage magnetic flux can be reduced.

In the description so far, the high-voltage coil 22 in Fig. 14 has been symmetrical.However, when applied to the low-voltage coil, the direction of the leakage magnetic flux in the low-voltage coil 21 shown in Fig. 14 is considered. The high-voltage coil 22 may be tilted in the opposite direction.

FIG. 21 shows an example in which eddy current loss needs to be further reduced in addition to the above-described means. That is, when it is necessary to further reduce the eddy current loss, a plurality of slits 26 are provided alternately in the width direction of the strip-shaped conductor 1 in parallel with the length direction of the strip-shaped conductor 1, and The surface area may be substantially dispersed.

By doing so, the flow path of the eddy current can be further restricted, which is effective in reducing the eddy current.

In FIG. 21, the force indicating a complete slit shape is not necessarily required to cut the conductor. For example, the thickness is limited by embossing a V-shaped groove ( For example, about 1/10), the effect can be obtained. In the case where a complete slit is provided, the heat conduction in the radial direction is slightly hindered by this, but the method of limiting the thickness can reduce the problem of heat conduction reduction. The effects of the various embodiments of the present invention described above can be summarized as follows. First, since the ripening conductivity in the radial direction can be increased, the size and weight can be reduced, and the increase in eddy current loss can be reduced. A coil winding and a transformer using the same can be provided.

Further, in the coil winding structure of the present invention, since the voltage between the top and bottom of the winding wound in the axial direction is only one turn (usually about several tens of volts), the partial discharge inside the coil winding is not generated. There is also an effect that the insulation properties are excellent, as it is hardly considered. Industrial applicability

According to the coil winding of the present invention described above, a transformer using the same, and a method of manufacturing the coil winding,

Insulating the strip conductors, or using an insulator interposed between the strip conductors to insulate them from each other as a prepreg tape, and a coil winding in which the strip conductors are fixed and integrated through the prepreg tape.

After the first end insulator is fitted into the insulating cylinder, the prepreg tape-wrapped band-shaped conductor is processed into a wavy shape, and it is wound around the insulating cylinder. An insulating material is provided, and then the direction in which the wave-shaped convex portion of the strip-shaped conductor protrudes is changed and a predetermined number of turns are wound up, and a second end insulating material is provided on the side opposite to the first end insulating material. After mounting, the outer layer is insulated, and then the whole is heated and cured while applying pressure from above and below, thus forming a coil winding.

Since the strip-shaped conductor is continuous from the inner circumference to the outer circumference without any insulator that divides in the radial direction, the heat generated inside the coil is efficiently transmitted to the inner and outer surfaces, resulting in excellent heat dissipation characteristics. Needless to say, since the prepreg tape is used, it is not necessary to perform the filling and curing of the conventional hardening resin as in the conventional case, and the resin strip flowing from the prepreg tape and the strip-shaped conductors are used. In addition, since other insulators can be fixedly integrated, there is an effect that not only the radiating characteristics are excellent, but also the manufacturing is simple and a small device can be obtained.

Also, at each end of the coil axial direction, the end on the inner diameter side of the cross section of the band-shaped conductor is the outer diameter. Is it inclined so that it is closer to the center in the axial direction than to the side end, or is it inclined so that the cross-section of the strip conductor at both ends in the coil axial direction is almost parallel to the direction of the leakage magnetic flux at both ends in the coil axial direction? Or a coil winding characterized in that the bent projections of the strip-shaped conductor are configured to be axially centered at both ends in the coil axial direction.

At each of the coil axial ends, the cross-sectional inner end force of the high-voltage coil band-shaped conductor is inclined so that it is closer to the center in the axial direction than the outer-diameter end, or the band is formed at both ends in the axial direction of the high-voltage coil. The cross section of the conductor is inclined so that it is substantially parallel to the direction of the leakage magnetic flux at both ends in the coil axis direction generated between the low-voltage coil and the high-voltage coil, or the bent convex portion of the strip conductor of the high-voltage coil is in the coil axial direction. It is configured so that both ends are on the axial center side, or at each of the coil axial ends, the cross-sectional outer diameter end of the low-voltage coil band-shaped conductor is axial center side compared to the inner diameter end. Or the cross section of the strip conductor at both ends in the axial direction of the low-voltage coil is approximately parallel to the direction of the leakage magnetic flux at both ends in the axial direction of the coil generated between the low-voltage coil and the high-voltage coil. Since it is obtained by a transformer that is inclined to so that,

For the same reason as above, not only the heat dissipation characteristics are excellent, but also the leakage flux generated between the low-voltage coil and the high-voltage coil and the strip-shaped conductor are almost parallel, and are generated inside the winding conductor. Since the eddy current loss can be reduced, not only the heat dissipation characteristics are excellent, but also the eddy current loss at the coil end can be reduced.

Claims

The scope of the claims

1. In a coil winding formed by winding a predetermined number of turns of a strip-shaped conductor and an insulating material interposed between the strip-shaped conductors or insulatingly interposed between the strip-shaped conductors while being stacked in the axial direction. ,

A coil winding, wherein the insulator is a prepreg tape, and the band-shaped conductors are fixed and integrated via the prepreg tape.

2. An insulating tube, a band-shaped conductor wound a predetermined number of times around the insulating tube, an insulating member for insulating the band-shaped conductor or interposed between the band-shaped conductors to insulate each other; An end insulator provided at both ends in the axial direction of the wound strip conductor; an intermediate insulator provided substantially at the center in the axial direction of the predetermined number of wound strip conductors; A coil winding formed by winding a predetermined number of turns while stacking the strip-shaped conductor and the insulator in the axial direction, comprising:

The insulating material is a prepreg tape, and the band-shaped conductors are fixed via the prepreg tape, and the end insulating material, the intermediate insulating material, and the outer insulating material are also fixed and integrated. A coil winding characterized in that:

3. The prepreg tape is made of a woven fabric of glass fiber, polymer fiber, or natural fiber, impregnated with a thermosetting resin, and partially cured to a semi-cured state by performing a curing reaction. The coil winding according to claim 1 or 2, wherein:

4. The prepreg tape shall be made of glass fiber, polymer fiber or natural fiber non-woven fabric as the base material, impregnated with thermosetting resin, and cured to some extent to make it semi-cured. The coil winding according to claim 1 or 2, wherein:

5. The prepreg tape is based on a film material, 3. The coil winding according to claim 1, wherein a curable resin is applied, and a curing reaction is performed to some extent to make a semi-cured state.

6. A band-shaped conductor, an insulator interposed between the band-shaped conductors to insulate the band-shaped conductors or insulating each other, and an inner peripheral side and an outer peripheral side of the predetermined number of turns of the band-shaped conductor. And a coil wound by winding a predetermined number of turns in the axial direction such that the widthwise ends of the strip-shaped conductor reach the inner circumferential insulator and the outer circumferential insulator, respectively.

The coil winding is characterized in that the band-shaped conductor is inclined at each end in the coil axial direction so that the inner diameter side end of the band-shaped conductor is closer to the center in the axial direction than the outer diameter side end. line.

7. A band-shaped conductor, an insulator that is provided between the band-shaped conductors for insulation or is interposed between the band-shaped conductors to insulate each other, and an inner circumferential side and an outer circumferential side of the predetermined number of turns of the band-shaped conductor. And a coil winding having a predetermined number of turns wound in the axial direction so that the widthwise ends of the strip-shaped conductor reach the inner circumferential insulator and the outer circumferential insulator, respectively.

A coil winding characterized in that the cross section of the band-shaped conductor at both ends in the coil axial direction is inclined so as to be substantially parallel to the direction of the leakage magnetic flux at both ends in the coil axial direction.

8. A band-shaped conductor, and an insulating material which is provided between the band-shaped conductors for insulation treatment or interposed between the band-shaped conductors to insulate the band-shaped conductors from each other. In a coil winding formed by winding a predetermined number of turns in the axial direction so that the bent convex portions between turns overlap,

A coil winding, wherein the bent projections of the strip-shaped conductor are configured so as to be axially centered at both ends in the coil axial direction.

9. The insulating material is formed of prepreg tape, and the band-shaped conductors are fixed and integrated via the prepreg tape. A coil winding according to claim 6, 7, or 8.

10. A transformer comprising an iron core, a low-voltage coil placed around the iron core, and a high-voltage coil mounted around the low-voltage coil,

The high-voltage coil is characterized in that a predetermined number of turns are wound while the strip-shaped conductor and the prepreg tape are stacked in the axial direction, and the strip-shaped conductors are fixedly integrated via the prepreg tape to be integrally formed. Transformer.

11. A transformer comprising an iron core, a low-voltage coil placed around the iron core, and a high-voltage coil mounted around the low-voltage coil,

The low-voltage coil is characterized in that a predetermined number of turns are wound while the strip-shaped conductor and the prepreg tape are stacked in the axial direction, and the strip-shaped conductors are fixedly integrated via the prepreg tape to be integrally formed. Transformer.

12. An iron core, a low-voltage coil placed around the iron core, and a high-voltage coil mounted around the low-voltage coil, wherein the high-voltage coil is subjected to insulation treatment or a predetermined voltage through an insulator. In a transformer formed by winding a predetermined number of turns in the axial direction such that the axial ends of the strip-shaped conductor wound several times reach the inner peripheral insulator and the outer peripheral insulator, respectively.

The band-shaped conductor of the high-voltage coil is characterized in that at each end in the coil axial direction, the cross-sectional inner diameter side end of the band-shaped conductor is inclined so as to be closer to the axial center than the outer diameter side end. And transformer.

13. An iron core, a low-voltage coil placed around the iron core, and a high-voltage coil attached around the low-voltage coil, wherein the high-voltage coil is subjected to insulation treatment or a predetermined voltage through an insulator. In a transformer formed by winding a predetermined number of turns in the axial direction such that the axial ends of the strip-shaped conductor wound several times reach the inner peripheral insulator and the outer peripheral insulator, respectively.

The cross section of the band-shaped conductor at both ends in the axial direction of the high-voltage coil may cause leakage at both ends in the axial direction of the coil generated between the low-voltage coil and the high-voltage coil. A transformer characterized by being inclined so as to be substantially parallel to a direction of a magnetic flux.

14. An iron core, a low-voltage coil placed around the iron core, and a high-voltage coil attached around the low-voltage coil, wherein the high-voltage coil is subjected to insulation treatment or a predetermined voltage through an insulator. In a transformer, a band-shaped conductor wound several times forms a bent protrusion at a fold, and a predetermined number of turns are wound in the axial direction such that the bent protrusion between each turn overlaps.

A transformer, wherein the bent projections of the strip-shaped conductor of the high-voltage coil are configured to be axially centered at both ends in the coil axial direction.

15. An iron core, a low-voltage coil placed around the iron core, and a high-voltage coil attached around the low-voltage coil, wherein the low-voltage coil is subjected to insulation treatment or a predetermined voltage through an insulator. In a transformer having a predetermined number of turns wound in the axial direction such that the axial ends of the strip-shaped conductor wound several times reach the inner peripheral insulator and the outer peripheral insulator, respectively.

The band-shaped conductor of the low-voltage coil is characterized in that at each end in the axial direction of the coil, the band-shaped conductor is inclined so that the cross-sectional outer diameter side end is closer to the axial center than the inner diameter side end. And transformer.

16. An iron core, a low-voltage coil placed around the iron core, and a high-voltage coil attached around the low-voltage coil, wherein the low-voltage coil is subjected to insulation treatment or a predetermined voltage through an insulator. In a transformer, a predetermined number of turns are wound in the axial direction such that the axial ends of the strip-shaped conductor wound several times reach the inner circumferential insulator and the outer circumferential insulator, respectively.

The cross-section of the strip conductor at both ends in the axial direction of the low-voltage coil is inclined so as to be substantially parallel to the direction of leakage magnetic flux at both ends in the axial direction of the coil generated between the low-voltage coil and the high-voltage coil. Transformer.

17. After fitting the first end insulator to the insulating cylinder, the band-shaped conductor wrapped with prepreg tape is processed into a wavy shape, and it is wound around the insulating cylinder. The intermediate insulator is provided at the time when the winding has progressed to the center, and then, the direction in which the wavy convex portion of the strip-shaped conductor protrudes is changed and the winding is further wound up by a predetermined number, and the second insulator is provided on the opposite side to the first end insulator. A method of manufacturing a coil winding, comprising: applying an outer insulator after attaching an end insulator, and then heating and curing the whole while applying pressure from above and below.