JP3774266B2 - Amorphous winding core transformer - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an amorphous wound core transformer using a wound core made of an amorphous magnetic alloy ribbon.
[0002]
[Prior art]
Amorphous magnetic alloys are supplied in the form of extremely thin strips (for example, a nominal thickness of 0.025 mm). Therefore, when forming an iron core for a transformer using an amorphous magnetic alloy, the shape of the wound core must be It is normal to take.
[0003]
When manufacturing an amorphous wound iron core transformer, for example, a plurality of unit laminates having a predetermined length formed by cutting a laminate of thin ribbons are stacked while shifting the position in the longitudinal direction by a predetermined shift dimension. The laminated body is made into one laminated body block, a plurality of laminated body blocks are sequentially wound around the winding frame, and both ends of the unit laminated body of each laminated body block are butt joined (butt joint) or lap joined (overlapping joined). ) To produce a rectangular wound core having a structure in which the joints are arranged stepwise on one yoke part.
[0004]
In the present specification, of the two yoke portions facing each other in the rectangular wound core, the yoke portion having no joint portion is defined as the first yoke portion, and the yoke portion having the joint portion is defined as the second yoke portion. The yoke part. One and the other of the two leg portions extending in parallel between the first and second yoke portions are defined as first and second leg portions, respectively. Here, the leg portion means a portion to be disposed in the window portion of the winding when the winding is fitted to the wound iron core, and the yoke portion is the outside from the window portion of the winding. It means the part arranged in a protruding state.
[0005]
FIG. 11 shows an example of a rectangular wound iron core 1, in which 1a and 1b are first and second yoke portions, 1c and 1d are first and second leg portions, respectively. Yes, the joint J is formed in the second yoke portion 1b. In the example shown in the drawing, a wound iron core is constituted by four laminate blocks, and the joints J formed on the second yoke portion 1b are the joints J1 to J1 of the first to fourth laminate blocks. It consists of J4. Junction portions of a plurality of unit laminate bodies constituting each laminate block are arranged in a step-distributed state.
[0006]
The rectangular wound iron core manufactured as described above is carried into an annealing furnace for annealing and is annealed. After the iron core is annealed, the second yoke portion 1b is opened at the joint portion, and the portions 1b1 and 1b2 on both sides of the joint portion of the second yoke portion 1b and the first and second legs 1c and 1d is inserted into the windows of the windings W1 and W2, respectively, and both windings W1 and W2 are fitted to the first and second legs 1c and 1d, respectively. After the winding is fitted, the second yoke portion 1b is closed to complete the transformer.
[0007]
Since the amorphous magnetic alloy is easily deformed by its own weight, a reinforcing frame 2 made of stainless steel or the like is disposed on the innermost periphery of the wound iron core to reinforce the iron core. The reinforcing frame 2 is configured to be divided into two large and small U-shaped frame members 2A and 2B. After the winding members W1 and W2 are fitted with the frame member 2B removed, the second joint is formed. The frame member 2B is attached before closing the iron part 1b. An outer peripheral protection plate made of a stainless steel strip or the like is wound around the outermost periphery of the wound core 1 and welded in a state where both ends are overlapped.
[0008]
Since the amorphous magnetic alloy becomes brittle by annealing, the iron core is chipped when the work of fitting the windings W1 and W2 is performed, and large and small pieces are generated from the laminated surface. If this debris comes off the iron core and adheres to the winding or mixes with the insulating oil in the transformer case, the insulation performance of the transformer will deteriorate, and in the worst case, the transformer may burn out. There is. Therefore, in this type of transformer, it is necessary to take measures to contain the fragments so that the amorphous magnetic alloy fragments do not separate from the iron core.
[0009]
An example of a conventional amorphous wound core transformer in which measures are taken to contain debris of amorphous magnetic alloy is shown in FIGS. 9 (A) to 9 (D) and FIG. FIGS. 9A to 9D sequentially show the process of assembling the transformer by fitting the windings W1 and W2 to the annealed wound core 1. FIG. FIG. 10 shows the state of the wound iron core after the winding is fitted, with the winding omitted.
[0010]
When the windings W1 and W2 are fitted, as shown in FIG. 10, the first yoke portion 1a of the wound core 1 and the first and second leg portions 1c and 1d on both sides thereof are formed. Each laminated surface of the U-shaped core part 101 is covered with a U-shaped main cover 4 made of insulating paper, and an oil-resistant adhesive tape 5 is applied across the peripheral edge of each U-shaped cover 4 and the iron core 1. The main cover 4 is fixed to the iron core 1 with the adhesive tape 5 and the space between the main cover 4 and the iron core 1 is sealed.
[0011]
Thereafter, the second yoke portion 1b of the iron core 1 is opened at the joint, and the windings W1 and W2 are fitted to the first and second legs 1c and 1d, respectively, as shown in FIG. 9A. To do. After the winding is fitted, the frame member 2B of the reinforcing frame 2 is attached as shown in FIG. In FIG. 9A, reference numeral 3 denotes an outer peripheral protection plate arranged along the outermost periphery of the wound iron core.
[0012]
After the windings W1 and W2 are fitted to the first and second legs as shown in FIG. 9A, the second yoke portion 1b is closed and the outer periphery is closed as shown in FIG. 9B. Both ends of the protective plate 3 are overlapped and welded. Next, a corner cover 6 that covers the laminated surface near the inner corner between the second yoke portion 1b of the iron core 1 and the first and second legs 1c and 1d and the corner portion, An inner cover 7 that covers each laminated surface of the yoke portion 1b is disposed, and a band 8 is wound around the yoke portion 1b and the inner cover 7 in the vicinity of the joint portion of the second yoke portion 1b, so that a corner cover is provided. 6, the inner cover 7 and the band 8 are bonded to the iron core. Further, as shown in FIG. 9 (C), a bag-shaped bottom cover 9 that accommodates the second yoke portion 1b to which the corner cover 6, the inner cover 7 and the band 8 are attached is attached. 9 is fixed to the iron core by the adhesive tape 10 (see FIG. 10), and as shown in FIG. 9D, the transformer body 12 having the windings W1 and W2 fitted on the wound iron core is completed. The transformer body 12 is housed in a transformer case (not shown), and the case is filled with insulating oil and used as an oil-filled transformer.
[0013]
In the above example, the corner cover 6, the inner cover 7 and the band 8 are all made of insulating paper, and the bottom cover 9 is made by bending the insulating paper three-dimensionally and bonding the important points.
[0014]
As is well known, in an oil-filled transformer, after the transformer main body is accommodated in the case, vacuum lubrication is performed in order to infiltrate the insulating oil into the winding and the iron core. At that time, in order to facilitate the penetration of the insulating oil into the iron core, in the above transformer, a felt filter 11 is attached to the inside of the window portion 9a provided in the bottom cover 9, and the cover is passed through the filter. The inside air and the insulating oil are smoothly replaced, and the iron core fragments are prevented from leaking through the window portion 9a.
[0015]
In the above example, the windings W1 and W2 are fitted to the first and second legs 1c and 1d of the wound core 1, respectively, but the winding is fitted only to one of the legs. In some cases, one leg part of two wound iron cores arranged side by side is arranged next to each other, and the two leg parts arranged next to each other of the two wound iron cores as one winding fitting leg part, In some cases, a winding is fitted to the winding fitting leg.
[0016]
[Problems to be solved by the invention]
As described above, in the conventional amorphous wound core transformer, the main cover 4, the corner cover 6, the inner cover 7, the band 8 and the bottom cover 9 are attached to contain the fragments of the iron core, and these covers and the outer peripheral protection plate The core was completely covered with 3 to contain the fragments of the core. However, since there are many types of covers for covering the core, it is possible to avoid an increase in the number of assembly steps and an increase in manufacturing cost. There wasn't.
[0017]
Further, since the bottom cover 9 used in the conventional amorphous winding core transformer needs to be assembled by folding the insulating paper, it is troublesome to manufacture and the cost is unavoidable.
[0018]
SUMMARY OF THE INVENTION An object of the present invention is to provide an amorphous wound core transformer that can contain iron core fragments without using a cover having a complicated shape and using fewer types of covers than conventional ones.
[0019]
[Means for Solving the Problems]
The present invention comprises a laminate of amorphous magnetic alloy ribbons, and first and second yoke portions and first and second legs extending between the first and second yoke portions. A wound iron core transformer comprising: a substantially rectangular wound core in which a joint is provided in the second yoke portion; and a winding fitted to at least one leg of the wound core It is related to.
[0020]
In the present invention, each laminated surface of the U-shaped core portion composed of the first yoke portion and the first and second leg portions on both sides of the first yoke portion is covered with the U-shaped cover, and the wound core The entire surface of each laminated surface of the second yoke part is covered with a resin coating layer.
[0021]
The U-shaped cover has a U-shaped shape corresponding to each laminated surface of the U-shaped iron core portion and is arranged along each laminated surface, and the U-shaped laminated surface covered portion. The outer peripheral surface and inner peripheral surface of the U-shaped core part are bent so as to cover the outer peripheral surface of the U-shaped core part and the vicinity of the end of the inner peripheral surface near the laminated surface, respectively, and are formed on the outer peripheral surface and inner peripheral surface of the U-shaped core part. Each includes an outer peripheral side covering portion and an inner peripheral side covering portion fixed by an adhesive tape.
[0022]
Each U-shaped cover has a window portion in a part corresponding to the first yoke portion of the U-shaped laminated surface covering portion. A first filter sheet is disposed between the window part of each U-shaped cover and the laminated surface of the U-shaped core part, and the first filter sheet is bonded to the peripheral part of the window part. A second filter sheet is disposed between both ends of each U-shaped cover and the laminated surface of the U-shaped core part, and these filter sheets are bonded to the inner surface of the U-shaped cover and the laminated surface of the U-shaped core part. ing.
[0023]
The first and second filter sheets are formed of a sheet-like material having air permeability and oil permeability and a compactness that prevents passage of fragments generated from the wound iron core.
[0024]
As a resin for forming the resin coating layer covering each laminated surface of the second yoke portion of the wound core, an appropriate resin may be selected from oil- and heat-resistant resins. In view of the above, it is preferable to use a thermosetting resin. As a thermosetting resin used for forming the resin coating layer, for example, a one-component epoxy thermosetting resin or a two-component epoxy thermosetting resin can be used.
[0025]
When the resin coating layer covering the laminated surface of the second yoke part is formed of a thermosetting resin, the thermosetting resin in an uncured state is applied to the laminated surface of the second yoke part and then applied. In this case, if the resin in an uncured state penetrates deeply between the lamination surfaces of the second yoke part, the iron core is distorted, which is preferable. Absent. Therefore, as the thermosetting resin for forming the resin coating layer so as to reduce the penetration depth of the resin between the laminations of the lamination surface of the second yoke portion as much as possible, when the thermosetting resin is in an uncured state It is preferable to use one having a sufficiently high viscosity (for example, a paste-like one).
[0026]
When the above resin coating layer is formed of a thermosetting resin, in order to further complete the coating of the laminated surface of the second yoke portion, a yoke cover is further disposed on the resin coating layer. The yoke cover is preferably adhered to each laminated surface of the second yoke portion with a resin forming the resin coating layer.
[0027]
The yoke cover used in this case absorbs the flexibility that fits the irregularities of the laminated surface of the second yoke part and the uncured thermosetting resin applied to the laminated surface of the second yoke part. And a sheet-like material having the property of capturing.
[0028]
Here, the flexibility to adjust to the unevenness of the laminated surface is a state in which each part is almost in close contact with the laminated surface by being easily deformed according to the unevenness existing on the laminated surface when pressed against the laminated surface of the iron core. Thus, the large gap is not generated between the laminated surfaces. The property of absorbing and capturing an uncured thermosetting resin is a property of absorbing and capturing the resin when the resin is in an uncured state (liquid state). These properties are generally properties possessed by a porous material such as cloth (woven fabric or non-woven fabric) or spun.
[0029]
As the filter sheet and the yoke cover, it is preferable to use a nonwoven fabric such as felt.
[0030]
As described above, when the resin coating layer is formed so as to cover the entire surface of each laminated surface of the second yoke portion, each laminated surface of the second yoke portion is covered with the resin coating layer, and the resin coating Since it is hardened by the resin constituting the layer, it is possible to prevent the iron core fragments from leaking from the laminated surface of the second yoke portion.
[0031]
Also, a yoke cover having flexibility and a property of supplementing the uncured resin is disposed on the resin coating layer, and the yoke cover is made of the resin that forms the resin coating layer with the second yoke portion. In the case of adopting a configuration of adhering to the laminated surface, the adhesive applied to the laminated surface of the second yoke part can be absorbed and captured by the yoke cover. Can be prevented from flowing down and a portion where the adhesive does not adhere to the laminated surface can be prevented. Therefore, the laminated surface of the second yoke portion can be completely covered with the resin coating layer, and the iron core fragments can be prevented from being detached from the laminated surface of the yoke portion.
[0032]
Further, since the yoke cover has a property of capturing uncured resin, the resin applied to the second laminated surface can be prevented from penetrating deeply between the laminated cores, and the resin penetrated between laminated layers. It is possible to prevent the iron core from being distorted when it is cured.
[0033]
Furthermore, since the laminated surface of the U-shaped core part composed of the first yoke part and the first and second leg parts on both sides of the first yoke part is covered with the U-shaped cover, the iron core starts from the laminated surface of the U-shaped core part. Can prevent the shards from leaking out.
[0034]
Further, as described above, a window portion is provided in the U-shaped cover, and the filter sheet is disposed inside the window portion, and the filter sheet is also disposed between both ends of the U-shaped cover and the laminated surface of the iron core. Then, when vacuum oiling is performed, the air and oil inside the U-shaped cover can be replaced through each filter sheet, so that the insulating oil can be satisfactorily penetrated into the iron core.
[0035]
As described above, in the present invention, only the U-shaped cover is used, or only two types of covers, the U-shaped cover and the yoke cover, are used to prevent the amorphous magnetic alloy fragments from being detached from the iron core. be able to. Further, since a cover having a complicated structure such as a conventionally used bottom cover is not used, the cost of the cover can be reduced.
[0036]
As described above, according to the present invention, since it is possible to reduce the number of parts of the cover for covering the iron core and the number of assembly steps, it is not necessary to have a complicated shape cover that is troublesome to process. In combination, the cost of the amorphous wound core transformer can be reduced.
[0037]
DETAILED DESCRIPTION OF THE INVENTION
The structural example of the amorphous wound core transformer concerning this invention was shown in FIG. 1 thru | or FIG. FIGS. 1A to 1D are perspective views sequentially showing a process of assembling a transformer by fitting windings W1 and W2 to an annealed wound core 1, and FIG. It is the perspective view which showed the U-shaped cover attached to a wound iron core. 3 and 4 are an explanatory view and a cross-sectional view of the main part for explaining the process of attaching the yoke cover that covers the second yoke part, respectively. 5 and 6 show a state in which the yoke cover is attached to the second yoke portion, and FIG. 7 shows the state of the wound iron core after the winding is fitted to the leg portion, omitting the winding. Show.
[0038]
The wound iron core 1 used in this example is the same as that shown in FIG. 11, and the first and second yoke portions 1a and 1b and the first and second leg portions 1c extending between these yoke portions. And 1d.
[0039]
In the present invention, prior to fitting the windings W1 and W2, first, as shown in FIG. 2, the first yoke portion 1a of the wound core 1 and the first and second leg portions 1c on both sides thereof. And the U-shaped core portion 101 made of 1d are covered with a U-shaped cover 20 made of insulating paper.
[0040]
The U-shaped cover 20 has a U-shape corresponding to each laminated surface of the U-shaped core part 101 (same shape as each laminated surface and can completely cover each laminated surface), and each laminated surface. The U-shaped laminated surface covering portion 20a disposed along the outer periphery and the inner peripheral edge of the U-shaped laminated surface covering portion are bent near the outer peripheral surface and the inner peripheral surface of the U-shaped core portion. The outer peripheral side covering portion 20b and the inner peripheral side covering portion 20c are formed so as to cover the vicinity of the end portions. A window portion 20d is formed at the center of the portion corresponding to the first yoke portion 1a of the U-shaped laminated surface covering portion 20a. A first filter sheet 22 is disposed inside the laminated surface covering portion 20a of the U-shaped cover 20 so as to close the window portion 20d, and the first filter sheet 22 is bonded to the peripheral edge portion of the window portion 20d. Yes. A gap is not formed in the bonding portion between the first filter sheet 22 and the peripheral edge portion of the window portion 20d. In addition, second filter sheets 23 and 23 are arranged inside both ends of the laminated surface covering portion 20a of the U-shaped cover 20, and the second filter sheets 23 and 23 are arranged on the laminated surface covering portion 20a and the U-shaped core portion. It is adhered to the laminated surface.
[0041]
The U-shaped cover 20 has the U-shaped laminated surface covering portion 20a opposed to the laminated surface of the U-shaped core portion 101 of the wound iron core, and the outer peripheral side covering portion 20b and the inner peripheral side covering portion 20c are respectively outer peripheral surfaces of the U-shaped core portion. And the outer peripheral side covering portion 20b and the inner peripheral side covering portion 20c are fixed to the U-shaped core portion 101 by adhesive tapes 24 and 25, respectively, in a state of being attached to the end portion of the inner peripheral surface near the laminated surface. . The adhesive tapes 24 and 25 are provided so as to completely seal the joints between the outer peripheral side covering portion 20b and the inner peripheral side covering portion 20c and the outer peripheral surface and inner peripheral surface of the U-shaped core portion.
[0042]
The first filter sheet 22 is arranged in a state where it is simply abutted without being bonded to the laminated surface of the iron cores, and the filter sheets 23 and 23 are arranged when the U-shaped cover 20 is attached to the U-shaped core part. Adhered to the laminated surface.
[0043]
The first and second filter sheets 22 and 23 are formed of a sheet-like material having air permeability and oil permeability and denseness that prevents passage of fragments generated from the wound core. As such a material, it is preferable to use a nonwoven fabric, particularly felt.
[0044]
In order not to lose the air permeability and oil permeability of the filter sheet, the first filter sheet 22 is not adhered to the laminated surface of the iron core. Also, the adhesive for adhering the second filter sheet 23 to the inner surface of the laminated surface covering portion 20a of the U-shaped cover and the laminated surface of the U-shaped iron core portion 101 does not penetrate deeply into the filter sheets 23, 23. The amount is kept small, or one that does not easily penetrate into the filter sheet is used.
[0045]
After covering the U-shaped core portion 101 of the wound core 1 with the U-shaped cover 20 as described above, the second yoke portion 1b of the wound core is opened to the left and right at the joint J to form the reinforcing frame 2. After removing the frame member 2B located on the second yoke portion 1b side out of the frame members 2A and 2B, as shown in FIG. 1A, the portions 1b1 and 1b2 on both sides of the joint portion J The first and second legs 1c and 1d are inserted into the windows of the windings W1 and W2, and both the windings W1 and W2 are fitted to the first and second legs 1c and 1d.
[0046]
After the windings W1 and W2 are fitted to the first and second legs 1c and 1d of the wound core, respectively, the frame member 2B of the reinforcing frame is attached as shown in FIG. In the illustrated example, the frame member 2B of the reinforcing frame is formed in a U shape and has curved portions at both ends thereof, and a gap is formed between the frame member 2B and the ends of the windings W1 and W2. Has been. In order to prevent iron core fragments from entering the windings from this gap, as shown in FIG. 3, an insulating plate such as a press board is provided between the end faces in the axial direction of the windings W1 and W2 and the frame member 2B. The spacer 31 which consists of is inserted. Further, iron core fragments are prevented from entering the winding through gaps 32, 32 formed between both ends of the spacer 31 and both ends of the frame member 2B (a corner portion on the second yoke portion side of the wound core). In order to prevent this, the gaps 32, 32 are filled with gap fillers 33, 33 each made of a dice-like sponge, thereby closing these gaps.
[0047]
As described above, after the spacer 31 and the filler 33 are interposed between the frame member 2B of the reinforcing frame and the windings W1 and W2 (state shown in FIG. 1A), the state shown in FIG. Thus, the joint part of the 2nd yoke part 1b is closed, and the both ends of the outer periphery protection board 3 which consists of a stainless steel strip, a silicon steel strip, etc. are piled up and spot-welded.
[0048]
Next, as shown in FIGS. 1C and 4, an uncured thermosetting resin is applied to the entire laminated surface on both sides of the second yoke portion 1 b and the spacer 31 and the filler 33. The resin cover layer 35 is formed, the yoke cover 36 is disposed on each resin cover layer 35, and the resin cover layer 35 is made of the second cover portion 1b by the resin forming the resin cover layer 35. It adheres to the laminated surface on both sides, the spacer 31 and the filler 33.
[0049]
As the resin for forming the resin coating layer 35, it is preferable to use a resin made of a thermosetting resin that is provided in a paste-like semi-cured state and is cured by heating. As such an adhesive, for example, an adhesive made of a bisphenol epoxy resin can be used. The thermosetting resin provided in a paste-like semi-cured state is softened when heated, and once it becomes liquid, it is cured.
[0050]
The yoke cover 36 has a flexibility that adapts to the unevenness of the laminated surface of the second yoke portion 1b, and the resin applied to the laminated surface of the second yoke portion when the resin is in a liquid state. It is made of a sheet-like material having the property of absorbing and trapping. As the material constituting the yoke cover, it is preferable to use felt as in the case of the constituent material of the filter sheet. The yoke cover 36 is formed in a size that can cover the entire laminated surface of the second yoke portion 1b. Although the shape of the yoke cover 36 is arbitrary, in the illustrated example, the yoke cover 36 is formed in a rectangular shape.
[0051]
When the resin coating layer 35 is formed and the yoke cover 36 is bonded, the bisphenol-based material provided in paste form on each laminated surface of the second yoke portion 1b, the spacer 31 and the filler 33 After applying a thermosetting resin such as an epoxy resin, the yoke cover 36 is overlaid on the applied resin, and the yoke cover 36 is pressed against the laminated surface side of the second yoke portion in FIG. As shown in FIG. 3, the end portion of the yoke cover 36 is temporarily fixed to the outer periphery of the second yoke portion of the wound iron core by the adhesive tape 37. Next, the wound iron core fitted with the winding is carried into a heating furnace and heated to heat and cure the resin, thereby completing the transformer body as shown in FIG.
[0052]
In the completed state shown in FIG. 1 (D), each laminated surface of the U-shaped core portion 101 composed of the first yoke portion 1a of the wound core and the first and second leg portions 1c and 1d is a U-shaped cover. 20, each laminated surface of the second yoke portion 1 b is covered with a resin coating layer 35 and a yoke cover 36 that are applied and cured on the laminated surface. Further, the second filter sheet 23 disposed between both ends of the U-shaped cover 20 and the iron core is in a state where the end portion 23a (see FIG. 2) on the second yoke portion 1b side is exposed to the outside. .
[0053]
The resin forming the resin coating layer 35 is once softened and turned into a liquid state when heated, and then cured. The resin forming the resin coating layer 35 tends to flow down from the laminated surface of the second yoke portion 1b when it becomes liquid. When the resin flows down from the laminated surface of the second yoke portion, a part of the laminated surface is exposed, and there is a possibility that debris is generated from the exposed portion. In the present invention, since the resin in a liquid state is soaked and captured in the yoke cover 36, the resin forming the resin coating layer 35 does not flow down from the laminated surface of the second yoke portion, and the second yoke. A part of the laminated surface of the iron part is not exposed. Moreover, since the yoke cover 36 has the flexibility which can adapt to the unevenness | corrugation of the lamination surface of a 2nd yoke part, the yoke cover 36 adheres to the whole lamination surface of a 2nd yoke part. Thus, the thickness of the resin coating layer 35 existing between the yoke cover and the laminated surface of the second yoke portion is kept substantially uniform. Therefore, the resin forming the resin coating layer 35 is cured in a state where the entire laminated surface of the second yoke portion 1b is uniformly coated.
[0054]
Further, since the resin forming the resin coating layer 35 is absorbed and captured by the yoke cover when it becomes liquid, the liquid resin does not penetrate deeply between the laminations of the second yoke portion, In the state where the resin is cured, only the vicinity of the surface of the laminated surface of the second yoke portion is solidified with the resin. Therefore, it is possible to prevent the magnetic characteristics of the iron core from deteriorating due to a large stress generated inside the second yoke portion of the iron core after the resin is cured.
[0055]
If comprised as mentioned above, as shown in FIG. 7, the lamination | stacking surface of the U-shaped iron core part 101 which consists of the 1st yoke part 1a and the 1st and 2nd leg parts 1c and 1d will become the U-shaped cover 20 In addition, the entire laminated surface of the second yoke portion 1b is covered with the resin coating layer 35 and covered with the yoke cover 36, so that the amorphous magnetic alloy fragments are detached from the laminated surface of the iron core. Can be completely prevented.
[0056]
Further, as described above, the first filter sheet 22 is attached to the window portion 20d provided in the U-shaped cover 20, and the second filter sheets 23, 23 are disposed between both ends of the U-shaped cover 20 and the laminated surface of the iron core. After the transformer body is accommodated in the case, when vacuum lubrication is performed, the air and oil in the wound core are replaced through the filter sheets 22 and 23 to impregnate the wound core with insulating oil. be able to.
[0057]
In particular, in the present invention, since the laminated surface of the second yoke portion is covered with the resin coating layer, leakage of the iron core fragments from the laminated surface of the second yoke portion is prevented. It can arrange | position in the state which exposed each edge part 23a and 23a of the 2nd filters 23 and 23 provided in both ends outside. Therefore, the air in the wound core and the insulating oil are replaced through the window portion 20a, and at the same time, the air and the insulating oil in the wound core are replaced through the filters 23 and 23 at both ends of the U-shaped cover. And the impregnation of the insulating oil into the iron core can be performed satisfactorily.
[0058]
When vacuum lubrication is performed in a wound core transformer, the wound core is deformed due to a pressure difference between the inside and outside of the core and its magnetic characteristics change. Particularly in an amorphous wound iron core transformer, the wound iron core is easily deformed, so that the deterioration of the magnetic properties of the iron core after vacuum lubrication becomes a problem. The ratio we / ws between the no-load loss ws of the wound core alone and the no-load loss we in the state of vacuum lubrication after the winding is fitted to the wound core is the building factor B. F. This building factor B.I. F. Thus, the deterioration rate of the no-load loss of the iron core that occurs between the manufacturing of the wound iron core and the vacuum lubrication to complete the transformer is evaluated. The closer the building factor is to 1, the more magnetic properties of the iron core material can be utilized in the actual product.
[0059]
As shown in FIGS. 9 and 10, with respect to a plurality of amorphous wound core transformers having a conventional structure in which the laminated surface of the second yoke portion of the wound core is not covered with resin, the state of the wound core alone When the frequency distribution of the no-load loss was obtained, a curve a ′ in FIG. 8A was obtained. Further, the frequency distribution of the no-load loss after the winding was fitted to the same wound core and vacuum lubrication was performed was as shown by the curve b ′ in FIG. In FIG. 8 (A), σ s ′ indicates the standard deviation of no-load loss in the state of the wound core alone, and σ e ′ indicates the standard deviation of no-load loss after vacuum lubrication. In this case, the building factor B.B F. (Mean value of we / mean value of ws) is 1.20, and the building factor B.D. F. (= Σe ′ / σs ′) was 1.13.
[0060]
On the other hand, when the entire laminated surface of the second yoke portion 1b is covered with the resin coating layer as in the present invention, the frequency distribution of the no-load loss in the state of the iron core alone is as shown in FIG. As indicated by curve a, the frequency distribution of no-load loss after vacuum lubrication was as indicated by curve b in FIG. 8B. The building factor of the average value of no-load loss in this case F. Is 1.10 and the standard deviation building factor B.I. F. Was 0.86. That is, according to the present invention, it was possible to improve the building factor of the average value of the no-load loss by 0.10 and improve the building factor of the standard deviation by 0.27. This is presumably because the entire laminated surface of the second yoke part (the yoke part having a joint part) that is most easily deformed is solidified with a resin coating layer to suppress the deformation.
[0061]
In the above example, the resin coating layer 35 is formed so as to cover the entire laminated surface of the second yoke portion 1b, and the second yoke is formed using the resin forming the resin coating layer 35 as an adhesive. Although the yoke cover 36 is adhered to each laminated surface of the part, even when the resin forming the resin coating layer 35 is in an uncured state and its viscosity is the lowest, the viscosity is sufficiently high, The yoke cover 36 can be omitted when the second yoke portion 1b does not penetrate deeply between the laminated surfaces of the laminated surfaces.
[0062]
【The invention's effect】
As described above, according to the present invention, only a U-shaped cover is used without using a cover having a complicated structure such as a conventionally used bottom cover and without using various types of covers, or Using only two types of covers, a U-shaped cover and a yoke cover, it is possible to completely prevent the amorphous magnetic alloy fragments from separating from the iron core.
[0063]
According to the present invention, since it is possible to reduce the number of parts of the cover for covering the wound iron core and the number of assembly steps, it is coupled with the fact that a complicated shape cover that is troublesome to process is not required. In addition, the cost of the amorphous wound core transformer can be reduced.
[0064]
Further, according to the present invention, the laminated surface of the second yoke portion of the wound core is hardened by the resin coating layer so that the wound core is difficult to be deformed. It is possible to improve the building factor that shows the change in characteristics until the device is completed, and it is possible to obtain a low-loss transformer by utilizing the characteristics of the amorphous magnetic alloy.
[Brief description of the drawings]
FIGS. 1A to 1D are perspective views sequentially illustrating a process of assembling a transformer according to the present invention by fitting a winding to an annealed wound iron core.
FIG. 2 is a perspective view showing a wound iron core and a U-shaped cover attached to the wound iron core.
FIG. 3 is an explanatory diagram for explaining a process of attaching a yoke cover that covers the laminated surface of the second yoke portion of the wound core in the present invention.
FIG. 4 is a cross-sectional view showing a structure for attaching a yoke cover to be attached to a laminated surface of two yoke portions in the present invention.
FIG. 5 is a plan view of a main part showing a state in which a yoke cover is attached to a second yoke part of a wound core in the present invention.
6 is a right side view of FIG. 5. FIG.
FIG. 7 is a perspective view showing the state of the wound core after the winding is fitted to the legs of the wound core used in the present invention, omitting the winding.
FIGS. 8A and 8B show the frequency distribution of loss in the state of the iron core alone and the frequency distribution of loss after the winding is inserted into the iron core and vacuum lubrication is performed, respectively. FIG. 2 is a diagram illustrating a transformer and a transformer according to the present invention.
FIGS. 9A to 9D are perspective views sequentially illustrating a process of assembling a conventional transformer by fitting a winding to an annealed wound iron core. FIGS.
FIG. 10 is a perspective view showing the state of the wound core after the winding is fitted to the legs of the wound core used in a conventional transformer, with the winding omitted.
FIG. 11 is a front view showing an example of the structure of a wound iron core.
[Explanation of symbols]
1 Roll iron core
2 Reinforcement frame
20 U-shaped cover
20a U-shaped laminated surface covering part
20b Outer peripheral side covering part
20c Inner peripheral side covering part
22 First filter sheet
23 Second filter sheet
24,25 adhesive tape
35 Resin coating layer
36 yoke cover
W1, W2 winding

Claims (3)

It comprises a laminate of amorphous magnetic alloy ribbons, and has first and second yoke portions and first and second legs extending between the first and second yoke portions, In a wound core transformer comprising: a substantially rectangular wound core provided with a joint in the second yoke portion; and a winding fitted to at least one leg of the wound core;
Each laminate has a U-shape corresponding to each laminate surface of the U-shaped core portion composed of the first yoke portion and the first and second leg portions on both sides of the first yoke portion. A U-shaped laminated surface covering portion disposed along the surface, and the U-shaped laminated surface covering portion is bent from the outer peripheral edge and the inner peripheral edge of the U-shaped laminated surface covering portion, and is located near the outer peripheral surface and inner peripheral surface of the U-shaped core portion. The U-shaped laminate is composed of an outer peripheral side covering portion and an inner peripheral side covering portion that are formed so as to cover the vicinity of the end portions and are respectively fixed to the outer peripheral surface and the inner peripheral surface of the U-shaped iron core portion by an adhesive tape. A U-shaped cover in which a window is formed in a part of a portion corresponding to the first yoke portion of the surface covering portion;
A first filter sheet disposed between the window part of each U-shaped cover and the laminated surface of the U-shaped core part and bonded to the peripheral part of the window part;
A second filter sheet disposed between both ends of each U-shaped cover and the laminated surface of the U-shaped iron core portion and bonded to the inner surface of the U-shaped cover and the laminated surface of the U-shaped iron core portion;
An amorphous wound core transformer, wherein a resin coating layer is formed so as to cover the entire surface of each laminated surface of the second yoke portion of the wound core. It comprises a laminate of amorphous magnetic alloy ribbons, and has first and second yoke portions and first and second legs extending between the first and second yoke portions, In a wound core transformer comprising: a substantially rectangular wound core provided with a joint in the second yoke portion; and a winding fitted to at least one leg of the wound core;
Each laminate has a U-shape corresponding to each laminate surface of the U-shaped core portion composed of the first yoke portion and the first and second leg portions on both sides of the first yoke portion. A U-shaped laminated surface covering portion disposed along the surface, and the U-shaped laminated surface covering portion is bent from the outer peripheral edge and the inner peripheral edge of the U-shaped laminated surface covering portion, and is near the laminated surface of the outer peripheral surface and the inner peripheral surface of the U-shaped core portion. The U-shaped laminate includes an outer peripheral side covering portion and an inner peripheral side covering portion that are formed so as to cover the vicinity of the end portions and are respectively fixed to the outer peripheral surface and the inner peripheral surface of the U-shaped iron core portion by an adhesive tape. A U-shaped cover in which a window is formed in a part of a portion corresponding to the first yoke portion of the surface covering portion;
A first filter sheet disposed between the window part of each U-shaped cover and the laminated surface of the U-shaped core part and bonded to the peripheral part of the window part;
A second filter sheet disposed between both ends of each U-shaped cover and the laminated surface of the U-shaped core portion and bonded to the inner surface of the U-shaped cover and the laminated surface of the U-shaped core portion;
A resin coating layer made of a thermosetting resin formed so as to cover the entire surface of each laminated surface of the second yoke portion of the wound core;
A joint which is disposed on a resin coating layer covering each laminated surface of the second yoke portion and bonded to each laminated surface of the second yoke portion by a thermosetting resin which forms the resin coating layer. With an iron cover,
The first and second filter sheets are made of a sheet-like material having air permeability and oil permeability and denseness for preventing passage of fragments generated from the wound core,
The yoke cover absorbs and captures the flexibility of the unevenness of the laminated surface of the second yoke part and the uncured thermosetting resin applied to the laminated surface of the second yoke part. An amorphous wound core transformer, characterized in that it is made of a sheet-like material having the properties of: The amorphous wound core transformer according to claim 2, wherein the filter sheet and the yoke cover are made of felt.

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