Coil element and method for manufacturing a coil element

Abstract

This invention provides a coil element that effectively transfers heat from the center of the coil to the outside of the coil, thereby reducing the temperature rise while minimizing the increase in dimensions, even when used in large-capacity transformers. [Solution] A coil element comprising an iron core and a coil surrounding the iron core, further comprising a first heat sink interposed between the iron core and the coil, inserted between them after the coil is attached to the iron core, wherein the first heat sink includes a flat plate, and the iron core is a laminate, and one main surface of the plate of the first heat sink and one surface of the laminate of the iron core in the lamination direction are in close proximity and facing each other when viewed in the lamination direction.

Description

Technical Field

[0001] The present invention relates to a coil element including an iron core, a coil existing around the iron core, and a radiator, and a method for manufacturing the coil element.

Background Art

[0002] For industrial use, a transformer including an iron core and a coil existing around the iron core is used. As a conventional technique, Patent Document 1 discloses an electromagnetic device that is a transformer in which a coil is wound around a central iron core of an E-shaped core, and a member that radiates heat while fixing the transformer by contacting the outer periphery of the core or the outer periphery of the coil is used.

[0003] Further, Patent Document 2 discloses a mounting bracket for attaching a transformer body to a housing in order to reduce the number of parts and the manufacturing cost, and introduces a structure in which a coil wound around an iron core is fitted and fixed in a hole in the mounting bracket.

[0004] In addition, an auxiliary power supply device mounted on a train uses a transformer including an iron core and a coil existing around the iron core. There is an increasing demand for higher output in order to improve the performance of the auxiliary power supply device as an electrical component. Therefore, in the transformer mounted on the auxiliary power supply, a large-capacity specification is required in response to such a demand.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] As mentioned above, in the case of transformers used for auxiliary power supplies in electrical products, it is necessary to change the specifications according to the required specifications of the auxiliary power supply. In order to achieve a larger capacity, it is possible to increase the drive frequency of the transformer. On the other hand, when such a design change is made, the amount of heat generated by the transformer will increase, so further consideration of a structure that suppresses the temperature rise becomes necessary.

[0007] However, none of the above-mentioned conventional technologies have considered structures that can fully demonstrate heat dissipation performance. For example, in the transformer of Patent Document 1, no heat dissipation structure other than the iron core is provided in the center of the coil, making it difficult to transfer the heat from the center of the coil, where heat is most retained, to the outside and lower the temperature of the center of the coil. This problem is particularly evident in transformers in which the coil is wound around a core, and there has been a need to consider more effective heat dissipation structures. In addition, in the transformer of Patent Document 2, a metal mounting bracket is provided at the bottom of the core, and a heat transfer path is formed from the core to the structure further below via the mounting bracket. However, even in such a transformer, where the coil is wound around the center of an E-type core, unless a structure with a higher heat transfer coefficient than the core is interposed in the center of the coil, the heat inside the coil cannot be effectively released to the outside.

[0008] Therefore, the present invention aims to provide a coil element and a method for manufacturing a coil element that can effectively transfer heat from the center of the coil to the outside of the coil, thereby reducing the temperature rise while reducing the increase in dimensions, even when used in large-capacity transformers, in order to address the conventional problems described above. [Means for solving the problem]

[0009] As a result of various studies, the inventors have found that the above objective can be achieved by the present invention described below.

[0010] In other words, the coil element according to the present invention is A coil element comprising an iron core and a coil surrounding the iron core, Furthermore, it includes a first heat sink interposed between the iron core and the coil, The aforementioned core has a shape in which multiple long-side core sections, each having a long side and a main surface, are arranged in parallel. The first heat sink includes a flat plate-shaped body, and further includes a planar shape in which a plurality of long-side plate portions having long sides are arranged in parallel. The multiple long-side plate portions are stacked on the multiple long-side core portions in a direction perpendicular to the main surface of the core, so that the multiple long-side plate portions and the multiple long-side core portions constitute an assembly, and the multiple long-side plate portions are arranged along the long-side core portions. Furthermore, the first heat sink may be interposed between the iron core and the coil, and may be inserted between them after the coil has been attached to the iron core. Also, for example, when the plate body of the first heat sink is interposed between the iron core and the coil as described above, an insulator may be placed between them. In addition, the iron core may have multiple long-side iron core portions formed by a laminate of iron core plate material or the like.

[0011] Here, the phrase "the plurality of long-side plate portions are stacked on the plurality of long-side core portions in a direction perpendicular to the main surface of the core" includes, for example, a state in which one main surface of the long-side plate portion of the first heat sink and one main surface of the long-side core portion in the core stack are in close proximity and facing each other when viewed perpendicular to the main surface of the stack, and in some cases, a state in which they are in contact and facing each other when viewed perpendicular to the main surface. This "state in which they are in contact and facing each other" includes the case described above where they are in contact with an insulator or the like in between.

[0012] Furthermore, the phrase "the plurality of long-side plate portions are arranged along the long-side core portion" means, for example, that the plurality of long-side plate portions of the first heat sink and the long-side core portion of the core are arranged to correspond to each other and extend in the same direction, or to be parallel to each other. Moreover, in this state, as described above, the plurality of long-side plate portions of the first heat sink are stacked with respect to the long-side core portion of the core in a direction perpendicular to the main surface.

[0013] According to the coil element of the present invention, the first heat sink interposed between the iron core and the coil can dissipate the heat generated by the iron core surrounded by the coil. Furthermore, the structure of the first heat sink, which includes the flat plate-shaped body and in which the plurality of long-side plate portions are stacked perpendicular to the main surface of the iron core relative to the plurality of long-side core portions of the iron core, allows the first heat sink to be easily interposed between the iron core and the coil without requiring significant design changes. For example, if it is possible to insert the plates of the first heat sink between the parts, the first heat sink can be easily interposed between the parts.

[0014] Furthermore, by arranging the plurality of long-side plate portions of the first heat sink along the long-side core portion of the iron core, the heat dissipation effect can be enhanced compared to the conventional technology, effectively transferring heat from the center of the coil to the outside of the coil, and reducing the temperature rise while reducing the increase in dimensions, even in the specifications of a large-capacity transformer. Here, the center of the coil is the portion facing the iron core via the first heat sink, and in particular the inside of that portion or so-called interior, including, for example, the interior of the structure composed of the iron core, the coil and the first heat sink. In addition, with this structure, the first heat sink can be easily interposed between the iron core and the coil by, for example, inserting the plates of the first heat sink between them, without requiring any further significant design changes. Moreover, with this configuration, when interposing the first heat sink between the iron core and the coil as described above, it is also possible to insert it between them after the coil has been attached to the iron core. As described above, it is possible to reduce the temperature rise while reducing the increase in dimensions, and to achieve miniaturization and weight reduction.

[0015] The first heat sink is Each of the aforementioned multiple long-side plate portions has one long-side plate portion and the other long-side plate portion. The one long side plate portion and the other long side plate portion may be bent so that they are parallel to each other. This structure allows for the easy manufacture of an assembly composed of the plurality of long-side plate portions and the plurality of long-side core portions, as well as an arrangement in which the plurality of long-side plate portions are aligned along the long-side core portions. Also, In the first heat sink described above, the plurality of long-side plate portions each have one long-side plate portion and the other long-side plate portion. The iron core may be positioned between the one long side plate portion and the other long side plate portion. In this way, by arranging the multiple long-side plate sections along the long-side iron core section and positioning the iron core between one long-side plate section and the other long-side plate section, heat from the center of the coil can be effectively transferred to the outside of the coil, thereby reducing the temperature rise while minimizing the increase in dimensions, even in the specifications of a large-capacity transformer. Furthermore, by reducing the temperature rise while minimizing the increase in dimensions, miniaturization and weight reduction can also be achieved.

[0016] The width of the long side plate portion in the longitudinal direction and the width of the long side iron core portion in the longitudinal direction are the same in dimension. When the assembled body of the long side plate portion and the long side core portion is observed in a direction perpendicular to the main surface, there may be a region where the contours formed by the stacking of the long side plate portion and the long side core portion coincide. In short, as described above, when the dimensions of the width of the long side plate portion and the long side core portion, as well as other dimensions, coincide, the shapes or regions formed by the long side plate portion and the long side core portion, for example, in the projection perpendicular to the main surface, can be the same. Therefore, when observed perpendicular to the main surface, the contours formed by the stacking of the long side plate portion and the long side core portion can have a matching region, and typically they do. The contours formed by the stacking of the long side plate portion and the long side core portion refer, for example, to the contours of the regions or shapes of the long side plate portion and the long side core portion that come into contact with each other when stacked. As a result, without requiring any further major design modifications, for example, by inserting the plate body of the first radiator between them, the first radiator can be easily interposed between the core and the coil. In addition, this configuration can also contribute to effectively transferring the heat at the center of the coil to the outside of the coil, and reducing the temperature rise value while reducing the increase in dimensions even in the specifications of a large-capacity transformer.

[0017] Furthermore, a second radiator may be provided, and the second radiator may be in contact with the first radiator. As a result, the heat generated in the core and the coil of the coil element can be thermally conducted to the second radiator through the first radiator. Also, the second radiator, the core, and the coil can be fixed via a first heat dissipation plate. In addition, the second radiator may be provided with a first flat portion that receives a bulging portion that is a portion where the coil exists around the core, and a second flat portion that is provided adjacent to the first flat portion and contacts the first radiator. Thereby, the heat generated in the coil can be directly thermally conducted from the first flat portion to the second radiator. Also, with this structure, despite the presence of the bulging portion, the second radiator can be directly contacted with the first heat dissipation plate at the second flat portion. Therefore, the heat dissipation performance of the core and the coil can be improved, and the fixing of the second radiator to the core and the coil can be made more compact and strong.

[0018] Furthermore, a third radiator is provided, and the third radiator may be in contact with at least one of the second radiator, the first radiator, and the core. As a result, the heat of the core or the coil can be thermally conducted to the second radiator through the third radiator and further through the first radiator. Also, the third radiator and further the first radiator can fix the core, the coil, and the second radiator more firmly.

[0019] An insulating paper may be provided between at least one of the space between the core and the first radiator and the space between the core and the second radiator. This can reduce the generation of eddy currents and the like in the first heat dissipation plate and the second heat dissipation plate, and reduce the heat generation due to eddy currents.

[0020] The method for manufacturing a coil element according to the present invention is In a method for manufacturing a coil element including a core, a coil existing around the core, and a first radiator interposed between the core and the coil, A first step of attaching the coil to the core; A second step of inserting the first radiator therebetween, which is performed after the first step, The core includes a shape in which a plurality of long-side core portions having long sides and main surfaces are arranged in parallel, The first radiator includes a flat plate body, and further, the plate body includes a planar shape in which a plurality of long-side plate body portions having long sides are arranged in parallel, The plurality of long-side plate body portions are laminated in a direction perpendicular to the main surface of the core with respect to the plurality of long-side core portions, and the plurality of long-side plate body portions and the plurality of long-side core portions constitute an assembly.

[0021] The above method for manufacturing a coil element is a particularly advantageous method for manufacturing the coil element described so far, and is suitable for manufacturing a structure that effectively transfers the heat at the center of the coil to the outside of the coil. Even for the specifications of a large-capacity transformer, it is suitable for manufacturing a structure that reduces the increase in temperature while reducing the increase in dimensions.

Advantages of the Invention

[0022] The coil element and the method for manufacturing a coil element according to the present invention can effectively transfer the heat at the center of the coil to the outside of the coil, and can reduce the increase in temperature while reducing the increase in dimensions even for the specifications of a large-capacity transformer.

Brief Description of the Drawings

[0023] [Figure 1A] This is a perspective view showing an example of a transformer using a coil element according to one embodiment of the present invention. [Figure 1B] This is a plan view showing an example of the transformer. [Figure 1C] A side view showing an example of the transformer. [Figure 1D] This is a front view showing an example of the transformer. [Figure 1E] Figure 1D is an enlarged front view of the main part. [Figure 2A] This is an example of a perspective view showing the transformer disassembled. [Figure 2B] This is a perspective view showing an example of the same transformer after it has been assembled from the disassembled state shown in Figure 2A, with some parts omitted. [Figure 3] This is a perspective view showing an example of the first heat sink that constitutes the above-mentioned coil element. [Figure 4] This is a perspective view showing an example of a second heat sink that constitutes the above-mentioned coil element. [Figure 5] This is a perspective view showing an example of a third heat sink that constitutes the above-mentioned coil element. [Figure 6A] This is an equivalent circuit diagram showing an example of the primary and secondary circuit configurations of the above transformer. [Figure 6B] This is an equivalent circuit diagram showing another example of the primary and secondary circuit configurations in the above transformer. [Figure 7A] This is a schematic plan view showing an example of an iron core that constitutes the above coil element. [Figure 7B] This is a schematic plan view showing an example of the first heat sink that constitutes the above-mentioned coil element. [Modes for carrying out the invention]

[0024] Embodiments of the present invention will be described below with reference to the drawings. In each figure, the same reference numerals indicate the same or corresponding parts, and unless otherwise specified, their descriptions will be omitted as appropriate.

[0025] Figure 1A shows a coil element 100 according to one embodiment of the present invention and an example of a transformer TR using the coil element 100. The coil element 100 comprises an iron core or core 110 and a coil 130 surrounding the iron core 110. The material of the core 110 is not limited to iron, as will be described later. In this embodiment, the iron core 110 is further formed, for example, into a ring shape or a rounded rectangular parallelepiped shape having a through hole H in the center of the main surface in the Z-axis view in the same figure or in Figures 1B, 2A, and 2B that penetrates in the z-axis direction to the back surface (hereinafter simply referred to as ring shape), and is fixed by the core band 120 in Figure 1A.

[0026] In this embodiment, the iron core 110 is, for example, a laminate formed by winding and stacking so-called amorphous ribbons around the Z-axis direction in the figure so that they form a ring shape. Besides amorphous ribbons, other materials that can be used as the iron core material forming the laminate include, for example, iron plates, ferritic steel plates, or silicon steel plates. When using an iron core made of a laminate, a laminate stacked in the Z-axis direction in the figure may be used. A typical example of an iron core material made from a material other than a laminate is a compacted iron core. The coil 130 is, for example, a multi-layer winding and is wound around the iron core 100 via a bobbin (not shown). The coil 130 may also be molded.

[0027] The coil element 100 further includes a first heat sink or heat sink 150 interposed between the iron core 110 and the coil 130. With this structure, heat is hardly generated in the parts hidden by the coil 130 and the iron core 110, while the heat generated by the iron core 110 and the coil 130, especially the heat generated in the hidden parts, can be dissipated by the first heat sink 150, thereby reducing the temperature rise of the transformer TR itself. An insulator may be interposed between the iron core 110 and the first heat sink 150, and / or between the coil 130 and the first heat sink 150. With this configuration, the heat dissipation effect of this embodiment, which effectively transfers heat from the center of the coil to the outside of the coil, functions advantageously.

[0028] Furthermore, in this embodiment, the first heat sink 150 includes a flat plate body, and the plate body further includes a planar shape in which a plurality of long-side plate body portions having long sides are arranged in parallel. Specifically, the first heat sink 150 includes two parallel planar flat plate body portions in the Z direction, one above the other, and the plate body further includes long-side plate body portions having straight, parallel long sides on part or all of its circumference, such as the long side portions 151a, 151b, 152a, 152b, 153a, 153b, and 154a, 154b (Figure 3) described later. The long-side plate body portion is a rectangular parallelepiped portion that includes a region or shape on one surface such as the rectangular shape TK in Figure 7B. As shown in the figure, there are multiple long-side plate sections in a single plate (two in this embodiment), and each long-side plate section is arranged in parallel on the left and right sides in the Y-axis direction, for example, with each of the long sides being parallel.

[0029] The first heat sink 150, having a flat plate body, extends in the direction along the iron core 110 in the X direction in Figure 1A. Furthermore, the first heat sink 150, having a flat plate body, is inserted between the iron core 110 and the coil 130 in the same X direction. In addition, the first heat sink 150 in this embodiment includes a U-shaped or U-shaped (hereinafter collectively referred to as U-shaped) flat plate body. Furthermore, in this embodiment, the first heat sink 150 includes two of the above-mentioned U-shaped flat plate bodies (hereinafter also referred to as U-shaped flat plates) above and below in the Z direction, with the two U-shaped flat plates being parallel to each other. The above-mentioned long side plate body portion is included twice in each U-shaped flat plate body. The first heat sink 150 has a connecting portion 159 (Figure 3) parallel to the z direction that connects the two U-shaped flat plates.

[0030] In the two U-shaped flat plates, four partial plates (hereinafter also simply referred to as plates) 151, 152, 153, and 154 protrude from the connecting portion in the X-axis direction in the figure. Hereafter, the above shape of the U-shaped flat plate as shown in the figure will also be referred to as a hairpin shape. Here, the longitudinal direction of the four partial plates is parallel to the X-axis direction. Partial plates 151 and 152 are included in the upper U-shaped flat plate, and partial plates 153 and 154 are included in the lower U-shaped flat plate. The U-shaped flat plate and the connecting portion may be an integrated type made of separate members, but in this embodiment they are an integrated type made of the same member. With a U-shaped flat plate heat sink, as shown in Figure 2A, if coils are arranged on each of the yoke sections, which are the long sides of the core, the tip of the U-shaped flat plate can be inserted into each coil to effectively transfer heat from the center of the coil to the outside of the coil, thus easily forming a heat dissipation structure.

[0031] The first heat sink 150 (Figure 3) of this embodiment is, for example, a single-piece type made from the same material and includes a hairpin-like shape, but as an example, it is manufactured as follows: A rectangular steel plate is punched out, and two U-shaped flat plates are formed, each containing four partial plate bodies 151, 152, 153, and 154, with a connecting portion 159 sandwiched in between. Here, since the first heat sink 150 of this embodiment includes two flat plate bodies with the connecting portion 159 sandwiched in between, one long side plate body portion is formed in the upper flat plate body, and the other long side plate body portion is formed in the lower flat plate body. Note that the one long side plate body portion and the other long side plate body portion are included in the plurality of long side plate body portions.

[0032] Next, in the sheet metal after punching, the two U-shaped flat plate portions are bent perpendicularly to the flat connecting portion 159. That is, the sheet metal is bent twice so that one long side portion and the other long side portion are approximately parallel to each other. As a result, the two U-shaped flat plate portions are approximately parallel to each other in the vertical direction. Thus, the first heat sink 150 as shown in Figure 3 can be roughly manufactured. The first heat sink 150 of this embodiment can be manufactured by this simple manufacturing method. In the first heat sink 150, if necessary, notches, screw holes, grooves, etc. for attaching the first heat sink 150 may be formed in appropriate places during the punching and bending processes, and legs or protrusions such as flange shapes for stably attaching the first heat sink 150 may be formed, as shown in the lower left portion of the figure. Furthermore, when this leg or protruding portion is fitted into the hollow portion of the connecting portion 159, it can take on the shape of almost a single flat plate.

[0033] With the first heat sink 150 manufactured in this manner, the iron core is positioned between one long side plate portion and the other long side plate portion of the upper and lower plurality of long side plate portions, and in this embodiment, the first heat sink 150 manufactured by bending is positioned sandwiched above and below between the one long side plate portion and the other long side plate portion.

[0034] As shown in Figure 1B, the transformer TR according to this embodiment comprises the coil element 100, and also includes at least two coils 130A and 130B surrounding the iron core 110. A first heat sink 150, 150 is interposed between the iron core 110 and each of the two coils 130A and 130B in this embodiment. Specifically, in this embodiment, as described later, two of the four subplates of the first heat sink 150 are interposed between the iron core 110 and coil 130A, and the remaining two are interposed between the iron core 110 and coil 130B. The transformer TR according to this embodiment can be used, for example, as an auxiliary power source mounted on a train.

[0035] As shown in Figure 1D, in the coil element of this embodiment, the long side plate portion of the first heat sink plate 150 is further stacked in the direction perpendicular to the main surface (Z-axis direction) of the laminate of iron cores 110, which are wound and stacked around the Z-axis direction in the figure as described above, so that the multiple long side plate portions and the multiple long side iron core portions constitute an assembly. Specifically, the first heat sink plate 150 is further stacked in the direction perpendicular to the iron core 110 (Z-axis direction), for example, so that one main surface of the first heat sink plate 150 is in contact with one main surface of the long side iron core portion included in the laminate described later. Specifically, the four partial plate portions are sandwiched between the iron core 110 and the surfaces of coils 130A and 130B that are perpendicular to the z-axis direction. In essence, the four partial plates of the first heat sink 150, which form a hairpin shape, are inserted between the iron core 110 and the coil 130, for example, with their longitudinal direction aligned with the iron core 110 (Figure 2A, etc.). This configuration makes it possible to effectively transfer heat from the center of the coil to the outside of the coil, thereby reducing the temperature rise while minimizing the increase in dimensions, even with the specifications of a large-capacity transformer.

[0036] In this embodiment, the core 110 includes a shape in which multiple long-side core sections, each having a long side and a main surface, are arranged in parallel, and furthermore, multiple long-side core sections are formed by a laminate of the core plate material described above. Specifically, the core 110 is ring-shaped when viewed in the Z-axis direction, but in a part of the ring shape, it includes long-side core sections that have linear, parallel long sides on the left and right sides, such as the long side sections 111, 112 and long side sections 113, 114 (Figure 2A) described later, either partially or entirely around the circumference. The core 110 is also a rectangular parallelepiped portion that includes a region or shape on one surface, such as the rectangular shape TH in Figure 7A, and includes long-side core sections that have a substantially planar main surface parallel to the XY plane. As shown in the figure, there are multiple such long-side core sections (two in this embodiment), and each long-side core section has a shape in which, for example, the long sides described above are parallel, and are arranged in parallel on the left and right sides in the Y-axis direction. In this configuration, even with a coil element configuration in which a coil is provided in each of multiple cores, it is possible to effectively dissipate the heat generated at the center of each coil to the outside.

[0037] In the coil element of this embodiment, more specifically, the iron core 110 has parallel long sides at its edge portion, when viewed perpendicular to the main surface, and in this embodiment, it has long sides 111, 112 and long sides 113, 114 (Figure 2A). In this embodiment, these long sides are the portions covered by the coil 130 (130A, 130B) of the iron core 110, and their width in the longitudinal direction, i.e., their length in the longitudinal direction, is the same in the X direction in the figure. Therefore, in the ring-shaped iron core 110, the shapes formed by the corresponding parallel long sides, i.e., long sides 111, 112 and long sides 113, 114, have a rectangular shape TH represented by the hatched portion in Figure 7A when viewed perpendicular to the main surface, i.e., in the Z direction. The long side iron core portion includes the rectangular shape TH on one surface.

[0038] Furthermore, the first heat sink 150 has long sides at its edge portion that are parallel to each other when viewed perpendicular to the main surface. In this embodiment, it includes the plate body having long sides 151a, 151b, 152a, 152b, 153a, 153b, and 154a, 154b, and in this embodiment, there are four partial plate bodies 151, 152, 153, and 154 (Figure 3). In this embodiment, these long sides are the portions covered by the coil 130 of the first heat sink 150, i.e., coils 130A and 130B, and their width in the longitudinal direction, i.e., their length in the longitudinal direction, is the same in the X direction. Therefore, in the partial plates 151, 152, 153, and 154, the shapes formed by the corresponding parallel long sides, when observed in a direction perpendicular to the main surface, i.e., in a view in the Z direction, become the rectangular shape TK represented by the hatched portion in Figure 7B. The long side plate portions are included on one surface of the rectangular shape TK.

[0039] Here, the long sides 151a, 151b, 152a, 152b, 153a, 153b, 154a, and 154b of the first heat sink 150 are parallel to the long sides 111, 112, 113, and 114 of the iron core 110 (Figure 2A). In this embodiment, the long sides of the first heat sink 150 are positioned along the long sides of the iron core 110. Furthermore, in this embodiment, the width of these parallel long sides of the first heat sink 150 and the width of these parallel long sides of the iron core 110 are the same length. Therefore, the width of the long side plate portion in the longitudinal direction and the width of the long side iron core portion in the longitudinal direction are the same dimension.

[0040] Furthermore, considering Figures 1A, 2A, 2B, and 3 together, in this embodiment, the distances between the parallel long sides 151a, 151b, 152a, 152b, 153a, 153b, and 154a, 154b of the first heat sink 150 are the same as the distances between the parallel long sides 111, 112 and 113, 114 of the iron core 110. Furthermore, when the iron core 110 is observed perpendicular to the main surface, i.e., in the Z direction, the long sides 151a and 153a of the first heat sink 150 coincide with the long side 111 of the iron core, the long sides 151b and 153b of the first heat sink 150 coincide with the long side 112 of the iron core, the long sides 152a and 154a of the first heat sink 150 coincide with the long side 113 of the iron core, and the long sides 152b and 154b of the first heat sink 150 coincide with the long side 114 of the iron core.

[0041] In this case, in short, the rectangular shape TH of the iron core 110 and the rectangular shape TK of the first heat sink 150 coincide and are identical in shape, i.e., congruent. As a result, in a view in the Z direction, the contour formed by stacking the long side plate portion and the long side iron core portion has a region in each of the long side plate portion and the long side iron core portion where they come into contact with each other when stacked, or where the contours of their shapes coincide.

[0042] As shown in Figure 1C, the coil element 100 of this embodiment further includes a second heat sink or heat sink plate 140. The second heat sink 140 is in contact with the first heat sink plate 150. Therefore, the second heat sink 140, the iron core 110, and the coil 130 can be fixed together via the first heat sink plate 150, and the heat generated in the coil element 100 can be conducted to the second heat sink 140 via the first heat sink plate 150.

[0043] In this embodiment, the second heat sink 140 is a bottom plate 140 for fixing the transformer TR to a housing (not shown). Therefore, by the bottom plate 140 contacting the first heat sink 150, the coil element 100 can be fixed to the housing via the first heat sink 150 and the bottom plate 140. Furthermore, the larger the contact area between the housing and the bottom plate 140, the more heat generated in the coil element 100 can be conducted to the bottom plate 140 via the first heat sink 150, and further heat generated in the coil element 100 can be conducted to the housing. The bottom plate 140 and the coil element 100 are fixed by other means (not shown), such as via a core band 120. With this configuration, a suitable heat transfer path for the heat generated in the center of the coil is formed, so that even with the specifications of a large-capacity transformer, it is possible to reduce the temperature rise while reducing the increase in dimensions.

[0044] As shown in Figure 4, the second heat sink 140 is provided with a first flat portion 141 that receives a bulge 135 (Figures 1C and 2A) which is the portion where the coil 130 is located around the iron core 110. In a broad sense, the bulge 135 roughly coincides with the portion where the coil 130 is located, but in a narrow sense, it may be the portion of the coil 130 that is in contact with the bottom plate 140, i.e., the portion opposite to the Z-axis direction. Also, as shown in Figures 1C and 2A, the second heat sink 140 is provided with second flat portions 142 and 143 adjacent to the first flat portion 141, which the first heat sink 150 contacts.

[0045] This structure allows the heat generated in the coil element 100 to be directly conducted from the first flat portion 141 to the bottom plate 140. Furthermore, this structure allows the bottom plate 140 to be directly in contact with the first heat sink 150 at the second flat portions 142 and 143, despite the presence of the bulge portion 135. As a result, the heat generated in the coil element 100 can be conducted to the bottom plate 140 via the first heat sink 150, and the coil element 100 can be firmly fixed to the bottom plate 140 via the first heat sink 150 while being more compact and minimizing gaps, and can also be fixed to the housing via the bottom plate 140, etc. In this embodiment, the first flat portion 141 protrudes in the opposite direction to the Z-axis direction, and the adjacent second flat portions 142 and 143 protrude in the Z-axis direction.

[0046] The coil element 100 of this embodiment may further include a third heat sink or heat sink 160, as shown in Figure 5. The third heat sink 160 contacts the second heat sink 140, more specifically the second flat portion 143, and at least one of the first heat sink 150 and the iron core 110. In this embodiment, as shown in Figure 2B, the third heat sink 160 is in contact with the iron core 110. That is, the third heat sink 160 has a contact plate portion 161 that contacts the second heat sink 140, a contact plate portion 162 that contacts the iron core 110 or the first heat sink 150, and a communication portion 163 that connects them. The contact plate portions 161 and 162 and the communication portion 163 are orthogonal, and the contact plate portions 161 and 162 are parallel but protrude in opposite directions relative to the communication portion 163. Here, the contact plate portion 161, the contact plate portion 162, and the communication portion 163 may be an integrated unit made of separate components, but in this embodiment, they are an integrated unit made of the same component.

[0047] This structure allows heat from the iron core 110 to be conducted to the bottom plate 140 via the third heat sink 160. Furthermore, the third heat sink 160, and also the first heat sink 150, allows the coil element 100, the bottom plate 140, and the housing to be fixed more firmly than when only the core band 120 is used. In this configuration, these multiple metal structures form a heat transfer path, making it possible to effectively transfer the amount of heat inside the coil to the outside. This effect naturally contributes to reducing the temperature rise while reducing the increase in dimensions, even in the specifications of a large-capacity transformer. Note that in Figure 2B, coil 130A is shown for clarity, but coil 130B is omitted from the illustration.

[0048] As described above, the coil element 100 is equipped with a first heat sink 150 interposed between the iron core 110 and the coil 130. However, when the first heat sink 150 is not present, a small gap GP, as shown in Figure 1E, may exist between the iron core 110 and the coil 130. Therefore, by inserting the first heat sink 150, which is a flat plate, into this gap GP along the iron core 110 in the X direction in the figure, the first heat sink 150 can be interposed between the iron core 110 and the coil 130 without requiring significant design changes. At this time, the plate thickness of the first heat sink 150, i.e., the thickness in the Z-axis direction, is approximately equal to the height of the gap GP, i.e., the height δ in the Z-axis direction, or slightly thicker or slightly thinner. In other words, the thickness of the first heat sink 150 is set to a thickness that allows the first heat sink 150 to be in constant contact with either or both of the iron core 110 and the coil 130. However, if it is too thin, it will not be able to be in constant contact with either or both, and if it is too thick, it will not fit within the height δ of the gap GP, so care must be taken to keep this in mind.

[0049] When manufacturing the coil element 100 or the transformer TR, the iron core 110 and the coil 130 may be assembled so as to leave a predetermined gap GP between them. In this case, if the first heat sink 150 is manufactured so that it can constantly contact either or both of the iron core 110 and the coil 130, the problem of setting the thickness of the first heat sink 150 in relation to the height δ of the gap GP, as described above, is eliminated.

[0050] In this embodiment, if the first heat sink 150, the third heat sink 160, and the bottom plate 140 which is the second heat sink are not provided, thermocouple measurements have shown that, compared to the case where they are provided, there is a difference of approximately 40 degrees in the temperature of the outer surface of the iron core 110 where the coil 130 is absent. In the case where they are not provided, the temperature is 167.8°C, and in the case where they are provided, the temperature is 124.7°C.

[0051] As for other configurations, the coil element of this embodiment may include insulating paper interposed between the iron core 110 and the first heat sink 150, and between the iron core 110 and the second heat sink 140. This reduces the generation of eddy currents in the first heat sink 150 and the second heat sink 140, thereby reducing heat generation due to eddy currents. Furthermore, resin may be impregnated between the iron core 110 and the first heat sink 150, and between the iron core 110 and the second heat sink 140. This improves thermal conductivity. It is desirable to use materials such as aluminum that have high thermal conductivity while possessing strength for the first heat sink 150, the second heat sink 140, and the third heat sink 160.

[0052] In the coil element 100 or transformer TR of this embodiment, for example, the coil 130 may be attached to the iron core 110, and then the first heat sink may be inserted into the gap GP (Figure 1E). That is, referring together to Figures 2A and 2B, the manufacturing method of the coil element 100 according to this embodiment, which comprises at least an iron core 110, a coil 130 surrounding the iron core, and a first heat sink 150, includes a first step of attaching the coil 130 to the iron core 110 and a second step of inserting the first heat sink 150 into the gap GP, wherein the second step is performed after the first step.

[0053] As described above, a small gap GP may exist between the iron core 110 and the coil 130, so in the first heat sink 150 as in this embodiment, the second step can be performed after the first step. Furthermore, if a gap GP is provided between the iron core 110 and the coil 130 during the manufacturing of the coil element 100 or the transformer TR, the second step can be performed after the first step in the first heat sink 150 with the configuration as in this embodiment. Thus, the manufacturing method of this embodiment is suitable for manufacturing a structure that effectively transfers heat from the center of the coil to the outside of the coil, and is suitable for manufacturing a structure that reduces the temperature rise while reducing the increase in dimensions, even for large-capacity transformers. Moreover, a manufacturing method for such a structure can be provided without requiring significant design changes.

[0054] As shown in Figure 1A and other figures, the core 110 of the coil element 100 of this embodiment has one primary winding P with wire ends of Pu (U phase) and Pv (V phase), and two secondary windings S1 and S2 with wire ends of Su1 (U phase) and Sv1 (V phase) and Su2 (U phase) and Sv2 (V phase), respectively, wound around it. That is, the coil 130 of this embodiment consists of, for example, a primary winding P and two secondary windings S1 and S2. The secondary windings S1 and S2 of this embodiment can be connected in series as shown in Figure 6A or in parallel as shown in Figure 6B.

[0055] The present invention is not limited to the embodiments described above, and various additions, modifications, or deletions are possible without departing from the spirit of the invention. Therefore, such additions, modifications, or deletions are also included within the scope of the present invention.

[0056] For example, the above embodiment describes a configuration in which coils are arranged in each yoke portion of an O-shaped core, but the present invention is not limited to this and can also be applied to cores having three or more yoke portions, such as an E-shaped core. According to this, it is preferable to provide coils in each of the multiple yoke portions of an E-shaped core and attach the hairpin-shaped heat sink to this core. Even with such a structure, the heat from the center of the coil is effectively transferred to the outside, achieving the same effects as in the above embodiment. [Explanation of Symbols]

[0057] 100 coil elements 110 Iron Heart 111, 112, 113, 114 (Parallel long sides of the iron core) 130, 130A, 130B coils 140 Second heat sink 141 First flat section 142, 143 Second flat section 150 First heat sink 151, 152, 153, 154 Flat plate-shaped body (of the first heat sink) 151a, 151b, 152a, 152b, 153a, 153b, 154a, 154b (Parallel long sides of the first heat sink) 160 Third heat sink GP (between the iron core and the coil) TR Transformer

Claims

1. A coil element comprising an iron core and a coil surrounding the iron core, Furthermore, it includes a first heat sink interposed between the iron core and the coil, The aforementioned core has a shape in which multiple long-side core sections, each having a long side and a main surface, are arranged in parallel. The first heat sink includes a flat plate-shaped body, and further includes a planar shape in which a plurality of long-side plate body portions having long sides are arranged in parallel. The multiple long-side plate portions are stacked on the multiple long-side core portions in a direction perpendicular to the main surface of the core, so that the multiple long-side plate portions and the multiple long-side core portions constitute an assembly, and the multiple long-side plate portions are arranged along the long-side core portions. Coil element.

2. A coil element according to claim 1, The first heat sink is Each of the aforementioned multiple long-side plate portions has one long-side plate portion and the other long-side plate portion. A coil element in which one long side plate portion and the other long side plate portion are bent so that they are parallel.

3. A coil element according to claim 1, In the first heat sink described above, the plurality of long-side plate portions each have one long-side plate portion and the other long-side plate portion. The iron core is a coil element positioned between the one long side plate portion and the other long side plate portion.

4. A coil element according to claim 1, The width of the long side plate portion in the longitudinal direction and the width of the long side iron core portion in the longitudinal direction are the same in dimension. A coil element having a region where, when the assembled body of the long side plate portion and the long side core portion is observed in a direction perpendicular to the main surface, the contours formed by the stacking of the long side plate portion and the long side core portion coincide.

5. A coil element according to claim 1, Furthermore, it is equipped with a second heat sink, The second heat sink is in contact with the first heat sink. The coil element is provided with a second heat sink having a first flat portion that receives a bulge which is the portion where the coil is located around the iron core, and a second flat portion provided adjacent to the first flat portion which contacts the first heat sink.

6. A coil element according to claim 5, Furthermore, it is equipped with a third heat sink. The third heat sink is a coil element that contacts the second heat sink, the first heat sink, and at least one of the iron core.

7. A coil element according to claim 1, A coil element comprising insulating paper interposed between the iron core and the first heat sink, and between the iron core and the second heat sink, at least one of these.

8. A method for manufacturing a coil element comprising an iron core, a coil surrounding the iron core, and a first heat sink interposed between the iron core and the coil, A first step involves attaching the coil to the iron core, The process includes a second step, performed after the first step, in which the first heat sink is inserted between the aforementioned parts, The aforementioned core has a shape in which multiple long-side core sections, each having a long side and a main surface, are arranged in parallel. The first heat sink includes a flat plate-shaped body, and further includes a planar shape in which a plurality of long-side plate body portions having long sides are arranged in parallel. The multiple long-side plate portions are stacked on the multiple long-side core portions in a direction perpendicular to the main surface of the core, so that the multiple long-side plate portions and the multiple long-side core portions constitute an assembly. A method for manufacturing a coil element.

Images