Electromagnetic devices with coil cases
The electromagnetic device's design with fitting portions on the coil case and core body facilitates precise assembly by preventing radial misalignment, ensuring easy and accurate assembly.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2025-04-23
- Publication Date
- 2026-03-25
AI Technical Summary
The misalignment of the coil case in the radial direction of the core body complicates the accurate and easy assembly of electromagnetic devices.
The electromagnetic device incorporates a core body with a fitting portion on both the coil case and the core body, allowing for precise alignment and assembly by using protrusions and recesses that snap into place, preventing radial shifting.
This configuration ensures accurate and easy assembly of the electromagnetic device, preventing radial misalignment of the coil case relative to the core body, thereby enhancing assembly efficiency.
Smart Images
Figure 0007835930000001 
Figure 0007835930000002 
Figure 0007835930000003
Abstract
Description
Technical Field
[0001] The present invention relates to electromagnetic devices provided with a coil case, such as reactors, transformers, and the like.
Background Art
[0002] In recent years, electromagnetic devices including a core body having an outer peripheral core and a plurality of cores arranged inside the outer peripheral core have been developed. A coil is wound around each of the plurality of cores. Further, a technique of assembling an electromagnetic device with a coil housed in a coil case for the purpose of insulating between the core body and the coil is known. See, for example, Patent Document 1 and Patent Document 2. [[ID=?]]
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, when using a coil case, a situation may occur where the coil case is misaligned in the radial direction of the core body. As a result, it may be difficult to accurately and easily assemble the electromagnetic device.
[0005] Therefore, an electromagnetic device in which the coil case is not misaligned in the radial direction of the core body is desired.
Means for Solving the Problems
[0006] <?? It should be noted that there are some question marks in the translation where the original text seems to have incorrect or unclear tags. You may want to double-check the original text for accuracy.According to a first aspect of the present disclosure, an electromagnetic device is provided, comprising a core body, the core body including an outer core composed of a plurality of outer core portions, and at least three cores coupled to the plurality of outer core portions, further comprising a coil mounted on the at least three cores, and a coil case that at least partially covers each of the at least three cores and insulates them from the coil, wherein a fitting portion for fitting the core body and the coil case to each other is formed on the core body and the coil case, respectively. [Effects of the Invention]
[0007] In the first embodiment, the coil case and the core body are fitted together by a mating portion. Therefore, once fitted together, the coil case will not shift radially relative to the core body. This allows for accurate and easy assembly of electromagnetic equipment.
[0008] The object, features, and advantages of the present invention will become even clearer from the following description of embodiments related to the accompanying drawings. [Brief explanation of the drawing]
[0009] [Figure 1A] This is a cross-sectional view of the core body included in an electromagnetic device according to the first embodiment. [Figure 1B] Figure 1A is a perspective view of the electromagnetic device shown. [Figure 2A] This is a perspective view of the coil case of an electromagnetic device, seen from the radially inward direction. [Figure 2B] This is a perspective view of the coil case of an electromagnetic device, seen from the radially outer side. [Figure 2C] This is a partial top view of an electromagnetic device. [Figure 2D] This is a partial top view of an electromagnetic device in the prior art. [Figure 3] This is a partial perspective view of an electromagnetic device. [Figure 4A] This is a first partial cross-sectional view of the electromagnetic device in this disclosure. [Figure 4B]It is a second partial cross-sectional view of the electromagnetic device in the present disclosure. [Figure 4C] It is a third partial cross-sectional view of the electromagnetic device in the present disclosure. [Figure 5] It is another perspective view of the coil case similar to Figure 2B. [Figure 6] It is a diagram showing the magnetic flux density distribution of the outer peripheral core portion in the present disclosure. [Figure 7] It is a cross-sectional view of the core body included in the electromagnetic device based on the second embodiment. [Figure 8A] It is a cross-sectional view of the core body included in the electromagnetic device based on another embodiment. [Figure 8B] It is a cross-sectional view of the core body included in the electromagnetic device based on still another embodiment.
Mode for Carrying Out the Invention
[0010] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Throughout the drawings, common reference numerals are assigned to corresponding components. In the following description, a three-phase reactor will be mainly described as an example of the electromagnetic device. However, the application of the present disclosure is not limited to the three-phase reactor, and is widely applicable to polyphase reactors that require a certain inductance in each phase, and is also applicable to transformers. Further, the reactor according to the present disclosure is not limited to being provided on the primary side and the secondary side of an inverter in an industrial robot or a machine tool, and can be applied to various devices.
[0011] Figure 1A is a cross-sectional view of the core body included in the electromagnetic device based on the first embodiment. Figure 1B is a perspective view of the electromagnetic device shown in Figure 1A. As shown in Figure 1A and Figure 1B, the core body 5 of the electromagnetic device 6 includes an outer peripheral core 20 and three core coils 31 to 33 arranged inside the outer peripheral core 20. In Figure 1, the core coils 31 to 33 are arranged inside the substantially hexagonal outer peripheral core 20. These core coils 31 to 33 are arranged at equal intervals in the circumferential direction of the core body 5.
[0012] Note that the outer peripheral core 20 may have another rotationally symmetric shape, for example, a circular shape. Also, the number of the core coils only needs to be a multiple of 3. In that case, the reactor as the electromagnetic device 6 can be used as a three-phase reactor.
[0013] As can be seen from the drawings, each of the core coils 31 to 33 includes cores 41 to 43 extending only in the radial direction of the outer peripheral core 20 and coils 51 to 53 mounted on the cores. Each of at least three coils 51 to 53 is housed in coil cases 61 to 63. The coil cases 61 to 63 are preferably formed of a non-magnetic material, for example, resin.
[0014] The outer peripheral core 20 is composed of a plurality of, for example, three outer peripheral core parts 24 to 26 divided in the circumferential direction. The outer peripheral core parts 24 to 26 are integrally formed with the cores 41 to 43, respectively. As can be seen from FIG. 3 to be described later, the outer peripheral core parts 24 to 26 and the cores 41 to 43 are formed by laminating a plurality of magnetic plates, for example, iron plates, carbon steel plates, electromagnetic steel plates, or are formed of a compacted iron core. When the outer peripheral core 20 is composed of a plurality of outer peripheral core parts 24 to 26 like this, even when the outer peripheral core 20 is large, such an outer peripheral core 20 can be easily manufactured. Note that the number of the cores 41 to 43 and the number of the outer peripheral core parts 24 to 26 do not necessarily have to match.
[0015] Furthermore, the radially inner ends of each of the cores 41 to 43 are located near the center of the outer peripheral core 20. In the drawings, the radially inner ends of each of the cores 41 to 43 converge toward the center of the outer peripheral core 20, and the tip angle thereof is about 120 degrees. The radially inner ends of the cores 41 to 43 are spaced apart from each other via magnetically connectable gaps 101 to 103.
[0016] In other words, the radially inner end of the core 41 is spaced apart from the radially inner ends of the two adjacent cores 42 and 43 via the gaps 101 and 103. The same applies to the other cores 42 and 43. Note that the dimensions of the gaps 101 to 103 are equal to each other.
[0017] As shown in Figure 1A, the central core located in the center of the core body 5 is unnecessary, allowing the core body 5 to be constructed in a lightweight and simple manner. Furthermore, since the three core coils 31-33 are surrounded by the outer core 20, the magnetic field generated from coils 51-53 does not leak to the outside of the outer core 20. In addition, the gaps 101-103 can be provided at any thickness at low cost, which is advantageous in terms of design compared to conventional reactor structures.
[0018] Furthermore, in the core body 5 of this disclosure, the difference in magnetic path length between phases is smaller compared to conventional electromagnetic devices. Therefore, in this disclosure, it is also possible to reduce the inductance imbalance caused by the difference in magnetic path length.
[0019] As can be seen by referring to Figure 1B, each of the coils 51 to 53 mounted on the iron cores 41 to 43 is a flat wire coil formed by winding a flat wire at least once. Naturally, coils 51 to 53 (54) may be coils other than flat wire coils.
[0020] Figure 2A is a perspective view of the coil case as seen from the radially inward side of the electromagnetic device, and Figure 2B is a perspective view of the coil case as seen from the radially outward side of the electromagnetic device. In these drawings and other drawings described later, only the coil case 61 is shown as a representative example, but the other coil cases 62, 63, (64) are assumed to have a similar configuration. The coil case 61 has a housing 61b with an open top surface and radially inward surface, and a hollow projection 61c that protrudes radially inward from the radially outward end surface of the housing 61b.
[0021] The space between the housing 61b and the hollow projection 61c is a coil housing 61a with a shape suitable for housing the coil 51. Furthermore, as will be described later, the hollow portion of the hollow projection 61c has a shape suitable for receiving the iron core 41.
[0022] As shown in Figures 2A and 2B, a protrusion 70a, which serves as the first fitting portion 70, is formed on a portion of the outer circumferential surface of the housing 61b facing the outer circumferential core portion 24. Similarly, a protrusion 80a, which serves as the second fitting portion 80, is formed on a portion of the inner circumferential surface of the hollow projection 61c facing the core 41. In Figures 2A and 2B, two protrusions 70a and two protrusions 80a are formed on a single coil case 61.
[0023] As can be seen from the figure, these protrusions 70a have a semicircular cross-section and extend parallel to the axial direction of the electromagnetic device 6. The length of the protrusions 70a formed on the outer circumferential surface of the housing 61b is approximately equal to the height of the corresponding coil 51, and the length of the protrusions 80a formed on the inner circumferential surface of the hollow projection 61c is approximately equal to the height of the opening of the corresponding coil 51. Alternatively, the protrusions 70a and 80a may extend at least partially parallel to the axial direction of the electromagnetic device 6.
[0024] Figure 2C is a partial top view of the electromagnetic device. As shown in Figure 2C, a recess 70b is formed in the outer circumferential core portion 24 as a first fitting portion 70. The recess 70b fits into a protrusion 70a formed on the outer circumferential surface of the coil housing portion 61a. Similarly, a recess 80b is formed in the core 41 as a second fitting portion 80. The recess 80b fits into a protrusion 80a formed on the inner circumferential surface of the hollow projection portion 61c.
[0025] As can be seen from Figure 2C, the second mating portion 80 is closer to the center of the core body 5 than the first mating portion 70. In other words, the distance between the first mating portion 70 and the center of the electromagnetic device 6 is different from the distance between the second mating portion 80 and the center of the electromagnetic device 6.
[0026] Furthermore, Figure 3 is a partial perspective view of the electromagnetic device. As shown in Figure 3, the coil case 61, which houses the coil 51, is moved toward the outer periphery core portion 24. This causes the core 41, which is integral with the outer periphery core portion 24, to be inserted into the hollow projection 61c of the coil case 61.
[0027] Since the coil case 61 is made of resin, the inner and outer surfaces of the coil case 61 temporarily curve when inserted. Then, when the protrusions 70a and 80a fit into the recesses 70b and 80b, respectively, the inner and outer surfaces of the coil case 61 return to their original shape. In other words, the first fitting part 70 and the second fitting part 80 snap into place. This allows the coil 51 to be mounted on the iron core 41. The other coils 52 and 53 are also housed in their corresponding coil cases 62 and 63, and then similarly mounted on the iron cores 42 and 43 of the outer periphery iron core parts 25 and 26, respectively. After that, the outer periphery iron core parts 24 to 26 are assembled together, thereby forming the electromagnetic device 6 shown in Figure 1B.
[0028] Thus, in this disclosure, the coil cases 61-63 and the core body 5 are fitted together by the fitting portions 70 and 80. Therefore, once fitted together, the coil cases 61-63 will not shift position radially relative to the core body 5. As a result, the electromagnetic device 6 can be assembled accurately and easily.
[0029] Furthermore, as explained with reference to Figure 2C, if the distance between the first fitting portion 70 and the center of the electromagnetic device 6 is different from the distance between the second fitting portion 80 and the center of the electromagnetic device 6, it becomes possible to further prevent the coil cases 61-63 from shifting radially relative to the core body 5.
[0030] Figure 2D is a partial top view of an electromagnetic device in the prior art. In Figure 2D, the mating portions 70 and 80 are not formed. Therefore, the coil case 61' of the prior art may be misaligned in the radial direction. This disclosure overcomes this problem as described above.
[0031] In Figure 2A and other figures, a protrusion 70a is formed on the coil case 61, and a recess 70b is formed on the outer core portion 24. However, as shown in Figures 4A to 4C, which are partial cross-sectional views of the electromagnetic device in this disclosure, a recess 70b may be formed on the coil case 61, and a protrusion 70a may be formed on the outer core portion 24. The same applies to the second fitting portion 80.
[0032] Furthermore, in Figure 2A and other figures, the protrusion 70a has a semicircular cross-section. However, the cross-section of the protrusion 70a is not limited to a semicircle; for example, it may be rectangular as shown in Figure 4B or triangular as shown in Figure 4C. Naturally, the recess 70b shall have a shape corresponding to the protrusion 70a.
[0033] Figure 5 is another perspective view of the coil case, similar to Figure 2B. In Figure 5, in addition to the aforementioned protrusion 70a, an additional protrusion 70a' extending parallel to the protrusion 70a is shown by a dashed line on the outer circumferential surface of the housing 61b. Furthermore, a protrusion 80a similar to that in Figure 2B is shown by a dashed line, and an additional protrusion 80a' extending parallel to the protrusion 80a is shown by a dashed line on the inner circumferential surface of the hollow projection 61c. Naturally, when the additional protrusion 70a' and / or additional protrusion 80a' are formed, corresponding additional recesses 70b' and / or additional recesses 80b' may be formed in the outer circumferential core portion 24 and the core 41.
[0034] As can be inferred from Figure 5, the protrusion 70a and the additional protrusion 70a' may be formed on the housing 61b, thereby providing two first fitting portions 70 on one side of the outer circumferential surface of the housing 61b. Similarly, the protrusion 80a and the additional protrusion 80a' may be formed on the hollow projection 61c, thereby providing two second fitting portions 80 on one side of the inner circumferential surface of the hollow projection 61c. Furthermore, as can be inferred from Figure 5, the protrusion 70a may be formed on the housing 61a, thereby providing a configuration in which the core body 5 and the coil case 61 are fitted together only by the first fitting portion 70. Similarly, although not shown in the drawings, the protrusion 80a may be formed on the hollow projection 61c, thereby providing a configuration in which the core body 5 and the coil case 61 are fitted together only by the second fitting portion 80. In such cases, recesses corresponding to the aforementioned protrusions 70a and 70a' or protrusions corresponding to the aforementioned recesses 80a and 80a' are formed. Even in such cases, it will be clear that the same effect as described above will be achieved.
[0035] Furthermore, Figure 6 shows the magnetic flux density distribution of the outer core portion in this disclosure. For the sake of simplicity, Figure 6 shows the magnetic flux density distribution of only the outer core portion 24 when the electromagnetic device 6 as a reactor is being driven. The other outer core portions 25 and 26 are assumed to exhibit a magnetic flux density distribution similar to that of the outer core portion 24.
[0036] In Figure 6, the magnetic flux density is low at both ends of the outer core portion 24 of the electromagnetic device 6 in the circumferential direction, specifically at the ends adjacent to the radially inner end of the core 41, and at the radially inner end of the core 41 and their vicinity (indicated by region Z1). In contrast, the magnetic flux density is high at the radially outer end of the core 41, that is, at the central part of the inner circumference of the outer core portion 24 of the electromagnetic device 6 in the circumferential direction and its vicinity (indicated by region Z2).
[0037] If the mating portions 70 and 80 are formed in areas with high magnetic flux density, the core body 5 may overheat or become a source of noise. In this disclosure, the mating portions 70 and 80 are formed in the aforementioned areas with low magnetic flux density. Therefore, even if the mating portions 70 and 80 are formed, overheating and noise generation in the core body 5 can be suppressed.
[0038] Figure 7 is a top view of the core body of an electromagnetic device in another embodiment. The core body 5 shown in Figure 7 includes a substantially octagonal outer core 20 and four core coils 31-34, similar to those described above, arranged inside the outer core 20. These core coils 31-34 are arranged at equal intervals in the circumferential direction of the core body 5. Furthermore, it is preferable that the number of cores be an even number of four or more, thereby allowing the reactor as an electromagnetic device 6 to be used as a single-phase reactor.
[0039] As can be seen from the drawing, the outer core 20 is composed of four outer core sections 24-27 that are divided in the circumferential direction. Each core coil 31-34 includes a radially extending core 41-44 and coils 51-54 mounted on that core. The radially outer ends of each core 41-44 are integrally formed with each of the outer core sections 21-24. Note that the number of cores 41-44 does not necessarily have to match the number of outer core sections 24-27.
[0040] Furthermore, the radially inner ends of each of the cores 41-44 are located near the center of the outer core 20. In Figure 7, the radially inner ends of each of the cores 41-44 converge toward the center of the outer core 20, and their tip angles are approximately 90 degrees. The radially inner ends of the cores 41-44 are separated from each other by magnetically connectable gaps 101-104.
[0041] In Figure 7, at least three coils 51-54 are housed in coil cases 61-64 similar to those described above. The coil cases 61-64 and the core body 5 are formed with a first fitting portion 70 and a second fitting portion 80, similar to those described above. Therefore, the coil cases 61-64 and the core body 5 are fitted together by the fitting portions 70 and 80, preventing the coil cases 61-64 from shifting radially relative to the core body 5. Thus, it can be seen that the same effects as described above are obtained.
[0042] Furthermore, Figures 8A and 8B are cross-sectional views of the core body included in an electromagnetic device based on another embodiment. In these drawings, a transformer is shown as an example of the electromagnetic device 6. Since Figures 8A and 8B are similar to Figures 1A and 7, respectively, further explanation of already described components will be omitted. In Figures 8A and 8B, the radially inner ends of the iron cores 41-43(44) are in contact with the radially inner ends of adjacent iron cores 41-43(44). For this reason, the electromagnetic device 6 shown in Figures 8A and 8B does not include gaps 101-103(104).
[0043] In Figures 8A and 8B, the coil cases 61-63(64) and the core body 5 are formed with the first fitting portion 70 and the second fitting portion 80 in the same manner as described above. Therefore, it can be seen that the same effect as described above can be obtained even when the electromagnetic device 6 is a transformer.
[0044] The nature of this disclosure According to the first embodiment, an electromagnetic device (6) is provided, comprising a core body (5), the core body including an outer core (20) composed of a plurality of outer core portions (24-27), and at least three cores (41-44) coupled to the plurality of outer core portions, further comprising coils (51-54) mounted on the at least three cores, and coil cases (61-64) that at least partially cover each of the at least three cores and insulate them from the coils, wherein fitting portions (70, 80) for fitting the core body and the coil cases to each other are formed on the core body and the coil cases, respectively. According to a second embodiment, in the first embodiment, the fitting portion includes a recess formed to extend at least partially parallel to the axial direction of the core body and a protrusion that fits into the recess. According to the third embodiment, in the first or second embodiment, the fitting portion is formed between the inner circumferential surface of the coil case and the iron core, and between the outer circumferential surface of the coil case and the outer circumferential iron core, at least one of the two. According to the fourth embodiment, in the first or second embodiment, the fitting portion includes a first fitting portion formed between the outer circumferential surface of the coil case and the core and a second fitting portion formed between the inner circumferential surface of the coil case and the outer circumferential core, wherein the distance between the first fitting portion and the center of the electromagnetic device is different from the distance between the second fitting portion and the center of the electromagnetic device. According to the fifth embodiment, in any of the first to fourth embodiments, the number of at least three iron cores is a multiple of 3. According to the sixth embodiment, in any of the first to fourth embodiments, the number of at least three iron cores is an even number of four or more.
[0045] Effects of the configuration In the first embodiment, the coil case and the core body are fitted together by a mating portion. Therefore, once fitted together, the coil case will not shift radially relative to the core body. This allows for accurate and easy assembly of electromagnetic equipment. In the second and third embodiments, the aforementioned effects can be achieved with a simple configuration. In the fourth embodiment, the radial displacement of the coil case relative to the electromagnetic device can be suppressed. In the fifth embodiment, the electromagnetic device can be used as a three-phase reactor. In the sixth embodiment, the electromagnetic device can be used as a single-phase reactor.
[0046] While embodiments of the present invention have been described above, it will be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of disclosure of the claims described later. [Explanation of symbols]
[0047] 5 Core Unit 6 Electromagnetic equipment 20 Outer core 24-27 Outer core portion 31-34 Iron core coil 41-44 Iron Heart 51-54 coils 61-64 Coil Case 61a Coil housing 61b Housing 61c Hollow protrusion 70 First fitting part 80 Second fitting part 70a, 80a protrusions 70a', 80a' Additional protrusions 70b, 80b recess 70b', 80b' Additional recesses 101-104 Gap
Claims
1. In electromagnetic equipment, It comprises a core body, The core body includes an outer core composed of a plurality of outer core portions, and at least three cores coupled to the plurality of outer core portions. moreover, The coils mounted on the at least three iron cores, The coil case comprises, which covers each of the at least three iron cores at least partially to insulate them from the coil, A fitting portion for fitting the core body and the coil case together is formed on the core body and the coil case, respectively. The fitting portion includes a recess formed to extend at least partially parallel to the axial direction of the core body and a protrusion that fits into the recess, An electromagnetic device wherein one of the recess and the protrusion is formed at both ends of the outer peripheral core portion in the circumferential direction of the electromagnetic device, adjacent to the radially inner end of the core corresponding to the outer peripheral core, and the other of the recess and the protrusion is formed on the outer peripheral surface of the housing of the coil case.
2. The electromagnetic device according to claim 1, wherein the number of the at least three iron cores is a multiple of three.
3. The electromagnetic device according to claim 1, wherein the number of the at least three iron cores is an even number of four or more.
Citation Information
Patent Citations
JP1977005246U
JP1987080315U
JP1988080833U
Transformer
JP1991206604A
Coil component
JP1995283030A