Reactor including an outer core

Abstract

The present invention provides a reactor (6) including a core main body (5) including an outer peripheral core (20), at least three cores (41 to 44), and at least three coils (51 to 54). Gaps (101 to 104), which can be magnetically coupled together, are formed respectively between two adjacent cores. The reactor includes a vibration suppressing section (90) fixing at least three cores. The vibration suppressing section includes two fixing plates (91, 92) and a bar-like member (95) that clamps the two fixing plates, at least one of the two fixing plates includes at least three notches (61 to 64) extending from an edge toward the center of the fixing plate.

Description

Technical Field

[0001] The present invention relates to a reactor including an outer peripheral core.

Background Art

[0002] In recent years, reactors including an outer peripheral core and a plurality of core coils arranged inside the outer peripheral core have been developed. Each of the plurality of core coils includes a core and a coil wound around the core.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to suppress the vibration of a plurality of cores and the generation of noise during the use of the reactor, Japanese Patent Application Laid-Open No. 2018-206949 and Japanese Patent Application Laid-Open No. 2020-178081 disclose a vibration suppression portion as a fixture composed of two plate-like members and a plurality of rod-like members. Further, the vibration suppression portion of Japanese Patent Application Laid-Open No. 2018-117047 includes an extension portion that engages with the upper surface of the core.

[0005] However, since the iron core is created by laminating a plurality of magnetic plates, if there are variations in the height of each iron core, it is difficult to firmly fix the iron core with the fixtures disclosed in JP-A-2018-206949 and JP-A-2020-178081. Furthermore, since the extension part of JP-A-2018-117047 engages only with a part in the width direction of the iron core, there is a possibility that vibrations and noise may increase instead. Also, it is desired to simplify the structure of the vibration suppression part and reduce the manufacturing cost.

[0006] Therefore, a reactor that can suppress noise and vibration at low cost while absorbing variations in the height of each iron core is desired.

Means for Solving the Problem

[0007] According to the first aspect of the present disclosure, there is provided a reactor including a core body, the core body including an outer peripheral core composed of a plurality of outer peripheral core portions, at least three cores coupled to the plurality of outer peripheral core portions, and a coil wound around the at least three cores. A magnetically connectable gap is formed between one of the at least three cores and another core adjacent to the one core. Further, the reactor includes a vibration suppression part for fixing the at least three cores, the vibration suppression part including two fixing plates and one rod-shaped member for fastening the two fixing plates to each other. At least three cuts extending from the edge of the fixing plate toward the center are formed in at least one of the two fixing plates.

Effect of the Invention

[0008] In the first aspect, since the fixing plate has cuts, the edge of the fixing plate between two adjacent cuts can be bent individually. Therefore, each edge bends according to the height of the corresponding core, and as a result, the height variation of each core is absorbed. Also, since it is sufficient to simply make cuts in the fixing plate, it is easy to form and the manufacturing cost can be suppressed. Furthermore, since the rod-shaped member is single, even when the vibration suppressing portion is formed of a magnetic material, current does not flow through the vibration suppressing portion in a loop shape, and heat generation of the reactor can be prevented.

[0009] The object, features, and advantages of the present invention will become more apparent from the following description of embodiments in relation to the accompanying drawings.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 9A

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Mode for Carrying Out the Invention

[0011] 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. However, the application of the present disclosure is not limited to three-phase reactors, and can be widely applied to polyphase reactors that require a certain inductance in each phase. 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.

[0012] FIG. 1 is a partial perspective view of the reactor in the first embodiment. FIG. 2 is a cross-sectional view of the core body of the reactor in the first embodiment. In particular, as shown in FIG. 2, the core body 5 of the reactor 6 includes an outer peripheral core 20 and three core coils 31 to 33 disposed inside the outer peripheral core 20. In FIG. 2, the core coils 31 to 33 are disposed 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.

[0013] Note that the outer peripheral core 20 may have another rotationally symmetric shape, for example, a circular shape. Also, the number of core coils may be a multiple of 3, and in that case, the reactor 6 can be used as a three-phase reactor.

[0014] As can be seen from the drawings, each of the core coils 31 to 33 includes cores 41 to 43 that extend only in the radial direction of the outer peripheral core 20, and coils 51 to 53 wound around the cores. In FIGS. 1 and other drawings described later, for the purpose of simplification, the illustrations of the coils 51 to 53, the core 42, and the outer peripheral core portion 25 may be omitted.

[0015] The outer peripheral core 20 is composed of a plurality of, for example, three outer peripheral core portions 24 to 26 that are circumferentially divided. The outer peripheral core portions 24 to 26 are integrally formed with the cores 41 to 43, respectively. The outer peripheral core portions 24 to 26 and the cores 41 to 43 are formed by laminating a plurality of magnetic plates, such as iron plates, carbon steel plates, and electromagnetic steel plates, in the axial direction of the reactor, or are formed from a powder core. When the outer peripheral core 20 is composed of a plurality of outer peripheral core portions 24 to 26 in this way, even if the outer peripheral core 20 is large, such an outer peripheral core 20 can be easily manufactured. Note that the number of cores 41 to 43 and the number of outer peripheral core portions 24 to 26 do not necessarily have to match.

[0016] The coils 51 to 53 are disposed in coil spaces 51a to 53a formed between the outer peripheral core portions 24 to 26 and the cores 41 to 43. In the coil spaces 51a to 53a, the inner peripheral surface and the outer peripheral surface of the coils 51 to 53 are adjacent to the inner walls of the coil spaces 51a to 53a.

[0017] 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 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.

[0018] In other words, the radially inner end portion of the iron core 41 is spaced apart from the radially inner end portions of two adjacent iron cores 42 and 43 via gaps 101 and 102, respectively. The same applies to the other iron cores 42 and 43. Note that the dimensions of the gaps 101 to 103 are equal to each other.

[0019] Thus, in the configuration shown in FIG. 1, since the central iron core located at the center of the core body 5 is unnecessary, the core body 5 can be configured to be lightweight and simple. Further, since the three core coils 31 to 33 are surrounded by the outer peripheral iron core 20, the magnetic fields generated from the coils 51 to 53 do not leak to the outside of the outer peripheral iron core 20. Also, since the gaps 101 to 103 can be provided at an arbitrary thickness at low cost, it is advantageous in design as compared with the reactor of the conventional structure.

[0020] Furthermore, in the core body 5 of the present disclosure, the difference in the magnetic path length between phases is reduced as compared with the reactor of the conventional structure. For this reason, in the present disclosure, it is also possible to reduce the inductance imbalance caused by the difference in the magnetic path length.

[0021] Referring to FIG. 1 again, a vibration suppression portion 90 is disposed at the center of the end face of the core body 5. The vibration suppression portion 90 serves to fix both end faces of the iron cores 41 to 43 to each other in the axial direction of the core body 5. FIG. 3 is a perspective view of the vibration suppression portion in the first embodiment. As shown in FIG. 3, the vibration suppression portion 90 includes two fixing plates 91 and 92 and a single rod-shaped member 95 that connects these fixing plates 91 and 92 to each other.

[0022] As can be seen from FIG. 1, the fixing plates 91 and 92 are respectively disposed on both end faces of the core body 5. In the first embodiment, it is preferable that the fixing plates 91 and 92 are triangular flat plates having an area that can include the gaps 101 to 103, whereby the fixing plates 91 and 92 do not interfere with the coils 51 to 53. Also, the fixing plates 91 and 92 may have other polygonal shapes or circular shapes.

[0023] FIG. 4A is a top view of the fixed plate of the vibration suppression unit in the first embodiment. Although the fixed plate 91 is shown in FIG. 4A, it is preferable that the fixed plate 92 has the same shape. However, it is not always necessary for the fixed plates 91 and 92 to have the same shape as each other. Also, the cut described later may be formed only in one of the fixed plates.

[0024] At least three cuts 61 to 63 extending from the outer peripheral edge portion of the fixed plate 91 toward the center are formed. In the embodiment shown in FIG. 4A, at least three cuts 61 to 63 partially extend from each vertex of the triangular fixed plate 91 toward the center. As shown in the drawing, the outer peripheral edge portions of the fixed plate 91 located between each of the cuts 61 to 63 are referred to as edge portions 91a to 91c.

[0025] In the first embodiment, as can be seen from FIG. 1, the rod-shaped member 95 is passed through the inside of the outer peripheral core 20 at the intersection locations of the gaps 101 to 103. The rod-shaped member 95 is slightly larger than the height (stacking direction height) of the core body 5. A typical rod-shaped member 95 is a bolt, and a threaded portion 94 is formed on at least one end side of the rod-shaped member 95. Therefore, thereby, the rod-shaped member 95 is screwed into the hole formed in the fixed plate 92.

[0026] As described above, the areas of the fixed plates 91 and 92 may include the gaps 101 to 103. For this reason, when the core body 5 is axially sandwiched between the fixed plates 91 and 92 by the rod-shaped member 95, both ends of the plurality of cores 41 to 43 are firmly held together.

[0027] As described above, the cuts 61 to 63 are formed in at least one of the fixed plates 91. For this reason, the distance between the closing ends of each of the two adjacent cuts 61 to 63 is shorter than the distance between the open ends of the cuts 61 to 63 (the length of each of the edge portions 91a to 91c). Therefore, a part of the fixed plate 91 located between two adjacent cuts 61 to 63 exhibits spring properties, and each of the edge portions 91a to 91c can be individually bent.

[0028] Thus, when assembling the vibration suppression portion 90, each of the edges 91a to 91c is curved according to the height of the corresponding cores 41 to 43, for example, the stacking height. Then, in a state where the height variations of the respective cores 41 to 43 are absorbed, the fixing plates 91 and 92 act so as to pull each other. As a result, both ends of the plurality of cores 41 to 43 are firmly held together, and the generation of vibration and noise can be further suppressed when the reactor is driven. Further, since it is only necessary to make cuts 61 to 63 in the fixing plates 91 and 92, the formation of the vibration suppression portion 90 is also easy, and the manufacturing cost can be suppressed.

[0029] Furthermore, the components of the vibration suppression portion 90 may be made of a non-magnetic material or may be made of a magnetic material. The reason is that in the present disclosure, the rod-shaped member 95 is single. On the other hand, when a plurality of, for example, three rod-shaped members fix two fixing plates, and both the two fixing plates and the plurality of rod-shaped members are magnetic bodies, when the reactor is driven, current flows in a loop through the two fixing plates and the plurality of rod-shaped members. As a result, the reactor generates heat, which may cause a failure. In other words, in the present disclosure, even when the entire vibration suppression portion 90 is formed of a magnetic material, current does not flow through the vibration suppression portion 90 in a loop, and heat generation of the reactor can be prevented.

[0030] FIG. 5 is a partial perspective view of the reactor in the second embodiment. The fixing plates 91 and 92 shown in FIG. 5 are smaller than the fixing plates 91 and 92 shown in FIG. 1. Even in such a case, the distance between the open ends of two adjacent cuts 61 to 63, for example, the length of each of the edges 91a to 91c, is preferably at least half of the width of the corresponding cores 41 to 43. Thereby, each of the edges 91a to 91c of the fixing plates 91 and 92 fixes most of the width of the cores 41 to 43, so that vibration and noise can be sufficiently suppressed.

[0031] FIG. 6 is a partial perspective view of the reactor in the third embodiment. The fixing plates 91 and 92 shown in FIG. 6 are circular. The diameters of the fixing plates 91 and 92 are preferably selected so as not to interfere with the coils 51 to 53. Further, as described above, it is preferable that the distance between the open ends of two adjacent cuts 61 to 63 is at least half of the width of the corresponding cores 41 to 43. In the third embodiment, it can be seen that the fixing plates 91 and 92 can be easily formed.

[0032] FIG. 7 is a perspective view of the reactor in the fourth embodiment, and FIG. 8 is a perspective view of the vibration suppression part in the fourth embodiment. Further, FIG. 9A is a top view of the fixing plate in the fourth embodiment, and FIG. 9B is a side view of the fixing plate taken along line A-A' of FIG. 9A.

[0033] In the fourth embodiment, at least one of the fixing plates 91 of the vibration suppression part 90 is formed of a magnetic material, for example, metal. And each edge part 91a - 91c of the fixing plate 91 is bent by a predetermined angle, for example, 90° with respect to the surface of the fixing plate 91. In this case, a part of the fixing plate 91 located between two adjacent cuts 61 to 63 further exhibits spring characteristics. As a result, it can be seen that vibration and noise can be further suppressed at low cost when the reactor is driven. Of course, the angle for bending each edge part 91a - 91c may be a value other than 90°.

[0034] FIG. 10 is a diagram for explaining the attachment of the vibration suppression part to the reactor in the fourth embodiment. For the purpose of easy understanding, in FIG. 10, the illustration of the outer peripheral core part 25 is omitted. First, a rod-shaped member 95 is inserted into the hole 60 of the fixing plate 91.

[0035] Then, move the fixing plate 91 toward one end face of the core body 5 so that the rod-shaped member 95 passes through the intersection of the gaps 101 to 103. When the fixing plate 91 reaches one end face of the core body 5, the tip of the rod-shaped member 95 protrudes from the other end of the core body 5. Next, dispose the fixing plate 92 on the other end face side of the core body 5, and rotate the rod-shaped member 95 to screw it into the fixing plate 92. For this purpose, it is preferable that a threaded portion is formed on the tip of the rod-shaped member 95 and the through-hole 60 of the fixing plate 92, respectively. Of course, other fasteners may be used to connect the fixing plates 91 and 92 to the rod-shaped member 95.

[0036] FIG. 11 is a perspective view of a bent fixing plate in still another embodiment. In FIG. 11, protruding portions 66 are formed at both ends of the bent edge of the fixing plate 91. Such protruding portions 66 may be created by cutting to notch the respective edges 91a to 91c before and after bending, or may be created by bending a flat plate having a shape provided with the protruding portions 66 in advance.

[0037] In FIG. 11, each of the edges 91a to 91c includes two protruding portions 66. And it is preferable that the inner dimension L between the two protruding portions 66 is approximately equal to the width of the corresponding cores 41 to 43. In this case, both ends of each of the edges 91a to 91c are respectively engaged with the side surfaces of the cores 41 to 43. That is, since the cores 41 to 43 are sandwiched between the two protruding portions 66, it is possible to prevent vibrations and noises caused by the movement of the cores 41 to 43 in the circumferential direction of the reactor.

[0038] FIG. 12 is a perspective view of a vibration suppression portion in another embodiment. In FIG. 12, an elastic member 96, such as a spring, is disposed at an intermediate portion of the rod-shaped member 95. Strictly speaking, the rod-shaped member 95 shown in FIG. 12 includes two rod bodies and an elastic member 96 that connects these rod bodies to each other. In this case, since the elastic member 96 biases the two fixing plates 91 and 92 to approach each other, it is possible to further suppress noises and vibrations.

[0039] FIG. 13 is a partial perspective view of the reactor in the fifth embodiment, and FIG. 14 is a cross-sectional view of the core body of the reactor in the fifth embodiment. As shown in FIG. 14, the core body 5 includes a substantially octagonal outer peripheral core 20 and four core coils 31 to 34 similar to those described above disposed inside the outer peripheral core 20. These core coils 31 to 34 are arranged at equal intervals in the circumferential direction of the core body 5. Further, the number of cores is preferably an even number of 4 or more, whereby the reactor provided with the core body 5 can be used as a single-phase reactor.

[0040] As can be seen from the drawings, the outer peripheral core 20 is composed of four outer peripheral core portions 24 to 27 divided in the circumferential direction. Each of the core coils 31 to 34 includes cores 41 to 44 extending in the radial direction and coils 51 to 54 wound around the cores. And the respective radially outer ends of the cores 41 to 44 are integrally formed with the respective ones of the outer peripheral core portions 21 to 24. Note that the number of the cores 41 to 44 and the number of the outer peripheral core portions 24 to 27 do not necessarily have to match.

[0041] Furthermore, the respective radially inner ends of the cores 41 to 44 are located near the center of the outer peripheral core 20. In FIG. 14, the respective radially inner ends of the cores 41 to 44 converge toward the center of the outer peripheral core 20, and the tip angle thereof is about 90 degrees. And the radially inner ends of the cores 41 to 44 are separated from each other via magnetically connectable gaps 101 to 104.

[0042] FIG. 4B is a top view of the fixed plate of the vibration suppression unit in the fifth embodiment. The fixed plate 91 shown in FIG. 4B is substantially square-shaped having an area that can include the gaps 101 to 104, and cuts 61 to 64 similar to those described above extend from the vertices of the fixed plate 91 toward the center. Similarly to the above, when the core body 5 is axially sandwiched between the fixed plates 91 and 92 by the rod-shaped members 95, both ends of the cores 41 to 44 are fixed to each other. It can be understood that the same effect as described above can be obtained in this case. Also, appropriately combining the above-described embodiments is included in the scope of the present disclosure.

[0043] Aspects of the present disclosure According to a first aspect, a core body is provided, the core body including an outer peripheral core composed of a plurality of outer peripheral core portions, at least three cores coupled to the plurality of outer peripheral core portions, and a coil wound around the at least three cores. A magnetically connectable gap is formed between one of the at least three cores and another core adjacent to the one core. Further, a vibration suppression unit for fixing the at least three cores is provided, the vibration suppression unit including two fixing plates and a rod-shaped member for fastening the two fixing plates to each other. At least three cuts extending from an edge of the fixing plate toward the center are formed in at least one of the two fixing plates. A reactor is provided. According to a second aspect, in the first aspect, the distance between two adjacent cuts among the at least three cuts is made to be at least half the width of the core. According to a third aspect, in the first or second aspect, the fixing plate in which the at least three cuts are formed is polygonal, the number of sides of the polygon is greater than or equal to the number of the at least three cores, and the at least three cuts extend from the vertices of the polygon toward the center. According to a fourth aspect, in the third aspect, each edge of the polygonal fixing plate is bent. According to a fifth aspect, in the fourth aspect, the inner dimension between both ends of each of the bent edges is made to be approximately equal to the width of the core. According to a sixth aspect, in the first or second aspect, the fixing plate in which the at least three cuts are formed is circular. According to a seventh aspect, in the first or second aspect, the rod-shaped member includes a bolt. According to an eighth aspect, in the first or second aspect, the rod-shaped member has an elastic member. According to a ninth aspect, in the first or second aspect, the number of the at least three core coils is a multiple of 3. According to the tenth aspect, in the first or second aspect, the number of the at least three core coils is an even number of 4 or more.

[0044] Effects of the aspect In the first aspect, since there are cuts in the fixing plate, the edges of the fixing plate between two adjacent cuts can be bent individually. Therefore, each edge bends according to the height of the corresponding core, and as a result, the height variation of each core is absorbed. Also, since it is sufficient to make cuts in the fixing plate, it is easy to form and the manufacturing cost can be suppressed. In the second aspect, since each edge of the fixing plate fixes most of the width of the core, vibration and noise can be sufficiently suppressed. In the third aspect, the fixing plate can be easily formed. In the fourth aspect, the fixing plate comes to have a function as a spring, and vibration and noise can be further suppressed at low cost. In the fifth aspect, since both ends of each edge engage with the side surface of the core, vibration and noise caused by the core moving in the circumferential direction of the reactor can be prevented. In the sixth aspect, the fixing plate can be easily formed. In the seventh aspect, noise and vibration can be further suppressed, and the rod-shaped member can be manufactured at low cost. In the eighth aspect, since the elastic member biases the two fixing plates to approach each other, noise and vibration can be further suppressed. In the ninth aspect, the reactor can be used as a three-phase reactor. In the tenth aspect, the reactor can be used as a single-phase reactor.

[0045] As described above, although the embodiments of the present invention have been described, it will be understood by those skilled in the art that various modifications and changes can be made without departing from the scope of the disclosure of the claims.

Explanation of reference numerals

[0046] 5 Core body 6 Reactor 20 Outer Peripheral Core 24 - 27 Outer Peripheral Core Portion 31 - 34 Core Coil 41 - 44 Core 51 - 54 Coil 61 - 64 Notch 66 Protrusion 90 Vibration Suppression Portion 91, 92 Fixing Plate 91a - 91c Edge 94 Threaded Portion 95 Rod - shaped Member 96 Elastic Member 101 - 104 Gap

Claims

1. Comprising a core body, The core body includes an outer peripheral core composed of a plurality of outer peripheral core portions, At least three cores coupled to the plurality of outer peripheral core portions, And a coil wound around the at least three cores, A magnetically connectable gap is formed between one of the at least three cores and another core adjacent to the one core, Furthermore, it comprises a vibration suppression portion for fixing the at least three cores, The vibration suppression portion includes two fixing plates and one rod-shaped member for fastening the two fixing plates to each other, A reactor, wherein at least three cuts extending from the edge of the fixing plate towards the center are formed on at least one of the two fixing plates.

2. The reactor according to claim 1, wherein the distance between two adjacent cuts among the at least three cuts is at least half of the width of the core.

3. The fixing plate on which the at least three cuts are formed is polygonal, The number of sides of the polygon is greater than or equal to the number of the at least three cores, The reactor according to claim 1 or 2, wherein the at least three cuts extend from the vertices of the polygon towards the center.

4. The reactor according to claim 3, wherein each edge of the polygonal fixing plate is bent.

5. The reactor according to claim 4, wherein the inner dimension between both ends of each of the bent edges is approximately equal to the width of the core.

6. The reactor according to claim 1 or 2, wherein the fixing plate on which the at least three cuts are formed is circular.

7. The reactor according to claim 1 or 2, wherein the rod-shaped member includes a bolt.

8. The reactor according to claim 1 or 2, wherein the rod-shaped member has an elastic member.

9. The reactor according to claim 1 or 2, wherein the number of the at least three core coils is a multiple of 3.

10. The reactor according to claim 1 or 2, wherein the number of the at least three core coils is an even number of 4 or more.

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