Filter device
The innovative bus bar arrangement in the filter device, with stacked and interconnected members, addresses the issue of space requirements for tool access, resulting in a compact and high-performance filter device with improved impedance.
Patent Information
- Application Number
- JP2024046897
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-22
- Publication Date
- 2025-10-03
AI Technical Summary
Conventional filter devices require significant space for tool access to connect bus bars, leading to increased device size and dimensions due to their radial extension, which affects the effective footprint and impedance characteristics.
The filter device incorporates an annular ring core with bus bars stacked on its inner periphery, featuring interconnected second members and a connecting member, allowing multiple turns and reducing the need for extra space for tool access, while incorporating insulating coatings to maximize bus bar insertion and improve impedance.
This configuration results in a more compact filter device with enhanced impedance characteristics, reduced manufacturing costs, and minimized device dimensions by optimizing bus bar arrangement and connection methods.
Smart Images
Figure 2025146228000001_ABST
Abstract
Description
[Technical Field]
[0001] The present disclosure relates to a filter device. [Background technology]
[0002] For example, a power conversion device is provided with a filter device for removing noise caused by high-frequency interference voltages, etc. One example of a filter device is known from Patent Document 1. The filter device according to Patent Document 1 mainly includes a plurality of ring cores and a plurality of bus bars inserted into the inner peripheries of these ring cores. [Prior art documents] [Patent documents]
[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-157747 Summary of the Invention [Problem to be solved by the invention]
[0004] However, in the filter device disclosed in Patent Document 1, the bus bars extend apart from each other in the radial direction of the ring core. This requires space for a tool to access the ends of the bus bars to connect other wiring. As a result, the filter device's effective footprint becomes large. This results in an increase in the size and dimensions of other devices into which the filter device is incorporated.
[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide a filter device that is more compact and has improved performance. [Means for solving the problem]
[0006] In order to solve the above-described problems, the filter device according to the present disclosure includes an annular ring core centered on an axis, and a plurality of bus bars inserted into the inner periphery of the ring core and stacked on the inner periphery in a diameter direction relative to the axis, wherein the bus bars have a first member extending in the axial direction, a second member formed integrally with the first member and extending from an end of the first member in the axial direction in a direction intersecting the axis, and a connecting member connecting the second member to the second member of another bus bar arranged offset in the axial direction, and the ring core is located between the second members connected by the connecting member in the axial direction. [Effects of the Invention]
[0007] According to the present disclosure, it is possible to provide a filter device that is more compact and has improved performance. [Brief explanation of the drawings]
[0008] [Figure 1] 1 is a plan view showing a configuration of a filter device according to a first embodiment of the present disclosure. [Figure 2] FIG. 2 is an enlarged plan view of the bus bar according to the first embodiment of the present disclosure. [Figure 3] FIG. 2 is a side view seen from a direction III in FIG. [Figure 4] 10A and 10B are explanatory diagrams illustrating a state in which a bus bar is inserted into a ring core according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is an enlarged plan view of a bus bar according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION
[0009] First Embodiment (Configuration of filter device 1) A filter device 1 according to a first embodiment of the present disclosure will be described below with reference to Fig. 1 to Fig. 4. The filter device 1 is mounted in, for example, a power conversion device and is used to remove high-frequency noise from a current.
[0010] As shown in Fig. 1, the filter device 1 includes a ring core 10, a bus bar 20, and a terminal block (not shown). The ring core 10 has an annular shape centered on an axis X. The ring core 10 is integrally formed from a magnetic material. The bus bar 20 is inserted into an opening on the inner periphery of the ring core 10.
[0011] The busbars 20 include a positive busbar 21 and a negative busbar 22. The only difference between the positive busbar 21 and the negative busbar 22 is their arrangement, and therefore the configuration of the positive busbar 21 will be representatively described here as the "busbar 20."
[0012] Specifically, the busbar 20 includes a busbar body 31 and a connecting member 32. The busbar body 31 includes a first member 41 and a pair of second members 42. The first member 41 extends in the direction of the axis X and has a plate shape that extends in a plane parallel to the axis X. In a plan view, the first member 41 has a rectangular shape.
[0013] One second member 42 is provided at each end of the first member 41 on both sides in the direction of the axis X. The second members 42 extend from the end of the first member 41 in a direction perpendicular to the axis X (referred to as the "orthogonal direction"), giving the busbar body 31 an overall C-shape. The first member 41 and the second member 42 are integrally formed from the same material. That is, both the first member 41 and the second member 42 are plate-shaped. A round hole is formed at the tip of the second member 42 for connecting other wiring. The dimensions of the pair of second members 42 in the orthogonal direction are the same. In addition, the outer corners of the connection between the first member 41 and the second member 42 are chamfered to form curved round portions 51. This is to prevent the busbar 20 from getting caught on the ring core 10 when it is inserted into the ring core 10, which will be described later.
[0014] As an example, two busbar bodies 31 configured as described above are provided on each of the positive and negative electrode sides. As shown in FIG. 2 , on the positive electrode side, two busbar bodies 31 are stacked so that their positions are offset in the direction of the axis X. The protruding directions of the second members 42 in the two stacked busbar bodies 31 are the same. That is, these second members 42 protrude radially outward from the ring core 10. On the other hand, because the positions are offset in the direction of the axis X, four second members 42 protrude radially outward in a plan view.
[0015] Of these four second members 42, the two innermost second members 42 are connected to each other by a connecting member 32. As shown in FIG. 2 or FIG. 3, the connecting member 32 has a pair of claw portions 61 and a bent portion 62 connecting the claw portions 61 to each other. The claw portions 61 are rectangular plate-shaped and stacked on the plate-shaped second member 42 in a direction normal to the second member 42. An opening having a diameter equal to or greater than the diameter of the circular hole formed in the second member 42 is formed in the center of each claw portion 61. A bolt 80 is inserted through the opening and the circular hole to fasten and fix the second member 42 and the claw portions 61. Note that in order to maintain the horizontal state of the bus bar 20 (or to align the extension direction of the bus bar 20 with the axis X), the claw portion 61 on one side is stacked below the second member 42. The claw portion 61 on the other side is stacked above the second member 42.
[0016] The bent portions 62 are formed integrally with the pair of claw portions 61. The bent portions 62 are connected to the radially outer edges of the claw portions 61 with respect to the axis X. When viewed from the direction of the axis X, the bent portions 62 extend in a direction perpendicular to the claw portions 61. In other words, the bent portions 62 are bent from the edges of the claw portions 61, thereby extending upward.
[0017] With respect to the busbar 20 configured as described above, the ring core 10 is located in the direction of the axis X between a pair of second members 42 connected by the connecting member 32. In other words, on the inner peripheral side of the ring core 10, one busbar 20 is inserted so as to form two loops.
[0018] 4 , when the busbar body 31 is inserted into the ring core 10, the end of the busbar body 31 on the second member 42 side is inserted into the opening of the ring core 10, and then the busbar body 31 is gradually rotated and the first member 41 is moved in the direction of the axis X. In other words, the inner diameter of the ring core 10 is set to be equal to or slightly larger than the width dimensions of the first member 41 and second member 42 of the busbar body 31.
[0019] Additionally, insulating coatings 70 made of a non-conductor are provided on the surfaces of the bus bars 20. Therefore, when the plurality of bus bars 20 are stacked, the insulating coatings 70 are in contact with each other, but the bus bars 20 themselves are not in contact with each other.
[0020] (Action and effect) In the conventional filter device 1, the bus bars 20 extend apart from each other in the radial direction of the ring core 10. This requires space for a tool to access the ends of the bus bars 20 in order to connect other wiring. As a result, the filter device 1 substantially occupies a large footprint. This results in a problem in that the dimensions and size of other devices into which the filter device 1 is incorporated also increase. To solve this problem, the present embodiment employs the above-described configurations.
[0021] According to the above configuration, multiple bus bars 20 are stacked on the inner periphery of the ring core 10, and the second members 42 of these bus bars 20 are connected to each other by the connecting member 32. Furthermore, the ring core 10 is positioned between these connected second members 42. This results in the appearance of one bus bar 20 being inserted through the ring core 10 so as to form two loops, i.e., make two turns. The impedance characteristics of the filter device 1 are inversely proportional to the square of the number of turns of the bus bar 20. According to the above configuration, the number of turns can be increased, significantly improving the impedance characteristics of a ring core 10 with the same dimensions and size. Furthermore, wiring to other devices can be connected to the second member 42 that is not connected by the connecting member 32. In other words, the multiple stacked plate-shaped bus bars 20 can be accessed with a tool, such as a wrench, from the stacking direction. This eliminates the need for extra space around the bus bars 20 for tool access, as in the conventional configuration. As a result, the footprint of the entire filter device 1 can be reduced. Ultimately, it becomes possible to significantly reduce the size and dimensions of devices and systems in which the filter device 1 is incorporated.
[0022] According to the above configuration, the corners on the outer periphery of the connection between the first member 41 and the second member 42 are chamfered. This significantly reduces the possibility that the corners will get caught on the inner periphery of the link core when the bus bar 20 is inserted into the link core. This improves assembly and reduces manufacturing costs. Furthermore, the dimensions of the bus bar 20 can be maximized to the maximum extent possible for insertion into the link core. This increases the space factor of the bus bar 20 on the inner periphery of the ring core 10, further improving impedance characteristics.
[0023] According to the above configuration, the connecting member 32 is fixed from the normal direction of the plate-shaped second member 42. As a result, when fixing the connecting member 32, it is only necessary to ensure space for access with a tool only in the normal direction. Therefore, the area occupied by the bus bar 20 in the planar direction can be reduced. As a result, the filter device 1 can be further miniaturized.
[0024] According to the above configuration, the bent portion 62 of the connecting member 32 expands in a direction intersecting the axis X. This makes it possible to reduce the area occupied by the filter device 1 in plan view while still ensuring a cross-sectional area for the connecting member 32 to pass a large current. This allows the filter device 1 to be made even more compact.
[0025] According to the above configuration, the surfaces of the bus bars 20 are covered with the insulating coating 70. Therefore, when stacking multiple bus bars 20, it is not necessary to provide gaps between the bus bars 20. As a result, more bus bars 20 can be inserted into the inner periphery of the ring core 10. This improves the space factor of the bus bars 20 on the inner periphery of the ring core, and further improves the impedance characteristics of the filter device 1.
[0026] The first embodiment of the present disclosure has been described above. Note that various changes and modifications can be made to the above configuration without departing from the gist of the present disclosure.
[0027] For example, in the first embodiment, an example has been described in which two bus bars 20 are provided on each of the positive and negative sides and are inserted into only one ring core 10. However, it is also possible to adopt a configuration in which three or more bus bars 20 are provided on each side and are inserted into two or more ring cores 10. Even in this case, the same effects as those described above can be obtained.
[0028] Second Embodiment Next, a second embodiment of the present disclosure will be described with reference to Fig. 5. Note that the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.
[0029] In this embodiment, the shape of the busbar 20 is different from that of the first embodiment. Specifically, as shown in FIG. 5 , the busbar 20 has a first member 41, a pair of second members 42, and a third member 43. The configurations of the first member 41 and the second member 42 are the same as those of the first embodiment. The third member 43 extends in the direction of the axis X from the tip of the second member 42 so as to be parallel to and face the first member 41. The tip of the third member 43 has a protruding dimension slightly larger than the thickness of the ring core 10 (i.e., the dimension in the direction of the axis X). A round hole is formed in the tip of the third member 43 for inserting a bolt 80 therethrough.
[0030] A pair of bus bars 20 configured as described above are stacked upside down as shown in Fig. 5. Then, the third members 43 are placed on top of each other, and the two bus bars 20 are fastened together by inserting bolts 80 into the circular holes. This positions the ring core 10 between the second members 42, making it possible to configure a bus bar 20 that makes two turns around the ring core 10, similar to the first embodiment.
[0031] (Action and effect) According to the above configuration, the first member 41, the second member 42, and the third member 43 are integrally formed as the bus bar 20. Furthermore, by directly connecting the third members 43 of the pair of bus bars 20 together, it is possible to easily assemble one bus bar 20 that makes two turns around the ring core 10. Therefore, it is possible to reduce the number of parts, thereby reducing manufacturing costs, and to improve the impedance characteristics of the filter device 1.
[0032] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure. [Example]
[0033] Next, an example of a filter device 1 according to the present disclosure will be described. As a comparative example, the specifications of a conventional filter device 1 are as follows: the outer diameter of the ring core 10 is 36 mm, the inner diameter is 24 mm, the number of turns is 1, and the number of cores is 3. In this case, the impedance Z0 is (36 / 24)×3=4.5. On the other hand, the specifications of the filter device 1 according to the present disclosure are: the outer diameter of the ring core 10 is 36 mm, and the inner diameter is 21 mm. In addition, the number of turns is 2, and the number of cores is 1. In this case, the impedance Z1 is Z1=36 / (21×2 2 )=6.86. That is, the filter device 1 according to the present disclosure can achieve a significant improvement in impedance compared to the conventional configuration.
[0034] <Additional Notes> The filter device 1 described in each embodiment can be understood, for example, as follows.
[0035] (1) A filter device 1 according to a first aspect includes an annular ring core 10 centered on an axis X, and a plurality of bus bars 20 inserted into the inner periphery of the ring core 10 and stacked on the inner periphery in a diameter direction relative to the axis X. Each bus bar 20 includes a first member 41 extending in the direction of the axis X, a second member 42 integrally formed with the first member 41 and extending from an end of the first member 41 in the direction of the axis X in a direction intersecting the axis X, and a connecting member 32 connecting the second member 42 to the second member 42 of another bus bar 20 disposed offset in the direction of the axis X. The ring core 10 is located between the second members 42 connected by the connecting member 32 in the direction of the axis X.
[0036] According to the above configuration, one bus bar 20 is inserted into the ring core 10 so as to form two loops, i.e., to make two turns. This makes it possible to significantly improve impedance characteristics. Also, unlike conventional configurations, there is no need to secure extra space around the ring core 10 for tool access.
[0037] (2) The filter device 1 according to a second aspect is the filter device 1 of (1), in which the corners on the outer periphery of the connection portion between the first member 41 and the second member 42 are chamfered.
[0038] According to the above configuration, when bus bar 20 is inserted into the link core, the possibility that the corner portion will get caught on the inner peripheral surface of the link core can be significantly reduced.
[0039] (3) The filter device 1 according to the third aspect is the filter device 1 of (1) or (2), wherein the first member 41 and the second member 42 are plate-shaped extending along a plane parallel to the axis X, and the connecting member 32 is fixed to the second member 42 in the normal direction of the second member 42.
[0040] According to the above configuration, the area occupied by bus bar 20 in the planar direction can be reduced.
[0041] (4) The filter device 1 according to the fourth aspect is the filter device 1 of (3), wherein the connecting member 32 has a pair of claw portions 61 fixed to the second member 42, and a bent portion 62 connecting the pair of claw portions 61 to each other and extending in a direction intersecting the axis X.
[0042] According to the above configuration, it is possible to reduce the area occupied by the filter device 1 when viewed from above.
[0043] (5) The filter device 1 according to a fifth aspect is the filter device 1 according to any one of the aspects (1) to (4), further including an insulating coating 70 covering the surface of the bus bar 20.
[0044] According to the above configuration, more bus bars 20 can be inserted into the inner periphery of the ring core 10 .
[0045] (6) A filter device 1 according to a sixth aspect includes a ring core 10 having an annular shape centered on an axis X and a plurality of bus bars 20 inserted through the ring core 10 from its inner circumferential side. The bus bars 20 each include a first member 41 extending in the direction of the axis X, a second member 42 integrally formed with the first member 41 and extending from each end of the first member 41 in a direction intersecting the axis X, and a third member 43 integrally formed with the second member 42 and extending from an end of the second member 42 to face the first member 41. The third member 43 is connected to the third member 43 of another bus bar 20 that is disposed offset in the direction of the axis X. The ring core 10 is located between the third members 43 that are connected to each other in the direction of the axis X.
[0046] According to the above configuration, it is possible to reduce the number of parts, thereby reducing manufacturing costs, and at the same time, improve the impedance characteristics of the filter device 1. [Explanation of symbols]
[0047] REFERENCE SIGNS LIST 1...Filter device 10...Ring core 20...Bus bar 21...Positive bus bar 22...Negative bus bar 31...Bus bar body 32...Connecting member 41...First member 42...Second member 43...Third member 51...Rounded portion 61...Claw portion 62...Bent portion 70...Insulating coating 80...Bolt X...Axis
Claims
1. an annular ring core centered on an axis; a plurality of bus bars inserted into an inner circumferential side of the ring core and stacked on the inner circumferential side in a diameter direction relative to the axis; A filter device comprising: The bus bar is a first member extending in the axial direction; a second member formed integrally with the first member and extending from an end of the first member in the axial direction in a direction intersecting the axis; a connecting member that connects the second member to the second member of another bus bar that is disposed offset in the axial direction; and A filter device in which the ring core is located between the second members connected by the connecting member in the axial direction.
2. The filter device according to claim 1 , wherein an outer corner of the connecting portion between the first member and the second member is chamfered.
3. The filter device according to claim 1 or 2, wherein the first member and the second member are plate-shaped and extend along a plane parallel to the axis, and the connecting member is fixed to the second member in a direction normal to the second member.
4. The connecting member has a pair of claw portions fixed to the second member; a bent portion that connects the pair of claw portions to each other and extends in a direction intersecting the axis; 4. The filter device of claim 3, comprising:
5. 3. The filter device according to claim 1, further comprising an insulating coating covering a surface of the bus bar.
6. an annular ring core centered on an axis; a plurality of bus bars inserted into the inner circumferential side of the ring core; A filter device comprising: The bus bar is a first member extending in the axial direction; a second member formed integrally with the first member and extending from both axial end portions of the first member in a direction intersecting the axis; a third member formed integrally with the second member and extending from an end of the second member so as to face the first member; and the third member is connected to the third member of another bus bar that is disposed so as to be shifted in the axial direction, A filter device in which the ring core is located between the third members that are connected to each other in the axial direction.
Citation Information
Patent Citations
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JP2018157747A