Noise filter

Abstract

According to the present invention, an edgewise coil is maintained in a state of being wound around a core, without performing high-temperature processing.　This noise filter is provided with a core (10) having a form in which an upper flange portion (12) and a lower flange portion (13) are disposed at both axial ends of a shaft portion (11), and a first edgewise coil (22A) and a second edgewise coil (22B) that are disposed so as to coaxially surround the shaft portion (11), wherein at least a portion of each of the first edgewise coil (22A) and the second edgewise coil (22B) overlaps the upper flange portion (12) and the lower flange portion (13) when the shaft portion (11) is viewed in the axial direction.

Description

Noise Filter

[0001] The present disclosure relates to noise filters.

[0002] Patent Document 1 discloses a noise filter in which a common mode inductance made up of an iron core and a coil is housed in a case.

[0003] JP 2008-193814 A

[0004] One possible method for fixing the coil to the iron core in this type of noise filter is to inject molten thermosetting resin into the case and use the solidified thermosetting resin to position the iron core and coil. However, if the case contains components that deteriorate in high-temperature environments, such as film capacitors, the method of injecting molten thermosetting resin cannot be used.

[0005] The noise filter of the present disclosure was developed based on the above circumstances, and aims to maintain an edgewise coil wound around a core without high-temperature treatment.

[0006] The noise filter of the present disclosure comprises a core having a pair of flange portions disposed at both axial ends of a shaft portion, and an edgewise coil disposed so as to coaxially surround the shaft portion, wherein at least a portion of the edgewise coil overlaps with the pair of flange portions when viewed in the axial direction of the shaft portion.

[0007] According to the present disclosure, the edgewise coil can be maintained in a wound state around the core without high-temperature treatment.

[0008] FIG. 1 is a perspective view of a noise filter of Example 1. FIG. 2 is a plan view of the noise filter. FIG. 3 is a front view of the noise filter. FIG. 4 is a left side view of the noise filter. FIG. 5 is a cross-sectional view taken along line XX in FIG. 2. FIG. 6 is a cross-sectional view taken along line YY in FIG. 3.

[0009] [Description of Embodiments of the Present Disclosure] First, embodiments of the present disclosure will be listed and described. Any combination of the following multiple embodiments within a range that does not cause contradictions is also included in the embodiments for carrying out the invention.

[0010] The noise filter of the present disclosure includes: (1) a core having a pair of flange portions disposed at both axial ends of a shaft portion; and an edgewise coil disposed to coaxially surround the shaft portion, wherein at least a portion of the edgewise coil overlaps with the pair of flange portions when viewed in the axial direction of the shaft portion. According to the configuration of the present disclosure, at least a portion of the edgewise coil is disposed so as to be sandwiched between the pair of flange portions, so there is no risk of the edgewise coil coming off the core in the axial direction. Therefore, according to the present disclosure, the coil can be maintained wound around the core without high-temperature treatment.

[0011] (2) In (1), the flange portion preferably has a protrusion that presses the edgewise coil in the axial direction. With this configuration, rattle of the edgewise coil in the axial direction relative to the core can be prevented.

[0012] (3) In (1) or (2), the core is preferably arranged with the axial direction facing up and down, and the lower flange portion of the pair of flange portions is preferably large enough to overlap the entire edgewise coil as viewed in the axial direction. With this configuration, the edgewise coil can be stably placed on the lower flange portion.

[0013] (4) In (1) or (2), it is preferable that the edgewise coil is elastically deformable in the radial direction, and that at least one of the pair of flange portions is large enough to overlap only an inner peripheral region of the edgewise coil when viewed in the axial direction. With this configuration, the edgewise coil can be easily inserted inside one of the flange portions.

[0014] (5) In (1) or (2), it is preferable that the shaft portion and the edgewise coil have a non-circular shape when viewed in the axial direction. With this configuration, it is possible to prevent the edgewise coil from rotating relative to the core.

[0015] (6) In (1) or (2), the edgewise coil preferably includes a first edgewise coil and a second edgewise coil made of a single rectangular wire, the first coil portion of the first edgewise coil and the second coil portion of the second edgewise coil being coaxially arranged in a common axial region, the first coil portion and the second coil portion being connected at their base ends in the axial direction, one end of the rectangular wire functioning as a first connecting terminal extending from the first coil portion at its tip end in the axial direction, and the other end of the rectangular wire functioning as a second connecting terminal extending from the second coil portion at its tip end in the axial direction. According to the configuration of the present disclosure, a double coil is formed using a single rectangular wire, the first coil portion and the second coil portion being connected to each other at their base ends in the axial direction. This makes it possible to position the first terminal connection portion and the second terminal connection portion, which are both ends of the flat wire, at the axial tip (one end) of the first coil portion and the second coil portion without extending the length of the flat wire that constitutes the first edgewise coil and the second edgewise coil.

[0016] (7) In (6), it is preferable that the first connection terminal abuts against the second coil portion in the axial direction, and the second connection terminal abuts against the first coil portion in the axial direction. Because the thickness direction of the flat wire in the first coil portion and the second coil portion is oriented in the axial direction, they can elastically deform individually to expand in the axial direction. If the first coil portion and the second coil portion elastically deform in different ways, there is a concern that the magnetic field may become unstable. To address this issue, the first connection terminal abuts against the second coil portion in the axial direction, and the second connection terminal abuts against the first coil portion in the axial direction. This configuration prevents the first coil portion and the second coil portion from elastically deforming in different ways, thereby avoiding magnetic field instability.

[0017] (8) In (7), it is preferable that the first coil portion is disposed radially inward, the second coil portion is disposed radially outward, and the first connection terminal portion abuts against the second coil portion so as to cross the flat wire in the radial direction. With this configuration, when viewed in the axial direction, it is only necessary to lead the first connection terminal portion radially outward without bending it.

[0018] (9) In (6), it is preferable that the first coil portion is disposed radially inward, the second coil portion is disposed radially outward, and the second connection terminal portion is bent radially inward as viewed in the axial direction, thereby contacting the first coil portion. According to this configuration, it is possible to realize a configuration in which the second connection terminal portion is bent to contact the first coil portion.

[0019] (10) In (6), it is preferable that the first connection terminal portion and the second connection terminal portion are arranged at positions that are rotationally symmetric when viewed in the axial direction. With this configuration, the first connection terminal portion and the second connection terminal portion can be arranged at predetermined positions without considering the orientation of the first edgewise coil and the second edgewise coil in the circumferential direction.

[0020] [Details of the Embodiments of the Present Disclosure] [Example 1] A noise filter according to Example 1 embodying the present disclosure will be described with reference to FIGS. 1 to 6. The present invention is not limited to these examples, but is defined by the claims, and includes all modifications within the meaning and scope of the claims. In Example 1, with regard to the front-to-rear direction, the F direction in FIGS. 1, 2, 4, and 6 is defined as the front. With regard to the up-down direction, the H direction in FIGS. 1, 3 to 5 is defined as the up. With regard to the left-to-right direction, the L direction in FIGS. 1 to 3, 5, and 6 is defined as the left. The up-down direction and the axial direction are used synonymously.

[0021] The noise filter of the first embodiment is configured to include one core 10 and one edgewise coil 20. The core 10 is a member made of a magnetic substance such as iron, or a member containing a magnetic material. The core 10 has a prismatic shaft portion 11 and upper and lower flange portions 12 and 13 formed on both axial ends of the shaft portion 11. The core 10 is used with the axis of the shaft portion 11 oriented in the vertical direction.

[0022] In an axial view (plan view) of the core 10 viewed in the axial direction of the shaft portion 11, the shaft portion 11, the upper flange portion 12, and the lower flange portion 13 form a square. The centers of the upper flange portion 12 and the lower flange portion 13 in the axial view coincide with the center of the shaft portion 11. The length of one side of the upper flange portion 12 is greater than the length of one side of the shaft portion 11. The length of one side of the lower flange portion 13 is greater than the length of one side of the upper flange portion 12. Four protrusions 14 are formed on the lower surface of the upper flange portion 12 (the surface facing the lower flange portion 13). The four protrusions 14 are located at the center positions of each side of the upper flange portion 12 in the longitudinal direction.

[0023] The edgewise coil 20 is a single component formed by bending a single rectangular wire 21. The cross-sectional shape of the rectangular wire 21 is a rectangular wire with a relatively large ratio of long sides to short sides. The rectangular wire 21 is a component in which a conductor made of a conductive material such as copper, aluminum, or carbon nanotubes is surrounded by an insulating coating. The rectangular wire 21 is bent to form a square when viewed in the axial direction, with the short side (thickness direction) facing the axial direction (up and down direction). The edgewise coil 20 is arranged to surround the shaft portion 11 when viewed in the axial direction. When viewed from the front of the noise filter, the edgewise coil 20 is arranged to be sandwiched between the upper flange portion 12 and the lower flange portion 13.

[0024] The edgewise coil 20 is composed of a first edgewise coil 22A and a second edgewise coil 22B. When viewed in the axial direction, the first edgewise coil 22A and the second edgewise coil 22B form a square as a whole. More specifically, at the corners of the square, two adjacent sides on the inner circumferential surface that are perpendicular to each other are connected via a quarter-circular arc with a small radius of curvature, and two adjacent sides on the outer circumferential surface that are perpendicular to each other are connected via a quarter-circular arc with a small radius of curvature.

[0025] The first edgewise coil 22A includes a first coil portion 23A and a first connection terminal portion 29A. The first coil portion 23A is a portion of the rectangular wire 21 formed into a spiral shape so as to form a square when viewed in the axial direction. The first coil portion 23A is elastically deformable, expanding in the axial and radial directions. The first coil portion 23A is arranged coaxially with the shaft portion 11, with its inner circumferential surface directly adjacent to and facing the outer circumferential surface of the shaft portion 11. The first coil portion 23A is placed on the upper surface of the lower flange portion 13 across its entire horizontal area. When viewed in the axial direction, the first coil portion 23A includes a first front edge portion 24A, a first rear edge portion 25A, a first right edge portion 26A, and a first left edge portion 27A.

[0026] The first front edge 24A is a portion located in front of the shaft 11 and is formed by stacking portions of the rectangular wire 21 extending in the left-right direction in the axial direction. The first rear edge 25A is a portion located behind the shaft 11 and is formed by stacking portions of the rectangular wire 21 extending in the left-right direction in the axial direction. The first right edge 26A is a portion located to the right of the shaft 11 and is formed by stacking portions of the rectangular wire 21 extending in the front-to-rear direction in the axial direction. The first left edge 27A is a portion located to the left of the shaft 11 and is formed by stacking portions of the rectangular wire 21 extending in the front-to-rear direction in the axial direction.

[0027] The front end of the portion of the rectangular wire 21 constituting the first edgewise coil 22A (first coil portion 23A) located at the bottom of the first left edge portion 27A is defined as a first base end portion 28A. The rectangular wire 21 constituting the first edgewise coil 22A extends spirally from the first base end portion 28A through the first left edge portion 27A, the first rear edge portion 25A, the first right edge portion 26A, and the first front edge portion 24A, and then returns to the first left edge portion 27A.

[0028] The portions of the rectangular wire 21 that make up the first rear edge 25A, the first right edge 26A, and the first left edge 27A are horizontally arranged in a front view and a side view of the noise filter. The portion of the rectangular wire 21 that makes up the first front edge 24A is inclined upward from the right end to the left end in a front view. The portion of the rectangular wire 21 that makes up the first front edge 24A is arranged to connect the front end of the right edge to the front end of the first left edge 27A, which is one step higher than the right edge.

[0029] The portion of the first edgewise coil 22A (flat wire 21) extending from the top of the first rear edge portion 25A is defined as the first connection terminal portion 29A. The first connection terminal portion 29A extends rightward without bending the right end of the first rear edge portion 25A as viewed in the axial direction. The extending end (right end) of the first connection terminal portion 29A is located to the right of the right edge of the lower flange portion 13.

[0030] The square region on the inner periphery of the first coil portion 23A overlaps with the upper flange portion 12 when viewed in the axial direction. In other words, the square region on the inner periphery of the first coil portion 23A is positioned so as to be recessed under the upper flange portion 12. The protrusions 14 of the upper flange portion 12 press against the upper surfaces of the first left edge portion 27A and the first rear edge portion 25A of the uppermost section of the first coil portion 23A. The first coil portion 23A is sandwiched between the lower flange portion 13 and the upper flange portion 12 in the vertical direction by the pressure of the protrusions 14. Therefore, the first coil portion 23A is held in a state in which its movement relative to the core 10 in the vertical direction (axial direction) is restricted.

[0031] The second edgewise coil 22B includes a second coil portion 23B and a second connection terminal portion 29B. The second coil portion 23B is a spiral portion formed from the rectangular wire 21 to form a square shape when viewed in the axial direction. The second coil portion 23B is elastically deformable, expanding in both the axial and radial directions. The second coil portion 23B is arranged coaxially with the shaft portion 11 and the first coil portion 23A, with its inner circumferential surface directly adjacent to and facing the outer circumferential surface of the first coil portion 23A. The entire horizontal area of ​​the second coil portion 23B is placed on the upper surface of the lower flange portion 13. When viewed in the axial direction, the second coil portion 23B includes a second front edge portion 24B, a second rear edge portion 25B, a second right edge portion 26B, and a second left edge portion 27B.

[0032] The second front edge portion 24B is located in front of the first front edge portion 24A and is formed by stacking the left-right extending portions of the rectangular wire 21 in the axial direction. The second rear edge portion 25B is located behind the first rear edge portion 25A and is formed by stacking the left-right extending portions of the rectangular wire 21 in the axial direction. The second right edge portion 26B is located to the right of the first right edge portion 26A and is formed by stacking the front-rear extending portions of the rectangular wire 21 in the axial direction. The second left edge portion 27B is located to the left of the second left edge portion 27B and is formed by stacking the front-rear extending portions of the rectangular wire 21 in the axial direction. The second coil portion 23B does not overlap the upper flange portion 12 throughout its entirety when viewed in the axial direction.

[0033] The front end of the rectangular wire 21 constituting the second edgewise coil 22B (second coil portion 23B) at the bottom of the second left edge 27B is defined as the second base end 28B. The rectangular wire 21 constituting the second edgewise coil 22B extends spirally from the second base end 28B through the second left edge 27B, the second rear edge 25B, the second right edge 26B, and the second front edge 24B, and then returns to the second left edge 27B. At the bottom of the edgewise coil 20, the second base end 28B and the first base end 28A are connected in a U-turn while in contact with the upper surface of the lower flange portion 13.

[0034] The portions of the rectangular wire 21 that form the second rear edge 25B, the second right edge 26B, and the second left edge 27B are horizontally arranged in front and side views. The portion of the rectangular wire 21 that forms the second front edge 24B is inclined upward from the right end to the left end in front view. The portion of the rectangular wire 21 that forms the second front edge 24B is arranged to connect the front end of the second right edge 26B to the front end of the second left edge 27B, which is one step higher than the second right edge 26B.

[0035] The portion of the second edgewise coil 22B (flat wire 21) extending from the second rear edge portion 25B located at the top is defined as the second connection terminal portion 29B. When viewed in the axial direction, the second connection terminal portion 29B bends rearward from the left end of the second front edge portion 24B along the left edge of the upper flange portion 12, then bends leftward from the rear end of the extension and extends away from the upper flange portion 12. The portion of the second connection terminal portion 29B along the left edge of the upper flange portion 12 is positioned to abut against or closely face the uppermost end surface of the first left edge portion 27A from above. Therefore, there is no risk of the first coil portion 23A moving upward relative to the second coil portion 23B. The extending end (left end) of the second connection terminal portion 29B is located to the left of the left edge of the lower flange portion 13.

[0036] The portion of the first connection terminal 29A that protrudes to the right of the upper flange 12 is bent so as to ride on the uppermost end surface of the second right edge 26B in a front view and is disposed so as to abut against or face closely to the rear end of the uppermost end surface of the second right edge 26B from above, thereby preventing the second coil 23B from moving upward relative to the first coil 23A.

[0037] In the axial direction of the core 10 and the edgewise coil 20, the first connection terminal 29A and the second connection terminal 29B are disposed at one end (upper end) of the edgewise coil 20. When viewed in the axial direction, the first connection terminal 29A and the second connection terminal 29B are in a rotationally symmetrical positional relationship. A communication circuit (not shown) that is the target of noise suppression by the noise filter is connected to the first connection terminal 29A and the second connection terminal 29B. One of the first connection terminal 29A and the second connection terminal 29B functions as an input terminal, and the other functions as an output terminal.

[0038] The noise filter of the first embodiment includes a core 10 and an edgewise coil 20. The core 10 has a shaft portion 11 and a pair of flange portions (an upper flange portion 12 and a lower flange portion 13) disposed at both axial ends of the shaft portion 11. The edgewise coil 20 is a member disposed to coaxially surround the shaft portion 11. When viewed in the axial direction of the shaft portion 11, at least a portion of the edgewise coil 20 (an inner peripheral region of the first coil portion 23A) overlaps with the upper flange portion 12 and the lower flange portion 13. With this configuration, at least a portion of the edgewise coil 20 is disposed so as to be sandwiched between the pair of flange portions (the upper flange portion 12 and the lower flange portion 13), and therefore there is no risk of the edgewise coil 20 detaching from the core 10 in the axial direction. Therefore, according to the first embodiment, the edgewise coil 20 can be maintained in a state where it is wound around the core 10 without performing high-temperature treatment such as injecting a molten thermosetting resin.

[0039] The upper flange 12 has a protrusion 14 that presses against the first coil portion 23A in the axial direction. This configuration can prevent the first coil portion 23A from rattling relative to the core 10 in the axial direction.

[0040] The core 10 is disposed with its axis oriented in the vertical direction. When viewed in the axial direction, the lower flange portion 13 of the pair of flange portions is large enough to overlap the entire first coil portion 23A and the entire second coil portion 23B. With this configuration, the first edgewise coil 22A (first coil portion 23A) and the second edgewise coil 22B (second coil portion 23B) can be stably placed on the lower flange portion 13.

[0041] The first coil portion 23A and the second coil portion 23B are elastically deformable in the radial direction. When viewed in the axial direction, at least one flange portion (the upper flange portion 12) of the pair of flange portions (the upper flange portion 12 and the lower flange portion 13) is sized to overlap only the inner peripheral region of the first coil portion 23A. With this configuration, when attaching the edgewise coil 20 to the core 10, the first coil portion 23A can be easily inserted into the space below the upper flange portion 12 (the space between the upper flange portion 12 and the lower flange portion 13).

[0042] When viewed in the axial direction, the shaft portion 11, the first coil portion 23A, and the second coil portion 23B are non-circular. This configuration prevents the first edgewise coil 22A and the second edgewise coil 22B from rotating relative to the core 10.

[0043] The edgewise coil 20 includes a first edgewise coil 22A and a second edgewise coil 22B, each made of a single rectangular wire 21. That is, the noise filter includes the first edgewise coil 22A and the second edgewise coil 22B, each made of a single rectangular wire 21. The first coil portion 23A of the first edgewise coil 22A and the second coil portion 23B of the second edgewise coil 22B are coaxially arranged and located in a common axial region. The first coil portion 23A and the second coil portion 23B are connected at their axial base ends (first base end 28A and second base end 28B). One of the ends of the rectangular wire 21 functions as a first connection terminal 29A extending from the first coil portion 23A at the axial tip end (the upper end of the edgewise coil 20). The other end of the rectangular wire 21 functions as a second connection terminal 29B extending from the second coil portion 23B at the upper end of the edgewise coil 20.

[0044] According to this configuration, a double coil consisting of the first coil portion 23A and the second coil portion 23B connected to each other at the base end in the axial direction is formed by using a single rectangular wire 21. This makes it possible to arrange the first and second terminal connection portions, which are both ends of the rectangular wire 21, at the axial tip ends (one end) of the first coil portion 23A and the second coil portion 23B without extending the length of the rectangular wire 21 that constitutes the first edgewise coil 22A and the second edgewise coil 22B.

[0045] Because the thickness direction of the flat wire 21 is oriented in the axial direction, the first coil portion 23A and the second coil portion 23B can elastically deform independently, stretching in the axial direction. If the first coil portion 23A and the second coil portion 23B elastically deform in different ways, there is a concern that the magnetic field may become unstable. To address this issue, the first connection terminal portion 29A is axially abutted against the uppermost end surface of the second coil portion 23B, and the second connection terminal portion 29B is axially abutted against the uppermost end surface of the first coil portion 23A. This configuration prevents the first coil portion 23A and the second coil portion 23B from elastically deforming in different ways, thereby avoiding magnetic field instability.

[0046] The first coil portion 23A is disposed radially inward, and the second coil portion 23B is disposed radially outward relative to the first coil portion 23A. The first connection terminal portion 29A abuts against the second coil portion 23B so as to cross the rectangular wire 21 in the radial direction. With this configuration, when viewed in the axial direction, the first connection terminal portion 29A only needs to be led out radially outward without being bent. The second connection terminal portion 29B abuts against the first coil portion 23A by being bent radially inward when viewed in the axial direction. With this configuration, a configuration in which the second connection terminal portion 29B abuts against the first coil portion 23A can be realized by bending the second connection terminal portion 29B.

[0047] The first connection terminal 29A and the second connection terminal 29B are arranged at positions that are rotationally symmetric when viewed in the axial direction. With this configuration, the first connection terminal 29A and the second connection terminal 29B can be arranged at predetermined positions without considering the circumferential orientation of the first edgewise coil 22A and the second edgewise coil 22B.

[0048] [Other Examples] The present invention is not limited to the examples described above and illustrated in the drawings, but is defined by the claims. The present invention includes the meaning equivalent to the claims and all modifications within the scope of the claims, including the following embodiments.

[0049] The protrusions may be provided on both of the pair of flanges (upper flange and lower flange). The first edgewise coil and the second edgewise coil may be relatively displaceable in the axial direction with respect to the core. The lower flange may be sized to overlap only a portion (inner peripheral region) of the second coil portion when viewed in the axial direction. The upper flange may be sized to overlap the entire first coil portion, the inner peripheral region of the second coil portion, or the entire second coil portion when viewed in the axial direction. The shapes of the outer peripheral surfaces of the shaft portion, the first coil portion, and the second coil portion are not limited to squares and may include polygons other than squares, trapezoids, circles, and curved shapes. The first connection terminal may have a bent shape when viewed in the axial direction. The first coil portion and the second coil portion may be arranged so that the flat wires of both coil portions alternate in the axial direction. The first connection terminal and the second connection terminal may be arranged in positions other than rotational symmetry.

[0050] REFERENCE SIGNS LIST 10...Core 11...Shaft portion 12...Upper flange portion (flange portion, one flange portion) 13...Lower flange portion (flange portion, lower flange portion) 14...Protrusion portion 20...Edgewise coil 21...Rectangular wire 22A...First edgewise coil 22B...Second edgewise coil 23A...First coil portion 23B...Second coil portion 24A...First front edge portion 24B...Second front edge portion 25A...First rear edge portion 25B...Second rear edge portion 26A...First right edge portion 26B...Second right edge portion 27A...First left edge portion 27B...Second left edge portion 28A...First base end portion 28B...Second base end portion 29A...First connection terminal portion 29B...Second connection terminal portion

Claims

1. A noise filter comprising: a core having a pair of flange portions disposed at both axial ends of a shaft portion; and an edgewise coil disposed so as to coaxially surround the shaft portion, wherein at least a portion of the edgewise coil overlaps with the pair of flange portions when viewed in the axial direction of the shaft portion.

2. A noise filter according to claim 1, wherein the flange portion has a protrusion that presses the edgewise coil in the axial direction.

3. A noise filter as described in claim 1 or claim 2, wherein the core is arranged with the axial direction facing up and down, and the lower flange portion of the pair of flange portions is large enough to overlap the entire edgewise coil when viewed in the axial direction.

4. A noise filter as described in claim 1 or claim 2, wherein the edgewise coil is capable of elastically deforming in the radial direction, and when viewed in the axial direction, at least one of the pair of flange portions is sized to overlap only the inner peripheral region of the edgewise coil.

5. A noise filter according to claim 1 or 2, wherein the shaft portion and the edgewise coil are non-circular when viewed in the axial direction.

6. A noise filter as claimed in claim 1 or 2, wherein the edgewise coil includes a first edgewise coil and a second edgewise coil made of a single flat wire, the first coil portion of the first edgewise coil and the second coil portion of the second edgewise coil are arranged coaxially with each other and in a common area in the axial direction, the first coil portion and the second coil portion are connected at their base ends in the axial direction, one of the two ends of the flat wire functions as a first connecting terminal portion extending from the first coil portion at its tip end in the axial direction, and the other end of the flat wire functions as a second connecting terminal portion extending from the second coil portion at its tip end in the axial direction.

7. A noise filter according to claim 6, wherein the first connection terminal abuts against the second coil portion in the axial direction, and the second connection terminal abuts against the first coil portion in the axial direction.

8. A noise filter as described in claim 7, wherein the first coil portion is arranged radially inward, the second coil portion is arranged radially outward, and the first connection terminal portion abuts against the second coil portion so as to cross the flat wire in the radial direction.

9. A noise filter as described in claim 6, wherein the first coil portion is arranged radially inward, the second coil portion is arranged radially outward, and the second connection terminal portion abuts against the first coil portion by forming a shape that is bent radially inward when viewed in the axial direction.

10. A noise filter according to claim 6, wherein the first connection terminal portion and the second connection terminal portion are arranged in positions that are rotationally symmetrical when viewed in the axial direction.

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