Noise filter

Abstract

In the present invention, both ends of a rectangular wire which forms an edgewise coil are arranged at one end in the axial direction without extending the length of the rectangular wire.　A first edgewise coil (22A) and a second edgewise coil (22B) are composed of only one rectangular wire (21). A first coil part (23A) and a second coil part (23B) are arranged coaxially with each other and are arranged in a common region in the axial direction. A first base end (28A) of the first coil part (23A) in the axial direction and a second base end (28B) of the second coil part (23B) in the axial direction are connected to each other. A first connection terminal part (29A) is formed in a manner extending from the leading end of the first coil part (23A) in the axial direction, and a second connection terminal part (29B) is formed in a manner extending from the leading end of the second coil part (23B) 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 one end of an insulated electric wire constituting a coil member extends to one side in the axial direction of the coil member, and the other end of the insulated electric wire extends to the other side in the axial direction. Both ends of the coil member function as a current input terminal and a current output terminal.

[0003] Japanese Patent Application Laid-Open No. 2016-076565

[0004] Depending on the wiring configuration of the circuit connected to the noise filter, it may be necessary to arrange both the input terminal and the output terminal at one end of the coil member in the axial direction. In this case, one of the input and output terminals must make a U-turn and extend to the vicinity of the other terminal, which results in a longer insulated wire constituting the coil member.

[0005] The noise filter of the present disclosure was completed based on the above circumstances, and aims to position both ends of the flat wire that constitutes the edgewise coil at one end in the axial direction of the edgewise coil without extending the length of the flat wire.

[0006] The noise filter of the present disclosure comprises: a first edgewise coil having a first coil portion and a first connection terminal portion; and a second edgewise coil having a second coil portion and a second connection terminal portion, wherein the first edgewise coil and the second edgewise coil are formed from only a single flat wire, the first coil portion and the second coil portion are arranged coaxially with each other and are arranged in a common area in the axial direction, a first base end portion in the axial direction of the first coil portion and a second base end portion in the axial direction of the second coil portion are connected to each other, the first connection terminal portion extends from a tip end portion in the axial direction of the first coil portion, and the second connection terminal portion extends from the tip end portion in the axial direction of the second coil portion.

[0007] According to the present disclosure, both ends of the rectangular wire can be arranged at one end in the axial direction of the edgewise coil.

[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 X-X in FIG. 2. FIG. 6 is a cross-sectional view taken along line Y-Y in FIG. 3. FIG. 7 is a perspective view of a noise filter of Example 2.

[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 comprises: (1) a first edgewise coil having a first coil portion and a first connection terminal portion, and a second edgewise coil having a second coil portion and a second connection terminal portion, wherein the first edgewise coil and the second edgewise coil are formed using only a single flat wire, the first coil portion and the second coil portion are arranged coaxially with each other and in a common area in the axial direction, a first base end in the axial direction of the first coil portion and a second base end in the axial direction of the second coil portion are connected to each other, the first connection terminal portion extends from a tip end in the axial direction of the first coil portion, and the second connection terminal portion extends from the tip end in the axial direction of the second coil portion.

[0011] The noise filter of the present disclosure uses a single rectangular wire to form a double coil consisting of a first coil portion and a second coil portion connected to each other at their axial base ends, thereby realizing that the first and second connection terminal portions, which are both ends of the rectangular wire, can be located at the axial tip ends (one end) of the first and second coil portions without unnecessarily extending the length of the rectangular wire that forms the first edgewise coil and the second edgewise coil.

[0012] (2) In (1), 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.

[0013] (3) In (2), 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 rectangular wire. With this configuration, when the first coil portion and the second coil portion are viewed in the axial direction, the first connection terminal portion can be led out radially outward without being bent.

[0014] (4) In (2) or (3), 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 to abut against the first coil portion. According to this configuration, a configuration in which the second connection terminal portion abuts against the first coil portion can be realized by bending the second connection terminal portion.

[0015] (5) In (1) or (2), 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 circumferential orientation of the first edgewise coil and the second edgewise coil.

[0016] (6) In any of (1) to (3), the core preferably includes a pair of flanges disposed at both axial ends of a shaft portion, the first coil portion and the second coil portion are disposed so as to coaxially surround the shaft portion, and at least a portion of the first coil portion and the second coil portion overlaps with the pair of flanges when viewed in the axial direction. According to the configuration of the present disclosure, at least a portion of the first coil portion and the second coil portion are disposed so as to be sandwiched between the pair of flanges, so there is no risk of the first coil portion or the second coil portion coming off the core in the axial direction. Therefore, according to the present disclosure, the first coil portion and the second coil portion can be maintained wound around the core without high-temperature treatment.

[0017] (7) In (6), the flange portion preferably has a protrusion that presses the first coil portion or the second coil portion in the axial direction. This configuration can prevent the first coil portion or the second coil portion from rattling in the axial direction relative to the core.

[0018] (8) In (6), it is preferable that the core is arranged with the axial direction facing up and down, and that the lower flange portion of the pair of flange portions has a size that overlaps the entire first coil portion and the entire second coil portion when viewed in the axial direction. With this configuration, the first coil portion and the second coil portion can be stably placed on the lower flange portion.

[0019] (9) In (6), it is preferable that the first coil portion and the second coil portion are elastically deformable in the radial direction, and at least one of the pair of flange portions is sized to overlap only an inner peripheral region of the first coil portion or the second coil portion when viewed in the axial direction. With this configuration, the first coil portion or the second coil portion can be easily slipped under at least one of the flange portions.

[0020] (10) In (6), the shaft portion, the first coil portion, and the second coil portion may have a non-circular shape when viewed in the axial direction. With this configuration, it is possible to prevent the first edgewise coil and the second edgewise coil from rotating relative to the core.

[0021] [Details of the Embodiments of the Present Disclosure] [Example 1] A noise filter 1 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, the F direction in FIGS. 1, 2, 4, and 6 is defined as the front. The H direction in FIGS. 1, 3 to 5 is defined as the up. The L direction in FIGS. 1 to 3, 5, and 6 is defined as the left. The up and down direction and the axial direction are used interchangeably.

[0022] The noise filter 1 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, an upper flange portion 12 formed at the upper end of the shaft portion 11 in the axial direction, and a lower flange portion 13 formed at the lower end of the shaft portion 11 in the axial direction. The core 10 is used with its axis oriented in the vertical direction.

[0023] 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.

[0024] 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 so that its short side (thickness direction) faces the axial direction (vertical direction) and forms a square when viewed in the axial 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 1, the edgewise coil 20 is arranged to be sandwiched between the upper flange portion 12 and the lower flange portion 13.

[0025] 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 straight 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 straight 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.

[0026] 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 direction. 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.

[0027] 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.

[0028] 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.

[0029] The portions of the rectangular wire 21 that form the first rear edge 25A, the first right edge 26A, and the first left edge 27A are horizontally arranged in a front view and in a side view of the noise filter 1. The portion of the rectangular wire 21 that forms the first front edge 24A is inclined upward from the right end toward the left end in a front view. The portion of the rectangular wire 21 that forms 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.

[0030] 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.

[0031] 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.

[0032] 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 of the rectangular wire 21 formed to form a square shape when viewed in the axial direction. The second coil portion 23B is elastically deformable, expanding in the axial direction. 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] The first connection terminal 29A and the second connection terminal 29B are disposed at one end (upper end) in the axial direction of the core 10 and the edgewise coil 20. When viewed in the axial direction, the first connection terminal 29A and the second connection terminal 29B are rotationally symmetrical. A communication circuit (not shown) that is the target of noise suppression by the noise filter 1 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.

[0039] The noise filter 1 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 (the 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 sandwiched between the pair of flange portions (the upper flange portion 12 and the lower flange portion 13), so 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 wound around the core 10 without high-temperature treatment.

[0040] 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.

[0041] 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.

[0042] 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 slipped under the upper flange portion 12.

[0043] 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.

[0044] The noise filter 1 includes a first edgewise coil 22A and a second edgewise coil 22B. The first edgewise coil 22A includes a first coil portion 23A and a first connection terminal portion 29A. The second edgewise coil 22B includes a second coil portion 23B and a second connection terminal portion 29B. The first edgewise coil 22A and the second edgewise coil 22B are formed using only a single rectangular wire 21. The first coil portion 23A and the second coil portion 23B are coaxially arranged and located in a common axial region. A first base end portion 28A of the first coil portion 23A in the axial direction and a second base end portion 28B of the second coil portion 23B in the axial direction are connected to each other. The first connection terminal portion 29A extends from the axial tip (upper end) of the first coil portion 23A. The second connection terminal portion 29B extends from the tip end (upper end) of the second coil portion 23B in the axial direction.

[0045] The noise filter 1 of the first embodiment forms a double coil consisting of a first coil portion 23A and a second coil portion 23B that are connected to each other at their axial base ends by using a single rectangular wire 21. This makes it possible to position both the first connection terminal portion 29A and the second connection terminal portion 29B, 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 unnecessarily extending the length of the rectangular wire 21 that forms the first edgewise coil 22A and the second edgewise coil 22B.

[0046] 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.

[0047] 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 second coil portion 23B is disposed so as to surround the first coil portion 23A when viewed in the axial direction. The first connection terminal portion 29A abuts against the second coil portion 23B so as to cross the rectangular wire 21. With this configuration, the first connection terminal portion 29A can be extended radially outward without bending when viewed in the axial direction. The second connection terminal portion 29B abuts against the first coil portion 23A by forming a shape that is 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.

[0048] 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.

[0049] A noise filter 2 according to a second embodiment of the present disclosure will be described with reference to Fig. 7. In this second embodiment, the F direction in Fig. 7 is defined as the front with respect to the front-to-rear direction. The H direction in Fig. 7 is defined as the top with respect to the top-to-bottom direction. The L direction in Fig. 7 is defined as the left with respect to the left-to-right direction.

[0050] The noise filter 2 of the second embodiment is configured to include one core 40 and one edgewise coil 50. The core 40 is a member made of a magnetic substance such as iron, or a single component containing a magnetic material. The core 40 has a prismatic shaft portion 41 and a flange portion 42 formed at the lower end of the shaft portion 41 in the axial direction. The core 40 is used with its axis oriented vertically. In an axial view (plan view) of the core 40 viewed in the axial direction of the shaft portion 41, the shaft portion 41 and the flange portion 42 form a concentric square.

[0051] The edgewise coil 50 is a single component formed by bending a single rectangular wire 60 (not shown). The cross-sectional shape of the rectangular wire 60 is a rectangular wire with a relatively large ratio of long sides to short sides. The rectangular wire 60 may consist of only a conductor, or may be a conductor surrounded by an insulating coating. The rectangular wire 60 has a folded portion 63, a first extending portion 61 extending from the folded portion 63, and a second extending portion 62 extending from the folded portion 63. The folded portion 63 is a portion where the rectangular wire 60 is bent in the thickness direction (short side direction). The first extending portion 61 and the second extending portion 62 extend parallel to each other, with the second extending portion 62 overlapping the first extending portion 61. The first extending portion 61 and the second extending portion 62 constitute a single deemed strand 64.

[0052] The edgewise coil 50 has one coil main body 52, a first connection terminal 58A, and a second connection terminal 58B. The coil main body 52 has a square shape when viewed in the axial direction and is disposed so as to surround the shaft portion 41 while being placed on the flange portion 42. The edgewise coil 50 is composed of a first edgewise coil 51A and a second edgewise coil 51B. The first edgewise coil 51A has a first coil portion 53A and a first connection terminal 58A. The second edgewise coil 51B has a second coil portion 53B and a second connection terminal 58B.

[0053] The first coil portion 53A and the second coil portion 53B form a square coil main body 52. ​​The coil main body 52 is formed by extending a wire 64 in a spiral shape from a folded portion 63. The first coil portion 53A is formed by a first extending portion 61. The second coil portion 53B is formed by a second extending portion 62. A first base end portion 59A (lower end portion) in the axial direction (vertical direction) of the first coil portion 53A and a second base end portion 59B (lower end portion) in the axial direction (vertical direction) of the second coil portion 53B are connected at the folded portion 63. In the coil main body 52, the first extending portions 61 and the second extending portions 62 are arranged so as to be alternately stacked in the axial direction. The first extending portions 61 of the first coil portion 53A and the second extending portions 62 of the second coil portion 53B alternately overlap in the axial direction. Therefore, it is difficult for the first coil portion 53A and the second coil portion 53B to elastically deform separately from each other in the axial direction.

[0054] The coil main body 52 has a front edge 54, a rear edge 55, a right edge 56, and a left edge 57. The front edge 54 is a portion located in front of the shaft 41 and is formed by stacking portions of the assumed wires 64 that extend in the left-right direction in the axial direction. The rear edge 55 is a portion located behind the shaft 41 and is formed by stacking portions of the assumed wires 64 that extend in the left-right direction in the axial direction. The right edge 56 is a portion located to the right of the shaft 41 and is formed by stacking portions of the assumed wires 64 that extend in the front-rear direction in the axial direction. The left edge 57 is a portion located to the left of the shaft 41 and is formed by stacking portions of the assumed wires 64 that extend in the front-rear direction in the axial direction.

[0055] The folded portion 63 of the rectangular wire 60 constitutes the base end of the assumed wire 64. The folded portion 63 (base end of the assumed wire 64) is located at the lowest stage on the right end of the left edge 57. The assumed wire 64 extends spirally, repeating a path from the folded portion 63 (base end) through the left edge 57, the rear edge 55, the right edge 56, the front edge 54, and back to the left edge 57.

[0056] The portions of the assumed wire 64 that form the rear edge 55, right edge 56, and left edge 57 are arranged horizontally in a front view and in a side view of the noise filter 2. The portion of the assumed wire 64 that forms the front edge 54 is inclined so as to become higher from the right end toward the left end in a front view. The portion of the assumed wire 64 that forms the front edge 54 is arranged to connect the front end of the right edge 56 to the front end of the left edge 57, which is one step higher than the right edge 56.

[0057] The first extension 61 is disposed around the entire circumference of the uppermost coil body 52. ​​The portion of the assumed wire 64 (flat wire 60) that extends from the rear end of the left edge 57 of the uppermost first extension 61 is defined as the first connection terminal 58A. When viewed in the axial direction, the first connection terminal 58A extends linearly rearward from the rear end of the left edge 57 without bending. The uppermost second extension 62 of the assumed wire 64 (flat wire 60) is disposed adjacent to and below the uppermost first extension 61. The portion of the assumed wire 64 that extends from the front end of the right edge 56 of the uppermost second extension 62 is defined as the second connection terminal 58B. When viewed in the axial direction, the second connection terminal 58B extends linearly forward from the front end of the right edge 56 without bending.

[0058] The first connection terminal 58A and the second connection terminal 58B are disposed at one end (upper end) of the core 40 and the coil body 52 (edgewise coil 50) in the axial direction. When viewed in the axial direction, the first connection terminal 58A and the second connection terminal 58B are rotationally symmetrical. A communication circuit (not shown) that is the target of noise suppression by the noise filter 2 is connected to the first connection terminal 58A and the second connection terminal 58B. One of the first connection terminal 58A and the second connection terminal 58B functions as an input terminal, and the other functions as an output terminal.

[0059] The noise filter 2 of the second embodiment includes a first edgewise coil 51A having a spiral-shaped first coil portion 53A and a second edgewise coil 51B having a second coil portion 53B arranged coaxially with the first coil portion 53A. The first edgewise coil 51A and the second edgewise coil 51B are formed from a single rectangular wire 60. The rectangular wire 60 has a folded portion 63 and a pair of extending portions (a first extending portion 61 and a second extending portion 62) extending parallel to and adjacent to each other from the folded portion 63. The first extending portion 61 constitutes the first coil portion 53A, and the second extending portion 62 constitutes the second coil portion 53B.

[0060] In the second embodiment, the first and second extending portions 61 and 62 constituting the coaxially arranged first and second coil portions 53A and 53B are adjacent to and parallel to each other in the axial direction (vertical direction). Therefore, the first and second coil portions 53A and 53B function as a single coil main body 52 in which the first and second extending portions 61 and 62 are spirally wound as a single assumed wire 64. Because the assumed wire 64 is made of a rectangular wire 60, the coil main body 52 has less dead space even if the cross-sectional area of ​​the assumed wire 64 is increased, compared to a coil made of a wire with a circular cross section. Therefore, the second embodiment can improve shielding performance without increasing dead space.

[0061] Because the single assumed wire 64 has a divided structure consisting of two extending portions (the first extending portion 61 and the second extending portion 62), the process of forming the assumed wire 64 into a spiral can be performed separately on the first extending portion 61 and the second extending portion 62. The cross-sectional area of ​​the first extending portion 61 is smaller than that of the single assumed wire 64, and the cross-sectional area of ​​the second extending portion 62 is smaller than that of the assumed wire 64. Therefore, compared to bending a single rectangular wire having the same cross-sectional area as the single assumed wire 64 into a spiral, the noise filter 2 shown in this Example 2 has an easier process of bending the flat wire 60 (the first extending portion 61 and the second extending portion 62) into a spiral.

[0062] The first edgewise coil 51A has a first connection terminal 58A that is continuous with the extending end of the first extending portion 61 and protrudes from the coil main body 52 (first coil portion 53A). The second edgewise coil 51B has a second connection terminal 58B that is continuous with the extending end of the second extending portion 62 and protrudes from the coil main body 52 (second coil portion 53B). The first connection terminal 58A and the second connection terminal 58B are continuous with a pair of extending portions (first extending portion 61 and second extending portion 62) that extend from the folded portion 63 adjacent to and parallel to each other in the axial direction. This makes it possible to arrange the first connection terminal 58A and the second connection terminal 58B at one end (upper end) of the coil main body 52 (first coil portion 53A and second coil portion 53B) in the axial direction.

[0063] The first connection terminal 58A and the second connection terminal 58B are arranged at positions that are rotationally symmetric when viewed in the axial direction of the coil main body 52 (the first coil portion 53A and the second coil portion 53B). With this configuration, the first connection terminal 58A and the second connection terminal 58B can be arranged at predetermined positions without considering the circumferential orientation of the first edgewise coil 51A and the second edgewise coil 51B.

[0064] The pair of extension portions includes a first extension portion 61 constituting the first coil portion 53A and a second extension portion 62 constituting the second coil portion 53B. The first extension portions 61 and the second extension portions 62 are arranged alternately in the axial direction of the coil main body portion 52 (the first coil portion 53A and the second coil portion 53B). With this configuration, when the coil main body portion 52 (the first coil portion 53A and the second coil portion 53B) is viewed in the axial direction, the projected area of ​​the coil main body portion 52 (the first coil portion 53A and the second coil portion 53B) can be reduced, thereby saving space.

[0065] The noise filter 2 of the second embodiment includes a first edgewise coil 51A and a second edgewise coil 51B. The first edgewise coil 51A includes a first coil portion 53A and a first connection terminal portion 58A. The second edgewise coil 51B includes a second coil portion 53B and a second connection terminal portion 58B. The first edgewise coil 51A and the second edgewise coil 51B are formed using only a single rectangular wire 60. The first coil portion 53A and the second coil portion 53B are coaxially arranged and are located in a common area in the axial direction (up and down). A first base end portion 59A of the first coil portion 53A in the axial direction and a second base end portion 59B of the second coil portion 53B in the axial direction are connected to each other. The first connection terminal portion 58A extends from the axial tip (upper end) of the first coil portion 53A. The second connection terminal portion 58B extends from the axial tip (upper end) of the second coil portion 53B.

[0066] According to the noise filter 2 of the second embodiment, a double coil is formed by using a single rectangular wire 60, with the first coil portion 53A and the second coil portion 53B connected to each other at their axial base ends (first base end 59A and second base end 59B). This makes it possible to arrange the first and second connection terminal portions 58A and 58B, which are both ends of the rectangular wire 60, at the axial tip ends (one end) of the first coil portion 53A and the second coil portion 53B without extending the length of the rectangular wire 60 that constitutes the first edgewise coil 51A and the second edgewise coil 51B.

[0067] Because the thickness direction of the flat wire 60 is oriented in the axial direction, the first coil portion 53A and the second coil portion 53B can elastically deform individually, stretching in the axial direction. If the first coil portion 53A and the second coil portion 53B 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 58A abuts against the second coil portion 53B in the axial direction, and the second connection terminal portion 58B abuts against the first coil portion 53A in the axial direction. This configuration prevents the first coil portion 53A and the second coil portion 53B from elastically deforming in different ways, thereby avoiding magnetic field instability.

[0068] Because the direction of the current flowing through the first coil portion 53A is opposite to that of the current flowing through the second coil portion 53B, the magnetic field generated by the current flowing through the first coil portion 53A and the magnetic field generated by the current flowing through the second coil portion 53B cancel each other out. Therefore, the current (signal) flowing through the coil main body 52 is less susceptible to the influence of noise from outside the noise filter 2.

[0069] [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.

[0070] In Examples 1 and 2, the first connection terminal portion may have a bent shape when viewed in the axial direction. In Examples 1 and 2, the first connection terminal portion and the second connection terminal portion may be arranged in positions other than rotationally symmetric. In Examples 1 and 2, the first edgewise coil and the second edgewise coil may be displaceable relative to the core in the axial direction. In Examples 1 and 2, the noise filter may not have a core. In Examples 1 and 2, the shape of the outer circumferential surface of the axial portion of the core, the shape of the first coil portion, and the shape of the second coil portion are not limited to a square, and may be a polygon other than a square, a trapezoid, a circle, or a shape including a curved surface. In Example 1, the protrusion portion may be provided on both of the pair of flange portions (upper flange portion and lower flange portion). In Example 1, the lower flange portion may be sized to overlap only a portion (inner peripheral region) of the second coil portion when viewed in the axial direction. In Example 1, the upper flange portion may be large enough 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. In Example 2, an upper flange portion may be provided at the upper end of the core so as to overlap the entire coil main body portion or a part of the coil main body portion when viewed in a plan view.

[0071] REFERENCE SIGNS LIST 1...Noise filter 2...Noise filter 10...Core 11...Shaft portion 12...Upper flange portion (flange portion, one flange portion) 13...Lower flange portion (flange portion, lower flange portion) 14...Projection 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 40...Core 41...Shaft portion 42...Flange portion 50...Edgewise coil 51A...First edgewise coil 51B...Second edgewise coil 52...Coil main body portion 53A...First coil portion 53B...Second coil portion 54...Front edge portion 55...Rear edge portion 56...Right edge portion 57...Left edge portion 58A...First connection terminal portion 58B...Second connection terminal portion 59A...First base end portion 59B...Second base end portion 60...Rectangular wire 61...First extension portion (extension portion, one extension portion) 62...Second extension portion (extension portion, other extension portion) 63...Folded portion 64...Elemental wire

Claims

1. A noise filter comprising: a first edgewise coil having a first coil portion and a first connection terminal portion; and a second edgewise coil having a second coil portion and a second connection terminal portion, wherein the first edgewise coil and the second edgewise coil are formed from only a single flat wire, the first coil portion and the second coil portion are arranged coaxially with each other and are arranged in a common area in the axial direction, a first base end in the axial direction of the first coil portion and a second base end in the axial direction of the second coil portion are connected to each other, the first connection terminal portion extends from a tip end in the axial direction of the first coil portion, and the second connection terminal portion extends from the tip end in the axial direction of the second coil portion.

2. A noise filter according to claim 1, 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.

3. A noise filter as described in claim 2, 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.

4. A noise filter as described in claim 2 or claim 3, 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.

5. A noise filter according to claim 1 or claim 2, wherein the first connection terminal portion and the second connection terminal portion are arranged in positions that are rotationally symmetric when viewed in the axial direction.

6. A noise filter according to any one of claims 1 to 3, comprising a core in the form of a pair of flange portions disposed at both axial ends of a shaft portion, the first coil portion and the second coil portion being disposed so as to coaxially surround the shaft portion, and at least a portion of the first coil portion and the second coil portion overlapping with the pair of flange portions when viewed in the axial direction.

7. A noise filter according to claim 6, wherein the flange portion has a protrusion that presses against the first coil portion or the second coil portion in the axial direction.

8. A noise filter as described in claim 6, 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 first coil portion and the entire second coil portion when viewed in the axial direction.

9. A noise filter as described in claim 6, wherein the first coil portion and the second coil portion are 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 first coil portion or the second coil portion.

10. The noise filter according to claim 6, wherein the shaft portion, the first coil portion, and the second coil portion are non-circular when viewed in the axial direction.

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