Coil device

Abstract

This invention provides a coil device that can be mounted on a circuit board, comprising: a coil having a winding portion and a lead wire extending from the winding portion; and a plate portion positioned relative to the coil. The plate portion includes: a main body portion; a cylindrical portion formed on one surface of the main body portion; and a through hole penetrating the cylindrical portion and the main body portion. The end of the lead wire can pass through the through hole. In this coil device, the movement of the lead wire within the through hole is restricted by the through hole, such that the end of the lead wire passing through the through hole is positioned. In the coil device of this invention, the end of the lead wire can be easily connected to the circuit board.

Description

Technical Field

[0001] This invention relates to coil devices. Background Technology

[0002] Coil devices such as reactors and transformers are known to be directly mounted on circuit boards. For example, there are known structures in which the lead wire of the coil is wound and soldered to the root of the lead wire terminal embedded in the winding frame, the lead wire terminal is inserted into the through hole of the circuit board, and connected to the circuit board by soldering or the like (Japanese Patent Application Publication No. 2004-79573), and structures in which the end of the lead wire of the coil is directly inserted into the through hole of the circuit board and connected to the circuit board by soldering or the like. Summary of the Invention

[0003] For example, in coil devices that carry large currents, such as reactors used in vehicles, wires with a large cross-sectional area (flat wire, thicker diameter round wire, etc.) are used as the coil material. Generally speaking, wires with a large cross-sectional area have high rigidity and are not easily deformed. Therefore, when using such wires, it is difficult to adopt a structure in which the coil lead wire is wound around the root of the lead terminal.

[0004] Therefore, a structure was considered in which the end of the coil lead was directly inserted into the through hole of the circuit board and connected to the circuit board. However, due to the high rigidity and non-deformability of the wire, it is difficult to accurately determine the position of the end of the lead and insert it into the through hole to connect it to the circuit board, especially in manual operations.

[0005] The present invention was developed in view of this situation, and its purpose is to provide a coil device that facilitates the connection of the end of the lead wire to a circuit board.

[0006] One embodiment of the present invention provides a coil device that can be mounted on a circuit board, comprising: a coil having a winding portion and a lead wire extending from the winding portion; and a plate portion positioned relative to the coil. The plate portion includes: a main body portion; a cylindrical portion formed on one surface of the main body portion; and a through hole penetrating the cylindrical portion and the main body portion. The end of the lead wire can pass through the through hole. In this coil device, the movement of the lead wire within the through hole is restricted by the through hole, such that the end of the lead wire passing through the through hole is positioned.

[0007] With such a coil device, even for high-rigidity and non-deformable wires, such as flat wires, whose position is difficult for the operator to determine or adjust with high precision by hand, the end of the lead wire can be easily inserted into a through hole of a circuit board, for example, located directly below a through hole (in other words, the end of the lead wire can be easily connected to the circuit board).

[0008] When the above conditions are met, the misalignment between the end of the lead wire and the connection portion (e.g., through-hole) on the circuit board is small, making it easy to connect the end of the lead wire to the connection portion. When the above conditions are not met, the misalignment between the end of the lead wire and the connection portion on the circuit board becomes large, making it difficult to connect the end of the lead wire to the connection portion.

[0009] In one embodiment of the invention, the through hole may also be configured such that a second portion is formed on the first opening side where the end of the lead wire is inserted, and a first portion is formed on the second opening side where the end of the lead wire inserted into the first opening extends. The second portion is formed into a tapered shape whose cross-section orthogonal to the vertical axis increases as it moves from the second opening side to the first opening side.

[0010] By setting the through hole to a shape that increases in size as it approaches the first opening (the opening at the end of the lead wire to be inserted), the end of the lead wire can be inserted into the through hole more easily.

[0011] In one embodiment of the invention, the plate portion may also be configured to have a receiving surface for receiving the surface of the circuit board. In this structure, the surface of the circuit board is received by the receiving surface, and the through hole extends in a direction perpendicular to the vertical axis relative to the surface of the circuit board.

[0012] The through-hole extends in a vertical direction relative to the surface of the circuit board, and the end of the lead wire extends out of the through-hole in a generally straight manner. Therefore, for example, the end of the lead wire can be easily inserted into a through-hole of the circuit board located directly below the through-hole.

[0013] In one embodiment of the present invention, the coil device may also be configured to further include a winding frame for holding the winding portion, wherein the plate portion is positioned relative to the coil by engaging with the winding frame.

[0014] The position of the plate relative to the coil held on the winding frame is determined, and therefore the position of the through hole in the plate relative to the coil's lead wire is also determined. This allows for easier insertion of the lead wire end into the through hole.

[0015] In one embodiment of the present invention, the plate portion is mounted on, for example, the lower surface of a winding frame, and a receiving surface is formed on the lower surface of the plate portion.

[0016] In one embodiment of the present invention, the through hole may be formed on the side of the winding frame, extending in a vertical axis direction perpendicular to the surface of the circuit board. Furthermore, the lead wire extends from the winding portion to the top of the winding frame, bends above the winding frame in a direction parallel to the surface of the circuit board, and bends towards the through hole in a vertical axis direction at a portion extending above the through hole located on the side of the winding frame. The end of the lead wire bent in the vertical axis direction passes through the through hole.

[0017] In this way, by bringing the lead wires back to the top and sides of the winding frame, the insulation distance between the lead wires and other components can be ensured.

[0018] In one embodiment of the present invention, the winding frame may also be configured such that the support portion supports the lead wire bent to a parallel direction above the winding frame, thereby maintaining a predetermined distance between the lead wire bent to a parallel direction and the core body partially housed in the hollow portion of the winding portion.

[0019] This ensures the insulation distance between the lead wire and the core above the winding frame.

[0020] In one embodiment of the invention, the through hole may be formed above the winding frame, extending in a vertical axis direction perpendicular to the surface of the circuit board. In this configuration, the lead wire extends from the winding portion along the vertical axis direction to the top of the winding frame, and its end passes through the through hole without bending. Furthermore, a second opening may be formed on one end face of the cylindrical portion for the end of the lead wire inserted into the through hole to protrude, and this end face may serve as a receiving surface.

[0021] In one embodiment of the present invention, the coil wire is, for example, a flat wire. Attached Figure Description

[0022] Figure 1 This is a perspective view of the coil device according to the first embodiment of the present invention.

[0023] Figure 2 This is an exploded perspective view of the coil device according to the first embodiment of the present invention.

[0024] Figure 3 This is a schematic diagram showing an example of the installation of the coil device according to the first embodiment of the present invention.

[0025] Figure 4 This is a perspective view of the plate portion of the first embodiment of the present invention viewed from an obliquely upward angle.

[0026] Figure 5 This is a perspective view of the plate portion of the first embodiment of the present invention viewed from a slightly lower angle.

[0027] Figure 6 This is a perspective view of the winding frame of the first embodiment of the present invention viewed from a slightly lower angle.

[0028] Figure 7 This is a cross-sectional view of the second base portion of the plate portion according to the first embodiment of the present invention.

[0029] Figure 8 This is a perspective view of the coil device according to the second embodiment of the present invention.

[0030] Figure 9 This is an exploded perspective view of the coil device according to the second embodiment of the present invention.

[0031] Figure 10 This is a schematic diagram illustrating an example of the installation of the coil device according to the second embodiment of the present invention.

[0032] Figure 11 This is a perspective view of the plate portion of the second embodiment of the present invention viewed from a slightly downward angle.

[0033] Figure 12 This is a cross-sectional view of the plate portion according to the second embodiment of the present invention. Detailed Implementation

[0034] Embodiments of the present invention will now be described with reference to the accompanying drawings. In the following description, identical or corresponding elements will be labeled with the same or similar reference numerals, and repeated descriptions will be omitted.

[0035] (First embodiment)

[0036] Figure 1 This is a perspective view of the coil device 1 according to the first embodiment of the present invention. Figure 2 This is an exploded perspective view of coil device 1. Figure 3 This is a schematic diagram showing an example of the mounting of the coil device 1 relative to the circuit board 2.

[0037] In the following explanation, Figure 1 The X-axis is defined as the direction from the upper right to the lower left, the Y-axis as the direction from the upper left to the lower right, and the Z-axis as the direction from bottom to top. The X, Y, and Z axes are orthogonal to each other. For ease of explanation, the positive side of the X-axis is called "front," and the negative side is called "rear." Similarly, the positive side of the Z-axis is called "above," and the negative side is called "below." These names are used to illustrate the relative positional relationships of the constituent elements and do not represent absolute directions. For example, the Z-axis (vertical direction) is not necessarily limited to a vertical direction; it can also be a horizontal direction.

[0038] Furthermore, not all elements in a drawing may be labeled with reference numerals. Specifically, when multiple identical elements are represented in a single drawing, sometimes only a subset of these elements are labeled, while the remaining elements are omitted from the reference numerals. For example... Figure 2 In the figure, the winding portion 11 of coil 10A is marked with reference numeral 11, while the winding portion 11 of coil 10B is omitted with reference numeral 11.

[0039] The coil device 1 is, for example, a reactor used in a power converter. The coil device 1 is merely one example of an embodiment of the present invention. The structure of the embodiments of the present invention is not limited thereto and can be appropriately modified. For example, this embodiment is an example of applying the present invention to a two-phase AC reactor, but the present invention can also be applied to single-phase or n-phase (n is a natural number of 3 or more) AC reactors. Furthermore, the coil device 1 is not limited to a reactor (inductor); for example, it can also be other devices having coils and cores, such as transformers or filters.

[0040] The coil assembly 1 includes a coil 10, a winding frame 20, a core 30, and a board portion 40. The coil assembly 1 is mounted on a circuit board 2 disposed below the coil assembly 1. Figure 3 ).

[0041] The coil device 1 is, for example, a two-phase AC reactor, and therefore has a pair of coils 10. Each coil 10 is a flat-wound coil made by flat-winding a flat wire. The flat wire is a conductive conductor of copper or aluminum with a rectangular cross-section. The outer periphery of this conductor is covered with an insulating material such as insulating varnish.

[0042] In this embodiment, a flat wire with a width of 8 mm and a thickness of 1 mm is used. However, the width and thickness of the flat wire are not limited to these. The flat wire may also have other widths (e.g., any from 3 mm to 14 mm) and other thicknesses (e.g., any from 0.6 mm to 2 mm).

[0043] A pair of coils 10 are arranged side by side in the Y-axis direction. Furthermore, when describing each individual coil 10 separately, Figure 1 In this document, the coil 10 located on the positive side of the Y-axis direction is referred to as "coil 10A", and the coil 10 located on the negative side of the Y-axis direction is referred to as "coil 10B".

[0044] Unlike multi-layered coils that use round wire as the wire material, coil 10 is a single-layered coil. Therefore, the temperature difference between the inside and outside of the winding of coil 10 is smaller, resulting in excellent heat dissipation and less temperature rise. Compared to coils using round wire, coil 10 helps suppress the temperature rise of the coil assembly 1.

[0045] The coil 10 has a winding portion 11 around the Y-axis with a flat wire wound around it and a pair of leads 12 extending from the winding portion 11. Each lead 12 extends from the winding portion 11 toward the top of the winding frame 20 (positive side in the Z-axis direction), and in the upward direction of the winding frame 20, it is perpendicular to the surface 2a of the circuit board 2. Figure 3The lead wire 12 is bent in a parallel direction (specifically, on the positive side of the Y-axis in coil 10A and on the negative side of the Y-axis in coil 10B), and further bent downwards (on the negative side of the Z-axis, and in the vertical axis direction described later) above the through hole 45 (details to be described later) located on the side of the core 30 (and the winding frame 20). The former bend is referred to as "bend portion 12a", and the latter bend is referred to as "bend portion 12b". By bringing the lead wire 12 back above and to the side of the winding frame 20, the insulation distance between the lead wire 12 and other components is ensured.

[0046] The winding frame 20 ensures the insulation distance between the coil 10 and the core 30, and has a pair of winding frame portions 21 and a spacer portion 25. The winding frame portions 21 and the spacer portion 25 are formed using insulating materials such as phenolic resin, epoxy resin, unsaturated polyester resin, polyurethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), and PBT (Polybutylene Terephthalate). The winding frame portions 21 and the spacer portion 25 can be formed using the same material or different materials. Furthermore, in the case of describing each of the pair of winding frame portions 21 separately... Figure 1 In this document, the winding frame section 21 located on the positive side in the Y-axis direction is referred to as "winding frame section 21A", and the winding frame section 21 located on the negative side in the Y-axis direction is referred to as "winding frame section 21B".

[0047] The winding frame section 21 has a frame section 22 and a cylindrical section 23.

[0048] The frame portion 22, when viewed from above (i.e., from the positive side in the Z-axis direction), is U-shaped, having a first wall portion 22a extending along the X-axis direction, and a pair of second wall portions 22b extending from both ends of the first wall portion 22a in the X-axis direction toward the Y-axis direction. Each of the second wall portions 22b of the winding frame portion 21A extends from each end of the first wall portion 22a toward the negative side in the Y-axis direction. Each of the second wall portions 22b of the winding frame portion 21B extends from each end of the first wall portion 22a toward the positive side in the Y-axis direction.

[0049] A mating portion with a concave-convex structure is formed at the front end of each second wall portion 22b of each winding frame portion 21. Specifically, in the winding frame portion 21A, a recess 22bA is formed at the front end of one second wall portion 22b, and a protrusion 22bB is formed at the front end of the other second wall portion 22b. In the winding frame portion 21B, a protrusion 22bB is formed at the front end of the second wall portion 22b of the winding frame portion 21A opposite to the recess 22bA, and a recess 22bA is formed at the front end of the second wall portion 22b of the winding frame portion 21A opposite to the protrusion 22bB. The recess 22bA of the winding frame portion 21A and the protrusion 22bB of the winding frame portion 21B fit together, and the protrusion 22bB of the winding frame portion 21A and the recess 22bA of the winding frame portion 21B fit together, thereby completing a rectangular frame when viewed from above.

[0050] The cylindrical portion 23 is formed between a pair of second wall portions 22b, protruding from the inner wall of the first wall portion 22a toward the Y-axis. Specifically, the cylindrical portion 23 of the winding frame portion 21A protrudes from the inner wall of the first wall portion 22a toward the negative side toward the Y-axis. The cylindrical portion 23 of the winding frame portion 21B protrudes from the inner wall of the first wall portion 22a toward the positive side toward the Y-axis.

[0051] The spacer portion 25 is a plate-shaped member with an opening 26 formed in the center. The spacer portion 25 is disposed between coils 10A and 10B to ensure the insulation distance between coils 10A and 10B. Furthermore, in this embodiment, ribs are formed around the opening 26 to improve the rigidity of the spacer portion 25, which is a plate-shaped member.

[0052] The cylindrical portion 23 of the winding frame portion 21 is inserted and housed in the hollow portion 11a of the winding portion 11. Thus, the outer surface of the cylindrical portion 23 is substantially entirely covered by the winding portion 11. Furthermore, the coil 10 is held in the winding frame 20. Additionally, during the insertion of the cylindrical portion 23 into the hollow portion 11a, the lead wire 12 of the coil 10 is either unbent or only the bent portion 12a is bent.

[0053] Regarding the shape of the cylindrical portion 23 extending along the Y-axis, the front end portion 23a is smaller than the other portions throughout the entire circumference. The shape of the front end portion 23a is defined by appropriate tolerances of the opening 26 of the spacer portion 25, and it has the same shape and the same size as the opening 26.

[0054] When the second wall portion 22b of the winding frame portion 21A and the second wall portion 22b of the winding frame portion 21B are engaged, the front end portion 23a of the cylindrical portion 23 of each winding frame portion 21 engages with the opening portion 26 of the partition portion 25. Thus, the partition portion 25 is fixed between the coil 10A and the coil 10B, ensuring their insulation distance.

[0055] A pair of support portions 22aA are formed on the upper surface of the first wall portion 22a of the frame portion 22 of the winding frame portion 21. A portion of each lead wire 12 bent at the bending portion 12a is placed on the support surface 22aB of each support portion 22aA. Thus, above the winding frame 20, the lead wire 12 is supported by the support portions 22aA, and the Z-axis spacing between the lead wire 12 (more specifically, the portion of the lead wire 12 from the bending portion 12a to the bending portion 12b) and the core 30 (more specifically, the connecting portion 33) is maintained at a predetermined spacing (e.g., 6 mm), ensuring the insulation distance between the lead wire 12 and the core 30.

[0056] A protrusion 22aC extending in the Y-axis direction is formed at each end of the support surface 22aB in the X-axis direction. These protrusions 22aC restrict the movement of the lead wire 12, which is placed on the support surface 22aB, in the X-axis direction. Therefore, the end 12c of the lead wire 12 can be easily inserted into the through hole 45, which will be described later.

[0057] The core 30 has a pair of middle legs 31, a pair of outer legs 32, and a pair of connecting parts 33. The core 30 is formed using a magnetic material with high magnetic permeability (such as mineral powder core, amorphous core, silicon steel plate, nanocrystalline core, ferrite core, etc.).

[0058] An opening 22aD is formed in the first wall portion 22a of the frame portion 22 of the winding frame portion 21, which connects to the hollow portion 23b of the cylindrical portion 23. A middle leg portion 31 is inserted into the hollow portion 23b. The middle leg portion 31 inserted into the hollow portion 23b extends to a position where it contacts a connecting portion 33 positioned between a pair of upper and lower flanges protruding from the outer wall surface of the first wall portion 22a. The end face 31a of the middle leg portion 31, which passes through the hollow portion 23b and is exposed from the opening 22aD, and the central portion 33a of the connecting portion 33 positioned as described above (in...) Figure 2 (The text is incomplete and contains several typographical errors. A more accurate translation would require the full context.)

[0059] Alternatively, a gap can be provided within the core 30 (e.g., between a pair of middle legs 31). This gap prevents magnetic saturation in the coil assembly 1 and ensures the inductance value even when a large current is flowing.

[0060] The core 30 is not limited to the structure of this embodiment. The core 30 can also be combined, for example, two E-shaped cores.

[0061] Figure 4 This is a three-dimensional view of the plate section when viewed from a slightly upward angle. Figure 5 This is a three-dimensional view of the plate section when viewed from a slightly lower angle. Figure 6 This is a three-dimensional view of the winding frame 20 viewed from a slightly lower angle.

[0062] The plate portion 40 has a main body portion 41. The main body portion 41 is formed using an insulating material such as phenolic resin, epoxy resin, unsaturated polyester resin, polyurethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), or PBT (Polybutylene Terephthalate). The plate portion 40 may be formed using the same material as the winding frame portion 21 and the spacer portion 25, or it may be formed using a different material.

[0063] The main body 41 has a pair of second bases 43 extending in the X-axis direction, which are respectively connected to the first base 42 and the two ends of the first base 42 in the Y-axis direction.

[0064] The first base 42 is formed into a rectangular frame shape when viewed from above, with a rectangular opening 42a in the center. Additionally, a plurality of elongated holes 42b (four in this embodiment) extending along the Y-axis are formed in the first base 42. The upper surface 42c of the first base 42 is lower than the upper surface 43c of the second base 43, creating a height difference between the upper surfaces 42c and 43c. The upper surfaces 42c and 43c are connected via a height difference surface 42d perpendicular to both.

[0065] A pair of second bases 43 are sandwiched between the first base 42 and arranged opposite each other in the Y-axis direction. Therefore, the height difference surface 42d between the first base 42 and one second base 43, and the height difference surface 42d between the first base 42 and the other second base 43 are also opposite each other in the Y-axis direction.

[0066] like Figure 6 As shown, a plurality of protrusions 27 (four in this embodiment) are formed on the lower surface of the winding frame 20. The width (dimension in the X-axis direction) and length (dimension in the Y-axis direction) of the protrusions 27 are both equal to those of the elongated hole 42b. Figure 4 The shapes of the protrusions 27 are defined by appropriate tolerances of the elongated holes 42b. Therefore, the positions of the plate portion 40 relative to the winding frame 20 in the X and Y directions are determined by fitting each protrusion 27 into each elongated hole 42b.

[0067] like Figure 6 As shown, in the Y-axis direction, the lower side surface 28a of the winding frame 20 and the lower side surface 28b formed on the opposite side of the lower side surface 28a are separated by a distance D1. Additionally, as... Figure 4As shown, the opposing pair of height difference surfaces 42d are also separated by a distance D1 in the Y-axis direction. Therefore, when each protrusion 27 is fitted into each elongated hole 42b, the lower part of the winding frame 20 is also fitted between the pair of height difference surfaces 42d. Through this fitting, at least the position of the plate portion 40 relative to the winding frame 20 in the Y-axis direction is determined.

[0068] In this way, the plate portion 40 determines the position relative to the coil 10 held on the winding frame 20 by fitting with the winding frame 20. In addition, the upper surface 42c of the first base portion 42 of the plate portion 40 and the lower surface 29 of the winding frame 20 are bonded and fixed together.

[0069] Figure 7 The YZ section of the second base 43 is represented in the figure. Figure 7 The YZ section is utilized Figure 4 The cut line AA represents the cross section.

[0070] A pair of cylindrical portions 44 are formed on the upper surface 43 of each second base 43. The cylindrical portions 44 are integrally formed with the second base 43. A through hole 45B extending in the Z-axis direction is formed in the cylindrical portion 44. The through hole 45B is defined by the inner wall surface of the cylindrical portion 44. In addition, a through hole 45A extending in the Z-axis direction is formed in the second base 43. The through hole 45B and the through hole 45A are connected to form a through hole 45. Hereinafter, the through hole 45A will be referred to as the first portion 45A of the through hole 45, and the through hole 45B will be referred to as the second portion 45B of the through hole 45. An opening (first opening 45a) on the positive side of the through hole 45 in the Z-axis direction is formed on the upper end surface of the cylindrical portion 44, and an opening (second opening 45b) on the negative side of the through hole 45 in the Z-axis direction is formed on the lower surface 43d of the second base 43.

[0071] In this embodiment, the cylindrical portion 44 has a rectangular shape with sides in the X-axis and Y-axis directions when viewed from above. However, the shape of the cylindrical portion 44 is not limited to this and may have other shapes (e.g., circular when viewed from above).

[0072] like Figure 5 As shown, a plurality of (four in this embodiment) bearing surfaces 46 are formed on the lower surface of the plate portion 40 (more specifically, the lower surface 43d of the second base portion 43). The bearing surface 46 is the surface above a cylindrical boss protruding downward from the lower surface 43d and is orthogonal to the Z-axis.

[0073] like Figure 3As shown, the orientation of the coil device 1 relative to the circuit board 2 is determined by the surface 2a of the circuit board 2 supported by each receiving surface 46 (i.e., each receiving surface 46 is in surface contact with surface 2a), and the position of the coil device 1 relative to the circuit board 2 in the Z-axis direction is also determined. Through the surface 2a supported by each receiving surface 46, the through hole 45 extends in a direction perpendicular to the vertical axis relative to surface 2a on the side of the winding frame 20. Furthermore, with... Figure 1 In the figures represented by [example figure], the vertical axis direction is consistent with the Z-axis direction.

[0074] When the plate portion 40 and the winding frame 20 are engaged, the position of the plate portion 40 relative to the coil 10 held on the winding frame 20 is determined, and therefore the position of the through hole 45 relative to the lead wire 12 is also determined. Therefore, the end 12c of the lead wire 12, which is bent downward (to the negative side of the Z-axis direction) with the bent portion 12b facing the through hole 45, can be easily inserted into the through hole 45 through the first opening 45a.

[0075] like Figure 7 As shown, the through hole 45 forms a first portion 45A on the side of the second opening 45b and a second portion 45B on the side of the first opening 45a. The second portion 45B of the through hole 45 is a conical shape whose XY cross-section, orthogonal to the vertical axis (Z-axis), increases as it moves from the second opening 45b side toward the first opening 45a side. The XY cross-sectional shape of the second portion 45B is similar to, for example, the cross-sectional shape of the end 12c of the lead wire 12 (i.e., a rectangle with sides in the X-axis and Y-axis directions), and its total length throughout the Z-axis direction is larger than that of the lead wire 12 in both the X-axis and Y-axis directions.

[0076] The largest part of the second portion 45B of the through hole 45 is the first opening 45a. This first opening 45a is, for example, 1 mm to 2 mm larger than the first portion 45A of the through hole 45 in both the X and Y axes. Since the first opening 45a is larger than the first portion 45A (which is larger than the lead wire 12), even if the center position of the first opening 45a and the center position of the end 12c of the lead wire 12 in the XY plane deviate due to the accumulation of deviations within the tolerances of the components constituting the coil device 1, the end 12c of the lead wire 12 can still be easily inserted into the through hole 45 through the first opening 45a. That is, the tapered second portion 45B acts as a guide to guide the lead wire 12 towards the first opening 45a.

[0077] The end 12c of the lead wire 12 inserted into the through hole 45 from the first opening 45a is guided toward the second portion 45B of the through hole 45, which is formed in a conical shape, and inserted into the first portion 45A of the through hole 45. The lead wire 12 inserted into the first portion 45A passes through the through hole 45 from the second opening 45b formed on the lower surface 43d of the second base 43 to the end 12c, protruding by a predetermined amount.

[0078] The XY cross-section of the first portion 45A of the through hole 45, orthogonal to the vertical axis (Z-axis) perpendicular to the surface 2a of the circuit board 2, is fixed along its total length in the Z-axis direction. The XY cross-sectional shape of the first portion 45A is similar to, for example, the cross-sectional shape of the end 12c of the lead wire 12 (i.e., a rectangle with sides in the X-axis and Y-axis directions), and its total length along the Z-axis is only slightly larger than that of the lead wire 12 in each of the X-axis and Y-axis directions (for example, by about 0.3 mm to 0.5 mm in each direction). Therefore, the movement of the lead wire 12 in the X-axis and Y-axis directions within the first portion 45A is substantially restricted by the first portion 45A. Thus, the position of the end 12c of the lead wire 12 passing through the through hole 45 (in other words, the end 12c protruding from the second opening 45b) is determined with respect to each of the X-axis and Y-axis directions.

[0079] In this embodiment, the XY cross-sectional shape of the first portion 45A and the second portion 45B of the through hole 45 is rectangular (i.e., a shape similar to the cross-sectional shape of the lead wire 12, which is a flat wire), but the shape of the first portion 45A and the second portion 45B is not limited to this. The XY cross-sectional shape of the first portion 45A and the second portion 45B can also be a shape dissimilar to the cross-sectional shape of the lead wire 12. As an example, the XY cross-sectional shape of the first portion 45A and the second portion 45B can also be circular. In this case, the first portion 45A has a diameter that is able to pass through the lead wire 12 and is slightly larger than the width of the lead wire 12 (here, the dimension in the Y-axis direction) in such a way that the movement of the lead wire 12 within the first portion 45A is substantially restricted by the first portion 45A.

[0080] Constructing the coil 10 using a circular wire is also within the scope of this invention. In this case, the cross-sectional shape of the lead wire 12 becomes circular. In this case, the XY cross-sectional shapes of the first portion 45A and the second portion 45B of the through hole 45 can also be circular (i.e., similar to the cross-sectional shape of the lead wire 12) by analogy with the cross-sectional shape of the lead wire 12. By making the XY cross-sectional shapes of the first portion 45A and the second portion 45B similar to the cross-sectional shape of the lead wire 12, the XY cross-sectional shapes of the first portion 45A and the second portion 45B can be minimized, thereby helping to reduce the size of the cylindrical portion 44.

[0081] In this embodiment, the position of the end 12c of each lead 12 is determined by passing each lead 12 through each through hole 45. Therefore, even for high-rigidity and non-deformable wires, such as flat wires, which are difficult for operators to determine or adjust their position with high precision by hand, the end 12c can be easily inserted into each through hole 2b of the circuit board 2 located directly below each through hole 45 (in other words, the end 12c can be easily connected to the circuit board 2).

[0082] In this embodiment, the surface 2a of the circuit board 2 is supported by the receiving surface 46, and the through hole 45 is positioned to extend in the vertical axis direction relative to the surface 2a. Therefore, the end 12c of the lead wire 12 passing through the through hole 45 protrudes approximately straight from the second opening 45b in the Z-axis direction. Thus, it is easy to insert each end 12c into each through hole 2b of the circuit board 2 located directly below each through hole 45.

[0083] In this embodiment, all through holes 45 are formed in a single part (i.e., board portion 40). Therefore, the misalignment of the through holes 45 with each other is included in the deviation within the tolerance of the single part. Thus, the misalignment of the ends 12c of the leads 12 passing through each through hole 45 with each other is suppressed, and it is easy to insert each end 12c into each through hole 2b of the circuit board 2.

[0084] The insulation material covering the lead wire 12 is stripped from the end 12c. Therefore, the coil 10 and the circuit board 2 are electrically connected by soldering the end 12c that passes through the through hole 2b of the circuit board 2.

[0085] Furthermore, the coil assembly 1 is mounted to the cooler 3 using a mounting metal part (not shown). An opening 2c, the same size as the opening 42a formed in the first base 42 of the plate portion 40, is formed on the circuit board 2. A heat sink 4, disposed on the cooler 3, is arranged in this opening 2c. That is, in this embodiment, the heat sink 4 is disposed directly below the coil assembly 1. The heat sink 4 is disposed, for example, in contact with the coil 10. This heat sink 4 helps to suppress the temperature rise of the coil assembly 1.

[0086] Generally, the components constituting the coil device 1 have deviations within tolerances. Due to these deviations, the direction in which the lead wire 12 extends within the first portion 45A of the through hole 45 is not completely aligned with the Z-axis direction, but is slightly inclined relative to the Z-axis direction. The greater this inclination, and the longer the protruding length L1 from the through hole 45 at the end 12c of the lead wire 12 passing through the through hole 45, the greater the misalignment of the end 12c relative to the through hole 2b of the circuit board 2.

[0087] The longer the length L2 of the first portion 45A of the through hole 45 in the Z-axis direction, the more effectively the tilting of the lead wire 12 relative to the Z-axis direction is suppressed. In this embodiment, by adopting a structure in which a cylindrical portion 44 is provided on the upper surface 43c of the second base 43 of the plate portion 40, the total length of the through hole 45 in the Z-axis direction is longer compared to a structure without a cylindrical portion 44 on the upper surface 43c. As a result, the length L2 can be ensured for a longer period, and the tilting of the lead wire 12 relative to the Z-axis direction can be suppressed.

[0088] Furthermore, in this embodiment, such as Figure 7As shown, the length L2 of the first portion 45A is the same as the thickness of the second base 43. However, in other embodiments, the length of the second portion 45B in the Z-axis direction can be shortened, and the length L2 can be extended accordingly. In this case, the length L2 is longer than the thickness of the second base 43, which can further suppress the tilt of the lead wire 12 relative to the Z-axis direction.

[0089] The thickness (dimension in the Z-axis direction) of the plate portion 40, except for the portion where the cylindrical portion 44 is provided, is reduced. This reduces the amount of resin required for molding the plate portion 40. Furthermore, the reduced wall thickness suppresses the occurrence of molding defects. Specifically, it lessens sink marks that may occur during cooling after molding.

[0090] When the above formula is satisfied, the misalignment of the end 12c of the lead wire 12 relative to the through hole 2b of the circuit board 2 is small, so it is easy to insert the end 12c into the through hole 2b. When the above formula is not satisfied, the misalignment of the end 12c relative to the through hole 2b of the circuit board 2 becomes large, making it difficult to insert the end 12c into the through hole 2b.

[0091] (Second embodiment)

[0092] Figure 8 This is a perspective view of the coil device 101 according to the second embodiment of the present invention. Figure 9 This is an exploded perspective view of the coil device 101. Figure 10 This is a schematic diagram showing an example of the mounting of the coil device 101 relative to the circuit board 102.

[0093] The coil assembly 101 includes a coil 110, a winding frame 120, a core 30, and a plate portion 140. The coil assembly 101 is mounted on a circuit board 102 of a circuit disposed above the coil assembly 101.

[0094] The coil device 101 has a pair of coils 110 arranged along the Y-axis. The coils 110 are flat-wound coils made by flat-winding flat wire.

[0095] The winding frame 120 has a pair of winding frame portions 121 and a spacer portion 25. Furthermore, in the case of separately describing each of the pair of winding frame portions 121, Figure 8 In this document, the winding frame portion 121 located on the positive side in the Y-axis direction is referred to as "winding frame portion 121A", and the winding frame portion 121 located on the negative side in the Y-axis direction is referred to as "winding frame portion 121B".

[0096] The winding frame 121 has a frame 122 and a cylinder 23.

[0097] The frame portion 122 is U-shaped when viewed from above, and has a first wall portion 122a extending along the X-axis direction, and a pair of second wall portions 122b extending along the Y-axis direction from both ends of the first wall portion 122a in the X-axis direction. The recess 22bA of the winding frame portion 121A and the protrusion 22bB of the winding frame portion 121B fit together, and the protrusion 22bB of the winding frame portion 121A and the recess 22bA of the winding frame portion 121B fit together, thereby completing a rectangular frame when viewed from above.

[0098] The end face 31a of the middle leg portion 31, which is inserted into the hollow portion 23b of the cylindrical portion 23 and housed therein, is bonded and fixed to the connecting portion 33 of the core 30, which is positioned between a pair of upper and lower flanges protruding from the outer wall surface of the first wall portion 122a. Furthermore, the ends of the outer feet 32 ​​of the core 30, positioned between the upper and lower flanges protruding from the outer wall surface of the second wall portion 122b, are bonded and fixed to the ends of the connecting portions 33 positioned as described above. Thus, the core 30 has a shape in which a pair of middle legs 31 arranged side-by-side along the Y-axis are enclosed by a rectangular frame formed by a pair of feet 32 ​​and a pair of connecting portions 33 when viewed from above.

[0099] Figure 11 This is a three-dimensional view of the plate section 140 degrees from a slightly lower angle.

[0100] The plate portion 140 has a main body portion 141. A plurality of recesses 141b (four in this embodiment) are formed on the lower surface 141a of the main body portion 141. The shape of the recesses 141b when viewed from the negative side in the Z-axis direction is rectangular.

[0101] On the upper surface of the first wall portion 122a of the frame portion 122 of the winding frame portion 121, a plurality of rectangular protrusions 127 (two in each first wall portion 122a in this embodiment) are formed when viewed from above. The width (dimension in the Y-axis direction) and length (dimension in the X-axis direction) of the protrusions 127 are approximately the same as those of the recesses 141b. The shape of the protrusions 127 is defined by appropriate tolerances of the recesses 141b. Therefore, by fitting each protrusion 127 into each recess 141b, the position of the plate portion 140 relative to the winding frame 120 in each of the X and Y axis directions is determined.

[0102] In this way, the plate portion 140 determines the position relative to the coil 110 held in the winding frame 120 by fitting with the winding frame 120. In addition, the recess 141b of the plate portion 140 and the protrusion 127 of the winding frame 120 are bonded and fixed together.

[0103] Figure 12 The middle section represents the YZ section of plate 140. Figure 12 The YZ section is utilized Figure 11 The cut line BB represents the cross section.

[0104] A plurality of (four in this embodiment) first cylindrical portions 144a protruding downward (to the negative side in the Z-axis direction) relative to the lower surface 141a of the main body 141 are formed. A second cylindrical portion 144b protruding upward relative to the upper surface 141c of the main body 141 is formed above (to the positive side in the Z-axis direction) each of the first cylindrical portions 144a sandwiching the main body 141.

[0105] Multiple (four in this embodiment) through holes 145 extending along the Z-axis are formed in the plate portion 140. The through holes 145 penetrate the first cylindrical portion 144a, the main body portion 141 located directly above the first cylindrical portion 144a, and the second cylindrical portion 144b located further above in the Z-axis direction. An opening (first opening 45a) on the negative side of the through holes 145 in the Z-axis direction is formed on the lower end surface of the first cylindrical portion 144a, and an opening (second opening 45b) on the positive side of the through holes 145 in the Z-axis direction is formed on the upper end surface 144c (one end face of the cylindrical portion) of the second cylindrical portion 144b.

[0106] The upper end face 144c of the second cylindrical portion 144b becomes the receiving surface of the surface 102a that receives the circuit board 102. For example... Figure 10 As shown, the orientation of the coil assembly 101 relative to the circuit board 102 is determined by the contact surface 102a of each upper end face 144c (i.e., each upper end face 144c makes surface contact with surface 102a), and the position of the coil assembly 101 relative to the circuit board 102 in the Z-axis direction is also determined. Through the contact surface 102a of each upper end face 144c, the through hole 145 is positioned above the winding frame 120 (and below the circuit board 102) in an orientation that extends along the vertical axis relative to surface 102a.

[0107] The coil 110 has a pair of leads 112 extending from the winding portion 11. Each lead 112 extends from the winding portion 11 toward the top of the winding frame 120 (on the positive side in the Z-axis direction) and along the vertical axis direction without bending, and is inserted into a through hole 145 extending in the Z-axis direction through the first opening 45a. Furthermore, when the plate portion 140 and the winding frame 120 are fitted together, the position of the plate portion 140 relative to the coil 110 held in the winding frame 120 is determined, and therefore, the position of the through hole 145 relative to the lead 112 is also determined. Therefore, the insertion of the lead 112 relative to the through hole 145 becomes easy.

[0108] The end 112c of the lead wire 112 inserted from the first opening 45a into the through hole 145 is guided toward the second portion 45B of the through hole 145, which is formed in a conical shape, and inserted into the first portion 45A of the through hole 145. The lead wire 112 inserted into the first portion 45A passes through the through hole 145 from the second opening 45b formed on the upper end face 144c of the second cylindrical portion 144b and protrudes a predetermined amount from the end 112c. As in the first embodiment, the movement of the lead wire 112 in the X-axis and Y-axis directions within the first portion 45A is substantially restricted by the first portion 45A. Thus, the position of the end 112c of the lead wire 112 passing through the through hole 145 (in other words, the end 112c protruding from the second opening 45b) is determined with respect to the X-axis and Y-axis directions.

[0109] Thus, in this embodiment, as in the first embodiment, the position of the end 112c of each lead 112 is determined by passing each lead 112 through each through hole 145. Therefore, even for flat wires, which are highly rigid and not easily deformed and whose position is difficult for an operator to determine or adjust precisely by hand, it is easy to insert each end 112c into and pass through each through hole 102b of the circuit board 102 located directly above each through hole 145 (in other words, it is easy to connect the end 112c to the circuit board 102).

[0110] The coil 110 and the circuit board 102 are electrically connected by soldering the end 112c of the lead wire 112 that passes through the through hole 102b of the circuit board 102.

[0111] Furthermore, the coil assembly 101 is mounted to the cooler 103 using a mounting metal piece 105. Specifically, the protruding piece 105a of the mounting metal piece 105 is bonded and fixed in a state where it engages with and is held between the recess 128 formed in the first wall portion 122a and the connecting portion 33. The mounting metal piece 105 and the cooler 103 are fastened using screws (not shown) passing through screw holes 105b in the mounting metal piece 105.

[0112] A heat sink 104 is disposed between the coil assembly 101 and the cooler 103. The heat sink 104 is used to suppress the temperature rise of the coil assembly 101.

[0113] In the first embodiment, the lead wire 12 is led back to the top and side of the winding frame 20, and connected to the circuit board 2 located below the coil device 1 via a through hole 45 located on the side of the winding frame 20. Figure 3 As shown, the cylindrical portion 44 with a through hole 45 is positioned on the side of the winding frame 20, thus suppressing the height of the coil assembly 1. Therefore, the coil assembly 1 can be easily installed in devices with limited height space above the circuit board 2.

[0114] In contrast, in this embodiment, the lead wire 112 extends upwards towards the winding frame 120 and is connected to the circuit board 102 located above the coil assembly 101 via a through hole 145 located above the winding frame 120. Figure 10 As shown, the cylindrical portions (first cylindrical portion 144a and second cylindrical portion 144b) with through holes 145 are disposed above the winding frame 120, thus reducing the proprietary area of ​​the coil device 101 on the circuit board 102 (in other words, the projected area of ​​the coil device 101 onto the surface 102a of the circuit board 102). Therefore, for example, the size (area) of the circuit board 102 can be reduced, or more of the mounting area of ​​components other than the coil device 101 on the circuit board 102 can be ensured.

[0115] The above is a description of exemplary embodiments of the present invention. The embodiments of the present invention are not limited to the methods described above, and various modifications can be made within the scope of the technical concept of the present invention. For example, structures that appropriately combine the embodiments exemplarily shown in the specification or self-evident embodiments are also included in the embodiments of the present invention.

Claims

1. A coil device capable of being mounted on a circuit board, characterized in that, include: A coil having a winding section and lead wires extending from the winding section; and The plate portion where the coil is positioned, The plate portion includes: Main body; A cylindrical portion formed on one side of the main body; and A through hole connecting the cylindrical portion and the main body portion. The end of the lead wire can pass through the through hole. The through hole restricts the movement of the lead wire within it, thereby positioning the end of the lead wire passing through the through hole. The plate portion has a receiving surface for receiving the surface of the circuit board. The through hole is positioned such that it receives the surface of the circuit board via the receiving surface, and extends in a direction perpendicular to the vertical axis relative to the surface of the circuit board. It also has a winding frame for holding the winding section. The plate is positioned relative to the coil by engaging with the winding frame. During the process of the winding frame fitting into the plate, the end of the lead wire is inserted into the through hole.

2. The coil device according to claim 1, characterized in that: The through hole includes a first portion, the cross section of which is orthogonal to a vertical axis perpendicular to the surface of the circuit board.

3. The coil device according to claim 2, characterized in that: The through hole has a second portion formed on the first opening side for the end of the lead wire to be inserted, and the first portion is formed on the second opening side for the end of the lead wire inserted into the first opening to protrude. The second portion is formed into a cone shape whose cross-section orthogonal to the vertical axis increases as it moves from the second opening side toward the first opening side.

4. The coil device according to claim 1, characterized in that: The plate is mounted on the lower surface of the winding frame. The receiving surface is formed on the lower surface of the plate.

5. The coil device according to claim 1, characterized in that: The through hole is formed on the side of the winding frame, extending in a vertical axis direction perpendicular to the surface of the circuit board. The lead wire, It extends from the winding section to the top of the winding frame. Above the winding frame, it is bent in a direction parallel to the surface of the circuit board. The portion extending above the through hole located on the side of the winding frame bends towards the through hole in the direction of the vertical axis. The end of the lead wire, bent to the vertical axis direction, passes through the through hole.

6. The coil device according to claim 5, characterized in that: The winding frame has a support portion that supports the lead wire bent to the parallel direction above the winding frame, thereby maintaining a predetermined interval between the lead wire bent to the parallel direction and the core partially housed in the hollow portion of the winding portion.

7. The coil device according to claim 1, characterized in that: The through hole is formed above the winding frame, extending in a vertical axis direction perpendicular to the surface of the circuit board. The lead wire extends from the winding section along the vertical axis to the top of the winding frame, and its end passes through the through hole without bending.

8. The coil device according to claim 7, characterized in that: A second opening is formed on one end face of the cylindrical portion for the end of the lead wire inserted into the through hole to extend out. One of the end faces becomes the receiving surface.

9. The coil device according to claim 1, characterized in that: The coil is made of flat wire.

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