Coil device

Abstract

To provide a coil device which exhibits an excellent heat discharge property while adjusting leakage.SOLUTION: A spacer 10 has a predetermined thickness along a winding axis. The spacer 10 includes at least one of an outside flow passage 11 for allowing the flow in a radial direction of a fluid from the outside to the inside of one of a first facing end 42 of a first wire winding part 40 and a second facing end 52 of a second wire winding part 50; an inside flow passage 12 for allowing the flow of a fluid from the inside to the outside in a radial direction of one of the first facing end 42 and the second facing end 52; and a flow passage 16 in the axial direction for allowing the flow of a fluid from the first facing end 42 to the second facing end 52.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a coil device used, for example, as a transformer. [Background technology]

[0002] For example, as disclosed in Patent Document 1 below, a coil device is known in which an insulating plate is disposed between a primary coil and a secondary coil to adjust leakage between the primary coil and the secondary coil.

[0003] Furthermore, in recent years, as the current of the coil device increases, heat generation from the wires constituting the primary coil and secondary coil has become an issue. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2011-77255 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil device that is excellent in heat dissipation while allowing for adjustment of leakage. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to a first aspect of the present invention comprises: A first wire winding portion; a second wire winding portion disposed adjacent to the first wire winding portion along a winding axis of the first wire winding portion; a spacer disposed between a first opposing end of the first wire winding portion along the winding axis and a second opposing end of the second wire winding portion along the winding axis, The spacer has a predetermined thickness along the winding axis, and The spacer is The rotor has at least one of an outer flow passage that allows a fluid to flow from the outside to the inside in the radial direction of the first opposing end or the second opposing end, an inner flow passage that allows a fluid to flow from the inside to the outside in the radial direction of the first opposing end or the second opposing end, and an axial flow passage that allows a fluid to flow from the first opposing end toward the second opposing end.

[0007] In the coil device according to the present invention, since the spacer having a predetermined thickness is disposed between the first wire winding portion and the second wire winding portion, the distance between the first opposing end of the first wire winding portion and the second opposing end of the second wire winding portion can be controlled by the thickness of the spacer, and as a result, leakage of the coil device can be adjusted.

[0008] In the coil device according to the present invention, the spacer having a predetermined thickness has at least one of an outer flow passage, an inner flow passage, and an axial flow passage, and therefore, a cooling fluid (e.g., cooling air, heat dissipating resin, etc.) can be introduced between the first and second opposing ends through these flow passages, improving the heat dissipation of the coil device.

[0009] Preferably, at least one of the outer flow passage, the inner flow passage, and the axial flow passage is a plurality of flow passage forming regions from which a member constituting the spacer is removed and which does not contact the first opposing end and / or the second opposing end. Also, preferably, the plurality of flow passage forming regions are present at a plurality of positions along the circumferential direction of the spacer.

[0010] By providing the flow passage forming regions, in which no spacer-constituting members are present, at a plurality of positions along the circumferential direction on the surface of the spacer, it becomes possible for the cooling fluid to be introduced between the first opposing end and the second opposing end at a plurality of positions along the circumferential direction, and the heat dissipation performance of the coil device is further improved. Even if the flow passage forming regions are formed at a plurality of positions along the circumferential direction, the coil device leakage adjustment is well maintained because the spacer has a predetermined thickness. In addition, the flow passage forming regions may be grooves formed only on one side of the surface of the spacer, grooves formed on both sides of the spacer, or notches or through holes penetrating the front and back surfaces of the spacer.

[0011] At least one of the flow passage forming regions may have an outer recess recessed from an outer peripheral position to an inner peripheral position of the spacer and not in contact with the first opposing end and / or the second opposing end. Through the outer recess, a cooling fluid can be drawn between the first opposing end and the second opposing end from the outside to the inside in the radial direction of the winding part. The outer recess may be a notch or a groove as long as it is recessed from the outside to the inside in the radial direction of the winding part and is not in contact with at least one of the first opposing end and the second opposing end. The outer recess may also penetrate from the outside to the inside in the radial direction of the spacer.

[0012] Preferably, the first and second opposing ends of the winding are formed with a continuous helical recess in the circumferential direction in accordance with the helical shape of the wire constituting the winding. The cooling fluid drawn into the inside of the winding through the outer recess can also flow through the helical recess into the inner recess located adjacent in the circumferential direction.

[0013] The width of the outer recess along the circumferential direction may be greater at the outer circumferential position than at the inner circumferential position. With this configuration, it becomes easier to draw a cooling fluid between the first opposing end and the second opposing end from the outside to the inside in the radial direction of the winding.

[0014] At least one of the flow passage forming regions may have an inner recess recessed from an inner peripheral position to an outer peripheral position of the spacer and not in contact with the first opposing end and / or the second opposing end. Through the inner recess, a cooling fluid can be drawn between the first opposing end and the second opposing end from the inside to the outside or from the outside to the inside in the radial direction of the winding part. Note that the inner recess may be a notch or a groove as long as it is recessed from the inside to the outside in the radial direction of the winding part and is not in contact with at least one of the first opposing end and the second opposing end. Also, the inner recess may penetrate from the inside to the outside in the radial direction of the spacer.

[0015] The width of the inner recess along the circumferential direction may be wider at the inner circumferential position than at the outer circumferential position. This configuration makes it easier to draw the cooling fluid between the first and second opposing ends from the inside to the outside in the radial direction of the winding part. Alternatively, the cooling fluid can be drawn between the first and second opposing ends along the inner recess from the outside to the inside in the radial direction of the winding part, and the cooling fluid can be stored at the inner circumferential position where the width of the inner recess is wider, thereby improving heat dissipation from the inside of the winding part and the outer circumferential surface of the middle leg part of the core.

[0016] At least one of the plurality of flow path forming regions may have a through hole communicating from the first opposing end to the second opposing end. A cooling fluid can be circulated between the first opposing end and the second opposing end through the through hole. The through hole may be a notch as long as it is a flow path forming region that does not contact both the first opposing end and the second opposing end and is not in contact with both. The through hole may also be configured to function as an outer recess or an inner recess.

[0017] The plurality of flow path forming regions include an inner recess that is recessed from an inner peripheral position of the spacer toward an outer peripheral position thereof and does not contact the first opposing end and / or the second opposing end; The spacer may have an outer recess that is arranged circumferentially adjacent to the inner recess, is recessed from an outer peripheral position toward an inner peripheral position of the spacer, and does not contact the first opposing end and / or the second opposing end.

[0018] The inner and outer recesses are arranged adjacent to each other along the circumferential direction, so that the cooling fluid can be drawn between the first and second opposing ends both radially from the inside to the outside and from the outside to the inside of the windings, further improving heat dissipation. Also, the cooling fluid can flow between the adjacent inner and outer recesses, for example through a spiral recess in the first or second opposing end.

[0019] The width of the outer recess along the circumferential direction may be wider than the width of the inner recess along the circumferential direction. Since the middle leg of the core may be closely arranged in the central opening of the spacer, it is easier to create a flow of cooling fluid from the outside to the inside in the radial direction of the spacer than a flow of cooling fluid from the inside to the outside in the radial direction of the spacer. Therefore, by making the width of the outer recess along the circumferential direction wider than the width of the inner recess along the circumferential direction, it becomes easier to draw the cooling fluid between the first opposing end and the second opposing end.

[0020] A coil device according to a second aspect of the present invention comprises: A first wire winding portion; a second wire winding portion disposed adjacent to the first wire winding portion along a winding axis of the first wire winding portion; a spacer disposed between a first opposing end of the first wire winding portion along the winding axis and a second opposing end of the second wire winding portion along the winding axis, The spacer has a predetermined thickness along the winding axis, and The spacer is The valve has at least one of an outer recess that allows a fluid to flow from the outside to the inside in the radial direction of the first opposing end or the second opposing end, an inner recess that allows a fluid to flow from the inside to the outside in the radial direction of the first opposing end or the second opposing end, and a through hole that allows a fluid to flow from the first opposing end to the second opposing end.

[0021] At least one of the first wire constituting the first wire winding portion and the second wire constituting the second wire winding portion is made of a conductor coated with an insulating layer having at least a heat-sealing layer. This configuration makes it easier to join parts of the wires that contact each other for each winding turn by heat fusion, making it easier to form an air-core coil in which the wire is wound into a coil shape. In addition, by combining the first wire winding portion, the spacer, and the second wire winding portion and thermocompressing them in the winding axis direction, it becomes easier to manufacture a coil body in which the first wire winding portion, the spacer, and the second wire winding portion are integrated.

[0022] The first opposing end of the first wire winding portion or the second opposing end of the second wire winding portion may be joined to a surface of the spacer by a method of joining the first opposing end of the first wire winding portion or the second opposing end of the second wire winding portion using a thermocompression bonding method that uses a heat-sealing layer of a wire or a method that uses an adhesive.

[0023] The spacer may be made of an insulating material and / or a metal material. When the spacer is made of an insulating material, the insulation between the first wire winding portion and the second wire winding portion is also improved. When the spacer is made of a metal material, the heat transfer characteristics of the spacer itself are improved, and the heat dissipation is further improved. The wire is preferably a wire covered with an insulating film.

[0024] Preferably, the coil device further includes a core, and preferably, the spacer has a central opening penetrating along the winding axis, and the core has a middle leg disposed in the central opening through the first wire winding portion or the second wire winding portion.

[0025] The core may further have a side leg covering at least a part of the outer periphery of the first wire winding portion or the outer periphery of the second wire winding portion, and a predetermined gap may be provided between the outer periphery end of the spacer and the inner periphery of the side leg. The outer periphery end of the spacer may contact the inner periphery of the side leg, but it is preferable that the inner periphery of the side end of the core is not damaged.

[0026] The coil winding device may further include a case that houses at least a part of the first wire winding portion and the second wire winding portion. In this case, the inside of the case is preferably filled with a heat dissipating resin up to a position where the spacer located between the first wire winding portion and the second wire winding portion is immersed. With this configuration, the heat dissipating resin enters between the first opposing end of the first wire winding portion and the second opposing end of the second wire winding portion as the above-mentioned cooling fluid, thereby particularly improving heat dissipation. [Brief description of the drawings]

[0027] [Figure 1] FIG. 1 is a schematic perspective view of a coil device according to a first embodiment of the present invention. [Figure 2A] FIG. 2A is a schematic perspective view of the coil device shown in FIG. 1 with the case removed. [Figure 2B] FIG. 2B is a schematic exploded perspective view of the coil device shown in FIG. 2A. [Figure 2C] FIG. 2C is a schematic exploded perspective view of the terminal block shown in FIG. 2B. [Figure 2D] FIG. 2D is a perspective view of the coil body shown in FIG. 2B with a portion thereof omitted. [Diagram 3] FIG. 3 is a perspective view of the terminal block body shown in FIG. 2C, seen from a different angle. [Figure 4A1] FIG. 4A1 is a schematic cross-sectional view taken along line IVA-IVA of the coil device shown in FIG. [Figure 4A2] 4A2 is a schematic perspective sectional view taken along line IVA-IVA of the coil device shown in FIG. [Figure 4B] FIG. 4B is a schematic cross-sectional view taken along line IVB-IVB of the coil device shown in FIG. 4A1. [Diagram 5] FIG. 5 is a schematic perspective view showing a flow direction of the heat dissipating resin in the spacer shown in FIG. 4A2. [Figure 6A] FIG. 6A is a schematic perspective view of the spacer shown in FIG. 4A2. [Figure 6B] FIG. 6B is a schematic perspective view showing a modification of the spacer shown in FIG. 6A. [Figure 6C] FIG. 6C is a schematic perspective view showing another modified example of the spacer shown in FIG. 6A. [Figure 6D] FIG. 6D is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. [Figure 6E] FIG. 6E is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. [Figure 6F] FIG. 6F is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. [Figure 6G] FIG. 6G is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. [Figure 6H] FIG. 6H is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. [Figure 6I] FIG. 6I is a schematic perspective view showing still another modified example of the spacer shown in FIG. 6A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the contents shown in the drawings are merely schematic and illustrative for understanding the present invention, and the appearance and dimensional ratios may differ from the actual product. In addition, the present invention is not limited to the following embodiment.

[0029] (First embodiment) A coil device 1 according to an embodiment of the present invention shown in Fig. 1 functions as, for example, a leakage transformer and is used in a power supply circuit of an in-vehicle charger or various electric devices. The coil device 1 has a core 2, a first wire 4, a second wire 5, a terminal block 7, and a case 8. In the drawings, the X-axis, Y-axis, and Z-axis are perpendicular to each other, and the Z-axis is parallel to the height direction of the coil device 1 (the winding axis direction of the coil). In the following description, for each of the X-axis, Y-axis, and Z-axis, the direction toward the center of the coil device 1 is referred to as the inside, and the direction away from the center of the coil device 1 is referred to as the outside.

[0030] As shown in Fig. 2A, the coil core assembly 3 has a core 2, a first wire 4, a second wire 5, and a terminal block 7 equipped with a terminal 6. Note that the heat sink 9 shown in Fig. 1 is omitted in Fig. 2. As shown in Fig. 2B, in this embodiment, the core 2 can be disassembled into a first core 21 arranged on the lower side along the Z axis, and a second core 22 arranged on the upper side of the first core 21 along the Z axis.

[0031] In this embodiment, the first core 21 and the second core 22 are each an E-shaped core having a substantially E-shape in a cross section parallel to a plane including the Z-axis and the Y-axis, and have the same shape, but may be different from each other. For example, one core may be an E-shaped core and the other core may be an I-shaped core. Also, in this embodiment, the core 2 is configured by combining two-piece cores 21 and 22, but it is not limited to being divided into two, and may be configured by combining a core divided into three or four or more parts.

[0032] In this embodiment, the first core 21 has a base portion 21a having a bottom surface parallel to a plane including the X-axis and the Y-axis, a middle leg portion 21b extending upward from the center of the base portion 21a along the Z-axis, and a pair of side legs 21b extending upward from both ends of the base portion 21a along the Y-axis along the Z-axis. The second core 22 has a base portion 22a having an upper surface parallel to the plane including the X-axis and the Y-axis, a middle leg portion 22b extending downward from the center of the base portion 22a along the Z-axis along the Z-axis, and a pair of side legs 21b extending downward from both ends of the base portion 22a along the Y-axis along the Z-axis along the Z-axis.

[0033] These cores 21 and 22 are each made of ferrite, a metal magnetic material, or a resin containing magnetic powder. In this embodiment, as shown in Fig. 5, the tip of center leg 21b and the tip of center leg 22b are butted against each other and are in contact with each other, and the tip 21c1 of side leg 21c and the tip 22c1 of side leg 22c are butted against each other and are in contact with each other. However, in another embodiment, the tip of center leg 21b and the tip of center leg 22b may not be in direct contact with each other, and a gap may be formed between them. The heat dissipating resin 82 shown in Fig. 1 may be inserted into the gap, or another member may be interposed.

[0034] As shown in FIG. 2B, in this embodiment, the coil core assembly 3 includes a core 2 having a first core 21 and a second core 22, a coil body 30, and a terminal block 7 having a terminal 6. The coil body 30 includes a first wire winding portion 40 in which the first wire 4 is wound in a coil shape, a second wire winding portion 50 in which the second wire 5 is wound in a coil shape, and a spacer 10 disposed between these winding portions. In this embodiment, the second wire winding portion 50 is disposed above the first wire winding portion 40 along the Z axis, but the opposite is also possible. In this embodiment, for example, the first wire winding portion 40 is a primary coil of a transformer, and the second wire winding portion 50 is a secondary coil of the transformer, but the opposite is also possible.

[0035] In this embodiment, the first wire 4 and the second wire 5 are each composed of a self-bonding conductive wire having a fusion layer and an insulating layer, and the type of the conductive wire is not particularly limited, and may be a conductive core wire such as a round wire, a rectangular wire, a twisted wire, a Litz wire, or a braided wire. The material of the fusion layer or insulating layer covering the core wire is not particularly limited, and examples thereof include polyurethane, polyamideimide, polyimide, and polyester. In this embodiment, the first winding part 40 around which the first wire 4 is wound and the second winding part 50 around which the second wire 5 is wound are each preferably formed into a coil shape in advance, and are preferably provided in the form of an air-core coil before being integrated with the spacer 10.

[0036] In this embodiment, both the first wire 4 and the second wire 5 are made of a self-bonding wire, but only one of them may be a self-bonding wire, or both may be made of other wires. At least one of the first wire winding portion 40 and the second wire winding portion 50 may be a flat coil. The wire diameters of the first wire 4 and the second wire 5 may be the same or different, and are not particularly limited, but are preferably within the range of 1.0 to 3.0 mm, for example.

[0037] Lead portions 41a, 41b are formed on both ends of the first wire 4 constituting the first wire winding portion 40, and the respective lead portions 41a, 41b are drawn out from the first winding portion 40 to the upper side along the Z axis and connected to the respective terminals 6, 6. Also, lead portions 51a, 51b are formed on both ends of the second wire 5 constituting the second wire winding portion 50, and the respective lead portions 51a, 51b are drawn out from the second winding portion 50 to the upper side along the Z axis and connected to the respective terminals 6, 6.

[0038] The terminals 6 to which the leads 41a, 41b, 51a, and 51b are connected are attached to a terminal block 7. The terminal block 7 has a cover 70, and the terminals 6 are fixed along the Y-axis at a predetermined interval along the longitudinal direction of the terminal block 7 by attaching the cover 70 to the terminal block 7. The terminal block 7 and the cover 70 are preferably made of an insulating material such as synthetic resin, and may be made of the same insulating material or different insulating materials. In this embodiment, the terminal block 7 is directly fixed to the core 2 with an adhesive or the like, but it is not necessarily fixed to the core 2. For example, the terminal block 7 may be fixed to the case 8 shown in FIG. 1, or in another embodiment, it may be attached to a bobbin (not shown) or formed as a part of the bobbin.

[0039] As shown in Fig. 2C, in this embodiment, the multiple terminals 6 each have the same shape and include a terminal base portion 60, a connection portion 61 provided at one end of the terminal base portion 60 along the X-axis, and an external connection portion 62 provided at the other end of the terminal base portion 60 along the X-axis. Any of the lead portions 41a, 41b, 51a, and 51b shown in Fig. 2B is connected to the connection portion 61 by crimping, thermocompression bonding, laser welding, soldering, or the like. The external connection portion 62 is a portion that is connected to an external connection terminal (not shown) or a terminal connection recess of a circuit board.

[0040] The terminal base portion 60 of each terminal 6 is mounted in a plurality of mounting grooves 71 provided at predetermined intervals along the Y-axis direction on the terminal block 7, and minute protrusions formed in the mounting grooves 71 fit into fitting holes in the terminal base 60, enabling thermocompression bonding. Note that the base portion 60 of the terminal 6 may be fixed in the mounting grooves 71 by other methods. Note that the terminal 6 can be formed, for example, by pressing a metal plate.

[0041] The terminal block 7 has a base plate portion 72 in which a mounting groove 71 is formed, a pair of flat plate pieces 73 extending downward along the Z-axis from both ends of the base plate portion 72 along the Y-axis, and a bent piece 74 that is integrated and continuous between the pair of flat plate pieces. As shown in Fig. 3, the bent piece 74 of the terminal block 7 has an inner surface convex portion 74a shaped to match the surface of the concave portion 22a1 formed at the end along the X-axis of the base portion 22a of the second core 22 shown in Fig. 2B. In addition, the flat plate piece 73 has an inner surface 73a shaped to match the planar shape of the side end surface 22c2 along the X-axis of the side leg portion 22c of the second core 22 shown in Fig. 2B.

[0042] An inner surface 72a of the base portion 72 of the terminal block 7 shown in Fig. 3 is attached to the upper surface of the base portion 22a of the second core 22 shown in Fig. 2B, and can be fixed, for example, by an adhesive. Also, an inner surface 74a of a bent piece 74 of the terminal block 7 shown in Fig. 3 fits into a recess 22a1 of the base portion 22a of the second core 22 shown in Fig. 2B, and an inner surface 73a of a flat piece 73 of the terminal block 7 shown in Fig. 3 can be closely attached to a side end surface 22c2 of a side leg portion 22c of the second core 22 shown in Fig. 2B. In this embodiment, the terminal block 7 can be directly fixed to the core 2 (specifically, the second core 22) without using a bobbin.

[0043] As shown in Fig. 2B, the cover 70 attached to the terminal block 7 has gripping pieces 70a at both ends in the Y-axis direction, with claws 70b at their tips. The claws 70b engage with inner recesses 72b provided at both ends along the Y-axis of the base plate portion 72 of the terminal block as shown in Fig. 3, so that the cover 70 can be fixed to the terminal block 7.

[0044] 1, the case 8 has a substantially rectangular bottom plate 80 and side plates 81 that are raised from the four sides of the bottom plate 80 along the Z axis to form a bottomed storage space inside, and an upper opening is formed at the upper part along the Z axis. The lower half or more of the coil core assembly 3 is housed inside the case 8, and it is preferable that the liquid level of the heat dissipating resin 82 filled inside the case 8 is at a position where at least the lower half or more of the first wire winding portion 40 and the second wire winding portion 50 are filled with the heat dissipating resin 82. More preferably, the liquid level of the heat dissipating resin 82 filled inside the case 8 is at least at a position where at least the first wire winding portion 40 and the second wire winding portion 50 are filled with the heat dissipating resin 82.

[0045] The heat dissipating resin 82 is also called potting resin, and is made of silicone resin, urethane resin, epoxy resin, etc. that remain soft even after injection, and the longitudinal elastic modulus of the potting resin is preferably 0.1 to 100 MPa. In this embodiment, for example, heat generated in the first winding part 40, the second winding part 50, and the core 2 can be efficiently dissipated from the bottom of the case 8 to the outside through the heat dissipating resin 82 and the case 8, thereby improving the cooling efficiency of the coil device 1. The heat dissipating resin 82 may be filled in the case 8 in advance and then the core coil assembly 3 as shown in FIG. 2A is accommodated therein, or the heat dissipating resin 82 may be poured into the case 8 after the core coil assembly 3 as shown in FIG. 2A is accommodated in the case 8.

[0046] As shown in Fig. 2B, a spacer 10 is disposed between the first opposing end 42 of the first wire winding portion 40 and the second opposing end 52 of the second wire winding portion 50. As shown in Figs. 2D, 4A1, 4A2, 5, and 6A, the spacer 10 has a predetermined thickness t1 (see Fig. 2D) along the winding axis (Z-axis) of the first wire winding portion 40 and the second wire winding portion. The predetermined thickness t1 is not particularly limited, but is, for example, 0.2 to 2.0 mm.

[0047] In this embodiment, the spacer 10 is preferably fixed to the first opposing end 42 of the first wire winding portion 40 and / or the second opposing end 52 of the second wire winding portion 50 by means of thermocompression, adhesion, or the like. Preferably, these are thermocompression-bonded in the axial direction by a thermocompression layer coated on the outer periphery of the wires 4 and 5 constituting the wire winding portions 40 and 50.

[0048] 5, the spacer 10 has a plurality of outer recesses 11 along the circumferential direction, which are recessed from the outer circumferential position of the spacer 10 toward the inner circumferential position of the spacer 10 and do not contact the first opposing end 42 of the first wound portion 40 and the second opposing end 52 of the second wound portion 50. The spacer 10 also has a plurality of inner recesses 12 along the circumferential direction, which are recessed from the inner circumferential position of the spacer 10 toward the outer circumferential position of the spacer 10 and do not contact the first opposing end 42 of the first wound portion 40 and the second opposing end 52 of the second wound portion 50.

[0049] In this embodiment, both the outer periphery and the inner periphery of the ring-shaped spacer 10 have a repeated concave-convex shape, and outer recesses 11 and inner recesses 12 are alternately provided along the circumferential direction. The number of repetitions of the outer recesses 11 or inner recesses 12 along the circumferential direction is not particularly limited, but is preferably about 3 to 20, and more preferably about 5 to 15.

[0050] The outer recess 11 and the inner recess 12 could have been grooves formed on the front or back surface of the spacer 10, but in this embodiment, they are notches formed alternately on the outer and inner peripheral portions of the ring-shaped plate-shaped spacer, and therefore penetrate both the front and back surfaces of the spacer 10.

[0051] Therefore, the outer recess 11 functions as an outer flow path that allows a fluid to flow (including the reverse flow) from the outside to the inside in the radial direction of the first opposing end 42 or the second opposing end 52, and also functions as an axial flow path that allows a fluid to flow (including the reverse flow) from the first opposing end 42 to the second opposing end 52. The inner recess 12 functions as an inner flow path that allows a fluid to flow (including the reverse flow) from the inside to the outside in the radial direction of the first opposing end 42 or the second opposing end 52, and also functions as an axial flow path that allows a fluid to flow (including the reverse flow) from the first opposing end 42 to the second opposing end 52.

[0052] In this embodiment, as shown in Fig. 2D, preferably, the width wo along the circumferential direction of the outer recess 11 is wider at the outer peripheral position than at the inner peripheral position, and preferably, the width wi along the circumferential direction of the inner recess 12 is wider at the inner peripheral position than at the outer peripheral position. Also, under the same radial position, it is preferable that the width wo along the circumferential direction of the outer recess 11 is wider than the width wi along the circumferential direction of the inner recess 12, but they may be the same or vice versa.

[0053] In this embodiment, the spacer 10 is formed into a ring shape that is continuous along the circumferential direction, but it does not necessarily have to be continuous, and there may be a discontinuous part (cut part) that penetrates the outer circumference and the inner circumference at one or more places in the circumferential direction. For example, in this embodiment, all the inner recesses 12 and the outer recesses 11 are continuous along the circumferential direction, but one or more of the inner recesses 12 or the outer recesses 11 may have a cut part that penetrates the outer circumference and the inner circumference.

[0054] 4A1, outer periphery 13, which has the greatest outer diameter along the radial direction of spacer 10, is designed to be close to the inner periphery of side leg 21C or 22c of core 2, and preferably protrudes outward from the outer periphery of wire winding portion 40 or 50, but does not have to protrude or may be flush. By having outer periphery 13 protrude outward from the outer periphery of wire winding portion 40 or 50, contact between wire winding portions 40 and 50 can be effectively suppressed.

[0055] 4A2, inner periphery 14, which has the smallest inner diameter along the radial direction of spacer 10, is designed to be close to the outer periphery of center leg 21b or 22b of core 2, and preferably protrudes inward from the inner periphery of wire winding portion 40 or 50, but does not have to protrude and may be flush. Inner periphery 14 may be in contact with the outer periphery of center leg 21b or 22b of core 2. In the case of contact, heat from center leg 21b or 22b of core 2 is easily transferred to the spacer, improving heat dissipation.

[0056] 4B, there may be a gap between the inner peripheral surface of the wire winding portion 40 or 50 and the outer peripheral surface of the center leg portion 21b or 22b of the core 2, or the inner peripheral surface may be in close contact with the outer peripheral surface of the center leg portion 21b or 22b of the core 2. When there is a gap, the heat dissipation resin 82 shown in FIG.

[0057] 2D, in the coil device 1 according to this embodiment, the spacer 10 having a predetermined thickness is disposed between the first wire winding portion 40 and the second wire winding portion 50, and therefore the distance between the first opposing end 42 of the first wire winding portion 40 and the second opposing end 52 of the second wire winding portion 50 can be controlled by the thickness t1 of the spacer 10. As a result, the leakage of the coil device 1 can be adjusted.

[0058] In addition, in the coil device 1 according to this embodiment, the spacer 10 having a predetermined thickness t1 has an outer recess 11 corresponding to the outer flow path and the axial flow path, and an inner flow path 12 corresponding to the inner flow path and the axial flow path.

[0059] 5, heat dissipating resin 82, which is a cooling fluid, can be drawn between first opposed ends 42 and second opposed ends 52 from the outside to the inside in the radial direction of winding portions 40 and 50 through outer recess 11. Also, inner recess 12 can draw heat dissipating resin 82 between first opposed ends 42 and second opposed ends 52 from the inside to the inside or from the outside to the inside in the radial direction of winding portions 40 and 50.

[0060] Furthermore, in this embodiment, as shown in Fig. 4B, the first opposing end 42 of the winding portion 40 and the second opposing end 52 of the winding portion 50 are formed with a spiral recess 45 or 55 that continues along the circumferential direction in accordance with the spiral shape of the wire 4 or 5 that constitutes the winding portion 40 or 50, respectively. As shown in Fig. 5, the heat dissipating resin 82 drawn into the inside of the winding portion 40 or 50 through the outer recess 11 can also flow into the inner recess 12 located adjacent in the circumferential direction through the spiral recess 45 or 55. Alternatively, conversely, it can flow from the inner recess 12 located adjacent in the circumferential direction to the outer recess 11 through the spiral recess 45 or 55.

[0061] Furthermore, the outer recess 11 and the inner recess 12 are also axial through holes that do not contact both the first opposing end 42 and the second opposing end 52, and therefore allow the heat dissipating resin to flow along the Z-axis direction. In this manner, the heat dissipating resin 82 shown in Fig. 1 can be introduced between the first opposing end 42 and the second opposing end 52, and heat is transferred from the inner periphery side of the winding parts 40 and 50, where heat is most likely to be trapped, to the case 8 via the spacer 10 and the heat dissipating resin 82 located in the recesses 11 and 12, improving the heat dissipation of the coil device 1.

[0062] In this embodiment, the outer recess 11 and the inner recess 12 formed in the spacer 10 also serve as a plurality of flow path forming regions from which the members constituting the spacer 10 have been removed and which do not come into contact with the first opposing end 42 of the winding portion 40 and the second opposing end 52 of the winding portion 50. Furthermore, these plurality of flow path forming regions are present at a plurality of positions along the circumferential direction of the spacer 10.

[0063] By providing the surface of the spacer 10 with flow path forming regions in a plurality of locations along the circumferential direction where no components constituting the spacer 10 are present, it becomes possible for the heat dissipating resin, which is a cooling fluid, to be introduced between the first opposed end 42 and the second opposed end 52 at a plurality of locations along the circumferential direction, further improving the heat dissipation of the coil device 1. Even if the flow path forming regions are formed at a plurality of locations along the circumferential direction, the spacer 10 has a predetermined thickness t1, so that the leakage adjustment of the coil device 1 is well maintained.

[0064] In addition, in this embodiment, as shown in FIG. 2D, the circumferential width of the outer recess 11 is wider at the outer circumferential position compared to the inner circumferential position, making it easier to draw the heat dissipating resin 82 between the first opposing end 42 and the second opposing end 52 from the outside to the inside in the radial direction of the winding portion 40 or 50.

[0065] 2D, the width of the inner recess 12 along the circumferential direction is wider at the inner circumferential position than at the outer circumferential position, which makes it easier to draw the heat dissipating resin 82 between the first opposing end 42 and the second opposing end 52 from the inside to the outside in the radial direction of the winding portion 40 or 50. Alternatively, the heat dissipating resin 82 can be drawn between the first opposing end 42 and the second opposing end 52 along the inner recess 12 from the outside to the inside in the radial direction of the winding portion 40 or 50, and the heat dissipating resin 82 can be stored at the inner circumferential position where the width of the inner recess 12 is wider, thereby improving heat dissipation from the inside of the winding portion 40 or 50 and the outer circumferential surface of the middle leg portion 21b or 22b of the core 2.

[0066] In this embodiment, the inner recess 12 and the outer recess 11 are arranged adjacent to each other along the circumferential direction, so that the heat dissipating resin can be drawn between the first opposing end 42 and the second opposing end 52 in both the radial direction of the winding portion 40 or 50 from the inside to the outside and from the outside to the inside, thereby further improving the heat dissipation. In addition, the heat dissipating resin 82 can also flow between the adjacent inner recess 12 and outer recess 11 through, for example, the spiral recess 45 or 55 formed in the first opposing end 42 or the second opposing end 52.

[0067] Further, in this embodiment, as shown in Fig. 2D, the width wo of the outer recess 11 along the circumferential direction is made wider than the width wi of the inner recess 11 along the circumferential direction. As shown in Fig. 4B, the middle leg parts 21b and 22b of the core 2 are arranged in close contact with the inner peripheral part 14 which is the central opening of the spacer 10, so that it is easier to make the flow of the heat dissipating resin 82 from the outside to the inside in the radial direction of the spacer 10 than the flow of the heat dissipating resin 82 from the inside to the outside in the radial direction of the spacer 10. Therefore, by making the width wo of the outer recess 11 along the circumferential direction wider than the width wi of the inner recess 12 along the circumferential direction, it becomes easier to draw the heat dissipating resin 82 between the first opposing end 42 and the second opposing end 52.

[0068] Furthermore, in this embodiment, at least one of the first wire 4 constituting the first wire winding portion 40 and the second wire 5 constituting the second wire winding portion 50 is made of a conductor coated with an insulating layer having at least a heat-sealing layer. This configuration makes it easier to join parts of the wires 4 or 5 that contact each other for each winding turn by heat fusion, making it easier to form an air-core coil in which the wires 4 or 5 are wound in a coil shape. In addition, by combining the first wire winding portion 40, the spacer 10, and the second wire winding portion 50 and thermocompressing them in the winding axis direction, it becomes easier to manufacture the coil body 30 in which the first wire winding portion 40, the spacer 10, and the second wire winding portion 50 are integrated.

[0069] In this embodiment, the spacer 10 may be made of an insulating material and / or a metal material. Examples of insulating materials include synthetic resin, ceramic, and glass. When the spacer 10 is made of an insulating material, the insulation between the first wire winding portion 40 and the second wire winding portion 50 is also improved. In particular, in the case of ceramic, it is difficult to deform even when used at high temperatures, so it is easy to stabilize the coil characteristics regardless of temperature. When the spacer 10 is made of a metal material, the heat transfer characteristics of the spacer 10 itself are improved, and the heat dissipation is further improved. In addition, when the spacer 10 is made of a metal material, it is preferable that the wires 4 and 5 are wires coated with an insulating film. The spacer 10 may also be made of a composite member of a metal member and an insulating member. For example, the spacer 10 may be a member in which the surface of a metal plate is coated with an insulating member such as resin. Alternatively, the spacer 10 may be made of an insulating member in which metal powder is dispersed inside.

[0070] Second embodiment In this embodiment, the coil device is assembled in the same manner as in the above-described embodiments, except that spacers 10b to 10i shown in FIGS. 6B to 6I are used instead of the spacer 10 shown in FIG. 6A used in the first embodiment.

[0071] In the spacer 10b shown in FIG. 6B, the number of repetitions of the outer recess 11 and the inner recess 12 along the circumferential direction is different from that of the spacer 10 shown in FIG. 6A. In addition, in the spacer 10 shown in FIG. 6A, the shape connecting the inner periphery 14 along the circumferential direction is elliptical, whereas in the spacer 10 shown in FIG. 6B, the shape connecting the inner periphery 14 along the circumferential direction is circular. Similarly, in the spacer 10 shown in FIG. 6A, the shape connecting the outer periphery 12 along the circumferential direction is elliptical, whereas in the spacer 10 shown in FIG. 6B, the shape connecting the outer periphery 12 along the circumferential direction is circular. In accordance with the shapes of the inner periphery 14 and the outer periphery 13 of the spacer 10b, the outer periphery shape of the center leg 21b or 22b of the core 2 and the inner periphery shape of the side leg 21c or 22c are circular.

[0072] A spacer 10c shown in FIG. 6C is a modified version of the spacer 10b shown in FIG. 6B, and is similar to the spacer 10b except that the ratio of the circumferential width of the outer recess 11 to the circumferential width of the inner recess 12 is different.

[0073] A spacer 10d shown in Fig. 6D is a modified example of the spacer 10 shown in Fig. 6A, and does not have the outer recess 11 and the inner recess 12 of the spacer 10 shown in Fig. 6A, and the overall shape of the spacer 10d is an elliptical ring plate, and a plurality of through holes 16 that are elongated in the radial direction are arranged at predetermined intervals along the circumferential direction. Other than that, it is the same as the first embodiment described above.

[0074] 6D, a cooling fluid such as heat dissipating resin 82 can be circulated between the first opposed end 42 and the second opposed end 52 through the through hole 16. Note that the through hole 16 is a flow path forming region that is not in contact with both the first opposed end 42 and the second opposed end 52, and is configured not to be in contact with both.

[0075] A spacer 10e shown in Fig. 6E is a modified example of the spacer 10d shown in Fig. 6D, in which the shape of the through holes 16 has changed from an elongated hole to a circular shape. A spacer 10f shown in Fig. 6F is a modified example of the spacer 10d shown in Fig. 6D, in which each through hole 16 of the spacer 10d communicates with the inner periphery of the spacer 10d to form an inner recess 12. In other words, the through holes also serve as the inner recess 12.

[0076] 6G is a modified example of the spacer 10d shown in FIG. 6D, in which each through hole 16 of the spacer 10d communicates with the outer periphery of the spacer 10d and forms an outer recess 11. In other words, the through holes also serve as the outer recess 11.

[0077] A spacer 10h shown in FIG. 6H is a modified example of the spacer 10g shown in FIG. 6G, and the circumferential width of each outer recess of the spacer 10h is different from the circumferential width of the outer recess 11 of the spacer 10g.

[0078] Furthermore, a spacer 10i shown in FIG. 6i is an example in which the outer recesses 11 of the spacer 10g shown in FIG. 6G and the inner recesses 12 of the spacer 10f shown in FIG. 6F are formed alternately along the circumferential direction.

[0079] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0080] For example, in the above-described embodiment, the first opposing end 42 of the first wire winding portion 40 or the second opposing end 52 of the second wire winding portion 50 may be joined to the surface of the spacer 10 using a joining method other than thermocompression bonding, such as using an adhesive.

[0081] In the above embodiment, the first wire 4 constituting the first wire winding section 40 and the second wire 5 constituting the second wire winding section 50 are each composed of separate wires, but the first wire 4 and the second wire 5 may be composed of a single continuous wire. In that case, the first wire winding section 40 and the second wire winding section 50 form a continuous single coil without constituting a transformer in the circuit, and can be used as a part of a transformer or as a coil device other than a transformer. Examples of coil devices other than a transformer include inductors, resonant coils, choke coils, PFC coils, and reactor coils.

[0082] Although the spacers 10, 10b to 10i are ring-shaped, they may be partially cut out or divided in the circumferential direction. The spacers 10, 10b to 10i are preferably configured as a single layer along the Z-axis (winding axis) direction, but may be configured as a laminate of multiple spacers.

[0083] The spacers 10, 10b to 10i may be meshes themselves, or radial or mesh-like grooves that connect the outside and inside of the spacer in the radial direction may be formed on one or both sides of the spacer.

[0084] In the above-described embodiment, the flow path forming region of the spacers 10, 10b to 10i is configured by a notch or a through hole penetrating the front and back surfaces of the spacer, but the flow path forming region may be a groove formed on only one surface of the spacers 10, 10b to 10i, or may be a groove formed on both surfaces of the spacer.

[0085] For example, the outer recess 11 may be a notch or a groove as long as it is recessed from the outside to the inside in the radial direction of the winding portion 40 or 50 and is not in contact with at least one of the first opposing end 42 and the second opposing end 52. Furthermore, at least a portion of the outer recess 11 or the inner recess 12 may penetrate the spacer 10 from the outside to the inside in the radial direction.

[0086] In the coil device 1 of this embodiment, the coil core assembly 3 shown in Fig. 2A is housed inside a case 8 filled with a heat dissipating resin to improve heat dissipation, but in some cases, the case 8 and the heat dissipating resin 82 may not be necessary. For example, a cooling fluid such as cooling air may be directly applied to the coil core assembly 3 shown in Fig. 2A.

[0087] Moreover, a coil device may be assembled by combining any of the above-described embodiments. [Explanation of symbols]

[0088] 1...Coil device 2. Core 21…First core 21a…Base section 21b...middle leg 21b1...Tip 21c...Side leg 21c1...Tip 22…Second core 22a…Base section 22a1...recess 22b…middle leg 22b1...tip 22c...Side leg 22c1...Tip 22c2…Side end surface 3...Coil core assembly 30…Coil body 4…First wire 40…First wire winding portion 41a, 41b...Lead section 42…First opposing end 45…Spiral recess 5…Second wire 50...Second wire winding section 51a, 51b...Lead section 52...Second opposing end 55…Spiral recess 6…Terminal 60...Terminal base 61...Connection section 62…External connection part 7...Terminal block 70…Cover 70a...Gripping piece 70b…Claw part 70c...Through hole 71…Mounting groove 72…Base plate section 72a…Inner surface 72b…Inner recess 73...Flat piece 73a…Inner surface 74...Bending piece 74a…Inner surface 8. Case 80...Bottom plate 81…Side panel 82…Heat dissipating resin 9…Heat sink 90…Tabletop 91…Side 10…Spacer 11...Outer recess 12…Inner recess 13...Outer periphery 14...Inner circumference 16...Through hole

Claims

1. A first wire winding; a second wire winding portion disposed adjacent to the first wire winding portion along a winding axis of the first wire winding portion; a spacer disposed between first opposing ends of the first wire winding portion along the winding axis and a second opposing end of the second wire winding portion along the winding axis, The spacer has a predetermined thickness along the winding axis, and The spacer is A coil device having at least one of an outer flow passage that allows a fluid to flow from the outside to the inside in the radial direction of the first opposing end or the second opposing end, an inner flow passage that allows a fluid to flow from the inside to the outside in the radial direction of the first opposing end or the second opposing end, and an axial flow passage that allows a fluid to flow from the first opposing end toward the second opposing end.

2. At least one of the outer flow passage, the inner flow passage, and the axial flow passage has a plurality of flow passage forming regions in which a member constituting the spacer is removed and which does not contact the first opposing end and / or the second opposing end, The coil device according to claim 1 , wherein a plurality of the flow passage forming regions are present at a plurality of positions along the circumferential direction of the spacer.

3. The coil device according to claim 2, wherein at least one of the plurality of flow path forming regions has an outer recess that is recessed from an outer peripheral position of the spacer toward an inner peripheral position thereof and does not contact the first opposing end and / or the second opposing end.

4. The coil device according to claim 3 , wherein a width of the outer recess along the circumferential direction is larger at the outer circumferential position than at the inner circumferential position.

5. The coil device according to claim 2, wherein at least one of the plurality of flow path forming regions has an inner recess that is recessed from an inner peripheral position of the spacer toward an outer peripheral position thereof and does not contact the first opposing end and / or the second opposing end.

6. The coil device according to claim 5 , wherein a width of the inner recess along the circumferential direction is larger at the inner circumferential position than at the outer circumferential position.

7. The coil device according to claim 2 , wherein at least one of the plurality of flow passage forming regions has a through hole that communicates from the first opposing end to the second opposing end.

8. The plurality of flow path forming regions include an inner recess that is recessed from an inner peripheral position of the spacer toward an outer peripheral position thereof and does not contact the first opposing end and / or the second opposing end; 3. The coil device according to claim 2, further comprising: an outer recess arranged circumferentially adjacent to the inner recess, recessed from an outer peripheral position of the spacer toward an inner peripheral position, and not in contact with the first opposing end and / or the second opposing end.

9. The coil device according to claim 8 , wherein a width of the outer recess along a circumferential direction is greater than a width of the inner recess along the circumferential direction.

10. A first wire winding; a second wire winding portion disposed adjacent to the first wire winding portion along a winding axis of the first wire winding portion; a spacer disposed between first opposing ends of the first wire winding portion along the winding axis and a second opposing end of the second wire winding portion along the winding axis, The spacer has a predetermined thickness along the winding axis, and The spacer is A coil device having at least one of an outer recess that allows a fluid to flow from the outside to the inside in the radial direction of the first opposing end or the second opposing end, an inner recess that allows a fluid to flow from the inside to the outside in the radial direction of the first opposing end or the second opposing end, and a through hole that allows a fluid to flow from the first opposing end to the second opposing end.

11. A coil device as described in any one of claims 1 to 10, wherein at least one of the first wire constituting the first wire winding portion and the second wire constituting the second wire winding portion is made of a conductor coated with an insulating layer having at least a heat-sealing layer.

12. A coil device according to any one of claims 1 to 10, wherein the first opposing end of the first wire winding portion or the second opposing end of the second wire winding portion is joined to a surface of the spacer.

13. The coil device according to any one of claims 1 to 10, wherein the spacer is made of an insulating material and / or a metallic material.

14. Further comprising a core; the spacer has a central opening extending therethrough along the winding axis; The coil device according to any one of claims 1 to 10, wherein the core has a middle leg portion disposed in the central opening through the first wire winding portion or the second wire winding portion.

15. The coil device according to claim 14, wherein the core further has a side leg portion covering at least a portion of an outer periphery of the first wire winding portion or an outer periphery of the second wire winding portion, and a predetermined gap is provided between the outer periphery end of the spacer and an inner periphery of the side leg portion.

16. a case that accommodates the first wire winding portion and at least a portion of the second wire winding portion; A coil device as described in any one of claims 1 to 10, wherein the inside of the case is filled with heat dissipating resin at least up to a position where the spacer located between the first wire winding portion and the second wire winding portion is immersed.

Images