Coil device

Abstract

To provide a highly reliable coil device capable of effectively preventing insulation failure and disconnection of a lead portion of a wire.SOLUTION: A coil device includes: a core 2; a winding portion 3 of a wire; and a base plate portion 50 to which terminals 4a, 4b are attached to which lead portions 31a to 34a, 31b to 34b of the wire drawn out from the winding portion 3 are connected. The core 2 is installed on a first surface 50a on one side of the base plate portion 50. Joint portions 41a, 41b of the terminal are installed on a second surface 50b of the other side located at an opposite side to the first surface 50a. On the base plate portion 50, base side paths 51, 52 are formed that allow a lead portion of the wire from the winding portion 3 to pass therethrough and guide it to the joint portions 41a, 41b.SELECTED DRAWING: Figure 2A

Description

Technical Field

[0001] The present invention relates to a coil device used in various electronic devices.

Background Art

[0002] For example, a coil device shown in Patent Document 1 is known. In this coil device, the terminal (lead portion) of the wire wound in a coil shape is configured to be prevented from being on the base. For this purpose, a protruding portion is provided on the side surface of the base, and the coil terminal is configured to pass from below the protruding portion toward the terminal.

[0003] However, in such a configured coil device, in order to perform wire connection outside the side surface of the base plate portion, the lead portion of the wire abuts on the outer peripheral edge of the base plate portion, and the insulating coating of the lead portion of the wire is likely to be damaged, and there is a risk of insulation failure or disconnection of the lead portion of the wire.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of such a situation, the present invention is made, and its object is to provide a coil device capable of effectively preventing insulation failure and disconnection of the lead portion of the wire and having excellent reliability.

Means for Solving the Problems

[0006] To achieve the above object, a coil device according to an aspect of the present invention includes a core having a bobbin portion, a winding portion of a wire disposed in a coil shape around the bobbin portion, A coil device having a base plate portion to which a terminal to which a lead portion of the wire drawn from the winding portion is connected, The core having the bobbin portion is installed on one first surface of the base plate portion, A connecting wire portion of the terminal is disposed on the other second surface of the base plate portion located on the side opposite to the first surface, A base-side passage is formed in the base plate portion to guide the lead portion of the wire from the winding portion through the connecting wire portion.

[0007] In the coil device according to one aspect of the present invention, since a base-side passage for guiding the lead portion of the wire from the winding portion to the connecting wire portion is formed in the base plate portion, it is difficult for the lead portion of the wire to contact the outer peripheral edge of the base plate portion. Therefore, the insulating coating of the lead portion of the wire is hardly damaged, it is possible to effectively prevent insulation failure and disconnection of the lead portion of the wire, and the reliability of the coil device is improved.

[0008] Preferably, the base-side passage formed in the base plate portion is a notch-shaped recess or a through hole penetrating the first surface and the second surface. By configuring in this way, when guiding the lead portion of the wire through the notch-shaped recess or the through hole through the base plate portion, it becomes difficult for the lead portion of the wire to contact the outer peripheral edge of the base plate portion.

[0009] It is preferable that the inner peripheral edge end of the base-side passage extends close to the bobbin portion. By configuring in this way, when guiding the lead portion of the wire from the winding portion of the wire arranged around the bobbin portion to the connecting wire portion located on the second surface of the base plate portion, it becomes more difficult for the lead portion of the wire to contact the outer peripheral edge of the base plate portion.

[0010] The core may have a flange portion magnetically connected to the bobbin portion. Preferably, the flange portion is disposed on the base plate portion and has a core-side passage communicating with the base-side passage. By configuring in this way, the lead portion of the wire can be easily guided from the winding portion of the wire disposed around the bobbin portion to the connection portion of the wire located on the second surface of the base plate portion through the core-side passage and the base-side passage in sequence.

[0011] Therefore, it becomes more difficult for the lead portion of the wire to come into contact with the outer peripheral edge of the base plate portion, and it also becomes difficult for the lead portion of the wire to come into contact with the outer peripheral edge of the flange portion of the core. As a result, the insulating coating of the lead portion of the wire is less likely to be damaged, and it is possible to more effectively prevent insulation failure and disconnection of the lead portion of the wire, and the reliability of the coil device is further improved.

[0012] The base plate portion may have a convex portion that surrounds at least a part of the core including the flange portion so as to protrude from the first surface of the base plate portion. This convex portion can position the core with respect to the base plate portion and can improve the insulation between the core disposed on the first surface and the connection portion of the terminal disposed on the second surface.

[0013] The core-side passage may have at least a pair of core-side passages. Preferably, one and the other of the pair of core-side passages are located on opposite sides around the bobbin portion. By configuring in this way, it becomes possible to use, for example, passing the lead portion of the wire constituting the primary-side coil through one of the pair of core-side passages and passing the lead portion of the wire constituting the secondary-side coil through the other, and it becomes easier to position the terminals where the leads of the wires that require high insulation are connected on opposite sides around the bobbin portion.

[0014] The coil device may further have a case that houses the core and the winding portion of the wire so that at least the winding portion of the wire disposed around the bobbin portion is covered. Preferably, the inside of the case is filled with a heat-dissipating resin up to a position where at least a part of the winding portion of the wire is immersed.

[0015] By filling with a heat-dissipating resin, the heat generated in the core winding portion and the wire winding portion of the core can be efficiently transmitted to the case through the heat-dissipating resin, and the coil device can be effectively cooled. Further, the heat-dissipating resin and the case can effectively protect the wire winding portion and the core. When the case is made of metal, the heat dissipation is further improved, but the case may be made of resin (preferably a resin excellent in heat dissipation), and in that case, the insulation property is improved.

[0016] The heat-dissipating resin may be filled in the case so as to cover the wire connecting portion of the terminal disposed on the second surface of the base plate portion. By configuring in this way, since the wire connecting portion is covered with the heat-dissipating resin, the wire connecting portion can also be protected.

[0017] The terminal may have the wire connecting portion, a connecting portion formed at one end of the wire connecting portion, and an external connection portion formed at the other end of the connecting portion. Preferably, the connecting portion is fixed to a fixing convex portion formed to protrude from the second surface of the base plate portion, and the top of the fixing convex portion and the external connection portion of the terminal protrude from the heat-dissipating resin. Since the external connection portion of the terminal protrudes from the heat-dissipating resin, the mounting of the coil device becomes easy.

Brief Description of the Drawings

[0018]

Figure 1A

Figure 1B

Figure 2A

Figure 2B

Figure 3

Figure 4

Figure 5

Figure 6

DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments will be described with reference to the drawings. Note that the illustrated content is only shown schematically and exemplarily, and the appearance, dimensional ratios, etc. may be different from the actual object. Also, the present invention is not limited to the following embodiments.

[0020] First Embodiment The coil device 1 according to the embodiment shown in FIG. 1A is used, for example, as a transformer and is used in a charger or a power supply circuit of various electrical devices. The coil device 1 includes a core 2, a coil body (wire winding portion) 3, terminals 4, a terminal block 5, and a case 6. 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 (coil winding axis direction) of the coil device 1. 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 inner side, and the direction away from the center of the coil device 1 is referred to as the outer side.

[0021] As shown in FIG. 2A, the core 2 is configured by assembling a first core 21 disposed on the lower side along the Z-axis and a second core 22 disposed on the upper side along the Z-axis of the first core 21. The first core 21 and the second core 22 are each configured by an E-shaped core having a substantially E-shaped cross section parallel to the plane including the Z-axis and the X-axis, but they may be cores of different types.

[0022] For example, one core may be an E-shaped core and the other core may be an I-shaped core. Further, in the present embodiment, the core 2 is configured by combining the two-divided cores 21 and 22. However, the core is not limited to two divisions, and for example, it can also be configured by combining cores divided into three or four or more parts.

[0023] In the present embodiment, as shown in FIG. 6, the first core 21 has a flange portion 21a having a bottom surface parallel to the plane including the X-axis and the Y-axis, a middle leg portion (winding core portion) 21c extending upward along the Z-axis from the center of the flange portion 21a, and a pair of side leg portions 21b extending upward along the Z-axis from both ends of the flange portion 21a along the X-axis.

[0024] Further, as shown in FIG. 2A, the second core 22 has a flange portion 22a having an upper surface parallel to the plane including the X-axis and the Y-axis, a middle leg portion 22c extending downward along the Z-axis from the center of the flange portion 22a, and a pair of side leg portions 22b extending downward along the Z-axis from both ends of the flange portion 22a along the X-axis. In the present embodiment, the cross section perpendicular to the Z-axis of the middle leg portions 21c and 22c is circular, but it may be, for example, elliptical, polygonal, or other shapes.

[0025] In the present embodiment, a pair of first recesses 24 and second recesses 25 are formed in the flange portion 21a of the core 21 close to the terminal block 5 among the cores 21 and 22. The second core 22 has the same configuration as the first core 21 except that the recesses 24 or 25 are not formed.

[0026] As shown in FIG. 6, the first recess 24 and the second recess 25 are located on opposite sides along the Y-axis with the middle leg portion 21c interposed therebetween, and are each formed to be recessed in a notch shape from the outer peripheral edge of the flange portion 21a toward the middle core portion 21c along the Y-axis. Each of the recesses 24 and 25 penetrates the flange portion 21a so that one surface and the other surface of the flange portion 21a along the Z-axis communicate with each other. As will be described later, each of the recesses 24 and 25 constitutes a core-side passage for the lead portions 31a to 34a and 31b to 34b of the wires 31 to 34 shown in FIG. 2A to pass through.

[0027] As shown in Fig. 6, the recess 24 is formed so as to extend along the radial direction of the middle leg portion 21c toward the middle leg portion 21c. The depth D1 along the Y-axis from the open end to the recess bottom end 24a of the recess 24 is determined such that the gap D2 between the recess bottom end 24a and the middle leg portion 21c is 0 or more, and the gap D2 is preferably 1 mm or less. By reducing the gap D2, for example, it becomes easier to pass the lead portions 31a and 31b of the innermost peripheral side wire 31 disposed around the middle leg portion 21c through the recess 24, and the risk of the lead portions 31a and 31b contacting the core 21 can be reduced.

[0028] The distance between the pair of concave side ends 24b of the recess 24, that is, the width W1 along the X-axis of the recess 24, is smaller than, for example, the width W2 along the X-axis of the flange portion 21a excluding the side leg portion 21b, and is preferably smaller than the width W3 along the X-axis of the middle leg portion W3. Further, the width W1 is larger than the wire diameters of the wires 31 to 34 shown in Fig. 2A, and is preferably 1.5 times or more the wire diameters of the wires 31 to 34. The width W1 and the depth D1 of the recess 24 are determined such that the wires 31 to 34 passing through the recess 24 can easily enter the recess 24 and do not deteriorate the magnetic characteristics of the core 21.

[0029] Note that the shape of the recess bottom end 24a is a flat surface in the present embodiment, but is not limited thereto, and may be a curved surface shape. The recess bottom end 24a and the concave side end 24b are continuous, and the corner edges where each of the ends 24a and 24b intersects with the upper surface or the lower surface of the flange portion 21a are preferably processed into a curved surface or a tapered surface. By configuring in this way, even if the lead portions 31a, 31b, 33a, and 33b of the wires 31 and 33 passing through the recess 24 contact the core 21, damage to these wires 31 and 33 can be minimized.

[0030] The recess bottom end 25a and the concave side end 25b of the recess 25 are determined in terms of shape and size in the same manner as the recess bottom end 24a and the concave side end 24b of the recess 24, and are preferably of the same shape and the same size, but the shapes do not necessarily have to be the same, and the sizes may also be different.

[0031] The cores 21 and 22 are not particularly limited as long as they are cores each having a magnetic material, and for example, they may be composed of ferrite, a metal magnetic material, or a resin containing magnetic powder. In the present embodiment, the tip of the middle leg portion 21c shown in FIG. 6 and the tip of the middle leg portion 22c shown in FIG. 2A are butted against each other to form a bobbin core portion, and the tip of the side leg portion 21b and the tip of the side leg portion 22b are butted against each other and in contact. However, in another embodiment, the tips of the middle leg portions 21c and 22c may not be in direct contact with each other, and a gap may be formed therebetween. A heat-dissipating resin 63 shown in FIG. 1B may enter the gap, or other members may be interposed.

[0032] As shown in FIG. 2A, the two cores 21 and 22 may be integrated using an adhesive after mounting the coil body 3 therebetween, or may be integrated using a fixing tape or the like, or they may be integrated in combination. As the adhesive, a resin material having good thermal conductivity such as heat-dissipating grease may be used.

[0033] In the present embodiment, the coil body 3 is a wire winding portion around which a plurality of wires 31 to 34 are wound. For example, in the present embodiment, the winding portion of the wire 32 is arranged around the winding portion of the wire 31, the winding portion of the wire 33 is arranged around the winding portion of the wire 32, and the winding portion of the wire 34 is arranged around the winding portion of the wire 33. For example, the wire 31 has a pair of lead portions 31a and 31b drawn out from the winding portion of the wire 31, the wire 32 has a pair of lead portions 32a and 32b drawn out from the winding portion of the wire 32, the wire 33 has a pair of lead portions 33a and 33b drawn out from the winding portion of the wire 33, and the wire 34 has a pair of lead portions 34a and 34b drawn out from the winding portion of the wire 34.

[0034] In this embodiment, each of the wires 31 to 34 is constituted by, for example, a self-fusing conductive wire having an insulating layer and a fusing layer. The type of the conductive wire is not particularly limited, and examples of the conductive core wire include round wire, flat wire, stranded wire, Litz wire, braided wire, etc. The material of the fusing layer or insulating layer covering the core wire is not particularly limited, and examples thereof include polyurethane, polyamideimide, polyimide, polyester, etc.

[0035] Note that in this embodiment, all of the wires 31 to 34 are constituted by self-fusing wires, but at least one of them may be a self-fusing wire, or all of them may be constituted by other wires.

[0036] The wire diameters of these wires 31 to 34 may be the same or different, and are not particularly limited, but may be, for example, within the range of 1.0 to 3.0 mm. These wires 31 to 34 may be directly wound in a coil around at least one of the middle legs 21c and / or 22c of the cores 21 or 22, but it is preferably formed as an air-core coil in advance and then disposed around the middle legs 21c, 22c of the cores 21, 22.

[0037] As shown in FIG. 2A, a plurality of terminals 4a, 4b are mounted on the terminal block 5. In this embodiment, the terminal block 5 has two types of terminals 4a, 4b, but it may have one type of terminal, or may have three or more types of terminals. In this embodiment, two pairs of each of the two types of terminals 4a, 4b are mounted on both ends along the Y axis of the terminal block 5.

[0038] As shown in FIG. 3, the terminal 4a has a wire connecting portion 41a, an external connection portion 43, and a connecting portion 42 connecting these. The terminal 4b has a wire connecting portion 41b, an external connection portion 43, and a connecting portion 42 connecting these. The difference between the terminal 4a and the terminal 4b is that they have the same configuration except that the length of the wire connecting portion 41a is longer than the length of the wire connecting portion 41b. These terminals 4a, 4b can be formed, for example, by pressing a single metal plate.

[0039] In this embodiment, these multiple terminals 4a and 4b are attached by insert molding to a terminal block 5 as will be described later, but they may also be attached by inserting them into the terminal block 5 or by adhesion.

[0040] As shown in FIG. 6, in this embodiment, the terminal block 5 has a base plate portion 50 having a plane parallel to the X-axis and the Y-axis. The shape of the outer peripheral edge of the base plate portion 50 is rectangular in accordance with the outer peripheral edge shape of the first core 21 (and the second core 22), but other shapes such as polygons, circles, ellipses, and other shapes may also be used.

[0041] The base plate portion 50 has a first surface 50a to which the lower surface along the Z-axis of the flange portion 21a of the first core 21 is attached, and a second surface 50b located on the opposite side thereof. The lower surface along the Z-axis of the flange portion 21a of the first core 21 may be fixed to the upper surface of the base plate portion 50 with an adhesive or other means. Also, the first core 21 and the second core 22 may be fixed by an adhesive or by other methods.

[0042] On the base plate portion 50, first recesses 51 and second recesses 52 are formed in accordance with the positions of the recesses 24 and 25 of the first core 21. The first recesses 51 and the second recesses 52 are located on opposite sides along the Y-axis with the middle leg portion 21c of the core 21 interposed therebetween, and are each formed to be recessed in a notch shape from the outer peripheral edge of the base plate portion 50 toward the center along the Y-axis.

[0043] Each of the recesses 51 and 52 penetrates the base plate portion 50 so that one first surface 50a and the other second surface 50b along the Z-axis of the base plate portion 50 communicate with each other. Each of the recesses 51 and 52 is aligned with and communicates with each of the recesses 24 and 25, and constitutes a base-side passage for the lead portions 31a to 34a and 31b to 34b of the wires 31 to 34 shown in FIG. 2A to pass through.

[0044] As shown in FIG. 6, the depth D2 along the Y-axis from the opening end to the bottom end 51a of the recess 51 is preferably approximately equal to the depth D1 of the first recess 24 of the core 21, and may be larger than that, but it is preferable that the recesses 51 and 52 are not connected. The distance between the pair of concave side ends 51b of the recess 51, that is, the width W2 along the X-axis of the recess 51 is preferably about the same as the width W1 of the recess 24 of the core 21, for example, but may be wider than that. The width W2 and the depth D2 of the recess 51 are determined so that the wires 31 to 34 passing through the recess 51 can easily enter the recess 51.

[0045] Note that the shape of the bottom end 51a of the recess 51 is a flat surface in this embodiment, but is not limited thereto, and may be a curved surface shape. The bottom end 51a and the concave side ends 51b are continuous, and the corner edges where each of the ends 51a, 51b intersects with the first surface 50a or the second surface 50b of the base plate portion 50 are preferably processed into a curved surface or a tapered surface. By configuring in this way, even if the lead portions 31a, 31b, 33a, 33b of the wires 31 and 33 passing through the recess 51 come into contact with the bottom end 51a or the concave side ends 51b, damage to these wires 31 and 33 can be minimized.

[0046] The bottom end 52a and the concave side ends 52b of the recess 52 are determined in terms of shape and size in the same manner as the bottom end 51a and the concave side ends 51b of the recess 51, and are preferably of the same shape and the same size, but the shapes do not necessarily have to be the same, and the sizes may also be different.

[0047] On the outer peripheral edge of the base plate portion, there is a frame-shaped convex portion 53 that surrounds at least a part of the core 21 including the flange portion 21a so as to project upward along the Z-axis from the first surface 50a of the base plate portion 50. In the present embodiment, the frame-shaped convex portion 53 is integrally formed on the base plate portion 50 so as to surround the outer peripheral edge of the core 21 other than the recesses 24 and 25. The protruding height of the frame-shaped convex portion along the Z-axis is not particularly limited, and for example, it may be larger than 1 / 5 of the thickness of the flange portion 21a along the Z-axis and equal to or less than the equivalent of that thickness. The size of the inner peripheral edge of the frame-shaped convex portion 53 is determined such that the flange portion 21a of the core 21 fits within the frame-shaped convex portion 53, and the positions of the recesses 24 and 25 of the flange portion 21a and the positions of the recesses 51 and 52 of the base plate portion 50 can be aligned with each other, respectively.

[0048] As shown in FIG. 3, in the central portion along the Y-axis of the second surface 50b of the base plate portion 50, a reinforcing rib 54 extending along the X-axis is integrally formed with the base plate portion 50. In the portion where the reinforcing rib 54 is located, compared with other portions, it protrudes from the second surface 50b of the base plate portion 50, the thickness of the plate becomes larger, and the strength of the base plate portion 50 where the recesses 51 and 53 are formed is reinforced, effectively preventing deformation such as warping of the base plate portion 50.

[0049] Also, at both ends of the base plate portion 50 along the Y-axis, fixing convex portions 55 are integrally formed so as to project downward along the Z-axis from the second surface 50b in portions other than the recesses 51 and 52. The protruding height of the fixing convex portions 55 from the second surface 50b is preferably larger than the protruding height of the reinforcing rib 54. The fixing convex portions 55 are separated into a total of four along the X-axis by the respective recesses 51 or 52, and a pair of terminals 4a and 4b are fixed to each convex portion 55, respectively.

[0050] Actually, the connecting portions 42 of the respective terminals 4a and 4b are integrally formed so as to be embedded in the fixing portion 55. As shown in FIG. 1B, the wire connecting portions 41a and 41b are located on the second surface 50b side of the base plate portion 50 from the inside (the central side along the Y axis) of the fixing portion 55. Further, the external connection portions 43 of the respective terminals 4a and 4b protrude from the protruding top of the fixing portion 55 and extend to the outside of the case 6. The external connection portion 43 is connected to an external connection terminal (not shown) or a terminal connection portion of a circuit board.

[0051] In this embodiment, the respective wire connecting portions 41a and 41b protrude linearly from the fixing portion 53, but are not limited thereto and may protrude in a curved shape. Further, the protruding tips of the wire lead portions 31a, 31b (or 32a, 32b) and the lead portions 33a, 33b (or 34a, 34b) taken out to the second surface 50b side through the same recess 51 (or 52) and connected to each other are directed to the same side along the Y axis, but the arrangement is not limited to such.

[0052] In this embodiment, the terminal block 5 preferably has at least the base plate portion 50, and preferably has at least one of the frame-shaped convex portion 53, the reinforcing rib 54, or the fixing convex portion 55. These are integrally formed together with the terminals 4a and 4b by insert molding of an insulating resin or the like. Note that the terminal block 5 including the base plate portion 50 may be made of an insulating member other than resin.

[0053] Also, in this embodiment, the lead portions 31a, 31b, 33a, and 33b of the wires 31 and 33 shown in FIG. 2A pass through the first recess 24 of the core 21 and the first recess 51 of the base plate portion 50, and as shown in FIG. 1B, are respectively connected to the tips of the wire connecting portions 41a and 41b arranged in contact or non-contact on the second surface 50b.

[0054] Further, each lead portion 32a, 32b, 34a, 34b of the wires 32 and 34 shown in FIG. 2A passes through the second recess 25 of the core 21 and the second recess 52 of the base plate portion 50, and as shown in FIG. 1B, is connected to the tip of each connecting wire portion 41a, 41b disposed in contact or non-contact on the second surface 50b, respectively.

[0055] The method of these connections is not particularly limited, but caulking followed by laser welding is preferred, and other methods may be used for connection. Examples of other methods include caulking, thermocompression bonding, resistance connection, solder bonding, and the like.

[0056] As shown in FIG. 5, in this embodiment, the core 2 with the coil body 3 mounted on the terminal block 5 having the terminals 4a, 4b is fixed, and the coil core assembly 35 in which the terminals 4a, 4b and the lead portion of the coil body 3 are connected is housed inside the case 6 from the open end of the case 6 filled with the heat-dissipating resin 63. Note that the heat-dissipating resin 63 may be filled after the coil core assembly 35 is housed inside the case 6 from the open end 62. In FIG. 5, the vertical direction (the direction of the arrow of the Z axis) of the coil device 1 shown in FIGS. 1A to 4 and FIG. 6 is reversed.

[0057] In this embodiment, the case 6 has a substantially rectangular bottom plate 60 and side plates 61 that are raised upward along the Z axis from the four side positions of the bottom plate 60 to form a bottomed accommodation space inside, and an open end 62 is formed at the upper part of FIG. 5 along the Z axis. The case 6 is preferably made of a metal such as aluminum with excellent thermal conductivity, but may also be made of resin.

[0058] Inside the case 6, more than half of the coil core assembly 35 is accommodated. The liquid level of the heat-dissipating resin 63 filled inside the case 10 (the interface with air after curing) is preferably at a position where at least more than half of the coil body 3 is filled with the heat-dissipating resin 63. More preferably, the liquid level of the heat-dissipating resin 63 filled inside the case 6 is at a position where at least all of the coil body 3 is filled with the heat-dissipating resin 63. Particularly preferably, the wire connection portions 41a and 41b of the terminals 4a and 4b are covered with the heat-dissipating resin 63, and the protruding top surface of the fixing projection 55 is exposed from the liquid level of the heat-dissipating resin 63.

[0059] The heat-dissipating resin 63 is also called a potting resin and is composed of a soft silicone resin, urethane resin, epoxy resin, etc. even after injection. The longitudinal elastic modulus of the potting resin is preferably 0.1 to 100 MPa. In this embodiment, for example, through the heat-dissipating resin 63 and the case 6, the heat generated in the winding portion of the first wire 31, the winding portion of the second wire 32, and the core 2 can be efficiently dissipated to the outside of the case 6, and the cooling efficiency of the coil device 1 can be improved.

[0060] In the coil body 3 shown in FIG. 2A, when there is a gap between the winding portion of the first wire 31 located on the innermost circumferential side and the outer peripheral surface of the middle leg portion 21c or 22c of the core 2, the heat-dissipating resin 63 shown in FIG. 5 intervenes through the gap, and the heat dissipation performance of the outer peripheral surfaces of the middle leg portions 21b and 22b shown in FIG. 2A and the inner peripheral surface of the winding portion of the coil body 3 is improved.

[0061] In the coil device 1 according to this embodiment, as shown in FIG. 2A, in the base plate portion 50, recesses 51 or 52 serving as base-side passages for guiding at least a part of the lead portions 31a to 34a and 31b to 34b of the wires 31 to 34 from the coil body 3 to the connection portions 41a and 41b are formed. Therefore, it becomes difficult for the lead portions 31a to 34a and 31b to 34b of the wires 31 to 34 to contact the outer peripheral edge of the base plate portion 50. As a result, the insulating coating of the lead portions 31a to 34a or 31b to 34b of the wires 31 to 34 is less likely to be damaged, it is possible to effectively prevent insulation failure or disconnection of the lead portions 31a to 34a or 31b to 34b of the wires 31 to 34, and the reliability of the coil device 1 is improved.

[0062] Also, in this embodiment, the recesses 51 or 52 serving as base-side passages formed in the base plate portion 50 are notch-shaped recesses penetrating the first surface 50a and the second surface 50b. By configuring in this way, when guiding the lead portions 31a to 34a or 31b to 34b of the wires 31 to 34 through the notch-shaped recesses 51 or 52 and penetrating the base plate portion 50, it becomes difficult for the lead portions 31a to 34a or 31b to 34b of the wires 31 to 34 to contact the outer peripheral edge of the base plate portion 50.

[0063] Furthermore, since the lead portions 31a to 34a or 31b to 34b of a large number of wires 31 to 34 can be guided through the recesses 51 and 52 of the base plate portion 50, the drawing out of the lead portions does not interfere with the winding of the wires, it is easy to wind the wires densely, and the occupancy rate of the wires is improved. Also, since it becomes easy to wind a large number of wires 31 to 34 in the radial direction, it also contributes to making the coil device thinner.

[0064] As shown in FIG. 6, in the present embodiment, the concave edges (inner peripheral edges) 51a and 52a of the recesses 51 and 52 serving as the base-side passages extend close to the middle leg portion 21c serving as the bobbin core portion. By configuring in this way, when leading the lead portions 31a to 34a and 31b to 34b of the wire from the coil body 3 shown in FIG. 2A arranged around the middle leg portion 21c to the connection portions 41a and 41b located on the second surface 50b of the base plate portion 50, it becomes more difficult for the lead portions 31a to 34a and 31b to 34b of the wire to come into contact with the outer peripheral edge of the base plate portion 50.

[0065] As shown in FIG. 6, in the present embodiment, the core 2 has a flange portion 21a magnetically connected to the middle leg portion 21c. The flange portion 21a is arranged on the base plate portion 50 and has recesses 24 and 25 communicating with the respective recesses 51 and 52. By configuring in this way, the lead portions 31a to 34a and 31b to 34b of the wire can be led from the coil body 3 arranged around the middle leg portion 21c to the connection portions 41a and 41b located on the second surface 50b of the base plate portion 50 through the respective recesses 24 and 25 communicating with the respective recesses 51 and 52 in sequence.

[0066] Therefore, it becomes more difficult for the lead portions 31a to 34a and 31b to 34b of the wire to come into contact with the outer peripheral edge of the base plate portion 50, and it also becomes difficult for them to come into contact with the outer peripheral edge of the flange portion 21a of the core. As a result, the insulating coating of the lead portions 31a to 34a and 31b to 34b of the wire is less likely to be damaged, it is possible to more effectively prevent insulation failure and disconnection of the lead portions 31a to 34a and 31b to 34b of the wire, and the reliability of the coil device 1 is further improved.

[0067] Further, the base plate portion 50 has a frame-shaped convex portion 53 that surrounds at least a part of the core 2 including the flange portion 21a so as to protrude from the first surface 50a of the base plate portion 50. This convex portion 53 can position the core 2 with respect to the base plate portion 50 and can improve the insulation between the core 2 arranged on the first surface 50a and the connection portions 41a and 41b of the terminals 4a and 4b arranged on the second surface 50b.

[0068] Furthermore, as the core-side passages, one of at least a pair of recesses 24 and 25 and the other are located on opposite sides along the Y-axis around the middle leg portions 21c. By configuring in this way, it becomes possible to use one of the pair of recesses 24 and 25 to pass the lead portions of the wires constituting the primary-side coil, and the other to pass the lead portions of the wires constituting the secondary-side coil. Thus, it becomes easier to position the terminals where the lead portions of the wires that require high insulation are connected to each other on opposite sides around the bobbin core portion.

[0069] As shown in FIG. 5, the coil device 1 further includes a case 6 that houses a coil core assembly 35 having a core 2 and a coil body 3 such that the coil body 3 is at least covered. Inside the case 6, a heat-dissipating resin 63 is filled up to a position where at least a part of the coil body 3 is immersed.

[0070] By filling the heat-dissipating resin 63, the heat generated in the middle leg portions 21c and 22c of the core 2 and the coil body 3 can be efficiently transmitted to the case 6 through the heat-dissipating resin 63, and the coil device 1 can be effectively cooled. Also, the heat-dissipating resin 63 and the case 6 can effectively protect the coil body 3 and the core 2. When the case 6 is made of metal, the heat dissipation is further improved, but the case 6 may be made of resin (preferably a resin with excellent heat dissipation), and in that case, the insulation property is improved.

[0071] As shown in FIG. 4, it is preferable that the heat-dissipating resin 63 is filled in the case 6 so as to cover the wire connection portions 41a and 41b of the terminals arranged on the second surface 50b of the base plate portion 50. By configuring in this way, since the wire connection portions 41a and 41b are covered with the heat-dissipating resin 63, the wire connection portions 41a and 41b can be effectively protected.

[0072] The terminals 4a and 4b have connection parts 41a and 41b, a connection part 42 formed at one end of the connection parts, and an external connection part 43 formed at the other end of the connection part 42. The connection part 42 is fixed to a fixing projection 55 formed to protrude from the second surface 50b of the base plate part 50, and the top of the fixing projection 55 and the external connection parts 43 of the terminals 4a and 4b protrude from the heat-dissipating resin 63. By the external connection parts 43 of the terminals 4a and 4b protruding from the heat-dissipating resin 63, the mounting of the coil device 1 becomes easy.

[0073] Second Embodiment In the coil device 1A of the present embodiment shown in FIG. 2B, the core 2A has the same configuration and the same operational effects as the core 2 of the coil device 1 of the above-described embodiment, except that the configuration of the core 2A is different from that of the core 2 of the coil device 1 of the above-described embodiment.

[0074] In the embodiment shown in FIG. 2B, the core 2A is configured by combining a first core 21A, a second core 22A, and a pair of side leg parts 22b1. The final configuration of the core after combination is the same as the configuration of the core 2.

[0075] In the present embodiment, the two middle leg parts 21c and 22c in the core 2 of the above-described embodiment are integrated into a middle leg part 22c1 and are integrated with the flange part 22a. Further, the pair of side leg parts 21b and the pair of side leg parts 22b in the core 2 of the above-described embodiment are integrated into side leg parts 22b1 respectively, are formed separately from the flange parts 21a and 22a, and are joined to both ends along the X-axis of these flange parts 21a and 22a respectively.

[0076] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0077] For example, in the above-described embodiment, as shown in FIG. 6, recesses 51 and 52 that are substantially rectangular when viewed from the Z-axis direction are formed on both sides along the Y-axis of the base plate portion 50. However, shapes other than substantially rectangular, such as triangular, polygonal, partial circular, partial elliptical, or other shapes, may also be used. Further, only one of the recesses 51 or 52 may be formed in the base plate portion 50, or three or more recesses may be formed. Further, instead of the notch-shaped recesses 51 or 52, a hole penetrating the first surface 50a and the second surface 50b of the base plate portion 50 may be used as the base-side passage.

[0078] Further, the recesses 24 or 25 formed in the flange portion 21a are substantially rectangular when viewed from the Z-axis direction in accordance with the shapes of the recesses 51 and 52. However, shapes other than substantially rectangular, such as triangular, polygonal, partial circular, partial elliptical, or other shapes, may also be used. Further, only one of the recesses 24 or 25 may be formed in the flange portion 21c, or three or more recesses may be formed. Further, instead of the notch-shaped recesses 24 or 25, a through-hole may be used as the core-side passage.

[0079] Note that the sizes of the recesses 24 and 25 are preferably substantially equal to the sizes of the recesses 51 and 52, but it is not always necessary to match them. The width W1 of the recesses 24 and 25 may be different from the width W2 of the recesses 51 and 52. For example, the width W1 of the recesses 24 and 25 may be made larger than the width W2 of the recesses 51 and 52, or vice versa. For example, when the width W1 of the recesses 24 and 25 is larger than the width W2 of the recesses 51 and 52, it is possible to effectively prevent the lead portion of the wire from strongly contacting the edge portions of the concave-side ends 24b and 25b of the recesses 24 and 25.

[0080] Further, the depth D1 of the recesses 24 and 25 is preferably substantially equal to the depth D2 of the recesses 51 and 52, but they may be different. For example, the depth D1 of the recesses 24 and 25 may be made larger than the depth D2 of the recesses 51 and 52, or vice versa. For example, when the depth D1 of the recesses 24 and 25 is larger than the depth D2 of the recesses 51 and 52, it is possible to effectively prevent the lead portion of the wire from strongly contacting the edge portions of the recessed bottom ends 24a and 25a of the recesses 24 and 25.

Explanation of Signs

[0081] 1, 2A... Coil device 2, 2A... Core 21, 21A... First core 21a... Flange portion 21b... Side leg portion 21c... Middle leg portion (bobbin portion) 21c1... Middle leg portion (bobbin portion) 22, 22A... Second core 22a... Flange portion 22b, 22b1... Side leg portions 22c... Middle leg portion (bobbin portion) 24... First recess (core side passage) 24a... Recessed bottom end 24b... Recessed side end 25... Second recess (core side passage) 25a... Recessed bottom end 25b... Recessed side end 3... Coil body (wire winding portion) 31 to 34... Wires 31a to 34a, 31b to 34b... Lead portions 35... Coil core assembly 4a, 4b... Terminals 41a, 41b... Connecting wire portions 42... External connection portion 43... Connecting portion 5... Terminal block 50... Base plate portion 50a... First surface 50b... Second surface 51... First recess (base side passage) 51a... First recessed bottom end 51b... First recessed side end 52…Second recess (base-side passage) 52a…Bottom end of the second recess 52b…Side end of the second recess 53…Frame-shaped convex portion 54…Reinforcing rib 55…Convex portion for fixing 6…Case 60…Bottom plate 61…Side plate 62…Open end 63…Heat-dissipating resin

Claims

1. A core having a bobbin portion, a winding portion of a wire disposed in a coil around the bobbin portion, a coil device having a base plate portion to which a terminal to which a lead portion of the wire drawn from the winding portion is connected is attached, wherein the core having the bobbin portion is installed on one first surface of the base plate portion, a connection wire portion of the terminal is disposed on the other second surface of the base plate portion located on the side opposite to the first surface, a coil device in which a base-side passage for guiding the lead portion of the wire from the winding portion through the base plate portion to the connection wire portion is formed.

2. The coil device according to claim 1, wherein the base-side passage formed in the base plate portion is a notch-shaped recess or a through-hole penetrating the first surface and the second surface.

3. The coil device according to claim 1, wherein an inner peripheral edge end of the base-side passage extends near the bobbin portion.

4. The core has a flange portion magnetically connected to the bobbin portion, the coil device according to claim 1, wherein the flange portion is disposed on the base plate portion and has a core-side passage communicating with the base-side passage.

5. The coil device according to claim 4, wherein the base plate portion has a convex portion surrounding at least a part of the core including the flange portion so as to protrude from the first surface of the base plate portion.

6. The core-side passage has at least a pair of core-side passages, the coil device according to claim 1, wherein one and the other of the pair of core-side passages are located on opposite sides around the bobbin portion.

7. further comprising a case in which the core and the winding portion of the wire are accommodated so as to at least cover the winding portion of the wire disposed around the bobbin portion, the coil device according to claim 1, wherein the inside of the case is filled with a heat-dissipating resin up to a position where at least a part of the winding portion of the wire is immersed.

8. The coil device according to claim 7, wherein the heat-dissipating resin is filled in the case so as to cover the connection wire portion of the terminal disposed on the second surface of the base plate portion.

9. The terminal has the connection wire portion, a connection portion formed at one end of the connection wire portion, and an external connection portion formed at the other end of the connection portion, the connection portion is fixed to a fixing convex portion formed to protrude from the second surface of the base plate portion. The coil device according to claim 8, wherein the top of the fixing convex portion and the external connection portion of the terminal protrude from the heat-dissipating resin.

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