Coil Device

Abstract

To provide a coil device that is easy to manufacture and has excellent coil positioning accuracy.SOLUTION: A coil device 1 includes a bobbin 20 including cores 30b and 30c, flat plate coils 93a to 93d having a flat plate shape, a through hole 210 in which legs 33b and 33c of the cores 30b and 30c are arranged, and accommodation grooves 220a to 220d into which the flat coils 93a to 93d can be inserted from the side, and a retaining member 80 inserted into the through hole 210 and arranged inside the flat plate coils 93a to 93d.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a coil device. [Background technology]

[0002] For example, as described in Patent Document 1, a coil device equipped with a coil having a flat plate shape (hereinafter referred to as a flat coil) is known as a coil device used as a transformer, etc. In the coil device described in Patent Document 1, the bobbin is divided into multiple members, and the flat coil is sandwiched between the members from above and below, and the flat coil is arranged between the members, making it possible to accommodate the flat coil inside the bobbin.

[0003] However, in the coil device described in Patent Document 1, when accommodating the flat coil inside the bobbin, the work of assembling each component with the flat coil is complicated, and manufacturing the coil device is not easy. Also, when the bobbin is divided into multiple components, the tolerances of each component affect the positioning accuracy of the flat coil, making it difficult to ensure sufficient positioning accuracy of the flat coil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 5-95026 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 easy to manufacture and has excellent coil positioning accuracy. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to the present invention comprises: The core and a flat coil having a flat plate shape; a bobbin having a through hole in which the leg portion of the core is disposed and an accommodating groove into which the flat coil can be inserted from the side; and a retaining member that is inserted into the through hole and disposed inside the flat coil.

[0007] In the coil device according to the present invention, the bobbin has a housing groove into which a flat coil can be inserted from the side. Therefore, the flat coil can be easily housed in the housing groove by inserting the flat coil into the housing groove from the side of the bobbin. Unlike conventional technology, there is no need to divide the bobbin into multiple components to house the flat coil inside the bobbin. This eliminates the need for complex work such as assembling each component with the flat coil, thereby simplifying the manufacture of the coil device. Furthermore, there is no need to consider the tolerances of each component, ensuring sufficient positioning accuracy for the coil device.

[0008] In particular, the coil device according to the present invention includes a retaining member that is inserted into the through hole and positioned inside the flat coil. By inserting the retaining member into the through hole while the flat coil is housed in the housing groove, the inside of the flat coil is caught by the retaining member, making it possible to prevent the flat coil from shifting in position relative to the insertion direction of the flat coil. Therefore, when the flat coil is inserted into the housing groove from the side of the bobbin, it is possible to prevent the flat coil from falling out of the insertion opening, and the flat coil can be fixed in a predetermined position in the housing groove. This significantly improves the positioning accuracy of the flat coil.

[0009] Preferably, the retaining member is separate from the bobbin. By configuring the retaining member as a separate member from the bobbin, it becomes possible to attach the retaining member to the bobbin later. In particular, by attaching the retaining member to the bobbin after the flat coil is accommodated in the accommodation groove, it is possible to prevent the insertion passage of the flat coil inside the accommodation groove from being blocked by the retaining member, and the flat coil can be smoothly inserted into the accommodation groove.

[0010] Preferably, the retaining member has a cylindrical portion, the legs of the core are disposed inside the cylindrical portion, and the cylindrical portion is disposed between the legs and the flat coil. With this configuration, the legs of the core and the flat coil can be well insulated via the cylindrical portion. Also, the retaining member can be easily fitted into the through hole of the bobbin.

[0011] Preferably, the cylindrical portion has a hole formed therein that penetrates the inner and outer peripheral surfaces of the cylindrical portion. With this configuration, for example, when filling a case of a coil device with heat-dissipating resin, the hole can function as a flow path for the heat-dissipating resin. In this case, the heat-dissipating resin filled in the case flows into the inside of the cylindrical portion through the hole. This allows the heat-dissipating resin to be sufficiently distributed inside the retaining member (cylindrical portion), thereby improving heat dissipation, particularly in the area surrounding the legs of the core that are arranged inside the cylindrical portion.

[0012] Preferably, the bobbin has a winding cylindrical portion and a flange portion extending radially outward from the outer peripheral surface of the winding cylindrical portion, and the flange portion has the accommodating groove. This configuration allows the flat coil to be accommodated inside the flange portion (accommodating groove). Forming the accommodating groove integrally with the flange portion in this manner simplifies the bobbin configuration compared to when the accommodating groove is formed on the bobbin separately from the flange portion. Additionally, it is possible to reduce the installation space for the accommodating groove, thereby enabling a more compact coil device.

[0013] Preferably, the winding cylinder portion is divided in the axial direction by the notch at a position in the winding cylinder portion corresponding to the accommodating groove. This configuration makes it possible to prevent the insertion passage for the flat coil inside the accommodating groove from being blocked by the winding cylinder portion. This allows the flat coil to be smoothly accommodated in the accommodating groove through the notch in the winding cylinder portion without being obstructed by the winding cylinder portion.

[0014] Preferably, the flange has an upper wall and a lower wall arranged opposite the upper wall in the axial direction of the bobbin, and the accommodation groove is formed between the upper wall and the lower wall. With this configuration, the flat coil can be accommodated in the accommodation groove so as to be surrounded by the upper and lower wall. This protects the flat coil from the external environment and effectively insulates the flat coil from other conductors.

[0015] Preferably, the flange has a side wall connecting an outer edge of the upper wall to an outer edge of the lower wall along the axial direction of the bobbin, and the side wall is located on the opposite side of the housing groove from the insertion opening for the flat coil in a direction perpendicular to the axial direction of the bobbin. With this configuration, the depth end of the housing groove is blocked by the side wall on the side opposite the insertion opening for the flat coil. Therefore, when the flat coil is inserted from the insertion opening toward the back of the housing groove, the flat coil can be prevented from falling out of the housing groove from the depth end of the housing groove.

[0016] Preferably, the coil device further includes a first coil and a second coil made of wire, and the bobbin includes a first bobbin on which the first coil is provided and a second bobbin on which the second coil is provided, and the flat coil is inserted into the second bobbin from the side. By providing both the flat coil and the second coil on one bobbin (second bobbin) in this way, the coil device can be made more compact. Furthermore, for example, by providing the second coil on the second bobbin and then inserting the flat coil into the second bobbin (accommodating groove), the second coil can be provided on the second bobbin without being obstructed by the flat coil. Furthermore, the flat coil can be provided on the second bobbin without being obstructed by the second coil.

[0017] Preferably, the core includes a first core and a second core, the first bobbin has a first through hole in which a first leg of the first core is disposed, and the second bobbin has a second through hole in which a second leg of the second core is disposed, and the width in a direction perpendicular to the extension direction of the first leg is different from the width in the direction perpendicular to the extension direction of the second leg. With this configuration, the magnetic characteristics of the coil device can be adjusted according to the difference between the width of the first leg of the first core and the width of the second leg of the second core.

[0018] Preferably, the coil device further includes a case that houses the core and the bobbin, and a heat-dissipating resin that is filled inside the case. With this configuration, heat from the bobbin and the core is transferred from the heat-dissipating resin to the case and then from the case to the outside. This makes it possible to efficiently dissipate heat from the bobbin and the core to the outside via the case, thereby improving the heat dissipation performance of the coil device. [Brief explanation of the drawings]

[0019] [Figure 1A] FIG. 1A is a perspective view of a coil device according to one embodiment of the present invention. [Figure 1B] FIG. 1B is a side view of the coil device shown in FIG. 1A as viewed from the direction IA. [Figure 2] FIG. 2 is an exploded perspective view of the coil device shown in FIG. 1A. [Figure 3] FIG. 3 is a perspective view of the flat coil shown in FIG. 1A. [Figure 4] 4 is a side view of the second bobbin shown in FIG. 2 as viewed from the direction IV. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV shown in FIG. 1A. [Figure 6] FIG. 6 is a perspective view of the first bobbin shown in FIG. 2 and a first stopper attached thereto. [Figure 7] FIG. 7 is a side view showing the winding pattern of the first coil and the second coil shown in FIG. 1B. [Figure 8A]8A is a perspective view of the second bobbin shown in FIG. 2, a second guide portion attached to the second bobbin, and a second stopper attached to the second guide portion. [Figure 8B] FIG. 8B is a perspective view of the second bobbin shown in FIG. 8A as viewed from a different angle. [Figure 9] FIG. 9 is a perspective view of a retaining member attached to the second bobbin shown in FIG. 8A. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0021] 1A functions as a transformer, for example, and is used in an on-board charger, a power supply circuit for home or industrial electrical equipment, or a power supply circuit for computer equipment. In the drawing, the positive Z-axis direction is defined as the upper side, the negative Z-axis direction is defined as the lower side, and the direction perpendicular to the Z-axis is defined as the lateral side. Furthermore, the direction toward the center of the coil device 1 is defined as the inward side, and the direction away from the center of the coil device 1 is defined as the outward side.

[0022] As shown in Fig. 2, the coil device 1 includes a first bobbin 10, a second bobbin 20, cores 30a to 30c, a case 40, a first coil 91 (Fig. 7), a second coil 92 (Fig. 7), and flat coils 93a to 93d. The coil device 1 is a vertical coil device, and the winding axis direction (Z-axis direction) of each of the first bobbin 10 and the second bobbin 20 corresponds to a direction perpendicular to a mounting board (mounting surface) not shown. The mounting board is disposed below the case 40.

[0023] The first coil 91 (FIG. 7) constitutes, for example, an inductor. The second coil 92 constitutes a primary coil (or secondary coil) of a transformer, and the flat coils 93a to 93d (FIG. 3) constitute secondary coils (or primary coils) of the transformer. The first coil 91 may be omitted.

[0024] The first coil 91 and the second coil 92 are each made of an insulating wire, such as a copper wire. The wire diameter of the wire constituting each of the first coil 91 and the second coil 92 is preferably 1.0 to 3.0 mm. The wire diameters of the wires may be the same or different.

[0025] 1A, a terminal 97 is attached to the lead-out portion 91a of the first coil 91. The same applies to the lead-out portion 92b of the second coil 92. Furthermore, a terminal 97 is attached to the lead-out portion 91b of the first coil 91 and the lead-out portion 92a of the second coil 92 so as to bundle them together. The first coil 91 and the second coil 92 are electrically connected via the lead-out portion 91b and the lead-out portion 92a.

[0026] As shown in FIG. 3, the flat coils 93a-93d are generally ring-shaped and made of flat conductors such as copper plates. A relatively large current can flow through the flat coils 93a-93d. The flat coil 93a has a two-layer structure consisting of two plates 93a1 and 93a2 to reduce AC resistance. Similarly, the flat coil 93b has a two-layer structure consisting of two plates 93b1 and 93b2, the flat coil 93c has a two-layer structure consisting of two plates 93c1 and 93c2, and the flat coil 93d has a two-layer structure consisting of two plates 93d1 and 93d2. Spacers (not shown) may be disposed between the plates.

[0027] The flat coil 93a has a lead-out portion 93a3, a lead-out portion 93a4, a convex portion 93a5, and a protruding end portion 93a6. The flat coil 93b has a lead-out portion 93b3, a lead-out portion 93b4, a convex portion 93b5, and a protruding end portion 93b6. The flat coil 93c has a lead-out portion 93c3, a lead-out portion 93c4, a convex portion 93c5, and a protruding end portion 93c6. The flat coil 93d has a lead-out portion 93d3, a lead-out portion 93d4, a convex portion 93d5, and a protruding end portion 93d6.

[0028] As shown in FIGS. 4 and 5, lead-out portion 93a3, lead-out portion 93b4, lead-out portion 93c3, and lead-out portion 93d4 each have a bent shape and are arranged overlapping each other. These are electrically connected to form a single terminal (for example, a center tap). Lead-out portion 93b3 and lead-out portion 93d3 each have a bent shape and are arranged overlapping each other. These are electrically connected to form a single terminal. Lead-out portion 93a4 and lead-out portion 93c4 each have a bent shape and are arranged overlapping each other. These are electrically connected to form a single terminal.

[0029] As shown in FIG. 3, the protrusions 93a5 to 93d5 are formed on the outer edges of the flat coils 93a to 93d. Two protrusions 93a5 are formed on the flat coil 93a. These protrusions 93a5 function to prevent rotation (misalignment) of the flat coil 93a when the flat coil 93a is placed in the second bobbin 20 (the housing groove 220a shown in FIG. 4). The protrusions 93b5, 93c5, and 93d5 have the same configuration and function as the protrusion 93a5. That is, the protrusions 93b5 to 93d5 function to prevent rotation (misalignment) of the flat coils 93b to 93d when the flat coils 93b to 93d are placed in the second bobbin 20 (the housing grooves 220b to 220d shown in FIG. 4).

[0030] The protruding end portion 93a6 has a protruding shape and is formed at the end of the flat coil 93a on the positive side of the X-axis, i.e., on the opposite side in the X-axis direction from the lead-out portions 93a3 and 93a4. The lead-out portion 93a3 is formed with two protruding end portions 93a6, which are arranged close to the third surface 45c (FIG. 2) of the case 40. These protruding end portions 93a6 are arranged at a predetermined interval in the Y-axis direction. The protruding end portions 93a6 have the function of improving the heat dissipation of the flat coil 93a and preventing the flat coil 93a from rotating. The protruding end portions 93b6 to 93d6 have the same configuration and function as the protruding end portion 93a6.

[0031] 2, the case 40 is for housing the first bobbin 10, the second bobbin 20, the cores 30a to 30c, etc. The case 40 is made of a metal with excellent cooling properties, such as aluminum, and is formed, for example, by bending a single metal plate. The case 40 has a case main body 41 and an opening 42.

[0032] The case body 41 is a housing with one open side, and houses the first bobbin 10, the second bobbin 20, the cores 30a to 30c, etc. The case body 41 surrounds the first bobbin 10, the second bobbin 20, the cores 30a to 30c, etc. at positions other than the opening 42. The inside of the case body 41 can be filled with potting resin 100 (FIG. 1A). The potting resin 100 is a heat-dissipating resin, and is made of silicone resin, urethane resin, epoxy resin, etc. The case body 41 has a bottom 43, an upper portion 44, and side portions 45.

[0033] The bottom 43 has a substantially rectangular shape and is disposed substantially parallel to a mounting substrate (mounting surface) not shown. A base equipped with, for example, a cooling mechanism is disposed below the bottom 43. The bottom 43 is fixed to the mounting substrate or the like via fasteners such as screws, other fixing members, or adhesive members. Fastening holes for fastening fasteners may be formed in the corners of the bottom 43.

[0034] The upper portion 44 is formed opposite the bottom portion 43 and is disposed approximately parallel to the bottom portion 43. The side portion 45 has a first surface 45a, a second surface 45b, and a third surface 45c. The first surface 45a, the second surface 45b, and the third surface 45c each extend upward from positions corresponding to three sides that constitute the outer edge of the bottom portion 43. The side portion 45 is not formed at a position corresponding to the remaining side that constitutes the outer edge of the bottom portion 43. The lower end of the side portion 45 is connected to the bottom portion 43, and the upper end of the side portion 45 is connected to the upper portion 44.

[0035] A wire protection member 96 made of, for example, an insulating material is attached to the end of second surface 45b on the negative X-axis direction side. As will be described later, the lead-out portions of first coil 91 and second coil 92 are led outward in the Y-axis direction along opening 42. Wire protection member 96 is intended to prevent the lead-out portions of first coil 91 and second coil 92 from coming into contact with the end of second surface 45b on the negative X-axis direction side and being damaged.

[0036] Opening 42 is formed at a position corresponding to one side that constitutes the outer edge of bottom 43, and only one opening 42 is provided in case 40. Opening 42 is formed at a position in case main body 41 where the lead-out portions of first coil 91 and second coil 92 are led out to the outside of case 40 (see FIG. 1A). Opening 42 is open only in one direction (the negative X-axis direction) toward the side of case main body 41.

[0037] As will be described in detail later, a portion of each of the first bobbin 10 and the second bobbin 20 protrudes laterally from the opening 42. Furthermore, the lead-out portions of each of the first coil 91 and the second coil 92 and the lead-out portions of the flat coils 93a to 93d protrude laterally from the opening 42.

[0038] 1A and 1B, when the first bobbin 10 and the second bobbin 20 are housed in the case main body 41, an upper part 44 of the case main body 41 is disposed above the first bobbin 10 so as to cover the first bobbin 10 from above. Also, a bottom part 43 of the case main body 41 is disposed below the second bobbin 20 so as to cover the second bobbin 20 from below. That is, the bottom part 43 and the upper part 44 of the case main body 41 surround the first bobbin 10 and the second bobbin 20, to which the cores 30a to 30c and the like are attached, from above and below.

[0039] The case main body 41 has a bottom 43, a top 44, and side sections 45 that surround the first bobbin 10 and the second bobbin 20, to which the cores 30a to 30c and the like are attached, so as to cover them from five directions including the top and bottom.

[0040] It is preferable that a gap be formed between the upper end of the first bobbin 10 or the upper end of the core 30a (base portion 31a) attached to the first bobbin 10 and the upper portion 44 of the case main body portion 41. The lower end of the second bobbin 20 or the lower end of the core 30c (base portion 31c) attached to the second bobbin 20 may be placed on the bottom portion 43 of the case main body portion 41.

[0041] As shown in FIG. 2, the cores 30a to 30c are each E-shaped and have approximately the same shape. The cores 30a and 30b are made of a magnetic material such as metal or ferrite, but the material is not particularly limited. The core 30a has a base portion 31a, a pair of outer legs 32a, and a center leg portion 33a, and is attached to the first bobbin 10 from above. The core 30b has a base portion 31b, a pair of outer legs 32b, and a center leg portion 33b, and is attached to the second bobbin 20 from above. The core 30c has a base portion 31c, a pair of outer legs 32c, and a center leg portion 33c, and is attached to the second bobbin 20 from below.

[0042] The base portions 31a to 31c have a flat plate shape with a predetermined thickness. The width of the base portions 31a to 31c in the X-axis direction decreases toward the center in the Y-axis direction. A partition plate 95 made of an insulating material is disposed on the upper surface of the base portion 31b. The core 30b is attached to the second bobbin 20 from below via the partition plate 95.

[0043] One of the pair of outer legs 32a protrudes downward from one end of the base portion 31a in the Y axis direction. The other of the pair of outer legs 32a protrudes downward from the other end of the base portion 31a in the Y axis direction. Similarly, one of the pair of outer legs 32b protrudes downward from one end of the base portion 31b in the Y axis direction. The other of the pair of outer legs 32b protrudes downward from the other end of the base portion 31b in the Y axis direction.

[0044] One of the pair of outer legs 32c protrudes upward from one end of base portion 31c in the Y-axis direction. The other of the pair of outer legs 32c protrudes upward from the other end of base portion 31c in the Y-axis direction. The inner surfaces of outer legs 32a to 32c (surfaces facing center legs 33a to 33c) are formed with curved surfaces that curve along the circumferential direction of center leg 33a.

[0045] Center legs 33a to 33c have a cylindrical shape and are formed in the center of bases 31a to 31c in the Y-axis direction. Center legs 33a and 33b protrude downward from the center of bases 31a and 31b in the Y-axis direction, respectively. Center leg 33c protrudes upward from the center of base 31c in the Y-axis direction.

[0046] 6, the first bobbin 10 is made of an insulating material and has a winding cylinder portion 11, flange portions 12a to 12c, core fixing portions 13a to 13d, and a protrusion 14. The winding cylinder portion 11 has a cylindrical shape and has a through hole 110. The center leg portion 33a (FIG. 2) of the core 30a is inserted into the through hole 110 from above.

[0047] The flanges 12a to 12c extend radially outward from the outer circumferential surface of the winding cylindrical portion 11. The flange 12a is formed at the upper end of the winding cylindrical portion 11, and the flange 12c is formed at the lower end of the winding cylindrical portion 11. The flange 12b is formed between the flanges 12a and 12c. A first coil 91 wound around the outer circumferential surface of the winding cylindrical portion 11 is disposed in the section between the flanges 12a and 12b and in the section between the flanges 12b and 12c (see FIG. 7). Note that, although one turn of the first coil 91 is disposed in each section, two or more turns may be disposed.

[0048] A notch is formed at the end of flange 12a on the positive side of the X-axis. Similar notches may be formed in flanges 12b and 12c. This notch functions, for example, as a flow path for potting resin 100 (FIG. 1B) filled inside case 40.

[0049] Core fixing portions 13a and 13b protruding upward are formed on the upper surface of flange portion 12a. Core fixing portions 13a and 13b are provided along the outer edge of base portion 31a of core 30a (FIG. 2) fixed to the upper surface of flange portion 12a, and function to position base portion 31a.

[0050] Similarly, core fixing portions 13c and 13d that protrude downward are formed on the underside of flange portion 12c. Core fixing portions 13c and 13d are provided along the outer edge of base portion 31b of core 30b (FIG. 2) that is fixed to the underside of flange portion 12c, and function to position base portion 31b.

[0051] The protrusion 14 is formed on the end (outer edge) of the first bobbin 10 on the negative X-axis direction side. As shown in FIGS. 1A and 1B , when the first bobbin 10 is housed inside the case body 41, the protrusion 14 protrudes or is exposed laterally in the X-axis direction from the case body 41 through the opening 42. As described above, the case 40 has one opening 42 through which the protrusion 14 can protrude. Therefore, the protrusion 14 protrudes from one side (the negative X-axis direction side) of the case body 41 through the opening 42. As shown in FIG. 5 , a portion of the first bobbin 10 located on the negative X-axis direction side of the imaginary line L (corresponding to the position of the opening 42) protrudes from the case body 41 as the protrusion 14.

[0052] As shown in Fig. 6, protrusion 14 has guide portion 15 and partition wall portion 17. Partition wall portion 17 is formed on the upper surface of flange portion 12a and the lower surface of flange portion 12c, and has a substantially L-shaped wall. Partition wall portion 17 formed on the upper surface of flange portion 12a protrudes upward and supports auxiliary flange portions 16a and 16b, which will be described later. Partition wall portion 17 formed on the lower surface of flange portion 12c protrudes downward and supports auxiliary flange portions 16c and 16d, which will be described later.

[0053] Guide portion 15 guides lead-out portions 91a and 91b (FIG. 7) of first coil 91 drawn out from first bobbin 10 in a predetermined direction. More specifically, guide portion 15 guides lead-out portions 91a and 91b, which have been drawn out to the side of case main body 41 through opening 42, along opening 42 (FIG. 1B) toward the outside in the Y-axis direction (a direction away from first bobbin 10).

[0054] The guide portion 15 has auxiliary flanges 16a to 16d. The auxiliary flanges 16a to 16d are arranged parallel to one another and protrude outward in the Y-axis direction. The protruding direction of the auxiliary flanges 16a to 16d corresponds to the extending direction of the drawn-out portions 91a and 91b. The auxiliary flanges 16a to 16d protrude to one side in the Y-axis direction (the positive Y-axis direction) and extend along the longitudinal direction of the core 30a (FIG. 2). The auxiliary flanges 16a to 16d also extend in a direction parallel to the bottom 43 or top 44 along the opening 42 (FIG. 1B) of the case 40.

[0055] Auxiliary flanges 16a and 16b are connected to a partition wall 17 formed on the upper surface of flange 12a. Auxiliary flange 16a is formed at the upper end of partition wall 17, and auxiliary flange 16b is formed at the lower end of partition wall 17. Auxiliary flanges 16a and 16b are arranged parallel to each other with a predetermined gap in the Z-axis direction. A guide path 161 through which lead-out portion 91a passes is formed between auxiliary flanges 16a and 16b. By pulling out lead-out portion 91a along guide path 161, lead-out portion 91a can be guided outward in the Y-axis direction (see FIG. 7).

[0056] Auxiliary flanges 16c and 16d are connected to a partition wall 17 formed on the underside of flange 12c. Auxiliary flange 16c is formed at the upper end of partition wall 17, and auxiliary flange 16d is formed at the lower end of partition wall 17. Auxiliary flanges 16c and 16d are arranged parallel to each other with a predetermined gap in the Z-axis direction. A guide path 162, through which lead-out portion 91b passes, is formed between auxiliary flanges 16c and 16d. By pulling out lead-out portion 91b along guide path 162, lead-out portion 91b can be guided outward in the Y-axis direction (see FIG. 7).

[0057] A flange extension 120 of flange 12b is disposed between auxiliary flange 16b and auxiliary flange 16c. As shown in Fig. 7, flange extension 120 serves to separate the first and second layers of first coil 91. Guide path 161 is located above the first layer of first coil 91, and lead-out portion 91a passes above the first layer of first coil 91 toward the outside in the Y-axis direction. Guide path 162 is located below the second layer of first coil 91, and lead-out portion 91b passes below the second layer of first coil 91 toward the outside in the Y-axis direction.

[0058] As shown in FIG. 6, a step 160 is formed on the upper surface of auxiliary flange 16a. A step 160 is also formed on the lower surface of auxiliary flange 16d. A first stopper 50 is fixed to each step 160. First stopper 50 has a main body 51 and a pair of fixing portions 52a and 52b. Fixing portion 52a is formed on the upper end of main body 51 and protrudes in a direction perpendicular to main body 51. Fixing portion 52b is formed on the lower end of main body 51 and protrudes in a direction perpendicular to main body 51.

[0059] 1B , main body 51 surrounds at least a portion of guide paths 161 and 162 from a direction (X-axis direction) perpendicular to the extension direction (Y-axis direction) of lead-out portions 91a and 91b. This prevents lead-out portions 91a and 91b, which are drawn out along guide paths 161 and 162, from shifting sideways (toward the X-axis direction) of lead-out portions 161 and 162, and prevents lead-out portions 91a and 91b from falling off guide paths 161 and 162.

[0060] 6, a notch 18 is formed in each of the auxiliary flanges 16a to 16d. The notch 18 is located approximately in the center of the first bobbin 10 in the Y-axis direction. For example, when the first coil 91 is formed by α-winding, the wire constituting the first coil 91 can be placed on the outer peripheral surface of the winding cylinder 11 via the notch 18, and the wire can be wound around it.

[0061] 8A, the second bobbin 20 is made of an insulating material and has a winding cylinder portion 21, flange portions 22a to 22d, core fixing portions 23a to 23d, and a protruding portion 24. The winding cylinder portion 21 has a cylindrical shape and has a through hole 210. The center leg portion 33b of the core 30b (FIG. 2) is inserted into the through hole 210 from above, and the center leg portion 33c of the core 30c is inserted into the through hole 210 from below.

[0062] 5, the width W1 in the X-axis direction of center leg 33a inserted into through-hole 110 of first bobbin 10 is different from the width W2 in the X-axis direction of center leg portions 33b and 33c inserted into through-hole 210 of second bobbin 20. The width W1 in the X-axis direction of center leg 33a is larger than the widths in the X-axis direction of center leg portions 33b and 33c. In this case, the magnetic characteristics of coil device 1 can be adjusted depending on the difference between widths W1 and W2. Note that widths W1 and W2 may be equal.

[0063] 8A, the flanges 22a to 22d extend radially outward from the outer circumferential surface of the winding cylinder 21. Although not particularly limited, the flanges 22a to 22d have a generally circular shape when viewed in the Z-axis direction. The flange 22a is formed at the upper end of the winding cylinder 21, and the flange 22d is formed at the lower end of the winding cylinder 21. The flange 22b is formed below the flange 22a, and the flange 22c is formed above the flange 22d. A second coil 92 wound around the outer circumferential surface of the winding cylinder 21 is disposed in the section between the flanges 22a and 22b, the section between the flanges 22b and 22c, and the section between the flanges 22c and 22d (see FIG. 7). Although the second coil 92 is arranged in each section with one turn, it may be arranged with two or more turns.

[0064] Core fixing portions 23a and 23b that protrude upward are formed on the upper surface of flange portion 22a. Core fixing portions 23a and 23b are provided along the outer edge of base portion 31b of core 30b (FIG. 2) that is fixed to the upper surface of flange portion 22a, and function to position base portion 31b.

[0065] Core fixing portions 23c and 23d are formed on the underside of flange 22d, protruding downward. Core fixing portions 23c and 23d are provided along the outer edge of base portion 31c of core 30c (FIG. 2) fixed to the underside of flange 22d, and function to position base portion 31c.

[0066] As shown in FIGS. 4 and 5, the flange portion 22a has an accommodating groove 220a, an upper wall portion 221a, a lower wall portion 222a, and a side wall portion 223a. The upper wall portion 221a and the lower wall portion 222a are disposed facing each other in the axial direction of the second bobbin 20. The side wall portion 223a connects the outer edge of the upper wall portion 221a to the outer edge of the lower wall portion 222a in the Z-axis direction. The side wall portion 223a is formed at the ends of the upper wall portion 221a and the lower wall portion 222a in the Y-axis direction as well as at the ends of the upper wall portion 221a and the lower wall portion 222a on the positive X-axis direction (see FIG. 8B). The accommodating groove 220a is formed between the upper wall portion 221a and the lower wall portion 222a. The accommodating groove 220a extends in a direction perpendicular to the axial direction of the second bobbin 20.

[0067] An insertion opening 224a for the flat coil 93a is formed at the end of the accommodating groove 220a on the negative side of the X-axis. The insertion opening 224a opens laterally in the X-axis direction and is located on the opposite side of the side wall 223a in the X-axis direction. The opening direction of the insertion opening 224a is the same as the opening direction of the opening 42 of the case 40 (FIG. 2) and is perpendicular to the axial direction of the bobbin 20. The flat coil 93a can be inserted into the accommodating groove 220a from the side in the X-axis direction through the insertion opening 224a. The flat coil 93a inserted into the accommodating groove 220a is fixed (positioned) by the side wall 223a formed at the end of the flange 22a on the positive side of the X-axis.

[0068] Flange portions 22b to 22d have the same configuration as flange portion 22a. That is, flange portions 22b to 22d have accommodating grooves 220b to 220d, upper wall portions 221b to 221d, lower wall portions 222b to 222d, and side wall portions 223b to 223d, and flat coils 93b to 93d are inserted into accommodating grooves 220b to 220d from the sides in the X-axis direction through insertion openings 224b to 224d. Flat coils 93b to 93d inserted into accommodating grooves 220b to 220d are fixed (positioned) by side wall portions 223b to 223d formed at the ends of flange portions 22b to 22d on the positive side of the X-axis.

[0069] 5, a plurality of notches 211 are formed in the winding cylinder portion 21 along the axial direction. The plurality of notches 211 are formed at positions corresponding to the accommodating grooves 220a to 220d (positions where the winding cylinder portion 21 and the accommodating grooves 220a to 220d intersect), respectively. Therefore, at the positions corresponding to the accommodating grooves 220a to 220d, the winding cylinder portion 21 is divided in the Z-axis direction by the notches 211. With this configuration, the flat coils 93a to 93d can be inserted into the accommodating grooves 220a to 220d from the sides in the X-axis direction without being obstructed by the winding cylinder portion 21.

[0070] 8A, uneven portions 225b to 225d are formed on flanges 22b to 22d. Uneven portions 225b to 225d are formed on the upper surfaces of upper wall portions 221b to 221d of flanges 22b to 22d. Therefore, second coil 92 is disposed on uneven portion 225b in the section between flanges 22a and 22b, on uneven portion 225c in the section between flanges 22b and 22c, and on uneven portion 225d in the section between flanges 22c and 22d.

[0071] As shown in Fig. 8B, flange portions 227a to 227d are formed on flange portions 22a to 22d. Flange portion 227a protrudes outward in the X-axis direction from the end of lower wall portion 222a (Fig. 5) of flange portion 22a on the positive X-axis side. Flange portions 227b to 227d protrude outward in the X-axis direction from the end of upper wall portions 221b to 221d (Fig. 5) of flange portions 22b to 22d on the positive X-axis side. Unlike flange portion 227a, flange portions 227b to 227d have a bifurcated shape.

[0072] The flange end 227a covers from below the protruding end 93a6 (FIG. 3) of the flat coil 93a (FIG. 5) accommodated inside the accommodation groove 220a, thereby protecting it. The flange ends 227b to 227d cover from above the protruding end 93b6 to 93d6 (FIG. 3) of the flat coils 93b to 93d (FIG. 5) accommodated inside the accommodation grooves 220b to 220d, thereby protecting them.

[0073] As shown in Fig. 8A, wide portions 226a and 226d are formed at the ends of flanges 22a and 22d on the negative side of the X axis. More specifically, wide portion 226a is formed on upper wall portion 221a of flange 22a and is wide in the Y axis direction. Wide portion 226d is formed on lower wall portion 222d of flange 22d and is wide in the Y axis direction. Wide portions 226a and 226d are intended to stably hold attachment guide portion 60, which will be described later.

[0074] The protrusion 24 is formed on the end (outer edge) of the second bobbin 20 on the negative X-axis direction side. As shown in FIGS. 1A and 1B , when the second bobbin 10 is housed inside the case main body 41, the protrusion 24 protrudes or is exposed laterally in the X-axis direction from the case main body 41 through the opening 42. As described above, the case 40 has one opening 42 through which the protrusion 24 can protrude. Therefore, the protrusion 24 protrudes from one side (the negative X-axis direction side) of the case main body 41 through the opening 42.

[0075] As shown in FIG. 5 , a portion of second bobbin 20 located on the negative X-axis side of imaginary line L protrudes from case main body 41 as protrusion 24. More specifically, the ends of upper wall portion 221a and lower wall portion 222a of flange 22a on the negative X-axis side protrude from case main body 41 as protrusion 24. Furthermore, the ends of upper wall portion 221b and lower wall portion 222b of flange 22b on the negative X-axis side protrude from case main body 41 as protrusion 24. Furthermore, the ends of upper wall portion 221c and lower wall portion 222c of flange 22c on the negative X-axis side protrude from case main body 41 as protrusion 24. Furthermore, the ends of upper wall portion 221d and lower wall portion 222d of flange 22d on the negative X-axis side protrude from case main body 41 as protrusion 24.

[0076] Therefore, the insertion openings 224a to 224d also protrude laterally from the case body 41, which makes it possible to easily insert the flat coils 93a to 93d into the accommodation grooves 220a to 220d.

[0077] Additionally, the ends or lead-out portions of the flat coils 93a to 93d on the negative X-axis side together with the protrusion 24 protrude from the case body 41 through the opening 42. Outside the case body 41, the ends of the flat coils 93a to 93d on the negative X-axis side are fixed to the protrusion 24 (the upper surfaces of the lower wall portions 222a to 222d of the flange portions 22a to 22d). This makes it possible to prevent the flat coils 93a to 93d from shifting in the Z-axis direction.

[0078] 8A, protruding portion 24 has clamped portion 25 and wall portion 26. Clamped portion 25 and wall portion 26 are formed on the upper surface of wide portion 226a and the lower surface of wide portion 226d. Wall portion 26 formed on the upper surface of wide portion 226a protrudes upward and extends from one end of wide portion 226a to the other in the Y-axis direction. Wall portion 26 formed on the lower surface of wide portion 226d protrudes downward and extends from one end of wide portion 226d to the other in the Y-axis direction.

[0079] The clamped portion 25 formed on the upper surface of the wide portion 226a has a flat plate shape that protrudes upward and extends a predetermined length along the Y-axis direction. Although not shown in detail, the clamped portion 25 formed on the lower surface of the wide portion 226d has a flat plate shape that protrudes downward and extends a predetermined length along the Y-axis direction. Clamping portions 62a and 62b and clamping portions 63a and 63b of the attachment guide portion 60, which will be described later, are attached to these clamped portions 25. Engagement protrusions 250 that engage with hook portions 620, 630 of clamping portions 62a and 63a are formed on these clamped portions 25.

[0080] The attachment guide portion 60 is separate from the second bobbin 20 and is configured to be attachable to the protrusion 24. Similar to the protrusion 24, the attachment guide portion 60 is a protrusion that protrudes laterally from the case main body 41. The attachment guide portion 60 guides the lead-out portions 92a and 92b of the second coil 92, which are drawn out from the second bobbin 20, in a predetermined direction. More specifically, as shown in FIG. 7 , the attachment guide portion 60 guides the lead-out portions 92a and 92b, which are drawn out laterally from the case main body 41 through the opening 42, along the opening 42 ( FIG. 1B ), toward the outside in the Y-axis direction (a direction away from the second bobbin 20). As shown in FIG. 8A , the attachment guide portion 60 includes a main body 61, clamping portions 62a and 62b, clamping portions 63a and 63b, guide paths 64 and 65, and fixing portions 66 and 67.

[0081] The main body 61 extends along the axial direction of the second bobbin 20. A pair of clamping portions 62a and 62b are formed on the upper end of the main body 61 and protrude in a direction perpendicular to the main body 61. The clamping portions 62a and 62b clamp the clamped portion 25 of the protrusion 24 formed on the flange 22a. A hook portion 620 is formed on the tip of the clamping portion 62a, and the hook portion 620 engages with the engaging protrusion 250 of the clamped portion 25.

[0082] The pair of clamping portions 63a and 63b are formed at the lower end of main body portion 61 and protrude in a direction perpendicular to main body portion 61. Clamping portions 63a and 63b clamp clamped portion 25 of protrusion 24 formed on flange portion 22d. A hook portion 630 is formed at the tip of clamping portion 63a, and hook portion 630 engages with engaging protrusion 250 of clamped portion 25. The attachment guide portion 60 can be attached to the second bobbin 20 via clamping portions 62a and 62b and clamping portions 63a and 63b.

[0083] Guide path 64 is a groove extending from one end to the other in the Y-axis direction of main body 61, and is formed below clamping portions 62a and 62b. Guide path 65 is a groove extending from one end to the other in the Y-axis direction of main body 61, and is formed above clamping portions 63a and 63b.

[0084] 7, the lead-out portion 92a is inserted into the guideway 64, and the lead-out portion 92b is inserted into the guideway 65. By pulling out the lead-out portions 92a and 92b along the guideways 64 and 65, the lead-out portions 92a and 92b can be guided outward in the Y-axis direction.

[0085] 8A, fixing portion 66 is formed at the upper end of main body portion 61 and has a substantially flat surface. Fixing portion 67 is formed at the lower end of main body portion 61 and has a substantially flat surface. Clamping portion 72a of second stopper 70 is fixed to fixing portion 66, and clamping portion 72b of second stopper 70 is fixed to fixing portion 67.

[0086] The second stopper 70 has a main body 71 and a pair of clamping portions 72a and 72b. The main body 71 extends in the same direction as the main body 61 of the attachment guide 60. The clamping portion 72a is formed at the upper end of the main body 71 and protrudes in a direction perpendicular to the main body 71. The clamping portion 72b is formed at the lower end of the main body 71 and protrudes in a direction perpendicular to the main body 71. The clamping portions 72a and 72b are fixed to the fixing portions 66 and 67 of the attachment guide 60, respectively, so as to clamp the main body 61 of the attachment guide 60. This makes it possible to attach the second stopper 70 to the attachment guide 60 via the clamping portions 72a and 72b.

[0087] 9, the retaining member 80 is made of an insulating material and has a cylindrical portion 81, a fixed flange portion 82, a hole portion 83, a groove portion 84, an elastic portion 85, and a hook portion 86. The retaining member 80 is formed as a separate body from the second bobbin 20 (FIG. 8A), and is inserted into the through-hole 210 of the second bobbin 20, for example, from below. When inserted into the through-hole 210, the retaining member 80 is disposed on the inner circumferential side of the flat coils 93a to 93d (FIG. 3).

[0088] The cylindrical portion 81 has a cylindrical shape. The upper end of the cylindrical portion 81 is open, and the lower end of the cylindrical portion 81 is closed. As shown in FIG. 5, when the retaining member 80 is installed inside the through-hole 210, the center leg portion 33b of the core 30b and the center leg portion 33c of the core 30c are disposed inside the cylindrical portion 81. Therefore, the cylindrical portion 81 is disposed between the outer peripheral surfaces of the center leg portions 33b and 33c and the inner peripheral surfaces of the flat coils 93a to 93d. A gap may be formed between the tip of the center leg portion 33b of the core 30b and the tip of the center leg portion 33c of the core 30c.

[0089] 9, the fixed flange 82 is formed at the lower end of the cylindrical portion 81 and forms the bottom of the cylindrical portion 81. The fixed flange 82 protrudes radially outward from the outer peripheral surface of the cylindrical portion 81. As shown in FIG. 5, the fixed flange 82 is fixed to the lower surface of the flange 22d (lower wall portion 222d) of the second bobbin 20. The fixed flange 82 serves to fix (position) the stopper member 80 at a predetermined position in the through-hole 210.

[0090] The hole 83 is formed on the outer peripheral surface of the cylindrical portion 81 and penetrates the inner and outer peripheral surfaces of the cylindrical portion 81. A plurality of holes 83 may be formed in the cylindrical portion 81. The hole 83 functions as a flow path for allowing the potting resin 100 filled inside the case 40 (FIG. 1A) to flow from the outside to the inside of the cylindrical portion 81.

[0091] The grooves (slits) 84 extend downward from the upper end of the cylindrical portion 81. Pairs of grooves 84 are formed in multiple locations on the cylindrical portion 81. Elastic portions 85 are formed between each pair of grooves 84. The elastic portions 85 have a relatively small width, which gives the elastic portions 85 elasticity (flexibility or deformability). Therefore, when the retaining member 80 is inserted into the through-hole 210 of the second bobbin 20 (FIG. 5), the elastic portions 85 elastically deform, allowing the retaining member 80 to be easily inserted into the through-hole 210.

[0092] Hook 86 is formed on the upper end of elastic portion 85, and protrudes radially outward from tubular portion 81. Hook 86 engages with engaging recess 212 (FIG. 8A) formed on the upper end of winding tubular portion 21.

[0093] Next, a method for manufacturing the coil device 1 will be described. First, the components shown in FIG. 2 are prepared. Next, the cores 30a and 30b are attached to the first bobbin 10. Note that the core 30b is attached to the first bobbin 10 via a partition plate 95. Furthermore, the cores 30b and 30c are attached to the second bobbin 20.

[0094] Next, a wire is wound around the winding cylinder portion 11 of the first bobbin 10 to form the first coil 91. A wire is also wound around the winding cylinder portion 21 of the second bobbin 20 to form the second coil 92. As shown in Fig. 5, the flat coils 93a to 93d are inserted into the housing grooves 220a to 220d from the sides in the X-axis direction through the insertion openings 224a to 224d, respectively. It is preferable to install the flat coils 93a to 93d in the housing grooves 220a to 220d after the second coil 92 is formed.

[0095] Next, the first bobbin 10 and the second bobbin 20 to which the cores 30a to 30c etc. are attached are housed inside the case 40 shown in Fig. 2. A wire protection member 96 is attached to the second surface 45b of the case main body 41. Next, the inside of the case main body 41 is filled with potting resin 100, which is then cured.

[0096] 1B and 7, lead-out portions 91a and 91b of first coil 91 are pulled out laterally in the X-axis direction of case main body 41 through opening 42. Also, lead-out portions 91a and 91b of first coil 91 are pulled out to the outside in the Y-axis direction of case main body 41 along guide paths 161 and 162 of guide portion 15. Thereafter, first stopper 50 is attached to guide portion 15.

[0097] 1B and 7, lead-out portions 92a and 92b of second coil 92 are pulled out to the side in the X-axis direction of case main body 41 through opening 42. Furthermore, attachment guide portion 60 is attached to second bobbin 20, and lead-out portions 92a and 92b of second coil 92 are pulled out to the outside in the Y-axis direction of case main body 41 along guide paths 64 and 65 of attachment guide portion 60. Thereafter, second stopper 70 is attached to attachment guide portion 60 as shown in FIG. 1B. In this manner, coil device 1 can be obtained.

[0098] As described above, in this embodiment, as shown in FIGS. 4 and 5, the flat coils 93a-93d can be easily accommodated in the accommodation grooves 220a-220d by inserting the flat coils 93a-93d into the accommodation grooves 220a-220d from the side of the second bobbin 20. Therefore, when accommodating the flat coils 93a-93d inside the second bobbin 20, it is not necessary to divide the second bobbin 20 into multiple members. This makes it possible to omit the complicated work of combining the respective members with the flat coils 93a-93d, thereby facilitating the manufacture of the coil device 1. Furthermore, there is no need to consider the tolerances of the respective members, and the positioning accuracy of the coil device 1 can be sufficiently ensured.

[0099] In particular, in this embodiment, by inserting the retaining member 80 into the through-hole 210 while the flat coils 93a-93d are accommodated in the accommodating grooves 220a-220d, the inner circumferential surfaces of the flat coils 93a-93d are caught on the cylindrical portion 81, preventing the flat coils 93a-93d from shifting in position relative to the insertion direction. Therefore, when the flat coils 93a-93d are inserted into the accommodating grooves 220a-220d from the side of the second bobbin 20, the flat coils 93a-93d are prevented from slipping out of the insertion openings 224a-224d, and the flat coils 93a-93d can be fixed in predetermined positions in the accommodating grooves 220a-220d. This significantly improves the positioning accuracy of the flat coils 93a-93d.

[0100] Furthermore, by configuring the retaining member 80 as a separate body from the second bobbin 20, it becomes possible to attach the retaining member 80 to the second bobbin 20 later. In particular, by attaching the retaining member 80 to the second bobbin 20 after the flat coils 93a-93d are accommodated in the accommodating grooves 220a-220d, it is possible to prevent the insertion passages of the flat coils 93a-93d inside the accommodating grooves 220a-220d from being blocked by the retaining member 80, and the flat coils 93a-93d can be smoothly inserted into the accommodating grooves 220a-220d.

[0101] Furthermore, the center legs 33b and 33c of the cores 30b and 30c are disposed inside the cylindrical portion 81. Therefore, the center legs 33b and 33c can be well insulated from the flat coils 93a to 93d via the cylindrical portion 81.

[0102] Furthermore, the potting resin 100 filled in the case 40 flows through the holes 83 (FIG. 9) to the inside of the tubular portion 81. This allows the potting resin 100 to be sufficiently distributed inside the tubular portion 81, thereby improving heat dissipation, particularly in the areas around the center legs 33b and 33c that are arranged inside the tubular portion 81.

[0103] Furthermore, since the accommodating grooves 220a to 220d are integral with the flange portions 22a to 22d, the configuration of the second bobbin 20 can be simplified compared to when the accommodating grooves 220a to 220d are formed separately from the flange portions 22a to 22d in the second bobbin 20. In addition, the installation space for the accommodating grooves 220a to 220d can be saved, and the coil device 1 can be made more compact.

[0104] Furthermore, at positions in the winding cylinder part 21 corresponding to the accommodating grooves 220a to 220d, the winding cylinder part 21 is divided in the axial direction by the cutout parts 211. This makes it possible to prevent the insertion passages of the flat coils 93a to 93d inside the accommodating grooves 220a to 220d from being blocked by the winding cylinder part 21. This allows the flat coils 93a to 93d to be smoothly accommodated in the accommodating grooves 220a to 220d through the cutout parts 211 in the winding cylinder part 21 without being obstructed by the winding cylinder part 21.

[0105] The flat coils 93a to 93d are accommodated in the accommodation grooves 220a to 220d so as to be surrounded by the upper wall portions 221a to 221d and the lower wall portions 222a to 222d, thereby protecting the flat coils 93a to 93d from the external environment and effectively insulating the flat coils 93a to 93d from other conductors.

[0106] The depth direction ends of the accommodating grooves 220a to 220d are closed by the side walls 223a to 223d, so that when the flat coils 93a to 93d are inserted into the accommodating grooves 220a to 220d from the insertion openings 224a to 224d toward the depths of the accommodating grooves 220a to 220d, the flat coils 93a to 93d can be prevented from falling out of the accommodating grooves 220a to 220d from the ends of the accommodating grooves 220a to 220d on the positive side of the X axis.

[0107] Furthermore, since both the flat coils 93a-93d and the second coil 92 are provided on one bobbin (second bobbin 20), it is possible to make the coil device 1 more compact. Furthermore, for example, by providing the second coil 92 on the second bobbin 20 and then inserting the flat coils 93a-93d into the accommodating grooves 220a-220d, the second coil 92 can be provided on the second bobbin 20 without being obstructed by the flat coils 93a-93d. Furthermore, the flat coils 93a-93d can be provided on the second bobbin 20 without being obstructed by the second coil 92.

[0108] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0109] In the above embodiment, an example of application of the present invention to a transformer has been described, but the present invention can also be applied to other coil devices in addition to transformers.

[0110] 2, in the above embodiment, the bobbin is composed of two parts, the first bobbin 10 and the second bobbin 20, but it may be composed of a single bobbin. Alternatively, the bobbin of the coil device 1 may be composed of three or more parts. Furthermore, the first bobbin 10 is not essential, and the first bobbin 10 may be omitted from the coil device 1 together with the first coil 91.

[0111] As shown in Figures 1A and 1B, in the above embodiment, the first bobbin 10 and the second bobbin 20 were housed in the case 40 so that their respective winding axes were approximately perpendicular to the mounting surface, but they may also be housed in the case 40 so that their respective winding axes are approximately parallel to the mounting surface.

[0112] As shown in FIG. 2, in the above embodiment, the case 40 is provided with one opening 42, but it may be provided with two or more openings 42.

[0113] In the above embodiment, the case 40 has the opening 42 that opens to the side, but the case 40 may also be open to the top. [Explanation of symbols]

[0114] 1...Coil device 10...1st bobbin 11... Winding cylinder part 110...Through hole 12a~12c…Tsubabe 120...Tsuba extension 13a to 13d...Core fixing part 14...Protrusion 15…Information Department 16a~16d…Auxiliary collar part 160...Step 161,162...Taxiway 17...Partition wall 18...Notch 20...Second bobbin 21... Winding cylinder part 210...Through hole 211...Notch 212...Engagement recess 22a~22d…Tsubabe 220a~220d... Storage groove 221a~221d...Top wall part 222a~222d…Lower wall part 223a~223d...Side wall part 224a~224d...Outlets 225b~225d…Uneven part 226a, 226d...wide section 227a~227d...Brim end 23a to 23d...Core fixing part 24...Protruding part 25...Pinched part 250…Engagement protrusion 26...Wall part 30a~30c...Core 31a~31c...Base section 32a~32c...outer leg 33a~33c…middle leg 40…case 41...Case body 42...Opening 43...bottom 44...Upper 45...Side 50...First stopper 51...Main body 52a, 52b…Fixed part 60...Installation guide 61...Main body 62a, 62b, 63a, 63b...gripping part 620,630…Hook part 64,65…taxiway 66,67…Fixed part 70...Second stopper 71...Main body 72a, 72b...gripping part 80...Prevention member 81...Cylinder part 82…Fixed collar part 83...hole 84...Groove 85...Elastic part 86...Hook part 91...1st coil 92...Second coil 93a, 93b, 93c, 93d...Flat coil 93a1,93a2,93b1,93b2,93c1,93c2,93d1,93d2...plate 93a3,93a4,93b3,93b4,93c3,93c4,93d3,93d4...Drawer part 93a5, 93b5, 93c5, 93d5...Convex parts 93a6,93b6,93c6,93d6...Protruding end 95...Partition board 96...Wire protection member 97...Terminal 100...Potting resin

Claims

1. The core and a flat coil having a flat plate shape; a bobbin having a through hole in which the leg portion of the core is disposed and an accommodating groove into which the flat coil can be inserted from the side; a retaining member that is inserted into the through hole and disposed inside the flat coil, the bobbin has a winding cylindrical portion and a flange portion extending radially outward from an outer circumferential surface of the winding cylindrical portion, The flange portion has the accommodation groove, a notch is formed in a part of the axial direction of the winding cylindrical portion, The coil device is such that the winding cylinder is divided in the axial direction by the notch at a position in the winding cylinder that corresponds to the accommodation groove.

2. The coil device according to claim 1 , wherein the retaining member is formed separately from the bobbin.

3. The retaining member has a cylindrical portion, The leg portion of the core is disposed inside the cylindrical portion, The coil device according to claim 1 or 2, wherein the cylindrical portion is disposed between the leg portion and the flat coil.

4. The coil device according to claim 3 , wherein the cylindrical portion has a hole formed therein, the hole penetrating the inner peripheral surface and the outer peripheral surface of the cylindrical portion.

5. the flange portion has an upper wall portion and a lower wall portion disposed opposite the upper wall portion in the axial direction of the bobbin, 5. The coil device according to claim 1, wherein the housing groove is formed between the upper wall portion and the lower wall portion.

6. the flange portion has a side wall portion that connects an outer edge portion of the upper wall portion and an outer edge portion of the lower wall portion along the axial direction of the bobbin, The coil device according to claim 5 , wherein the side wall portion is located on an opposite side of the accommodation groove from the insertion opening for the flat coil in a direction perpendicular to the axial direction of the bobbin.

7. The coil further includes a first coil and a second coil made of wire, the bobbin includes a first bobbin on which the first coil is provided and a second bobbin on which the second coil is provided, 7. The coil device according to claim 1, wherein the flat coil is inserted into the second bobbin from a side thereof.

8. The core includes a first core and a second core, the first bobbin has a first through hole in which the first leg portion of the first core is disposed, the second bobbin has a second through hole in which the second leg portion of the second core is disposed, The coil device according to claim 7 , wherein a width of the first leg in a direction perpendicular to the extending direction is different from a width of the second leg in a direction perpendicular to the extending direction.

9. a case that houses the core and the bobbin; 9. The coil device according to claim 1, further comprising a heat dissipating resin filled inside the case.

10. A core; a flat coil having a flat plate shape; a bobbin having a through hole in which the leg portion of the core is disposed and an accommodating groove into which the flat coil can be inserted from the side; a retaining member that is inserted into the through hole and disposed inside the flat coil; a first coil and a second coil made of wire; the bobbin includes a first bobbin on which the first coil is provided and a second bobbin on which the second coil is provided, The flat coil is inserted into the second bobbin from the side, The core includes a first core and a second core, the first bobbin has a first through hole in which the first leg portion of the first core is disposed, the second bobbin has a second through hole in which the second leg portion of the second core is disposed, A coil device in which the width of the first leg in a direction perpendicular to the direction in which the first leg extends is different from the width of the second leg in a direction perpendicular to the direction in which the second leg extends.

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