Coil device

Abstract

To improve adhesive strength and resolve resonance issues. [Solution] The coil device 1 includes a wire 5, a bobbin 3 on which a winding portion 50 of the wire 5 is formed, cores 2a and 2b attached to the bobbin 3, and a cover 4 that protects the winding portion 50. The cover 4 has an opening 46 formed in a position that simultaneously opens at least a portion of the cores 2a and 2b and at least a portion of the bobbin 3 to the outside. The bobbin 3, cores 2a and 2b and the cover 4 are fixed together with adhesive 8a provided in the opening 46.

Description

Technical Field

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

Background Art

[0002] As a coil device used in a transformer or the like, for example, a coil device such as that disclosed in Patent Document 1 is known. The coil device such as that in Patent Document 1 protects a winding portion of a wire wound around a bobbin with a cover. In such a coil device, the bobbin, the cover, and the core are fixed by an adhesive disposed at an end of the bobbin.

[0003] However, in the coil device such as that in Patent Document 1, the adhesive strength between the bobbin, the cover, and the core is not sufficient, and in the case of a higher voltage, problems such as a sound caused by resonance of each component may occur.

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 an object thereof is to improve the adhesive strength and improve the problem of resonance.

Means for Solving the Problems

[0006] To achieve the above object, a coil device according to the present invention includes a wire, a bobbin on which a winding portion of the wire is formed, a core attached to the bobbin, and a cover that protects the winding portion, The cover has an opening formed in a position that simultaneously opens at least a portion of the core and at least a portion of the bobbin to the outside. The bobbin, the core, and the cover are fixed together with adhesive provided in the opening.

[0007] With this configuration, a portion of the core and a portion of the bobbin can be observed simultaneously through the opening in the cover. By applying adhesive to this opening, the rim of the opening, a portion of the core, and a portion of the bobbin can be fixed together at the same time. This type of fixing ensures a sufficient bonding area for the adhesive to the bobbin, cover, and core. Furthermore, the adhesive can maintain a sufficient thickness at the opening. As a result, the bobbin, cover, and core are firmly bonded together by the adhesive. Because each component is firmly bonded in this way, problems such as noise caused by resonance can be eliminated. Such an opening may be a through hole or a slit.

[0008] Preferably, the bobbin has a flange, and at least a portion of the flange is fixed to the cover and the core with the adhesive. The flange of the bobbin protrudes outward from the winding portion and is suitable for fixing to the core with adhesive inside the opening of the cover.

[0009] Preferably, the flange portion has a projection that extends away from the winding portion, and the adhesive is in contact with the projection. Such a projection on the flange portion ensures a sufficient contact area with the adhesive, makes it easy to maintain the thickness of the adhesive, and allows each component to be firmly bonded with the adhesive.

[0010] Preferably, the bobbin has a plurality of flanges along the axial direction of the winding portion, and the opening is positioned at a location corresponding to each of the plurality of flanges. With this configuration, the flanges, core and cover are bonded at multiple positions, resulting in stronger adhesive strength.

[0011] Preferably, the cover has a first cover portion that covers the winding portion and a second cover portion that covers at least a part of the core outside the first cover portion, and the opening is formed in the second cover portion. With this configuration, the opening can be formed on the outside of the winding portion. By bonding each component on the outside of the winding portion, the adhesive strength is improved.

[0012] Preferably, the second cover portion has a second main cover portion having an outer surface that is lower in height than the outer surface of the first cover portion, and a second sub-cover portion that integrally connects the second main cover portion and the first cover portion. The opening may be formed in the second main cover portion and the second sub-cover portion, or in either one. With this configuration, the first cover portion that covers the winding portion does not need to have an opening, so the first cover portion can be made flat. Therefore, it is easier to transport the coil device by adsorption using a suction pad or the like.

[0013] Furthermore, it is preferable that the adhesive is continuously arranged along the axial direction of the winding portion at the boundary between the main portion of the second cover and the sub-portion of the second cover. By arranging the adhesive in such a position, a larger adhesion area of ​​the adhesive to the cover can be secured.

[0014] Preferably, the bobbin has a terminal block to which terminals to which the wire leads are connected are attached, and the second cover main portion is positioned near the core that protrudes outward from the cover and has an extension piece that covers at least a portion of one longitudinal end of the terminal block. In this configuration, the core is protected by the second cover main portion.

[0015] Preferably, the auxiliary adhesive is placed in a position where the part of the core protruding outward from the cover, the end of the extension piece, and the part of the terminal block are in close proximity. With this configuration, the part of the core, the end of the extension piece, and the part of the terminal block are simultaneously fixed by the auxiliary adhesive, thereby increasing the adhesive strength and preventing resonance. [Brief explanation of the drawing]

[0016] [Figure 1] FIG. 1 is an overall perspective view of a coil device according to an embodiment of the present invention. [Figure 2] FIG. 2 is an exploded perspective view of the coil device shown in FIG. 1. [Figure 3] FIG. 3 is a partial perspective view of the coil device shown in FIG. 1. [Figure 4] FIG. 4 is a perspective view showing the configuration of a cover of the coil device shown in FIG. 1. [Figure 5] FIG. 5 is a plan view of the coil device shown in FIG. 1. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI of the coil device shown in FIG. 5. [Figure 7] FIG. 7 is a side view of the coil device shown in FIG. 1.

Embodiments for Carrying Out the Invention

[0017] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The illustrated content is merely schematic and exemplary for the purpose of understanding the present invention, and the appearance and dimensional ratios may differ from the actual ones. Further, the present invention is not limited to the following embodiments.

[0018] The coil device 1 according to the first embodiment of the present invention shown in FIG. 1 is, for example, a surface-mounted transformer, and is mounted in an in-vehicle charger for an EV (Electric Vehicle), a PHV (Plug-in Hybrid Vehicle) or a commuter (vehicle), a power supply circuit of a household or industrial electric device, a power supply circuit of a computer device, etc.

[0019] As shown in FIG. 2, the coil device 1 includes a core 2a and 2b, a bobbin 3, a wire 5, and a cover 4. In FIG. 2 and the like, the X-axis is an axis parallel to the axis of the bobbin 3. The Y-axis is an axis perpendicular to the axis of the bobbin 3 when the bobbin 3 is viewed in plan. The Z-axis is an axis perpendicular to the X-axis and the Y-axis. Hereinafter, with respect to the Y-axis, the positive direction side and the negative direction side are referred to as the side. Also, with respect to the Z-axis, the positive direction side is referred to as the upper side, and the negative direction side is referred to as the lower side. Note that the lower side is the mounting surface side of the coil device 1, that is, the side on which a mounting substrate (not shown) on which the coil device 1 is mounted is disposed. Also, with respect to the X-axis and the Y-axis, the direction toward the center of the bobbin 3 is referred to as the inner direction, and the direction away from the center of the bobbin 3 is referred to as the outer direction.

[0020] The cores 2a and 2b are E-shaped cores and have the same shape. The cores 2a and 2b are magnetic bodies and are composed of a ferrite composition, a metal composition, or a composite composition of these and resin. The cores 2a and 2b are attached to the bobbin 3 so as to face each other. The cores 2a and 2b each have a base portion 21, a pair of outer leg portions 22m and 22n, and a middle leg portion 23.

[0021] The pair of outer leg portions 22m and 22n and the middle leg portion 23 are connected to the base portion 21. One of the outer leg portions 22m is connected to one end of the base portion 21 in the Y-axis direction and protrudes along the X-axis so as to be orthogonal to the base portion 21. The other outer leg portion 22n is connected to the other end of the base portion 21 in the Y-axis direction and protrudes along the X-axis so as to be orthogonal to the base portion 21. The middle leg portion 23 is located between the one outer leg portion 22m and the other outer leg portion 22n and protrudes along the X-axis so as to be orthogonal to the base portion 21.

[0022] The middle leg portion 23 of core 2a and the middle leg portion 23 of core 2b may be fixed together with, for example, an epoxy adhesive. Similarly, the outer leg portion 22m(22n) of core 2a and the outer leg portion 22m(22n) of core 2b may be fixed together with, for example, an epoxy adhesive. A gap may be formed along the X-axis at the abutting portion between the middle leg portion 23 of core 2a and the middle leg portion 23 of core 2b. Also, a gap may be formed along the X-axis at the abutting portion between the outer leg portion 22m(22n) of core 2a and the outer leg portion 22m(22n) of core 2b.

[0023] As shown in Figure 2, the bobbin 3 has a cylindrical portion 30 and end flanges 32a and 32b at both ends of the cylindrical portion 30 in the X-axis direction. The bobbin 3 also has intermediate flanges 33a to 33c, which are not required but divide the cylindrical portion 30 into multiple sections along the X-axis direction. In this specification, the end flanges 32a and 32b and the intermediate flanges 33a to 33c are also referred to as flanges. As shown in Figure 3, the bobbin 3 may further have engaging projections 35a and 35b and terminal blocks 36a and 36b. The bobbin 3 is made of plastic such as PPS, PET, PBT, LCP, nylon, or other insulating material (e.g., a heat-resistant material).

[0024] The cylindrical portion 30 is a bottomless cylindrical body that penetrates in the X-axis direction. The axis of the cylindrical portion 30 is arranged parallel to the mounting substrate (not shown) on which the coil device 1 is mounted. The cross-sectional shape (contour) of the cylindrical portion 30 is approximately elliptical, but it may also be a square, rectangle, other polygon, circle, etc. Inside the cylindrical portion 30, the middle leg portion 23 of the core 2a shown in Figure 2 is inserted from one side in the X-axis direction, and the middle leg portion 23 of the core 2b is inserted from the other side in the X-axis direction. As shown in Figure 2, the wire 5 is wound in a coil shape on the outer circumferential surface of the cylindrical portion 30, forming a coil portion 50. As shown in Figure 2, there may be multiple wires 5, and multiple coil portions 50 may be formed on the outer circumferential surface of the cylindrical portion 30.

[0025] Wire 5 is made of a single strand, but it may also be a stranded wire such as Litz wire. The diameter of wire 5 is not particularly limited, but for example it is 0.1 to 0.4 mm. Wire 5 may also be an insulated wire in which a core wire made of a metal such as copper is covered with an insulating coating.

[0026] As shown in Figure 2, the end flange 32a is formed at one axial end of the cylindrical portion 30 and protrudes radially outward from the outer circumferential surface of the cylindrical portion 30. The end flange 32a protrudes radially outward from the outer circumferential surface of the cylindrical portion 30 and extends circumferentially along the outer circumferential surface of the cylindrical portion 30. More specifically, the end flange 32a extends along the Z-axis along both sides of the cylindrical portion 30 in the Y-axis direction, and also extends along the Y-axis along the upper and lower parts of the cylindrical portion 30.

[0027] A projection 321a is formed on the end flange portion 32a. The projection 321a protrudes outward along the Y-axis from both sides (both ends) of the end flange portion 32a in the Y-axis direction. The projection 321a is formed on the upper part of the end flange portion 32a, more specifically, at the point where the upper part and the side of the end flange portion 32a intersect. The Y-axis side of the end flange portion 32a is the part of the end flange portion 32a that extends longitudinally along the Z-axis from the Y-axis side of the cylindrical portion 30. The upper part of the end flange portion 32a is the part of the end flange portion 32a that extends longitudinally along the Y-axis from the upper part of the cylindrical portion 30.

[0028] As shown in Figure 3, with the cores 2a and 2b attached to the bobbin 3, the protrusion 321a extends over the outer legs 22m and 22n of the core 2a. The protrusion 321a protrudes toward the upper surface of the outer legs 22m and 22n of the core 2a, and when viewed from above, the protrusion 321a and the outer legs 22m and 22n overlap. Gaps are formed between the protrusion 321a and the outer leg 22m, and between the protrusion 321a and the outer leg 22n. As shown in Figure 6, the overlap length L1 of the protrusion 321a and the outer legs 22m and 22n is not particularly limited, but it is preferably 1 / 10 or more of the width L2 of the outer legs 22m and 22n in the Y-axis direction.

[0029] As shown in Figure 2, the end flange 32b is formed at the other axial end of the cylindrical portion 30 and protrudes radially outward from the outer circumferential surface of the cylindrical portion 30. The end flange 32b protrudes radially outward from the outer circumferential surface of the cylindrical portion 30 and extends circumferentially along the outer circumferential surface of the cylindrical portion 30. More specifically, the end flange 32b extends along the Z-axis along both sides of the cylindrical portion 30 in the Y-axis direction, and also extends along the Y-axis along the upper and lower parts of the cylindrical portion 30.

[0030] A projection 321b is formed on the end flange portion 32b. The projection 321b protrudes outward along the Y-axis from both sides (both ends) of the end flange portion 32b in the Y-axis direction. The projection 321b is formed on the upper part of the end flange portion 32b, more specifically, at the point where the upper part and the side of the end flange portion 32b intersect. The Y-axis side of the end flange portion 32b is the part of the end flange portion 32b that extends longitudinally along the Z-axis from the Y-axis side of the cylindrical portion 30. The upper part of the end flange portion 32b is the part of the end flange portion 32b that extends longitudinally along the Y-axis from the upper part of the cylindrical portion 30.

[0031] As shown in Figure 3, with the cores 2a and 2b attached to the bobbin 3, the projection 321b extends over the outer legs 22m and 22n of the core 2a. Similar to the projection 321a shown in Figure 6, the projection 321b protrudes toward the upper (upper surface) of the outer legs 22m and 22n of the core 2a, and when viewed from above, the projection 321b and the outer legs 22m and 22n overlap. A gap is formed between the projection 321b and the outer leg 22m, and between the projection 321a and the outer leg 22n. The overlap length of the projection 321b and the outer legs 22m and 22n is not particularly limited, but is similar to the overlap length L1 of the projection 321a and the outer legs 22m and 22n described above (see Figure 6).

[0032] As shown in Figure 2, the intermediate flanges 33a to 33c are formed between one end and the other end of the cylindrical portion 30 in the axial direction (X-axis direction), and protrude radially outward from the outer circumferential surface of the cylindrical portion 30. The intermediate flanges 33a to 33c are each arranged at predetermined intervals along the axial direction (X-axis direction) of the cylindrical portion 30. Intermediate flange 33a is adjacent to the end flange 32a formed at one end of the cylindrical portion 30, and intermediate flange 33c is adjacent to the end flange 32b formed at the other end of the cylindrical portion 30. Intermediate flange 33b is located between intermediate flange 33a and intermediate flange 33b. By forming the intermediate flanges 33a to 33c on the outer circumferential surface of the cylindrical portion 30, it is possible to prevent the wire 5 wound around the outer circumferential surface of the cylindrical portion 30 from becoming distorted.

[0033] The intermediate flange portions 33a to 33c protrude radially outward from the outer circumferential surface of the cylindrical portion 30 and extend circumferentially along the outer circumferential surface of the cylindrical portion 30. More specifically, the intermediate flange portions 33a to 33c extend along the Z-axis from both sides of the cylindrical portion 30 in the Y-axis direction, and also extend along the Y-axis from the upper and lower parts of the cylindrical portion 30.

[0034] Projections 331a to 331c are formed on the intermediate flange portions 33a to 33c. The projections 331a to 331c protrude outward along the Y-axis from both sides (both ends) of the intermediate flange portions 33a to 33c in the Y-axis direction. The projections 331a to 331c are formed on the upper part of the intermediate flange portions 33a to 33c, more specifically at the point where the upper part and the side of the intermediate flange portions 33a to 33c intersect. The Y-axis side of the intermediate flange portions 33a to 33c refers to the portion of the intermediate flange portions 33a to 33c that extends longitudinally along the Z-axis from the Y-axis side of the cylindrical portion 30. The upper part of the end flange portion 32a refers to the portion of the intermediate flange portions 33a to 33c that extends longitudinally along the Y-axis from the upper part of the cylindrical portion 30.

[0035] As shown in Figure 3, with the cores 2a and 2b attached to the bobbin 3, the protrusions 331a to 331c extend over the outer legs 22m and 22n of the core 2a or 2b. Similar to the protrusion 321a shown in Figure 6, the protrusions 331a to 331c project towards the upper (top surface) of the outer legs 22m and 22n of the core 2a or 2b, and when viewed from above, the protrusions 331a to 331c and the outer legs 22m and 22n overlap. Gaps are formed between the protrusions 331a to 331c and the outer leg 22m, and between the protrusions 331a to 331c and the outer leg 22n. The overlap length between the protrusions 331a to 331c and the outer legs 22m and 22n is not particularly limited, but is the same as the overlap length L1 (see Figure 6) between the protrusion 321a and the outer legs 22m and 22n described above.

[0036] As shown in Figure 3, two engaging projections 35a are formed on the end face 322a of the end flange portion 32a, spaced apart along the Y-axis. The two engaging projections 35a are formed on the upper part of the end flange portion 32a. Similarly, two engaging projections 35b are formed on the end face 322b of the end flange portion 32b, spaced apart along the Y-axis. The two engaging projections 35b are formed on the upper part of the end flange portion 32b. The engaging projections 35a and 35b engage with the engaging recesses 471a and 471b of the cover 4 shown in Figure 2.

[0037] Terminal block 36a is formed at one axial end of the cylindrical portion 30, and terminal block 36b is formed at the other axial end of the cylindrical portion 30. Terminal blocks 36a and 36b are formed at the lower part of the cylindrical portion 30. The shapes of terminal blocks 36a and 36b are the same, but may be different. Terminal blocks 36a and 36b each have a main body portion 360 and a plurality of protrusions 362.

[0038] The main body portion 360 protrudes outward in the axial direction from the lower part of the cylindrical portion 30 at one end of the cylindrical portion 30 in the axial direction. The main body portion 360 has a width greater than the width of the cylindrical portion 30 along the Y axis and protrudes outward along the Y axis from one end and the other end of the cylindrical portion 30 in the Y axis direction. The upper surface of the main body portion 360 is a flat surface. The base portion 21 of the core 2a is positioned on the upper surface of the main body portion 360 of terminal block 36a. The base portion 21 of the core 2b is positioned on the upper surface of the main body portion 360 of terminal block 36b. The length of the main body portion 360 along the Y axis is longer than the length of the base portion 21 along the Y axis.

[0039] As shown in Figure 3, with the cores 2a and 2b attached to the bobbin 3, the core assembly consisting of the cores 2a and 2b is secured by surrounding it with tape 26, although this is not essential. Tape 26 is an insulating tape made of plastic or rubber.

[0040] Multiple protrusions 362 project downward from the bottom surface of the main body 360 and are formed at predetermined intervals from one end to the other in the Y-axis direction of the main body 360. Each of the multiple protrusions 362 has a terminal 6 formed on it. The terminals 6 are integrally molded (insert molded) with the protrusions 362, but may also be detachably attached to the protrusions 362.

[0041] The terminal 6 is made of a metal such as copper and has, for example, a connecting portion 61 and a mounting portion 62. The connecting portion 61 protrudes outward from the main body portion 360 along the X axis. The mounting portion 62 protrudes downward from the bottom of the protrusion 362 and is bent to extend along the X axis.

[0042] The lead-out portion 51 of one of the multiple wires 5 is connected to the connecting portion 61. The method of connecting the lead-out portion 51 and the connecting portion 61 is not particularly limited and may be done by soldering or by laser welding. The mounting portion 62 is connected to a circuit pattern on a circuit board or the like (not shown), thereby connecting the coil device 1 to the circuit board or the like via the terminal 6. Note that the terminal 6 may be a dummy terminal to which no wire 5 is connected.

[0043] As shown in Figure 1, the cover 4 is attached to the bobbin 3. As shown in Figure 4, the cover 4 has a first cover portion 40, second cover portions 42a, 42b, and engaging portions 47a, 47b that engage with the bobbin 3. The cover 4 is made of an insulating material (for example, LCP or nylon) that is more elastic than the bobbin 3, but it may also be made of the same material as the bobbin 3.

[0044] As shown in Figure 4, the first cover portion 40 has a flat outer surface 41. The first cover portion 40 is placed above the flange portions 32a, 32b, 33a-33c shown in Figure 3 in the Z-axis direction, thereby covering the winding portion 50 of the wire 5 from above in the Z-axis direction.

[0045] As shown in Figure 4, the second cover portion 42a is formed on one side of the first cover portion 40 in the Y-axis direction. The second cover portion 42a has a second cover main portion 43a and a second cover sub-portion 44a. The second cover portion 42a covers the outer leg portions 22m, 22m of the cores 2a, 2b shown in Figure 3 from above in the Z-axis direction, on the outward side of the first cover portion 40 in the Y-axis direction.

[0046] As shown in Figure 4, the second main cover portion 43a has an outer surface 431a that is lower in height than the outer surface 41 of the first cover portion 40. The second sub-cover portion 45a integrally connects the first cover portion 40 and the second main cover portion 43a. The outer surface 451a of the second sub-cover portion 45a is inclined with respect to the outer surface 41 of the first cover portion 40 and the outer surface 431a of the second main cover portion 43a.

[0047] As shown in Figure 4, the second cover main portion 43a has an extension piece 44a. The extension piece 44a is positioned outward in the Y-axis direction from the sides 222m, 222m of the outer leg portions 22m, 22m of the cores 2a, 2b shown in Figure 3. The end 441a of the extension piece 44a is positioned on the upper surface of the main body portion 360 of the terminal block 36a shown in Figure 3. The end 442a of the extension piece 44a is positioned on the upper surface of the main body portion 360 of the terminal block 36b shown in Figure 3.

[0048] As shown in Figure 4, the second cover portion 42a has openings 46. The number of openings 46 in the second cover portion 42a is not particularly limited, but in this embodiment, five openings are formed in the second cover portion 42a, corresponding to the number of flange portions 32a, 32b, 33a, 33b, and 33c shown in Figure 3.

[0049] In the second cover portion 42a, the opening 46 is formed at the boundary between the second cover main portion 43a and the second cover sub-portion 45a. The opening 46 may also be formed spanning the second cover portion 42a and the first cover portion 40. The shape of the opening 46 is not particularly limited and may be a through hole penetrating the second cover portion 42a as shown in Figure 4, or it may be a slit dividing the second cover portion 42a in the X-axis direction.

[0050] As shown in Figure 4, the second cover portion 42b is formed on the other side of the first cover portion 40 in the Y-axis direction. The second cover portion 42b has a second cover main portion 43b and a second cover sub-portion 44b. The second cover portion 42b covers the outer leg portions 22n, 22n of the cores 2a, 2b shown in Figure 3 from above in the Z-axis direction, on the outward side of the first cover portion 40 in the Y-axis direction.

[0051] As shown in Figure 4, the second main cover portion 43b has an outer surface 431b that is lower in height than the outer surface 41 of the first cover portion 40. The second sub-cover portion 45b integrally connects the first cover portion 40 and the second main cover portion 43b. The outer surface 451b of the second sub-cover portion 45b is inclined with respect to the outer surface 41 of the first cover portion 40 and the outer surface 431b of the second main cover portion 43b.

[0052] As shown in Figure 4, the second cover main portion 43b has an extension piece 44b. The extension piece 44b is positioned outward in the Y-axis direction from the sides 222n, 222n of the outer leg portions 22n, 22n of the cores 2a, 2b shown in Figure 3. The end 441b of the extension piece 44b is positioned on the upper surface of the main body portion 360 of the terminal block 36a shown in Figure 3. The end 442b of the extension piece 44b is positioned on the upper surface of the main body portion 360 of the terminal block 36b shown in Figure 3.

[0053] As shown in Figure 4, an opening 46 is formed in the second cover portion 42b. The number of openings 46 in the second cover portion 42b is not particularly limited, but five are formed in the second cover portion 42b, corresponding to the number of flange portions 32a, 32b, 33a, 33b, and 33c shown in Figure 3.

[0054] In the second cover portion 42b, the opening 46 is formed at the boundary between the second cover main portion 43b and the second cover sub-portion 45b. The opening 46 may also be formed spanning the second cover portion 42b and the first cover portion 40. The shape of the opening 46 is not particularly limited and may be a through hole penetrating the second cover portion 42b as shown in Figure 4, or it may be a slit dividing the second cover portion 42b in the X-axis direction.

[0055] As shown in Figures 5 and 7, with the cover 4 attached to the bobbin 3 and cores 2a and 2b, the opening 46 of the second cover portion 42a is positioned so that the outer legs 22m of the cores 2a and 2b and the protruding parts 321a, 321b, 331a to 33c of the flange portions 32a, 32b, 33a to 33c of the bobbin 3 are simultaneously open to the outside. By looking through the adhesive 8a, the opening 46 of the second cover portion 42a is positioned so that the upper surface 221m of the outer legs 22m of the cores 2a and 2b and the protruding parts 321a, 321b, 331a to 33c of the flange portions 32a, 32b, 33a to 33c of the bobbin 3 can be observed simultaneously.

[0056] As shown in Figure 5, the bobbin 3, cores 2a and 2b, and cover 4 are fixed together with adhesive 8a placed inside the opening 46 of the second cover portion 42a. The adhesive 8a is continuously arranged along the X-axis direction at the boundary between the main portion 43a of the second cover and the sub-portion 45a of the second cover. Part of the adhesive 8a is placed inside the opening 46 of the second cover portion 42a, and another portion is placed on the upper part of the second cover portion 42a.

[0057] As shown in Figures 6 and 7, with the cover 4 attached to the bobbin 3 and cores 2a and 2b, the protruding portion 321a of the end flange 32a is exposed inside the opening 46 of the second cover portion 42a. Also, as shown in Figure 6, the outer leg portion 22m is exposed inside the opening 46 of the second cover portion 42a. The protruding portion 321a and the outer leg portion 22m are positioned overlapping below the opening 46 of the second cover portion 42a in the Z-axis direction.

[0058] As shown in Figure 6, the adhesive 8a is in contact with the protrusion 321a, the outer leg portion 22m, and the edge of the opening 46 of the second cover portion 42a. The adhesive 8a is also placed above the protrusion 321a in the Z-axis direction and in the gap between the protrusion 321a and the upper surface 221m of the outer leg portion 22m. The description of fixing the protrusion 321a to the outer leg portion 22m also applies to fixing the protrusions 321b, 331a, 331b, 331c to the outer leg portion 22m.

[0059] As shown in Figure 5, with the cover 4 attached to the bobbin 3 and cores 2a and 2b, the opening 46 of the second cover portion 42b is positioned so that the outer legs 22n of the cores 2a and 2b and the protruding parts 321a, 321b, 331a to 33c of the flange portions 32a, 32b, 33a to 33c of the bobbin 3 are simultaneously open to the outside. If the adhesive 8a is viewed through, the opening 46 of the second cover portion 42b is positioned so that the upper surface 221n of the outer legs 22n of the cores 2a and 2b and the protruding parts 321a, 321b, 331a to 33c of the flange portions 32a, 32b, 33a to 33c of the bobbin 3 can be observed simultaneously.

[0060] As shown in Figure 5, the bobbin 3, cores 2a and 2b, and cover 4 are fixed together with adhesive 8a placed inside the opening 46 of the second cover portion 42b. The adhesive 8a is continuously placed along the X-axis direction at the boundary between the main portion 43b of the second cover and the sub-portion 45b of the second cover. Part of the adhesive 8a is placed inside the opening 46 of the second cover portion 42b, and another portion is placed on the upper part of the second cover portion 42b.

[0061] As shown in Figure 6, with the cover 4 attached to the bobbin 3 and cores 2a and 2b, the protruding portion 321a of the end flange portion 32a is exposed inside the opening 46 of the second cover portion 42b. Also, as shown in Figure 6, the outer leg portion 22n is exposed inside the opening 46 of the second cover portion 42b. The protruding portion 321a and the outer leg portion 22n are positioned overlapping below the opening 46 of the second cover portion 42b in the Z-axis direction.

[0062] As shown in Figure 6, the adhesive 8a is in contact with the protrusion 321a, the outer leg portion 22n, and the edge of the opening 46 of the second cover portion 42b. The adhesive 8a is also placed above the protrusion 321a in the Z-axis direction and in the gap between the protrusion 321a and the upper surface 221n of the outer leg portion 22n. The description of fixing the protrusion 321a to the outer leg portion 22n also applies to fixing the protrusions 321b, 331a, 331b, 331c to the outer leg portion 22n.

[0063] As shown in Figure 5, the bobbin 3 is bonded to the base portion 21 of the core 2a by the auxiliary adhesive 8b1 at the main body portion 360 of the terminal block 36a. The auxiliary adhesive 8b1 is arranged longitudinally along the base portion 21 of the core 2a. The auxiliary adhesive 8b1 may also be bonded to the base portion 21 via tape 26 (see Figure 1).

[0064] Furthermore, the auxiliary adhesive 8b1 is also placed in a position where the end portion 441a of the extension piece 44a of the second cover main portion 43a, the main body portion 360 of the terminal block 36a, and the base portion 21 of the core 2a are in close proximity, simultaneously fixing the end portion 441a of the extension piece 44a, the terminal block 36, and the base portion 21. The base portion 21 of the core 2a is fixed to the engaging portion 47a of the cover 4 with the auxiliary adhesive 8b2.

[0065] Furthermore, the auxiliary adhesive 8b1 is also placed in a position where the end portion 441b of the extension piece 44b of the second cover main portion 43b, the main body portion 360 of the terminal block 36a of the bobbin 3, and the base portion 21 of the core 2a are in close proximity, simultaneously fixing the end portion 441b of the extension piece 44b, the terminal block 36, and the base portion 21.

[0066] As shown in Figure 5, the auxiliary adhesive 8b1 is arranged longitudinally along the base portion 21 of the core 2b. The bobbin 3 is bonded to the base portion 21 of the core 2b by the auxiliary adhesive 8b1 at the main body portion 360 of the terminal block 36b. The auxiliary adhesive 8b1 may also be bonded to the base portion 21 via tape 26 (see Figure 1).

[0067] Furthermore, the auxiliary adhesive 8b1 is also placed in a position where the end portion 442a of the extension piece 44a of the second cover main portion 43a, the main body portion 360 of the terminal block 36b, and the base portion 21 of the core 2b are in close proximity, simultaneously fixing the end portion 442a of the extension piece 44a, the terminal block 36, and the base portion 21. The base portion 21 of the core 2b is fixed to the engaging portion 47a of the cover 4 with the auxiliary adhesive 8b2.

[0068] Furthermore, the auxiliary adhesive 8b1 is also placed in a position where the end portion 442b of the extension piece 44b of the second cover main portion 43b, the main body portion 360 of the terminal block 36b of the bobbin 3, and the base portion 21 of the core 2b are in close proximity, simultaneously fixing the end portion 442b of the extension piece 44b, the terminal block 36, and the base portion 21.

[0069] Adhesive 8a and auxiliary adhesives 8b1, 8b2 are not particularly limited, but from the viewpoint of preventing noise and improving adhesive strength, they are preferably silicone-based adhesives. In this case, adhesive 8a and auxiliary adhesives 8b1, 8b2 have the effect of absorbing vibration or shock, and the vibration resistance of the assembly consisting of the bobbin 3 and cores 2a and 2b is improved. Adhesive 8a and auxiliary adhesives 8b1, 8b2 may also be epoxy-based adhesives or the like.

[0070] As described above, as shown in Figure 5, the cover 4 of the coil device 1 according to this embodiment has an opening 46 formed in a position that simultaneously opens outward the outer legs 22m, 22n of the cores 2a, 2b and the flanges 32a, 32b, 33a~33c of the bobbin 3. As shown in Figure 1, adhesive 8a is provided in this opening 46, and by looking through the adhesive 8a, a part of the cores 2a, 2b and a part of the bobbin 3 can be observed simultaneously through the opening 46 of the cover 4. The adhesive 8a provided in the opening 46 fixes the 32a, 32b, 33a~33c of the bobbin 3, the outer legs 22m, 22n of the cores 2a, 2b and the rim of the opening 46 of the cover 4. The adhesive 8a may extend to the side surfaces 222m, 222n of the outer legs 22m, 22n, but from the viewpoint of preventing wire breakage, it is preferable that the adhesive 8a does not come into contact with the wire 5 (see Figure 3).

[0071] As shown in Figure 5, the adhesive 8a can simultaneously fix the bobbin 3, the cover 4, and the cores 2a and 2b at the opening 46. With this type of fixing, a sufficient bonding area between the adhesive 8a and the bobbin 3, cover 4, and cores 2a and 2b can be ensured. In addition, the flanges 32a, 32b, 33a-33c of the bobbin 3 protrude outward from the winding portion 50 (see Figure 3), making it easy to fix them to the cores 2a and 2b with the adhesive 8a inside the opening 46 of the cover 4.

[0072] As shown in Figure 3, the flange portions 32a, 32b, 33a-33c have protrusions 321a, 321b, 331a-331c that extend away from the winding portion 50. As described above, by bringing the adhesive 8a into contact with the protrusions 321a, 321b, 331a-331c, the protrusions 321a, 321b, 331a-331c can secure a sufficient bonding area with the adhesive 8a (see Figure 1), and it is easier to maintain the thickness of the adhesive 8a. As a result, the fixing of the bobbin 3, cover 4, and cores 2a, 2b by the adhesive 8a becomes stronger.

[0073] Furthermore, as shown in Figure 1, by applying adhesive 8a to the opening 46, the adhesive 8a can maintain a sufficient thickness. As a result, the bobbin 3, cover 4, and cores 2a and 2b are firmly bonded together by the adhesive 8a. Because each component is firmly bonded in this way, problems such as noise caused by resonance can be eliminated.

[0074] As shown in Figure 5, the multiple flange portions 32a, 32b, 33a-33c are arranged along the axial direction (X-axis direction) of the cylindrical portion 30 of the bobbin 3, and the tips of their protrusions 321a, 321b, 331a-331c are also arranged along the X-axis direction. The opening 46 is located at a position corresponding to each of the multiple flange portions 32a, 32b, 33a-33c. With this configuration, the flange portions 32a, 32b, 33a-33c, the cores 2a, 2b, and the cover 4 can be bonded at multiple positions. The opening 46 may be formed in the second cover main portion 43a, 43b and the second cover sub-parts 45a, 45b, or it may be formed in either one of them.

[0075] In this embodiment, as shown in Figure 6, the opening 46 is formed on the outside of the winding portion 50 (see Figure 3) in the Y-axis direction. As shown in Figure 5, the opening 46 is formed to span the second cover main portion 43a, 43b and the second cover sub-portion 45a, 45b. The adhesive 8a is arranged continuously along the X-axis direction at the boundary between the second cover main portion 43a, 43b and the second cover sub-portion 45a, 45b. By arranging the adhesive 8a in this position, a larger adhesion area of ​​the adhesive 8a to the cover 4 can be secured.

[0076] As shown in Figure 7, the outer surface 41 of the first cover portion 40 is flat. In this embodiment, no opening 46 is formed in the central part of the outer surface 41 of the first cover portion 40. Therefore, it is easy to transport the coil device 1 by adsorbing the outer surface 41 of the first cover portion 40 with an adsorption pad or the like. The outer surface 41 of the first cover portion 40 is positioned higher than the outer surface 431a of the second cover portion 42a by a height H1. The height H1 is not particularly limited, but from the viewpoint of facilitating the adsorption of the first cover portion 40 by an adsorption pad or the like, it is preferable that the height is such that the adhesive 8a is not positioned higher than the outer surface 41 of the first cover portion 40, for example, the height H1 may be 1 mm or more. The same applies to the outer surface 431b of the second cover portion 42b.

[0077] Furthermore, as shown in Figure 5, the extension pieces 44a and 44b of the second cover main parts 43a and 43b have one end 441a and 441b positioned near the base portion 21 of the core 2a that protrudes outward from the cover 4. The ends 441a and 441b are also positioned near the main body 360 of the terminal block 36a of the bobbin 3. The auxiliary adhesive 8b1 is positioned in close proximity to the ends 441a and 441b, the base portion 21 of the core 2a, and the main body 360 of the terminal block 36a. As a result, the auxiliary adhesive 8b1 allows one end 441a and 441b of the extension pieces 44a and 44b to be simultaneously fixed to the main body 360 of the terminal block 36a of the bobbin 3, thereby increasing the adhesive strength and preventing resonance.

[0078] Furthermore, as shown in Figure 5, the other ends 442a and 442b of the extension pieces 44a and 44b of the second cover main parts 43a and 43b are positioned near the base portion 21 of the core 2b that protrudes outward from the cover 4. The ends 442a and 442b are also positioned near the main body portion 360 of the terminal block 36a of the bobbin 3. The auxiliary adhesive 8b1 is positioned in close proximity to the ends 442a and 442b, the base portion 21 of the core 2a, and the main body portion 360 of the terminal block 36a. As a result, the auxiliary adhesive 8b1 allows the other ends 442a and 442b of the extension pieces 44a and 44b to be simultaneously fixed to the main body portion 360 of the terminal block 36b of the bobbin 3, thereby increasing the adhesive strength and preventing resonance.

[0079] Furthermore, as shown in Figure 5, the extension pieces 44a and 44b are fixed by bridging terminal block 36a and terminal block 36b. As a result, the fixing between the cover 4 and the bobbin 3 is more secure, improving the strength of the product.

[0080] It should be noted that the present invention is not limited to the embodiments described above, and can be modified in various ways within the scope of the present invention.

[0081] For example, as shown in Figure 2, both cores 2a and 2b are E-type cores, but one may be an E-type core and the other an I-type core. Also, both cores 2a and 2b may be U-type cores. Furthermore, one of cores 2a and 2b may be a U-type core and the other an I-type core. In addition, the E-type core and the U-type core may be a split structure. [Explanation of Symbols]

[0082] 1... Coil device 2a, 2b... Core 21...Base section 22m,22n…outer leg 221m,221n…Top surface 222m,222n…side 23...middle leg 26... Tape 3… Bobbin 30...Cylinder part 32a, 32b...end flange part 33a, 33b, 33c... Intermediate guard 321a, 321b, 331a, 331b, 331c...Protrusion 322a, 322b…end face 35a, 35b...Engagement protrusion 36a,36b…terminal block 360...Main unit 362... protruding part 4…cover 40…First cover section 41...External surface 42a, 42b... Second cover section 43a, 43b... Main part of the second cover 431a, 431b…External surface 44a, 44b...extension piece 441a, 442a, 441b, 442b...end 45a, 45b... Second cover sub-section 451a, 451b…External surface 46…Opening 47a, 47b...Engagement part 471a, 471b… Engaging recesses 5... Wire 50...Route 51... Lead section 6… Terminals 61...Connection section 62…Implementation Section 8a…Adhesive 8b1, 8b2... auxiliary adhesives

Claims

1. Wire and A bobbin on which the winding portion of the wire is formed, A core attached to the bobbin, It has a cover that protects the winding portion, The cover has an opening formed in a position that simultaneously opens at least a portion of the core and at least a portion of the bobbin to the outside. A coil device in which the bobbin, the core, and the cover are fixed together with an adhesive provided in the opening.

2. The bobbin has a flange portion, The coil device according to claim 1, wherein at least a portion of the flange is fixed to the cover and the core with the adhesive.

3. The flange portion has a projection that extends away from the winding portion, The coil device according to claim 2, wherein the adhesive is in contact with the protruding portion.

4. The bobbin has a plurality of flanges along the axial direction of the winding portion, The coil device according to claim 1, wherein the opening is positioned at a location corresponding to each of the plurality of flange portions.

5. The coil device according to claim 1, wherein the opening is a through hole or a slit.

6. The cover comprises a first cover portion that covers the winding portion and a second cover portion that covers at least a part of the core outside the first cover portion. The coil device according to any one of claims 1 to 5, wherein the opening is formed in the second cover portion.

7. The second cover portion comprises a second cover main portion having an outer surface that is lower in height than the outer surface of the first cover portion, and a second cover sub-portion that integrally connects the second cover main portion and the first cover portion. The coil device according to claim 6, wherein the opening is formed in the main part of the second cover and / or the sub-part of the second cover.

8. The coil device according to claim 7, wherein the adhesive is arranged continuously along the axial direction of the winding portion at the boundary between the second main cover portion and the second sub-cover portion.

9. The bobbin has a terminal block to which terminals are attached to which the lead portion of the wire is connected. The coil device according to claim 7, wherein the second main cover portion is positioned near the core protruding outward from the cover and has an extension piece that covers at least a portion of one longitudinal end of the terminal block.

10. The coil device according to claim 9, wherein a secondary adhesive is placed at a position where three things are in close proximity: a part of the core that protrudes outward from the cover, the end of the extension piece, and a part of the terminal block.

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