Coil components, bobbins, and coil devices

Abstract

To provide a coil component capable of effectively dissipating heat inside a coil by a heat dissipation material.SOLUTION: A coil component 1 includes: a bobbin 2 having a hollow cylindrical winding shaft unit 22; a coil 3 wound by a conductor 32 around the winding shaft unit; and a core 4 having a middle leg 42 inserted into a hollow section 24 of the winding shaft unit. In the bobbin, a groove 26 is formed on a surface in contact with the coil to communicate inside and outside of a region where the coil is arranged. A groove extending in a direction of a winding shaft 31 of the coil may be formed in the winding shaft unit.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a coil component, a bobbin, and a coil device.

Background Art

[0002] A wound coil component includes a bobbin having a hollow cylindrical winding shaft portion, a conducting wire wound around the outer periphery of the winding shaft portion to form a coil, and a core inserted into the hollow portion of the winding shaft portion. As is well known, a coil component generates heat due to the current flowing through the conducting wire. Therefore, for a coil component such as a transformer that handles high power, it is necessary to take heat countermeasures. Thus, in some cases, the coil component is installed in a metal case having a high thermal conductivity, as in the coil device described in Patent Document 1 below. And in such a case, a heat dissipation material having both thermal conductivity and insulation is filled in the case. By being filled between the coil component and the case, the heat dissipation material electrically insulates the coil component and the case while allowing the heat from the coil component to be released to the outside through the case. Note that as the heat dissipation material, a resin material called a well-known "potting material" or the like is used. Examples of the resin used as the potting material include a silicone resin, an epoxy resin, a urethane resin, and the like.

[0003] In addition, in the coil device described in Patent Document 2 below, a coil in which a primary winding and a secondary winding are wound concentrically around the winding shaft portion of a bobbin is provided, and the winding of the outer peripheral side coil is wound around the outer periphery of a bobbin cover that covers the outer periphery of the inner peripheral side coil. And the bobbin cover has an opening and a notch that communicate the inside and outside at a position below the region where the winding of the outer peripheral side coil is wound. Thereby, the potting resin supplied from the outside of the coil device can contact the outer surface of the inner peripheral side coil through the opening and the notch.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

[0005] As mentioned above, as a heat dissipation measure for coil components, potting resin is sometimes filled into the case in which the coil components are installed. Conventional heat dissipation measures for coil components involve bringing the potting resin into contact with the surface of the coil. In the coil device described in Patent Document 2, the potting agent is also brought into contact with the surfaces of both the outer and inner coils. Therefore, with conventional heat dissipation measures, it is difficult to effectively dissipate the heat from inside the coil formed by winding the conductor around the winding shaft of the bobbin. Furthermore, in recent years, coil components have been required to be even smaller and have higher output, and if heat dissipation measures are insufficient, the electrical characteristics of the coil components will deteriorate, making it difficult to meet the required specifications.

[0006] Therefore, the present invention aims to provide a coil component, bobbin, and coil device that can effectively dissipate heat from the inside of the coil using a heat dissipation material. [Means for solving the problem]

[0007] One aspect of the present invention for achieving the above objective is a coil component comprising a bobbin having a cylindrical winding shaft portion and a coil formed by winding a conductor wire around the winding shaft portion, The bobbin has a groove formed on the surface in contact with the coil that connects the inside and outside of the area where the coil is arranged, and a tongue portion that is continuous with the outer surface of the winding shaft portion and protrudes in a flat shape outward toward the area where the coil is arranged. As the groove, a first groove is formed that extends from the outer surface of the winding shaft portion in the winding axis direction of the coil and is continuous with the tongue portion. The first groove is formed along the direction in which the lead portions at the beginning and end of the winding of the conductor forming the coil are pulled out, extending to the edge of the tongue portion. It is a coil component.

[0008] With the winding axis direction of the coil as the front-to-back direction, The bobbin is provided with flange-shaped flanges at both the front and rear ends of the winding shaft portion. The tongue portion protrudes outward from the area where the coil is arranged through a notch formed by cutting out a part of the flange portion. In the flange portion, the second groove is located on the surface that contacts the coil. Formed, It may also be a coil component.

[0009] The aforementioned A coil component can also be formed in which the first groove and the second groove are continuously formed.

[0011] The bobbin constituting the coil component described in any of the above is also within the scope of the present invention, A bobbin is a cylindrical winding shaft around which a wire forming a coil is wound. and , on the surface in contact with the coil formed A groove connecting the inside and outside of the area where the coil is placed. It has a tongue portion that protrudes in a flat plate shape outward toward the area where the coil is arranged, continuously with the outer surface of the winding shaft portion. Furthermore, the bobbin is provided in which a first groove is formed as the groove, extending from the outer surface of the winding shaft portion in the winding axis direction of the coil and continuing to the tongue portion. Alternatively, with the winding axis direction of the coil as the front-to-back direction, The winding shaft portion is provided with flange-shaped flanges at both the front and rear ends, The tongue portion protrudes outward from the area where the coil is arranged through a notch formed by cutting out a part of the flange portion. The groove may be a bobbin having a first groove extending from the outer surface in contact with the coil in the winding shaft portion in the winding shaft direction and continuous with the tongue portion, and a second groove formed on the surface in contact with the coil in the flange portion.

[0012] The scope of the present invention includes any of the above coil components that are filled with a heat dissipation material made of resin. The coil device is housed in a bottom-box-shaped case, and the heat dissipation material covers the outer surface of the coil components of the coil device. The area in which the coil is placed is connected to the inside and outside of that area. This coil device is filled inside the groove and interposed in the region where the coil and the bobbin come into contact. [Effects of the Invention]

[0013] According to the present invention, a coil component, bobbin, and coil device are provided that can effectively dissipate heat from the inside of the coil using a heat dissipation material. Further effects will be described below. [Brief explanation of the drawing]

[0014] [Figure 1] It is an external view of the coil component according to the embodiment. [Figure 2] It is an exploded perspective view of the coil component according to the embodiment. [Figure 3] It is a perspective view when a part of the coil component according to the embodiment is cut. [Figure 4] It is an external view of the coil device provided with the coil component according to the embodiment. [Figure 5A] It is an external view of the bobbin constituting the coil component according to the embodiment. [Figure 5B] It is an external view of the bobbin constituting the coil component according to the embodiment. [Figure 6A] It is a diagram showing the filling path of the potting material in the coil component according to the embodiment. [Figure 6B] It is a diagram showing the filling path of the potting material in the coil component according to the embodiment. [Figure 7] It is a diagram showing the filling state of the potting material in the coil component according to the embodiment. [Figure 8] It is a diagram showing a modified example of the bobbin constituting the coil component according to the embodiment. [[ID=3l]]

Mode for Carrying Out the Invention

[0015] Embodiments of the present invention will be described with reference to the accompanying drawings. In the drawings used in the following description, the same or similar parts may be denoted by the same reference numerals and redundant descriptions may be omitted. Depending on the drawings, unnecessary reference numerals may also be omitted in the description.

[0016] ===Embodiment=== The overall configuration of the coil device 100 according to this embodiment is shown in FIGS. 1 and 2. As shown in FIGS. 1 and 2, the coil device 100 includes a coil component 1 and a case 10. In FIG. 1, the external appearance of the coil component 1 according to the embodiment is shown. In FIG. 2, an exploded perspective view of the coil component 1 is shown. In the following description, the direction parallel to the winding shaft 31 of the coil 3 is defined as the front-rear direction.

[0017] The coil component 1 according to the embodiment basically consists of a bobbin 2 having a hollow cylindrical winding shaft portion 22 with the same front-to-back direction as the winding shaft 31 as the cylindrical shaft 21, a coil 3 formed by winding a conductor 32 around the outer surface of the winding shaft portion 22, and a core 4 surrounding the coil 3 to form a closed magnetic path.

[0018] As shown in Figure 2, the core 4 in the coil component 1 according to the embodiment is composed of two E-shaped core members 41 facing each other in the front-rear direction, with the middle legs 42 of each core member 41 inserted into the hollow portion 24 of the winding shaft portion 22 of the bobbin 2. Hereinafter, it will be assumed that the outer legs 43 of the E-shaped core member 41 are formed on both the left and right sides relative to the middle legs 42, and the left-right direction will be defined as perpendicular to the front-rear direction, and the direction perpendicular to the front-rear direction and the left-right direction will be defined as the up-down direction. Furthermore, Figures 1 and 2 will be used to define the up and down directions as perspective views from above.

[0019] Figure 3 shows a perspective view of the coil component 1 when it is cut along a plane parallel to the left, right, up, and down directions, including the dashed line aa in Figure 1. The basic configuration of the coil component 1 according to the embodiment will be described below with reference to Figures 1 to 3. The coil component 1 according to the embodiment is a transformer, and two coils 3 are arranged coaxially in the front-to-back direction. In addition, the beginning and end portions of the conductors 32 that make up each of the two coils 3 are guided to the outside of the bobbin 2 as lead portions 33.

[0020] In the assembled coil component 1, as shown in Figure 1, tape 5a is wound around the front, back, left, and right surfaces of the core 4, preventing the two core members 41 from separating. Additionally, tape 5b is wound around the coil 3, primarily for insulation. Note that in Figures 2 and 3, the tapes (5a and 5b) are omitted to make the internal structure of coil component 1 easier to understand.

[0021] Incidentally, since the coil component 1 is ultimately mounted on a circuit board or the like, it is sometimes provided in the form of an electronic component (hereinafter sometimes referred to as "coil device 100") housed in a bottomed box-shaped metal case 10, as shown in Figures 1 and 3. In the coil device 100, the coil component 1 is housed in the case 10 covered with a heat dissipation material (hereinafter sometimes referred to as "potting material").

[0022] Figure 4 shows an external view of the coil device 100. The potting material 6, indicated by halftones in the figure, is filled between the inner surface of the case 10 and the coil component 1, so that most of the coil component 1 inside the case 10 is covered by the potting material 6. In the coil device 100 shown in Figure 4, the tips of the lead portions 33 that are connected to the circuit on the circuit board during mounting are bent upward and protrude outward from the potting material 6. Of course, the lead portions 33 may also be fixed while being covered with the potting material 6 and connected to a terminal block or the like, with the terminals of the terminal block protruding outward from the potting material 6. Note that Figure 4 shows the coil component 1 covered with the potting material 6 as a transparent view.

[0023] ===Heat dissipation structure=== As shown in Figures 1 to 3, in the coil component 1 according to the embodiment, a groove 26 is formed in the bobbin 2 that connects the inside and outside of the area where the coil 3 is placed. The coil component 1 is configured such that the heat generated in the conductor 32 of the coil 3 can be effectively released to the outside of the coil device 100 via the potting material 6 through the groove 26.

[0024] Figures 5A and 5B show the external appearance of the bobbin 2. Here, according to the above-mentioned provisions regarding the front, back, left, right, up, and down directions, Figure 5A is a perspective view of the bobbin 2 seen from above, and Figure 5B is a perspective view of the bobbin 2 seen from below. As shown in Figures 5A and 5B, the bobbin 2 has a structure in which two winding shafts 22 are coaxially connected in the front-to-back direction, corresponding to the two coils 3 that are arranged coaxially in the front-to-back direction in the coil component 1.

[0025] The end face of the winding shaft portion 22 is oval-shaped, with semicircular edges on both sides. At the front and rear ends of each of the two winding shaft portions 22, when viewed from the front-to-back direction, there are flange-like protrusions in the shape of an oval ring (hereinafter sometimes referred to as "flange portion 23a" and "flange portion 23b"). The flange portion 23a formed at both the front and rear ends of the bobbin 2 has a portion of the upper edge of the oval cut out in the area up to the outer surface 22s of the winding shaft portion 22. The upper surface 22u of the winding shaft portion 22 extends forward and backward through this cut-out area (hereinafter sometimes referred to as "notch portion 25"), protruding in a flat plate shape forward and backward from the open end of the hollow portion 24. Hereafter, this flat plate-like protruding portion will be referred to as the "tongue portion 27".

[0026] Furthermore, the bobbin 2 of the coil component 1 according to the embodiment has a groove 26 formed on the surface that contacts the coil 3, which connects the inside and outside of the area where the coil 3 is placed. Specifically, a groove extending in the front-rear direction (hereinafter sometimes referred to as the "first groove 26a") is formed on the outer surface 22s of the winding shaft portion 22. In addition, the two front and rear flange portions (23a, 23b) formed on each of the two winding shaft portions 22 have a groove (hereinafter sometimes referred to as the "second groove 26b") formed on the surfaces facing each other in the front-rear direction (hereinafter sometimes referred to as the "inner surface of the flange portion 23i") that extends from the inner circumference to the outer circumference of the oval-shaped flange portion 23.

[0027] In this embodiment, two first grooves 26a are formed on the upper surface 22u side and the lower surface 22d side of the winding shaft portion, respectively, so as to be parallel to each other from left to right. The first groove 26a on the upper surface 22u side of the winding shaft portion 22 extends through the notch 25 of the flange portion 23a to the edge 27e of the tongue portion 27, and opens at this edge 27e.

[0028] Furthermore, the two first grooves 26a on the upper surface 22u side of the winding shaft portion 22 each extend inward from the edge 27e of the tongue portion 27 and are individually continuous with the two second grooves 26b formed in the front and rear inward flange portions 23b. The two second grooves 26b formed in the front and rear inward flange portions 23b open on the upper edge side of the flange portions 23b.

[0029] On the other hand, the two first grooves 26a on the lower surface 22d side of the winding shaft portion 22 are continuous with a single wide groove 26c formed in the flange portions 23a at both the front and rear ends of the bobbin 2 so as to encompass the two first grooves 26a. Similar to the first grooves 26a on the upper surface 22u side, they are continuous with each of the two second grooves 26b formed in the front and rear inward flange portions 23b that extend from both the front and rear ends of the bobbin 2 toward the front and rear inward. These two second grooves 26b formed in the flange portions 23b open at the lower edge of the flange portions 23b.

[0030] ===Potting material filling status=== The coil component 1 according to the embodiment includes a bobbin 2 in which a groove 26 is formed in the region where the coil 3 is formed. To obtain the coil device 100, the coil component 1 is placed in a case 10, and then the case 10 is filled with potting material 6. In the coil component 1 according to the embodiment, when the potting material 6 is filled into the case 10, the potting material 6 is guided through the groove 26 to the inner surface of the coil 3, which is formed by winding a conductor 32 around a winding shaft portion 22 in a hollow cylindrical shape. As a result, in the coil component 1 according to the embodiment, the potting material 6 also comes into contact with the conductor 32 wound on the inner surface of the coil 3, allowing heat from the inner surface of the coil 3 to be effectively released.

[0031] Figures 6A and 6B show the filling paths of the potting material 6 in the coil component 1. Figures 6A and 6B are perspective views of the bobbin 2 with the coil 3 formed on it, when it is cut by a plane parallel to the vertical and horizontal directions, including the dashed line bb in Figure 1, and viewed from above and below.

[0032] When the coil component 1 is placed in the case 10 and the potting material 6 is filled into the case 10, the potting material 6 covers the surface of the coil component and is guided inward into the grooves (23a~23c) through the gap between the coil 3 and the flange portion 23, and through the openings of the grooves (23a~23c) at the edges of the flange portion 23 and the tongue portion 27, as shown by the white arrows in Figures 6A and 6B.

[0033] Figure 7 shows the state of filling the potting material 6 in the coil component 1. Figure 7 is a view of the cross-section of the coil component 1 as seen from the left and right directions, when the coil component 1 is cut by planes parallel to the upper, lower, front, and rear directions, including the cc line, as shown in Figure 4. As shown in Figure 7, the potting material 6 is filled between the coil 3 and the outer surface 22s of the winding shaft portion 22, and between the coil 3 and the inner surface 23i of the flange portion 23. This effectively dissipates heat from the inner surface of the coil 3, which is difficult to dissipate. Furthermore, in the coil component 1 of this embodiment, the potting material 6 penetrates between the conductors 32 from both the outer and inner surfaces of the coil 3, thereby increasing the contact area between the potting material 6 and the conductors 32 of the coil 3, and further enhancing the heat dissipation effect.

[0034] In the coil component 1 according to the embodiment, one first groove 26a and one second groove 26b are connected to each other, and the respective grooves (23a, 23b) are in contact with each other. Therefore, when filling the case 10 with potting material 6, the air between the inner surface of the coil 3 and the outer surface 22s of the winding shaft portion 22 and the inner surface 23i of the flange portion 23 can escape to the outside of the bobbin 2 through this groove 26. As a result, the potting material 6 is quickly filled throughout the entire area of ​​the groove 26. Furthermore, in the coil component 1 according to the embodiment, the first groove 26a on the upper surface 22u side of the winding shaft portion 22 is formed up to the edge 27e of the tongue portion 27 so as to be in the direction of the lead portion 33 of the conductor 32 being pulled out, so that the heat generated in the area of ​​the lead portion 33 can be reliably transferred to the potting material 6. Of course, the potting material 6 is also filled into the hollow portion 24 of the winding shaft portion 22, so that in the core 4, not only the heat from the portion exposed to the outside from the bobbin 2, but also the heat from the middle leg 42 can be released to the outside of the coil component 1.

[0035] ===Other Examples=== In the coil component 1 according to the above embodiment, the planar shape of the winding shaft portion 22 and flange portion 23 of the bobbin 2 when viewed from the front and rear direction was oval. However, the planar shape of the winding shaft portion 22 and flange portion 23 can be changed as appropriate, such as to be circular or rectangular, depending on the shape of the middle leg 42 of the core member 41 that is inserted into the hollow portion 24.

[0036] In the coil component 1 according to the above embodiment, the first groove 26a on the upper surface 22u side of the winding shaft portion 22 was formed to the edge 27e of the tongue portion 27 via the notches 25 in the flange portions 23a at both the front and rear ends of the bobbin 2. However, holes may be formed in the flange portions 23a to allow the first groove 26a and the lead portion 33 to pass through. Also, for example, as in the bobbin 102 shown in Figure 8, the first groove 26a formed on the upper surface 22u of the winding shaft portion 22 does not have to extend to the edge 27e of the tongue portion 27. Furthermore, in the coil component 1 according to the above embodiment, the first groove 26a formed in the winding shaft portion 22 was linear. However, for example, it may be formed to extend in the front-to-back direction so that it is helical with the front-to-back direction as the helical axis. In any case, it is sufficient that the ends of the grooves 26 formed in the winding shaft portion 22 and the flange portions 23 are outside the area in the bobbin 2 where the coil 3 is formed.

[0037] The groove 26 does not necessarily have to be present in both the winding shaft portion 22 and the flange portion 23; it may be present in only one of them. Furthermore, in the above embodiment, a pair of first grooves 26a were formed on the upper surface 22u and the lower surface 22d of the winding shaft portion 22, but one groove may be formed on each side. Of course, a single first groove 26a may be formed on at least one of the inner surfaces of the winding shaft portion or the flange portion.

[0038] When grooves 26 are provided in both the winding shaft portion 22 and the flange portion 23, the grooves 26 may be formed individually without being connected to each other.

[0039] In the above embodiment, the coil component 1 had an EE-type core structure, but any core 4 having a central leg 42 may be of other structures, such as an EI-type. Of course, the core 4 may be partially or entirely inserted into the hollow portion 24 of the winding shaft portion 22 in the bobbin 2. The coil component 1 may be an inductor or other coil component 1 other than a transformer. Furthermore, it may be a coreless coil component 1, such as an air-core coil. [Explanation of symbols]

[0040] 1 coil component, 2,102 bobbins, 3 coils, 4 cores, 5a, 5b tapes, 6 potting material, 10 case, 21 cylindrical shaft, 22 winding shaft section, 22d Lower surface of the winding shaft, 22u Upper surface of the winding shaft, 22s Outer surface of the winding shaft, 23,23a,23b collar part, 24 hollow part, 26,26a,26b,26c groove, 31 Winding shaft, 32 Conductor, 33 Lead section, 41 Core component, 42 Middle leg, 43 Outer leg, 100 Coil device

Claims

1. A coil component comprising a bobbin having a cylindrical winding shaft portion and a coil formed by winding a conductor around the winding shaft portion, The bobbin has a groove formed on the surface in contact with the coil that connects the inside and outside of the area where the coil is arranged, and a tongue portion that is continuous with the outer surface of the winding shaft portion and protrudes in a flat shape outward toward the area where the coil is arranged. As the groove, a first groove is formed that extends from the outer surface of the winding shaft portion in the winding axis direction of the coil and is continuous with the tongue portion. The first groove is formed along the direction in which the lead portions at the beginning and end of the winding of the conductor forming the coil are pulled out, extending to the edge of the tongue portion. Coil components.

2. A coil component according to claim 1, With the winding axis direction of the coil as the front-to-back direction, The bobbin is provided with flange-shaped flanges at both the front and rear ends of the winding shaft portion. The tongue portion protrudes outward from the area where the coil is arranged through a notch formed by cutting out a part of the flange portion. In the flange portion, a second groove is formed on the surface that contacts the coil. Coil components.

3. A coil component according to claim 2, wherein the first groove and the second groove are formed in a continuous manner.

4. The bobbin comprising the coil component described in claim 1, A cylindrical winding shaft portion around which a conductor wire forming a coil is wound, a groove formed on the surface in contact with the coil and connecting the inside and outside of the area where the coil is placed, and continuous with the outer surface of the winding shaft portion It has a tongue portion that protrudes in a flat shape outward toward the area in which the coil is arranged, As the groove, a first groove is formed that extends from the outer surface of the winding shaft portion in the winding axis direction of the coil and is continuous with the tongue portion. Bobbin.

5. The bobbin comprising the coil component according to claim 2 or 3, A cylindrical winding shaft portion around which a conductor wire forming a coil is wound, a groove formed on the surface in contact with the coil and connecting the inside and outside of the area where the coil is placed, and continuous with the outer surface of the winding shaft portion It has a tongue portion that protrudes in a flat shape outward toward the area in which the coil is arranged, With the winding axis direction of the coil as the front-to-back direction, The winding shaft portion is provided with flange-shaped flanges at both the front and rear ends, The tongue portion protrudes outward from the area where the coil is arranged through a notch formed by cutting out a part of the flange portion. The groove has a first groove that extends from the outer surface in contact with the coil in the winding shaft portion in the winding shaft direction and is continuous with the tongue portion, and a second groove formed on the surface in contact with the coil in the flange portion. Bobbin.

6. A coil device in which the coil component according to any one of claims 1 to 3 is housed in a bottomed box-shaped case filled with a heat dissipation material made of resin, The heat dissipation material covers the outer surface of the coil component and is filled inside the groove that connects the inside and outside of the area where the coil is placed, and is interposed in the area where the coil and the bobbin are in contact. Coil device.

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