Coil component
The EE-type core and integrally molded cover with U-shaped groove and protrusion in the coil component address the challenge of reducing height and mounting area while ensuring insulation, suitable for high-voltage applications and automatic mounting.
Patent Information
- Application Number
- JP2023114707
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2023-07-12
- Publication Date
- 2025-01-24
AI Technical Summary
Existing horizontal coil components face challenges in reducing height while ensuring adequate insulation distance, leading to increased mounting area and difficulty in miniaturization, especially when handling high voltages.
A coil component design featuring an EE-type core with E-shaped core members, a bobbin with a terminal block, and a cover made of integrally molded insulating material, which includes a U-shaped groove and protrusion to ensure creepage insulation without expanding the mounting area.
The design achieves a reduction in height and mounting area while maintaining sufficient insulation distance, suitable for high-voltage applications, and is compatible with automatic mounting processes.
Smart Images
Figure 2025012117000001_ABST
Abstract
Description
[Technical field]
[0001] The present invention relates to a coil component. [Background technology]
[0002] Some coil components are called surface mount type, which are equipped with a bobbin that also serves as a terminal block and can be mounted on a substrate. The bobbin of a surface mount type coil component is integrally formed with a winding shaft part around which the coil winding is wound and a terminal block, and a terminal protrudes from the terminal block. The base end of the terminal is embedded in the terminal block, and the start and end of the coil winding are connected to the base end of the terminal.
[0003] Incidentally, electronic components, not limited to coil components, are required to be miniaturized to reduce the mounting area and to be low-profile to suppress the vertical height when mounted. The height of a coil component can be suppressed by making it "horizontal" with the coil winding axis direction parallel to the mounting surface. The following non-patent document 1 describes the specifications of commercially available horizontal coil components. This horizontal coil component is mounted on the upper surface of a surface that defines three mutually orthogonal directions, left and right, front and rear, and up and down, and the winding axis direction is the front and rear direction. A terminal block is disposed below the winding axis, and terminals protrude forward and backward from the front and rear surfaces of the terminal block, respectively. In addition, the following patent document 1 describes a "winding component" equipped with an EE-type core with a middle leg disposed below the outer leg in relation to an embodiment of the present invention. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] JP 2015-162619 A [Non-patent literature]
[0005] [Non-Patent Document 1] TDK Corporation, "IGBT / FET Transformer VGT Series", [online], [searched June 22, 2023], Internet<URL:https: / / product.tdk.com / info / ja / catalog / datasheets / trans_gate-drive_vgt_ja.pdf> Summary of the Invention [Problem to be solved by the invention]
[0006] When a horizontal coil component handles high voltages, such as a gate drive transformer for an insulated gate bipolar transistor (IGBT), a specified insulation distance must be provided between the coil windings or core and the terminals according to the requirements of the electronic circuit and specifications such as the voltage value handled by the coil component.
[0007] Since the coil windings are usually provided with a coating layer made of an insulator on the surface, the insulation distance to be secured is the distance between the core and the terminal. The insulation distance includes the spatial insulation distance that connects the core and the terminal in the shortest way through space, and the creepage insulation distance that connects the core and the terminal in the shortest way while detouring along the surface of the insulator if there is an insulator on the path that connects the core and the terminal in the shortest way.
[0008] An example of a horizontal coil device 101 is shown in Figures 1 and 2. Figure 1 is a diagram showing the appearance of the horizontal coil device 101, and Figure 2 is an exploded perspective view of the coil device 101 shown in Figure 1. The horizontal coil device 101 basically includes a coil 2, a bobbin 104 in which a winding shaft part 104a around which the winding of the coil 2 is wound and a terminal block 104b to which a terminal 5 is attached are integrally formed, and a core 13 that surrounds the coil 2 to form a closed magnetic circuit.
[0009] Here, the direction of the winding axis 100 of the coil 2 is defined as the front-rear direction, the front-rear direction, the left-right direction, and the up-down direction are defined as being mounted on a surface including the front-rear and left-right directions, and the up-down directions are defined as being mounted on the upper surface of a substrate. The winding axis 104a of the bobbin 104 is a hollow cylinder with the front-rear direction as its cylindrical axis, and flanges are formed on both the front and rear ends. The winding of the coil 2 is wound between the front and rear flanges. A terminal block 104b is integrally formed below the winding axis 104a. A plurality of terminals 5 are attached to both the front and rear ends of the terminal block 104b, protruding in the front-rear direction and lined up in the left-right direction.
[0010] The core 13 is composed of two core members (13a, 13b) facing each other in the front-rear direction, and as shown in FIG. 1, the tape 6 is wound around the core 13 so that the two core members (13a, 13b) do not separate from each other. Also, as shown in FIG. 2, the core members (13a, 13b) have a rectangular flat back portion 131 with the front-rear direction as the thickness direction, outer legs 132 protruding in one front-rear direction at both left and right ends of the back portion 131, and a middle leg 133 protruding in one front-rear direction at the center of the left and right, and have an E-shape when viewed from the top and bottom. The core 13 is an EE type in which the two E-shaped core members (13a, 13b) are arranged facing each other in the front and rear such that the tips of the legs (131, 132) face each other. The middle leg 133 of each core member (13a, 13b) is inserted into the hollow portion 4c of the hollow cylindrical winding shaft portion 104a. In FIG. 2, in order to make it easier to understand the shapes of the bobbin 104 and the core 13, the tape 6 for fixing the coil 2 and the core 13 shown in FIG. 1 is omitted.
[0011] 1 and 2, horizontal coil component 101 is advantageous in terms of reducing the height, but there is a problem in that reducing the height makes it difficult to ensure an insulation distance in the vertical direction. For this reason, in horizontal coil component 101, it is necessary to make terminal block 104b wider in the front-to-rear direction and to increase the distance between core 13 and the front and rear end faces of bobbin 104 from which terminals 5 protrude. However, if one tries to ensure an insulation distance while achieving a low height, the size of bobbin 104 in the front-to-rear direction naturally increases, making it difficult to reduce the mounting area.
[0012] In order to reduce the mounting area while ensuring the insulation distance, it is possible to increase the vertical distance between the position where the terminal 5 protrudes from the bobbin 104 and the core 13. However, if the vertical distance between the terminal 5 and the core 13 is increased, the effect of reducing the height achieved by adopting a horizontal type cannot be obtained. FIGS. 3 and 4 show a coil component 201 in which the vertical distance between the terminal 5 and the core 13 is increased. FIG. 3 is an external view of the coil component 201, and FIG. 4 is an exploded perspective view of the coil component 201. Note that the tape 6 and the coil 2 are omitted in FIG. 4, as in FIG. 2. As shown in FIGS. 3 and 4, the mounting area can be reduced, but the effect of reducing the height achieved by adopting a horizontal type cannot be obtained.
[0013] Some horizontal coil components (101, 201) have a plate-shaped cover made of an insulator provided on the path between the core 13 and the terminal 5 passing through the space. Figures 5 and 6 show coil components (111, 211) in which a cover (107, 207) is provided for the coil components (101, 201) shown in Figures 1 and 3, respectively. The coil components (111, 211) shown in Figures 5 and 6 include a rectangular ring-shaped cover (107, 207) made of an insulator that surrounds the winding shaft portion (104a, 204a) of the bobbin (104, 204) and is supported by the terminal block (104b, 204b). In such coil components (111, 211), the cover (107, 207) is provided on the path that connects the core 13 and the terminal 5 in the shortest distance, so that it is sufficient to ensure a creepage insulation distance that is a path from the terminal 5 to the core 13 along the surface of the cover (107, 207). The coil components (111, 211) equipped with the cover (107, 207) have a larger creepage insulation distance than the coil components (101, 201) shown in Fig. 1 and Fig. 3. However, since the mounting area of the coil components (111, 211) is not the size of the terminal block (104b, 204b) but the projected area when viewed from the top and bottom, it is difficult to reduce the mounting area of the coil components (111, 211) equipped with the rectangular flat cover (107, 207) by using the cover (107, 207).
[0014] SUMMARY OF THE PRESENT DISCLOSURE OF THE PRESENT DISCLOSURE An object of the present invention is to provide a coil component that achieves a low profile without increasing the mounting area while ensuring a creepage insulation distance. [Means for solving the problem]
[0015] In order to achieve the above object, one aspect of the present invention is to The three directions, front to back, left to right, and up to down, are perpendicular to each other. A coil component having terminals and mounted on a surface including front-back and left-right directions, The coil is formed by winding a wire around a winding axis in the front-rear direction, a core made of two core members, a bobbin around which the wire is wound, and a cover made of an integrally molded insulating material, The core is an EE type consisting of an E-shaped core member having outer legs protruding in one direction from the left and right ends of a flat back portion and a middle leg protruding in one direction from the center of the left and right of the back portion, The bobbin has a hollow cylindrical winding shaft portion around which the winding is wound, the hollow cylindrical winding shaft portion having openings at the front and rear, and a terminal block is integrally formed below the hollow cylindrical winding shaft portion, The terminals are attached to both front and rear ends of the terminal block, the cover is an integrally molded product and has a base portion that opens upward and covers the lower sides and bottom surface of the left and right side surfaces of the back portion, and a protrusion portion that covers the lower sides and bottom surface of the left and right side surfaces of the middle leg and is inserted into the hollow portion of the winding shaft portion together with the middle leg, A U-shaped groove having an open end when viewed from above and below is formed on the outer side surface of the base. It is a coil component.
[0016] The core member may be a coil component in which the middle leg is disposed below the outer leg when viewed from the front-rear direction.
[0017] Alternatively, the coil component may be one in which the back portion is rectangular and flat, the cover is E-shaped when viewed from above, and the base portion is U-shaped when viewed from above, continuing from the underside of the back portion to cover the underside and the left and right side surfaces of the outer leg.
[0018] The coil component may be any one of the above, further comprising a cap having a flat upper surface attached to the upper part of the bobbin. Effect of the Invention
[0019] According to the present invention, there is provided a coil component that achieves a low profile without increasing the mounting area while ensuring a creepage insulation distance. Other effects will be made clear in the following description. [Brief description of the drawings]
[0020] [Figure 1] FIG. 1 is an external view of a conventional coil component. [Diagram 2]FIG. 13 is an exploded perspective view of a conventional coil component. [Diagram 3] FIG. 13 is an external view of another conventional coil component. [Figure 4] FIG. 13 is an exploded perspective view of another conventional coil component. [Diagram 5] FIG. 2 is an external view of a coil component according to a first comparative example. [Figure 6] FIG. 11 is an external view of a coil component according to a second comparative example. [Figure 7] 1 is an external view of a coil component according to an embodiment of the present invention. [Figure 8] FIG. 2 is an exploded perspective view of the coil component according to the embodiment. [Figure 9] 10A to 10C are diagrams for explaining an assembly procedure of the coil component according to the embodiment. [Figure 10] FIG. 11 is a diagram for comparing the sizes and creepage insulation distances of the coil component according to the above-mentioned Example, the coil component according to the above-mentioned Comparative Example 1, and the coil component according to the Comparative Example 2 when viewed from the front-rear direction. [Figure 11] FIG. 11 is a diagram for comparing the sizes and creepage insulation distances of the coil component according to the above-mentioned Example, the coil component according to the above-mentioned Comparative Example 1, and the coil component according to the Comparative Example 2 when viewed from the left and right. [Figure 12] 13 is an external view of a coil component according to a modified example of the present invention. FIG. [Figure 13] FIG. 13 is an exploded perspective view of a coil component according to the modified example. [Figure 14] FIG. 11 is a diagram for comparing the sizes and creepage insulation distances of the coil component according to the modified example, the coil component according to Comparative Example 1, and the coil component according to Comparative Example 2 when viewed from the front-rear direction. [Figure 15] FIG. 11 is a diagram for comparing the sizes and creepage insulation distances of the coil component according to the modified example, the coil component according to Comparative Example 1, and the coil component according to Comparative Example 2 when viewed from the left and right. [Figure 16] 1 is an external view of a coil component according to an application example of the present invention. [Figure 17] FIG. 2 is an exploded perspective view of the coil component according to the application example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The 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 are designated by the same reference numerals, and redundant explanations may be omitted. In some drawings, unnecessary reference numerals may be omitted in the description. === Example === 7 and 8 show a coil component 1 according to an embodiment. FIG. 7 is an external view of the coil component 1, and FIG. 8 is an exploded perspective view of the coil component 1. In the following, the up-down direction, left-right direction, front-rear direction, and up-down directions of the coil component 1 according to the embodiment will be defined in the same manner as the conventional coil components (101, 201, 111, 211) shown in FIGS. 1 to 6. In addition, for the sake of convenience, in the drawings, the z-axis + direction of a left-handed xyz three-dimensional coordinate system is defined as up, and the x-axis + direction is defined as forward, and the left-right direction is defined according to the left-right direction when viewed from the front to the rear.
[0022] 7, the coil device 1 according to the embodiment is a horizontal type with a winding axis 100 in the front-to-rear direction, similar to the conventional coil devices (101, 201, 111, 211) shown in FIGS. 1 to 6, and includes a bobbin 4 with a terminal block 4b provided below, and a core 3 made of two core members (3a, 3b), which is fixed with tape 6. Furthermore, the coil device 1 according to the embodiment includes a cover 7 having a different shape from the coil devices (111, 211) shown in FIGS. 5 and 6.
[0023] As shown in Fig. 8, the core 3 is an EE type having E-shaped core members (3a, 3b) arranged opposite each other in the front-rear direction, which are E-shaped when viewed from the top-bottom direction, but the external shape of the core members (3a, 3b) is different from that of the coil devices (101, 201, 111, 211) shown in Figs. 1 to 6. The core members (13a, 13b) of the coil devices (101, 201, 111, 211) shown in Figs. 1 to 6 are composed of a rectangular flat back portion 131 having flat surfaces in the top-bottom and left-right directions and a thickness direction in the front-rear direction, and legs (132, 133) protruding in one front-rear direction from the back portion 131, whereas the core members (3a, 3b) of the coil device 1 according to the embodiment have a shape in which a middle leg 33 is arranged below an outer leg 32, similar to the winding device described in the above-mentioned Patent Document 1. That is, when viewed from the front-rear direction, the back 31 has a shape in which the outer legs 32 are arranged at both the left and right ends and a shallow recess is formed in the left-right center of the upper edge of a rectangle, and an inverted trapezoidal area 31b continues below the recessed area 31a. The recessed area 31a continuing above the inverted trapezoidal area 31b of the back 31 is wider in the left-right outward direction than the upper edge of the inverted trapezoidal area 31b by the left-right width of the outer legs 32. The recessed area 31a may be a simple rectangle without a recess.
[0024] The cover 7 is an integrally molded product made of, for example, insulating resin, and is configured in a pair facing each other corresponding to the two front and rear core members (3a, 3b). As shown in Fig. 8, the cover 7 has a base 71 formed in a shape that covers the inverted trapezoidal region 31b in the back portion 31 of the core members (3a, 3b), and a protrusion 72 formed in a groove shape that protrudes in one direction from the center of the left and right of the base 71 and is open at its tip.
[0025] FIG. 9 shows an outline of the assembly procedure of the coil device 1 according to the embodiment. As shown in FIG. 9, a conductor wire is wound around the winding shaft portion 4a of the bobbin 4 to form the coil 2, and the cover 7 is attached to each of the two core members (3a, 3b) from below. At this time, the base portion 71 of the cover 7 covers the inverted trapezoid region 31b of the back portion 31. The inner depth of the base portion 71 is shallower than the vertical height of the inverted trapezoid region 31b of the core members (3a, 3b), and when the base portion 71 covers the region 31b, the upper surface of the base portion 71 and the lower end of the concave region 31a of the core members (3a, 3b) are slightly separated from each other. Of course, the base portion 71 of the cover 7 may have a depth sufficient to cover the entire inverted trapezoid region 31b of the back portion 31 when viewed from the front-rear direction.
[0026] The middle leg 33 has a vertical height from the bottom end of the inverted trapezoid region 31b to the vertical center of the concave region 31a in the back portion 31. Therefore, when the cover 7 is attached to the core members (3a, 3b), the protrusions 72 cover the bottom surface of the middle leg 33 and the bottoms of the left and right side surfaces. That is, the region of the middle leg 33 above the inverted trapezoid region 31b of the back portion 31 and the front end side are exposed outside the cover 7.
[0027] Once the cover 7 is attached to the core members (3a, 3b), the center leg 33, together with the protrusion 72 of the cover 7, is inserted into the hollow portion 4c of the hollow cylindrical winding shaft portion 4a of the bobbin 4, and the two core members (3a, 3b) are arranged facing each other in the front-to-rear direction to form the EE-type core 3. The core members (3a, 3b) are fixed in place by winding tape 6 around the core 3. The core 3 and bobbin 4, and the core 3 and cover 7 are fixed together with an adhesive. This completes the coil device 1 according to the embodiment shown in FIG. 7.
[0028] 7 to 9, a U-shaped groove 73 with an open end when viewed from the top-bottom direction is formed on the outer side surface of the base 71 of the cover 7. That is, the groove 73 is formed on the outer peripheral surface of the base 71 of the front cover 7, extending in the left-right direction on the front surface, continuing forward on the left and right side surfaces, and opening at the rear end, and the groove 73 is formed on the outer side surface of the base 71 of the rear cover 7, extending in the left-right direction on the rear surface, continuing backward on the left and right side surfaces, and opening at the front end. In the coil component 1 according to the embodiment, the creepage insulation distance is the distance along the unevenness of this groove 73, so that it is possible to achieve a low profile by making it horizontal without increasing the mounting area, while ensuring the creepage insulation distance.
[0029] 10 and 11 are diagrams for comparing the creepage insulation distance and size of the coil component 1 according to the embodiment with the conventional coil components (111, 211) with covers (107, 207) shown in Figs. 5 and 6. Here, assuming that the conventional coil component 111 shown in Fig. 5 is Comparative Example 1 and the conventional coil component 211 shown in Fig. 6 is Comparative Example 2, Fig. 10 is a comparative diagram of the coil component 1 according to the embodiment and the coil components (111, 211) according to Comparative Examples 1 and 2 when viewed from the front-back direction, and Fig. 11 is a comparative diagram of the coil component 1 according to the embodiment and the coil components (111, 211) according to Comparative Examples 1 and 2 when viewed from the left-right direction. Note that Fig. 10 shows the coil component 1 according to the embodiment as a cross-sectional view cut along a plane including the up-down and left-right directions corresponding to the cross section viewed from the arrow aa in Fig. 7, and shows the coil components according to Comparative Examples 1 and 2 as side views when viewed from the direction indicated by the white arrow in Figs. 5 and 6. In Fig. 11, the coil devices of the example and comparative examples 1 and 2 are shown as cross-sectional views taken along a plane including the winding axis 100 and the up-down direction, which corresponds to the cross-sections viewed from the arrows bb in Fig. 7, and Fig. 5 and Fig. 6. Fig. 11 also compares the up-down heights of the coil devices (1, 111, 211) of the example, comparative example 1, and comparative example 2. For the sake of convenience, Figs. 10 and 11 show the left-right and front-back directions in comparative examples 1 and 2 in the same way as coil device 1 of the example.
[0030] As shown in Figs. 10 and 11, the coil components (1, 111, 211) of the example and comparative examples 1 and 2 have the same size and shape of the coil 2, and the shape and size of the winding shaft portion (4a, 104a, 204a) are also substantially the same. The cores (3, 13) have the same front-to-back and left-to-right lengths. As shown in Fig. 10, the left-to-right widths of the coil component 111 of comparative example 1 and the coil component 211 of comparative example 2 are equivalent, and it can be seen that the coil component 1 of the example is narrower in the left-to-right width than the coil components (111, 211) of comparative examples 1 and 2. In addition, in the figure, the path R corresponding to the creepage insulation distance is indicated by a thick arrow. As shown in FIG. 10, the creepage insulation distance when viewed from the front-to-back direction is the distance from the terminal 5 at the left or right end along the surface of the cover (7, 107, 207) to the core (3, 13). In the coil component 1 of the embodiment, due to the groove 73 formed on the outer surface of the cover 7, the creepage insulation distance from the terminal 5 to the core via the outer surface of the cover 7 is longer than the creepage insulation distance in either of the coil components (111, 211) of comparison examples 1 and 2, and sufficient creepage insulation distance is ensured.
[0031] Also, as shown in FIG. 11, the covers (107, 207) in the coil parts (111, 211) of comparative examples 1 and 2 are rectangular and annular, and the cover 7 of the embodiment is composed of a pair of covers arranged opposite each other in the front-to-back direction. Therefore, the surface insulation distance of each coil part (1, 111, 211) when viewed from the left-to-right direction is the distance of the path from the terminal 5 via the upper surface of the cover (7, 107, 207) to the outer surface of the core (3, 13), shown on the right side of the center line 200 that divides each coil part (1, 111, 211) into left and right halves, and the distance of the path from the terminal 5 via the lower surface of the cover (7, 107, 207) to the middle leg (133, 33) of the core (3, 13), shown on the left side of the center line 200.
[0032] The covers (107, 207) of the coil components (111, 211) according to Comparative Examples 1 and 2 surround the winding shaft portions (104a, 204a) and do not extend into the winding shaft portions (104a, 204a). Therefore, the creepage insulation distance along the lower surface of the cover (107, 207) in the coil components (111, 211) according to Comparative Examples 1 and 2 is substantially the same regardless of the presence or absence of the cover (107, 207). In other words, even if the cover (107, 207) is provided on the coil components (101, 201) shown in FIG. 1 or FIG. 3, it is difficult to reduce the size of the terminal blocks (104b, 204b).
[0033] On the other hand, the cover 7 of the coil component 1 according to the embodiment has a base 71 with a groove 73 formed on its outer side surface, and a protrusion 72 that covers the lower surface of the center leg 33 and the lower sides of the left and right sides and is inserted into the hollow portion 4c of the winding shaft portion 4a together with the center leg 33. Therefore, both the creepage insulation distance through the lower surface of the cover 7 and the creepage insulation distance through the upper surface of the cover 7 are longer than those of the coil components (111, 211) of Comparative Examples 1 and 2. Also, in the coil component 1 according to the embodiment, the size in the up-down direction when viewed from the left-right direction is equivalent to that of the coil component 111 according to Comparative Example 1 which has achieved a low profile, and the size in the front-rear direction is equivalent to that of the coil component 211 of Comparative Example 2 in which the terminals 5 are positioned lower to reduce the mounting area.
[0034] In this way, in the coil component 1 according to the embodiment, the cover 7 having the groove 73 and the protrusion 72 achieves a low profile and a reduced mounting area while ensuring a sufficient creepage insulation distance. Also, the core members (3a, 3b) of the coil component 1 according to the embodiment have a shape in which the middle leg 33 is disposed below the outer leg 32, and the concave region 31a in the back 31 protrudes outward in the left and right directions from the inverted trapezoid region 31b. And, since the base 71 of the cover 7 is shaped to cover only the inverted trapezoid region 31b below the back 31, the cover 7 only protrudes outward slightly in the left and right directions from the inverted trapezoid region 31b as shown in FIG. 10, and the size in the left and right direction is small. That is, in the coil component 1 according to the embodiment, the shape of the core members (3a, 3b) also contributes to miniaturization. === Variations === The coil component 1 according to the above embodiment includes core members (3a, 3b) in which the middle leg 33 is disposed below the outer leg 32, but the core members (3a, 3b) may be changed to general E-shaped core members (13a, 13b) in which the outer leg 132 and the middle leg 133 are disposed parallel to the left and right direction on a rectangular back portion 131 similar to those in Comparative Examples 1 and 2. Thus, as a modification of the embodiment, a coil component that uses general E-shaped core members (13a, 13b) and achieves a low profile without increasing the mounting area while ensuring a creepage insulation distance will be presented.
[0035] 12 and 13 are diagrams showing a coil component 11 according to a modified example. FIG. 12 is an external view of the coil component 11 according to the modified example, and FIG. 13 is an exploded perspective view of the coil component 11. As shown in FIG. 12, the cover 17 covers the E-shaped core members (13a, 13b) from their lower surfaces to a height position that divides the E-shaped core members (13a, 13b) in the vertical direction. As shown in FIG. 13, the cover 17 has an E-shaped external shape when viewed from above, and is formed in a groove shape with the upper side and the three ends of the E open. That is, when viewed from above, the cover 17 has a U-shaped base 171 with a protrusion 172 connected to the left and right center of the base 171. The base 171 covers the lower half of the rectangular flat back 131 of the core members (13a, 13b) and the lower surfaces and left and right side surfaces of the outer legs 132, and the protrusion 172 covers the lower surface and left and right side surfaces of the middle leg 133.
[0036] 14 and 15 show diagrams comparing the creepage insulation distance and size of the coil components (111, 211) according to the comparative examples 1 and 2 and the coil component 11 according to the modified example. In the coil component 11 according to the modified example, due to the shape of the cover 17 described above, the creepage insulation distances passing through the upper and lower surfaces of the cover 17 are longer than those of the coil components (111, 211) according to the comparative examples 1 and 2. In addition, in the coil component 11 according to the modified example, the size in the up-down direction when viewed from the left-right direction is equivalent to that of the coil component 111 according to the comparative example 1, which achieves a low profile by being horizontal, and the size in the front-rear direction is equivalent to that of the coil component 211 according to the comparative example 2, in which the terminal 5 is positioned lower in order to reduce the mounting area. Note that, although the coil component 11 according to the modified example is larger in the front-rear direction than the coil component 1 according to the embodiment, it is possible to achieve a low profile equivalent to that of the coil component 111 according to the comparative example 1 while reducing the mounting area compared to the coil component 211 according to the comparative example 2, while using general E-shaped core members (13a, 13b). Therefore, the manufacturing cost of the coil device 11 according to the modified example can be easily reduced by, for example, standardizing the components. ===Application Examples=== In recent electronic circuits, electronic components are automatically mounted on a substrate by an automatic process using a robot. Therefore, as an application example of the coil component 1 according to the embodiment, a coil component adapted for automatic mounting is given. FIGS. 16 and 17 show a coil component 21 adapted for automatic mounting. FIG. 16 is an external view of the coil component 21 according to the application example, and FIG. 17 is an exploded perspective view of the coil component 21. In the coil component 21 according to the application example, a cap 8 having a flat upper surface 81 is attached to the upper end of the bobbin 24. In this way, during automatic mounting, the flat upper surface 81 is vacuum-adsorbed, so that the robot can easily hold the coil component 21. As shown in FIG. 17, in the coil component 21 according to the application example, the cap 8 can be formed, for example, of an integrally molded product made of insulating resin. The cap 8 has an external shape in which plate-shaped tongue pieces 82 extending downward are provided on both front and rear sides of a flat box that opens downward and covers the winding shaft portion 24a of the bobbin 24. The tongue piece 82 has a rectangular hole 83 formed therethrough in the front-rear direction.
[0037] On the other hand, the bobbin 24 to which the cap 8 is attached has a terminal block 24b formed integrally below a hollow cylindrical winding shaft portion 24a having flanges at both front and rear ends, as in the coil device 1 according to the embodiment. However, protrusions 24c that engage with holes 83 of the cap 8 are formed on the front and rear outer sides of the flanges of the winding shaft portion 24a. The cap 8 is attached to the bobbin 24 by snap-fitting. That is, when the cap 8 is attached to the winding shaft portion 24a of the bobbin 24 from above, the flexible tongue piece 82 rides over the protrusion 24c of the bobbin 24, and the protrusion 24c engages with the hole 83 of the tongue piece 82, and the cap 8 is fixed to the bobbin 24. In order to reliably prevent the cap 8 from falling off unintentionally, the cap 8 is fixed to the bobbin 24 using an adhesive in a state where it is attached to the bobbin 24 by snap-fitting. ===Other Examples=== The present invention is not limited to the above-mentioned embodiments, modifications, and applications, and may be modified in various ways without departing from the spirit of the present invention. For example, the above-mentioned embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those having all of the configurations described.
[0038] For example, in the cover 7 of the coil device 1 according to the embodiment, one groove 73 is formed in the vertical direction on the outer surface of the base 71, but two or more grooves may be formed. Also, the terminals 5 protrude forward and backward from the front and rear end surfaces of the terminal block 4b, respectively, but they may protrude downward from both the front and rear ends of the lower surface of the terminal block 4b. [Explanation of symbols]
[0039] 1,11,21,101,111,201,211 coil parts, 2 coils, 3a, 3b, 13a, 13b core members, 3, 13 core, 4,14,24,104,204 bobbins, 4a,14a,24a,104a,204a Winding shaft part, 4b, 14b, 24b, 104b, 204b terminal block, 4c hollow portion of winding shaft, 5 Terminal, 6 Tape, 7,17,107,207 Cover, 8 Cap, 31,131 Back of core member, 32,132 Outer leg, 33,133 Middle leg, 71,171 Cover base, 72,172 Cover projection, 73,173 Groove
Claims
1. The three directions, front to back, left to right, and up to down, are perpendicular to each other. A coil component having terminals and mounted on a surface including front-back and left-right directions, The coil is formed by winding a wire around a winding axis in the front-rear direction, a core made of two core members, a bobbin around which the wire is wound, and a cover made of an integrally molded insulating material, The core is an EE type consisting of an E-shaped core member having outer legs protruding in one direction from the left and right ends of a flat back portion, and a middle leg protruding in one direction from the left and right center of the back portion, The bobbin has a hollow cylindrical winding shaft portion around which the winding is wound, the hollow cylindrical winding shaft portion having openings at the front and rear, and a terminal block is integrally formed below the hollow cylindrical winding shaft portion, The terminals are attached to both front and rear ends of the terminal block, the cover is an integrally molded product and has a base portion that opens upward and covers the lower sides and bottom surface of the left and right side surfaces of the back portion, and a protrusion portion that covers the lower sides and bottom surface of the left and right side surfaces of the middle leg and is inserted into the hollow portion of the winding shaft portion together with the middle leg, A U-shaped groove having an open end when viewed from above and below is formed on the outer side surface of the base. Coil parts.
2. The coil component according to claim 1 , wherein the core member has a middle leg disposed below the outer leg when viewed from the front-rear direction.
3. The back portion is a rectangular flat plate, The cover is E-shaped when viewed from above, The base is U-shaped when viewed from above, and is continuous with the lower side of the back to cover the lower surface and the left and right side surfaces of the outer leg. The coil component according to claim 1 .
4. 4. The coil component according to claim 1, further comprising a cap having a flat upper surface attached to the upper side of the bobbin.
Citation Information
Patent Citations
Winding component
JP2015162619A