Molded coils and reactors

Abstract

To provide a mold coil which prevents disconnection of a lead wire of a sensor and melting of a coat and enables integration of the senor and a coil, and to provide a reactor including the mold coil.SOLUTION: A mold coil 10 includes: a coil; a sensor 1 which detects a physical amount of the mold coil 10; a sensor cover 2 attached to the sensor 1; and a coil mold resin 5 which covers the sensor 1 attached with the sensor cover 2 and the coil and integrates the sensor 1 with the coil. The sensor 1 has: a detection part which is protected by the sensor cover 2 and detects the physical amount; and a lead wire 12 connected to the detection part. The sensor cover 2 is disposed around the lead wire stored in a mold during mold forming.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a molded coil equipped with a sensor and a reactor equipped with this molded coil. [Background technology]

[0002] Coil components such as reactors are used in a variety of applications, including office equipment, solar power generation systems, and automobiles. Coil components consist of a coil wound around the outer periphery of a core made of magnetic material. A resin material is provided between the core and the coil to insulate them from each other.

[0003] In recent years, molded coils made from resin have come into widespread use. The coil is placed in a predetermined position in a mold, and resin is injected into the mold and allowed to harden, producing a molded coil whose inner and outer peripheral surfaces are coated with resin.

[0004] Coil components may be equipped with a sensor. The sensor is composed of a detection unit that detects a physical quantity of the coil component, such as temperature, a connector that connects to an external device, and a lead wire that connects to the detection unit at one end and the connector at the other end. The lead wire is composed of a metal wire and a coating made of an insulating material that covers the metal wire. When a sensor is equipped in a coil component, the sensor may be integrated with the coil during molding to create a molded coil. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-035844 Summary of the Invention [Problem to be solved by the invention]

[0006] When integrating a sensor with a coil through molding, the lead wires may be blown by the resin injection pressure, which could cause the lead wires to break. Therefore, a known method is to mold the sensor separately before molding it with the coil, and then cover the sensor with resin to protect it. However, when molding the sensor, there is a risk that the coating on the lead wires may melt due to the heat of the resin. Furthermore, although the injection pressure is lower than when integrating the sensor with the coil, there is still a concern about the lead wires breaking.

[0007] The present invention has been made to solve the above-mentioned problems, and its object is to provide a molded coil that can prevent breakage of the sensor lead wires and melting of the coating, and that can integrate the sensor and coil, and a reactor that includes this molded coil. [Means for solving the problem]

[0008] In order to achieve the above object, the molded coil of the present invention includes a coil, a sensor that detects a physical quantity of the molded coil, a sensor cover that is attached to the sensor, a molded resin that coats the sensor and the coil with the sensor cover attached and integrates the sensor and the coil with a resin, a coil cover disposed around the coil; the sensor has a detection unit that detects a physical quantity and a lead wire connected to the detection unit, the sensor cover has an eave portion, a pair of wall portions extending from both ends of the eave portion perpendicular to the eave portion, and an opening; the coil cover has a fixing portion that fixes the sensor cover, and the fixing portion fixes the sensor cover so as to close the opening of the sensor cover; The sensor cover is characterized in that it is disposed around at least a portion of the lead wire.

[0009] Another aspect of the present invention is a reactor including this molded coil and a core including a magnetic body attached to the molded coil. [Effects of the Invention]

[0010] According to the present invention, breakage of the lead wire and melting of the coating can be prevented, and the sensor and coil can be integrated. [Brief explanation of the drawings]

[0011] [Figure 1]FIG. 2 is a perspective view showing the overall configuration of a molded coil. [Figure 2] FIG. 2 is a perspective view showing a state in which a sensor cover is attached to a sensor. [Figure 3] FIG. 2 is a perspective view showing the sensor with the sensor cover attached, as viewed from the bottom. [Figure 4] FIG. 10 is a diagram showing a state in which a coil cover is attached to a coil. [Figure 5] FIG. [Figure 6] FIG. 10 is a diagram showing a state in which the sensor cover is fixed to the fixing portion. [Figure 7] FIG. 10 is a schematic diagram showing a state in which the sensor cover is fixed to the fixing portion. [Figure 8] FIG. 2 is a perspective view showing the overall configuration of a reactor. [Figure 9] FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment) A molded coil according to an embodiment will be described with reference to the drawings. Fig. 1 is a perspective view showing the overall configuration of the molded coil. In each drawing, thickness, dimensions, positional relationships, ratios, shapes, etc. may be emphasized for ease of understanding, but the present invention is not limited to such emphasis.

[0013] The molded coil 10 is formed by covering the sensor 1 and the coil 3 with a coil mold resin portion 5 by molding. The molded coil 10 is used as a component of the reactor 100, as will be described later. The molded coil 10 includes the sensor 1, a sensor cover 2, a coil 3, a coil cover 4, and a coil mold resin 5.

[0014] Fig. 2 is a perspective view showing the sensor with the sensor cover attached. Fig. 3 is a perspective view showing the sensor with the sensor cover attached, viewed from the bottom. Sensor 1 detects a physical quantity related to molded coil 10. Sensor 1 is, for example, a temperature sensor that detects the temperature of molded coil 10. Sensor 1 has a detection unit 11, lead wires 12, and a connector 13.

[0015] The detection unit 11 detects a physical quantity related to the molded coil 10. In this embodiment, the detection unit 11 is an element that detects the temperature of the molded coil 10, and a thermistor, for example, can be used. The detection unit 11 has a roughly rectangular parallelepiped shape. The detection unit 11 is disposed between the pair of coils 3.

[0016] One end of the lead wire 12 is connected to the detection unit 11, and the other end is connected to the connector 13. The lead wire 12 consists of a metal wire and a coating that covers it. The material of the metal wire can include copper, nickel, aluminum, silver, gold, or two or more of these. The metal wire can be a single solid wire or a stranded wire made by twisting multiple wires together. The coating covers the metal wire with an insulating material such as vinyl, silicone rubber, or fluororubber. Note that a portion of the metal wire on the detection unit 11 side is not covered by the coating.

[0017] The connector 13 is a member that is connected to a connector of an external device. The connector 13 is configured so that the connector of the external device can be attached and detached. Information detected by the detection unit 11 is transmitted to the external device connected to the connector 13 via the lead wire 12 and the connector 13.

[0018] The sensor cover 2 is a member that protects the sensor 1 and is placed around the sensor 1. The sensor cover 2 is separate from the sensor 1 and is fixed to the sensor 1 by attaching it to the sensor 1. In other words, the sensor cover 2 and the sensor 1 are not integrated, and the sensor cover 2 is detachable from the sensor 1. The sensor cover 2 is made of resin, and examples of the resin include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), and PBT (Polybutylene Terephthalate).

[0019] The sensor cover 2 has a U-shaped cross section with one side missing from a rectangle. That is, the sensor cover 2 is made up of a eaves portion 21 and a pair of wall portions 22 extending from both ends of the eaves portion 21, and has an opening 23 on the end face facing the eaves portion 21. The sensor 1 is inserted through this opening 23, and is housed in the internal space defined by the eaves portion 21 and the pair of wall portions 22.

[0020] The sensor cover 2 has a lead wire cover 24 that protects the lead wires 12. The lead wire cover 24 has an internal space defined by the eaves portion 21 and the wall portion 22, and an opening 23. The lead wires 12 of the sensor 1 are inserted through this opening 23, and the lead wires 12 are housed in the internal space of the lead wire cover 24. It is sufficient that the lead wire cover 24 is arranged around at least the portion of the lead wires 12 that is placed in the mold when the sensor 1 and coil 3 are molded with the coil mold resin 5.

[0021] The lead wire cover 24 has a flange 241 on the outer wall of each wall portion 22. The flange 241 protrudes from the outer wall of the wall portion 22 in a direction perpendicular to the wall portion 22.

[0022] The sensor cover 2 further has a detection unit cover 25 that protects a portion of the detection unit 11. The detection unit cover 25 has an internal space defined by the canopy portion 21 and the wall portion 22, and an opening 23. The detection unit 11 of the sensor 1 is inserted through this opening 23, and the detection unit 11 is housed in the internal space of the detection unit cover 25. The internal space that houses the detection unit 11 is approximately the same size as the detection unit 11. By press-fitting the detection unit 11 into the detection unit cover 25, the detection unit cover 25 and the detection unit 11 come into close contact, and the sensor cover 2 is fixed to the sensor 1. In other words, the internal space of the detection unit cover 25 serves as a fixing portion 251 that fixes the sensor cover 2 to the sensor 1. The detection unit cover 25 and the lead wire cover 24 are seamlessly connected as a single piece by being molded as a single unit.

[0023] FIG. 4 shows the coil with the coil cover attached. Coil 3 is a wound body in which a conductive material with an insulating coating such as enamel coating is wound into a cylindrical shape. Coil 3 is formed by winding the conductive material in a spiral shape while shifting the winding position for each turn along the winding axis. The conductive material of coil 3 is, for example, a rectangular wire, and is a spiral edgewise coil formed by winding the conductive material so that the wide surface of the conductive material extends in a direction perpendicular to the winding axis of coil 3. However, the wire material and winding method of coil 3 are not limited to a rectangular wire edgewise coil and may be other forms.

[0024] Two coils 3 are provided. The coils 3 are arranged facing each other with their winding axes parallel to one another. Lead wires 31 extend from the coils 3 and are connected to one end of a bus bar 6. The other end of the bus bar 6 is connected to a terminal of an external device, and current is applied to the coils 3 via the bus bar 6.

[0025] The coil cover 4 is provided on the outer periphery of the coil 3. Because the coil 3 is formed by winding a conductive material, variations in size may occur. Therefore, during molding, a mold is pressed firmly against the coil 3 to correct the variations in size of the coil 3. If the mold were to press the coil 3 directly, there is a risk that the insulating coating of the conductive material would be damaged, so the outer periphery of the coil 3 is covered with the coil cover 4 to protect the coil 3.

[0026] The coil cover 4 has an upper cover 41 placed on the upper surface of the coil 3, and a lower cover 42 placed on the lower surface of the coil 3. Here, the upper surface of the coil 3 refers to the surface of the coil 3 that faces the upper mold when placed in a mold, and the lower surface of the coil 3 refers to the surface of the coil 3 that faces the lower mold when placed in a mold. The upper cover 41 is a plate-shaped member that covers the upper surface of the coil 3.

[0027] The lower cover 42 has a lower surface abutment portion 421 and an annular plate 422. The lower surface abutment portion 421 and the annular plate 422 are seamlessly connected to each other by integral molding or the like. The lower surface abutment portion 421 abuts against the lower surface of the coil 3 and supports the coil 3.

[0028] The annular plate 422 extends perpendicular to the lower surface abutment portion 421 from the end of the lower surface abutment portion 421. The annular plate 422 covers the end surface of the coil 3 that is perpendicular to the winding axis. The annular plate 422 has an opening that is approximately flush with the inner periphery of the coil 3. The leg portion 711 of the core 71, which will be described later, is inserted into this opening. The annular plate 422 is fitted into the upper cover 41.

[0029] The lower cover 42 has fixing portions 43 extending from the annular plate 422. The fixing portions 43 fix the sensor 1 to which the sensor cover 2 is attached. The fixing portions 43 extend from the upper end of the annular plate 422 in the opposite direction to the coils 3. The fixing portions 43 are provided between the coils 3.

[0030] FIG. 5 is an enlarged view of the fixing portion 43. FIG. 6 shows the state in which the sensor cover 2 is fixed to the fixing portion 43. The fixing portion 43 has a mounting portion 431 and a pair of side walls 432. The mounting portion 431 is a flat member on which the sensor cover 2 is mounted. The side walls 432 extend perpendicular to the mounting portion 431 from an end of the mounting portion 431 that is parallel to the reel axis. When viewed from the direction of the reel axis, the mounting portion 431 and the pair of side walls 432 form a U-shape. There is a space between the pair of side walls 432 that is large enough to accommodate the sensor cover 2. The sensor cover 2 is inserted into the space defined by the mounting portion 431 and the pair of side walls 432 so that the tip of the wall 22 of the sensor cover 2 abuts against the mounting portion 431. In other words, the opening 23 is blocked by the mounting portion 431.

[0031] The side wall portion 432 is provided with a notch 44 extending from the tip thereof toward the mounting portion 431. The flange 241 of the sensor cover 2 is inserted into this notch 44. The depth of the notch 44 needs only to be such that the entire flange 241 can be accommodated therein.

[0032] FIG. 7 is a schematic diagram showing the sensor cover 2 fixed to the fixing portion 43. As shown in FIG. 7, a protrusion 45 protrudes from the mounting portion 431. The protrusion 45 is provided between a pair of side wall portions 432. The protrusion 45 protrudes in the same direction as the side wall portions 432, but protrudes to a lower height than the side wall portions 432. The length of the protrusion 45 in the direction in which the side wall portions 432 are aligned is approximately the same as the length between the wall portions 22 of the sensor cover 2. When the sensor cover 2 is housed in the fixing portion 43, the protrusion 45 enters the opening 23 and closes the opening 23. That is, the lead wire 12 is housed in a space defined by the canopy portion 21 of the lead wire cover 24, the pair of wall portions 22, and the protrusion 45, and is surrounded on all four sides.

[0033] 1, the coil mold resin 5 coats the sensor 1 with the sensor cover 2 attached and the coil 3 with resin, integrating the sensor 1 and the coil 3. Here, the bus bar 6 is also integrated with the sensor 1 and the coil 3. The coil mold resin 5 has recesses 51 that fit with the protrusions of the mold cores 7a and 7b, which will be described later.

[0034] Examples of resins that can be used to form the coil mold resin 5 include epoxy resin, unsaturated polyester resin, urethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), and PBT (Polybutylene Terephthalate). In particular, it is desirable to use a resin with high thermal conductivity. By using a resin with high thermal conductivity, heat from the coil 3 can be transferred to the outside.

[0035] Fig. 8 is a perspective view showing the overall configuration of the reactor. Fig. 9 is a perspective view of the molded core. As shown in Fig. 8, a reactor 100 is formed by combining a molded coil 10 with a pair of molded cores 7a and 7b. The reactor 100 is an electromagnetic component that converts electrical energy into magnetic energy and stores and releases it, and is used in a variety of applications, such as office equipment, solar power generation systems, and automobiles.

[0036] 9, molded cores 7a and 7b are produced by molding core 71 with core mold resin 72. Note that molded core 7a is produced by molding bus bar 6 together with core 71, and core 71 and bus bar 6 are molded integrally with core mold resin 72.

[0037] A powder magnetic core, a ferrite core, a laminated steel plate, a metal composite core, etc. can be used for the core 71. A metal composite core is a magnetic body made by kneading magnetic powder and resin and then hardening the resin.

[0038] Core 71 is made of a U-shaped core member having a pair of legs 711 and a yoke portion 712 connecting the pair of legs 711. Two such U-shaped core members are provided. Core 71 is formed into an annular shape by joining the legs 711 of the U-shaped core members together with an adhesive.

[0039] The core mold resin 72 is a resin member that covers at least a portion of the surface of the core 71. In this embodiment, the core mold resin 72 covers only the yoke portion 712 of the core 71, but it may also cover the leg portions 711 of the core 71. The bottom surface of the yoke portion 712 is exposed and not covered by the core mold resin 72. This allows heat from the core 71 to be effectively released to the outside of the reactor 100. The core mold resin 72 is formed integrally with the core 71 by molding. The type of resin for the core mold resin 2 can be the same as that for the coil mold resin 5.

[0040] The core mold resin 72 has protrusions 721 at positions corresponding to the recesses 51 of the molded coil 10. The protrusions 721 protrude toward the molded coil 10. The protrusions 721 fit into the recesses 51, thereby holding the molded coil 10 in the mold cores 7a and 7b.

[0041] (Action and effect) As described above, molded coil 10 in this embodiment includes coil 3, sensor 1 that detects a physical quantity of molded coil 10, sensor cover 2 attached to sensor 1, and coil mold resin 4 that covers sensor 1 with sensor cover 2 attached and coil 3, and integrates sensor 1 and coil 3. Sensor 1 has detection unit 11 that detects the physical quantity, and lead wire 12 connected to detection unit 11. Sensor cover 2 has lead wire cover 24 that is provided around lead wire 12 that is placed in a mold during molding.

[0042] In the past, the sensor was molded separately and then molded together with the coil to integrate the coil and sensor. When molding the sensor separately, there was a risk that the heat from the molten resin would melt the coating on the sensor's lead wire, or that the lead wire would break due to the injection pressure of the resin.

[0043] However, in the molded coil 10 of this embodiment, the sensor 1 is not molded, but a sensor cover 2 that is separate from the sensor 1 is attached to the sensor 1. This prevents the coating of the lead wire 12 from melting.

[0044] Furthermore, the sensor cover 2 is disposed around the lead wire 12 that is housed in a mold during molding to integrate the sensor 1 and the coil 3. Therefore, the lead wire 12 is protected by the sensor cover 2, and breakage of the lead wire 12 can be prevented.

[0045] The sensor cover 2 has a fixing portion 251 that is fixed to the sensor 1. This prevents the sensor cover 2 from shifting from its predetermined position due to the resin injection pressure during molding. Therefore, even if the resin injection pressure is high, it is possible to prevent the coating of the lead wire 12 from melting or the lead wire 12 from breaking due to the heat of the resin.

[0046] The sensor cover 2 has a detection unit cover 25 that is placed around the detection unit 11, and a fixing portion 251 of the detection unit cover 25 is fixed to the detection unit 11. In this way, the detection unit 11 of the sensor 1 is fixed by the sensor cover 2. Therefore, once the position of the sensor cover 2 is determined, the detection unit 11 is also positioned, and the detection unit 11 can be easily placed in a desired position.

[0047] The sensor cover 2 further includes a coil cover 4 that is arranged around the coil 3. The sensor cover 2 has an eave portion 21, a pair of wall portions 22 that extend from both ends of the eave portion 21 perpendicular to the eave portion 21, and an opening 23. The coil cover 4 has a fixing portion 43 that fixes the sensor cover 2, and the fixing portion 43 fixes the sensor cover 2 so as to close the opening 23 of the sensor cover 2.

[0048] This prevents resin from flowing into the space housing the lead wires 12 from the openings 23 of the sensor cover 2. This prevents the coating of the lead wires 12 from being melted by the resin during molding.

[0049] The fixing portion 43 has a protrusion 45 that is inserted into the opening 23 and disposed between the pair of wall portions 22 when the sensor cover 2 is fixed.

[0050] This more effectively prevents resin from flowing into the space accommodating lead wires 12 from opening 23 of sensor cover 2. Protrusion 45 also functions as a positioning element when inserting sensor cover 2 into fixing portion 43, making it easier to fix sensor cover 2 to fixing portion 43.

[0051] The coil cover 4 has an upper cover 41 that abuts against the upper surface of the coil 3 and a lower cover that abuts against the lower surface of the coil 3, and the fixing portion 43 is provided on the lower cover .

[0052] Since the dimensions of the coil 3 vary, the upper cover 41 is pressed firmly against the coil 3 during molding to correct the dimensional variation of the coil 3. As a result, the position of the upper cover 41 changes, and if the upper cover 41 has a fixing part 43, the position of the detection part 11 also changes.

[0053] On the other hand, since the lower cover 42 is sandwiched between the lower mold and the coil 3, its position does not change even when the upper cover 41 is pressed. Therefore, by providing the fixing part 43 on the lower cover 42, the detection part 11 can be arranged at a desired position without being affected by dimensional variations in the coil 3.

[0054] (Other embodiments) Although the present specification describes an embodiment of the present invention, this embodiment is presented as an example and is not intended to limit the scope of the invention. The above-described embodiment can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. The embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims.

[0055] In the above embodiment, the fixing portion 43 is provided on the lower cover 42, but it may also be provided on the upper cover 41. When the coil 3 is pressed by the upper cover 41, the coil 3 as a whole sinks toward the lower cover 42 together with the upper cover 41. Therefore, when the fixing portion 43 is provided on the upper cover 41, the relative positional relationship between the coil 3 and the detection unit 11 does not change significantly. Therefore, if it is desired to have the detection unit 11 detect the temperature of a predetermined position on the coil 3, it is better to provide the fixing portion 43 on the upper cover 41.

[0056] Furthermore, in the above embodiment, the internal space of the detection unit cover 25 functions as the fixing portion 251, and the detection unit 11 is press-fitted into the detection unit cover 25 to fix the sensor cover 2 to the sensor 1, but the method for fixing the sensor cover 2 to the sensor 1 is not limited to this. For example, the sensor cover 2 may be attached to the sensor 1 by applying an adhesive to the inner surface of the sensor cover 2 (the surface that defines the storage space for the sensor 1).

[0057] Furthermore, the tip of each wall portion 22 of the detection unit cover 25 may have a claw portion extending toward the opening 23. The claw portions of the detection unit cover 25 may be snap-fit ​​to fit the sensor cover 2 onto the sensor 1. This makes it easier to attach the sensor cover 2 to the sensor 1, improving assembly and workability.

[0058] Furthermore, a notch may be provided at the boundary between lead wire cover 24 and detection unit cover 25. The notch is cut into wall portion 22 from the opening 23 side and does not reach overhang portion 21. By providing a notch in this way, detection unit cover 25 can be deformed independently of lead wire cover 24, making it easier to fit sensor cover 2 to sensor 1 by snap-fit. [Explanation of symbols]

[0059] 100 reactor 10 Molded coil 1 sensor 11 Detection unit 12 Lead Wires 13 Connectors 2 Sensor cover 21 Eaves 22 Wall 23 Aperture 24 Lead wire cover 241 flange 25 Detector cover 251 Fixed part 3 coils 31 Leader 4 Coil cover 41 Upper cover 42 Lower cover 421 Bottom contact part 422 Annular Plate 43 Fixed part 431 Placement section 432 Side wall 44 Notch 45 Protrusion 5 Coil mold resin 51 Recess 6 Busbar 7a, 7b Mold core 71 cores 711 Legs 712 York 72 Core mold resin 721 Convex

Claims

1. A coil and a sensor for detecting a physical quantity of the molded coil; a sensor cover attached to the sensor; a mold resin that covers the sensor with the sensor cover attached and the coil and integrates the sensor and the coil; a coil cover disposed around the coil; Equipped with The sensor a detection unit that detects the physical quantity; A lead wire connected to the detection unit; and the sensor cover has an eave portion, a pair of wall portions extending from both ends of the eave portion perpendicular to the eave portion, and an opening; the coil cover has a fixing portion that fixes the sensor cover, the fixing portion fixes the sensor cover so as to close the opening of the sensor cover; the sensor cover is disposed around at least a portion of the lead wire; A molded coil characterized by:

2. the sensor cover has a fixing portion that is fixed to the sensor; The molded coil according to claim 1 ,

3. The sensor cover is also disposed around the detection unit, the fixed portion is fixed to the detection portion; The molded coil according to claim 2, characterized in that

4. the fixing portion has a protrusion that is inserted into the opening and disposed between the pair of wall portions when the sensor cover is fixed; 4. The molded coil according to claim 1, wherein:

5. The coil cover is an upper cover disposed on an upper surface of the coil; a lower cover disposed on a lower surface of the coil; and the fixing portion is provided on the lower cover; 5. The molded coil according to claim 1, wherein:

6. A molded coil according to any one of claims 1 to 5; a core including a magnetic material attached to the molded coil; A reactor comprising:

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