Molded coil manufacturing method and molded coil

Abstract

The invention provides a method for manufacturing a molded coil and a molded coil, which can suppress deformation of the coil and adjust the length of the coil in the winding axis direction. A method for manufacturing a molded coil in which a coil is molded includes: a winding step in which the coil (2) is wound such that the length of the coil (2) in the winding axis direction is longer than a desired length; a housing step in which the coil (2) is housed in a mold; a pressing step in which the coil (2) is pressed in the winding axis direction by a pressing member (9) after the accommodation step; and an injection step of injecting the resin into the mold after the pressing step. The coil (2) has a pressing surface (26) which is an end surface orthogonal to the winding axis. In the pressing step, the pressing member (9) presses the pressing surface (26), and in the ejection step, the resin is ejected toward the pressing surface (26). The pressing surface (26) is pressed by the ejection pressure of the pressing member (9) and the resin.

Description

Technical Field

[0001] This invention relates to a method for manufacturing molded coils and to molded coils. Background Technology

[0002] Coil components are used in various applications such as office automation (OA) equipment, solar power systems, and automobiles. An example of a coil component is the reactor. A reactor is an electromagnetic component that converts electrical energy into magnetic energy for storage and release.

[0003] The coil component mainly consists of a core, a coil, and a resin component. The core is made of a magnetic material, such as a pressed powder core. A coil is wound around the outer periphery of the core. Furthermore, a resin component is placed between the core and the coil to insulate them.

[0004] In recent years, molded coils, formed from resin components, have been applied in various applications. A molded coil is created by placing a coil in a predetermined position within a mold, injecting resin into the mold, and allowing the resin to cure. This produces a molded coil in which the inner and outer circumferences of the coil are covered by resin components.

[0005] Patent Document 1: Japanese Patent Application Publication No. 08-321424 Summary of the Invention

[0006] When forming the coil, winding deviations can occur. Therefore, in terms of the length of the coil in the spool direction, by making it slightly longer than the desired length, the coil is pressed along the spool direction during molding to adjust it to the desired length.

[0007] A known method for adjusting the coil length is to press the coil by the injection pressure of resin during molding. For example... Figure 16 The method described involves providing a resin injection gate G on the end face of the coil 200, which is orthogonal to the spool, and injecting resin towards this end face. The coil 200 is pressed along the spool direction by the injection pressure of the resin. However, if there is only one gate G, the coil 200 cannot be pressed evenly. Furthermore, the injection pressure is high, causing damage to the end face of the coil 200 near the gate G. Therefore, there is a concern that the coil 200 may deform and fail to be molded into the desired shape.

[0008] Therefore, there are methods to increase the number of gates G to achieve uniform pressing. For example, such as... Figure 17 As shown, two gates G are provided above and below the coil 200. In this case, compared with the case of one gate G, the pressing can be performed more evenly. However, if the number of gates G is increased, the number of welded sections that become the confluence points of the resin increases. The strength of the welded sections is low, thus affecting the durability of the molded coil.

[0009] To solve these problems, there are methods that not only use injection pressure but also press the end face of the coil using pressing components. For example, as... Figure 18 As shown, the pressing member 90 presses down on the four corners of the end face of the coil 200, which is orthogonal to the spool. In this case, the end face of the coil 200 can be pressed evenly. However, when the end face of the coil 200 is pressed down by the pressing member 90, the gate G is located above the coil. For example, as... Figure 18 As shown, a gate G is provided above the end face opposite to the end face pressed by the pressed member 90. In this case, the resin ejected from the gate G flows toward the end face pressed by the pressed member 90. Figure 18 (The direction of the blackened arrow). That is, the resin flows in the opposite direction to the pressing direction of the pressing member 90. Therefore, sometimes the pressing achieved by the pressing member 90 is hindered, making it difficult to adjust the coil 200 to the desired length.

[0010] The present invention was proposed to solve the above-mentioned problems. Its purpose is to provide a method for manufacturing a molded coil and a molded coil that can suppress the deformation of the coil and adjust the length of the coil in the winding direction.

[0011] The method for manufacturing a molded coil according to the present invention is a method for manufacturing a molded coil by molding a coil, characterized by comprising the following steps: a winding step, wherein the coil is formed by winding a conductive component; a housing step, wherein the coil is housed in a mold; a pressing step, wherein after the housing step, the coil is pressed into the winding direction by a pressing component; and a spraying step, wherein after the pressing step, resin is sprayed into the mold, the coil having an end face orthogonal to the winding shaft, namely a pressing surface, wherein in the pressing step, the pressing component presses the pressing surface, and in the spraying step, the resin is sprayed toward the pressing surface, and the pressing surface is pressed by the resin.

[0012] Furthermore, the molded coil of the present invention is characterized by having: a coil; and a molding resin portion that covers the coil, the coil having an end face orthogonal to the spool, i.e. a pressing surface, the molding resin portion having a pressing covering portion that covers the pressing surface, an injection mark formed on the upper side of the pressing covering portion, indicating that the resin constituting the molding resin portion was sprayed during molding, i.e., an injection mark, and a recessed portion formed on the lower side of the pressing covering portion.

[0013] The effects of the invention

[0014] According to the present invention, a method for manufacturing a molded coil and a molded coil capable of suppressing coil deformation and adjusting the length of the coil in the winding direction can be obtained. Attached Figure Description

[0015] Figure 1 It is a perspective view showing the overall structure of the molded coil.

[0016] Figure 2 It is a perspective view showing the coil with the cover installed.

[0017] Figure 3 This is a perspective view of the coil.

[0018] Figure 4 This is an oblique view of the lower cover when viewed from above.

[0019] Figure 5 This is a perspective view showing the state of the lower cover being installed on the coil.

[0020] Figure 6 This is a view of the lower cover when viewed from the direction of the pressure surface protection section.

[0021] Figure 7 This is an oblique view of the top cover when viewed from above.

[0022] Figure 8 This is an oblique view of the top cover when viewed from below.

[0023] Figure 9 This is an enlarged view of the protruding part of the fixed surface.

[0024] Figure 10 This is a side view of the top cover.

[0025] Figure 11 This is an oblique view of the molded coil when viewed from the bottom.

[0026] Figure 12 This is a perspective view of a molded coil.

[0027] Figure 13 It is a perspective view showing the state of a molded coil with a core installed.

[0028] Figure 14 It is a perspective view showing the overall structure of the reactor.

[0029] Figure 15 This is a schematic diagram showing the state of the coil during molding.

[0030] Figure 16 This is a schematic diagram showing the state of a coil during molding in the prior art.

[0031] Figure 17 This is a schematic diagram showing the state of a coil during molding in the prior art.

[0032] Figure 18 This is a schematic diagram showing the state of a coil during molding in the prior art. Detailed Implementation

[0033] (Implementation Method)

[0034] Referring to the accompanying drawings, the molded coil involved in the embodiment will be described. Figure 1 It is a perspective view showing the overall structure of the molded coil. Figure 2 This is a perspective view showing the coil with the cover installed. In the various figures, for ease of understanding, thickness, dimensions, positional relationships, proportions, or shapes are sometimes shown in an emphasized manner, but the invention is not limited by these emphasized manners.

[0035] Molded coil 1 is a key structural component of coil components such as reactors. Molded coil 1, as shown... Figure 1 and Figure 2 As shown, it has a coil 2, a lower cover 3, an upper cover 4, and a primary molding resin part 5. The coil 2, the lower cover 3, and the upper cover 4 are molded using the resin constituting the primary molding resin part, thereby producing a molded coil 1. Figure 3 This is a perspective view of the coil.

[0036] Coil 2 consists of a conductive component coated with an insulating material such as enamel. Coil 2 is formed by winding the conductive component into a cylindrical shape while offsetting the winding position along the spool direction. The conductor component is, for example, a flat wire, and coil 2 is a narrow-sided wound coil in which the wide side of the conductive component extends in a direction orthogonal to the spool of coil 2. Alternatively, coil 2 can also be a wide-sided wound coil. Furthermore, round wire can also be used as the conductive component.

[0037] Two coils 2 are provided. The two coils 2 are arranged laterally with the reels parallel. In this embodiment, the two coils 2 are connected by a connecting part 21 to form a connecting coil.

[0038] The coil 2 has four flat portions and four curved portions 25. The four flat portions are an upper surface flat portion 22, a lower surface flat portion 24, and two side surface flat portions 23. The curved portions 25 are respectively disposed between the four flat portions 22, 23, and 24, and the coil 2 is formed into a square tube shape.

[0039] Furthermore, the vertical direction refers to the direction orthogonal to the spool and the transverse arrangement direction of the coils 2. The upper surface flat portion 22 is the flat surface of the coils 2 opposite to the upper mold of the mold, and the lower surface flat portion 24 is the flat surface of the coils 2 opposite to the lower mold of the mold. The side surface flat portion 23 is the flat surface of the coils 2 orthogonal to the transverse arrangement direction of the coils 2. Additionally, sometimes the inner side of the coils 2 in the side surface flat portion 23, i.e., the side of the coils 2 facing each other, is called the side surface flat portion 23a, and the opposite side of the side surface flat portion 23a, located on the outer side of the coils 2, is called the side surface flat portion 23b.

[0040] The coil 2 has an end face orthogonal to the spool, namely a pressing surface 26 and a fixing surface 27. The pressing surface 26 and the fixing surface 27 are annular. As described later, the pressing surface 26 is the end face of the coil 2 that is pressed by a pressing component or a resin jet during molding. The fixing surface 27 is the end face of the coil 2 opposite to the pressing surface 26. The fixing surface 27 is fixed and does not move during molding by a mold or jig.

[0041] Coil 2 has leads 28 and 29 for electrical connection with external devices. Lead 28 is led out from the fixed surface 27 along the reel. Lead 29 is led out from the fixed surface 27 in a direction orthogonal to the flat side portion 23 of coil 2. The front ends of leads 28 and 29 are connected to a busbar (not shown) by welding or the like. The busbar is also connected to the terminals of the external device, supplying power to coil 2 from the external device via the busbar.

[0042] The lower cover 3 and the upper cover 4 cover the coil 2. Because the coil 2 has winding deviations, the coil 2 is pressed down by the mold during molding to flatten the upper surface flat portion 22 and the lower surface flat portion 24 of the coil 2. At this time, the lower cover 3 and the upper cover 4 act as buffer components to prevent the upper surface flat portion 22 or the lower surface flat portion 24 of the coil 2 from directly contacting the mold.

[0043] The lower cover 3 and the upper cover 4 are made of resin. Examples of resins include epoxy resin, unsaturated polyester resin, polyurethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), PBT (Polybutylene Terephthalate), or composites thereof.

[0044] Figure 4 This is a perspective view of the lower cover 3. Figure 5 A perspective view from below showing the lower cover 3 installed on the coil 2. (See image below.) Figure 4 and 5 As shown, the lower cover 3 has a pressing surface protection part 31, a connecting part 32, a bending surface protection part 33, a side protection part 34, and a plate-shaped part 35.

[0045] The pressing surface protection part 31 covers the pressing surface 26 of the coil 2. That is, the pressing surface protection part 31 is a thin plate-shaped ring with an opening 311 that is approximately the same as the inner diameter of the coil 2. The side of the pressing surface protection part 31 opposite to the coil 2 (the side pressed by the pressing member described later) is flat. Two pressing surface protection parts 31 are provided, and each pressing surface protection part 31 covers the pressing surface 26 of each coil 2.

[0046] One of the two pressing surface protection portions 31 is opposite to the connecting portion 21 of the coil 2. The pressing surface protection portion 31 opposite to the connecting portion 21 is called pressing surface protection portion 31a, and the other pressing surface protection portion 31 is called pressing surface protection portion 31b. The thickness of pressing surface protection portion 31a in the spool direction is thinner than the thickness of pressing surface protection portion 31b. In other words, pressing surface protection portion 31b has a thick-walled portion 312, and the thickness of pressing surface protection portion 31b is greater than that of pressing surface protection portion 31a by the amount of the thick-walled portion 312.

[0047] Figure 6 This is a view of the lower cover 3 as seen from the direction of the pressing surface protection part 31. (See diagram below.) Figure 6 As shown, the pressing surface protection portion 31a extends further outward than the pressing surface protection portion 31b. That is, the pressing surface protection portion 31a has a wide surface 313. The wide surface 313 extends from the edge of the opening 311 toward the outside of the molded coil 1. That is, the wide surface 313 extends along the transverse arrangement direction of the coil 2. The wide surface 313 only needs to extend to the extent that it covers the connecting portion 21 of the coil 2.

[0048] The pressing surface protection portion 31 has a connecting region 314 that connects to the curved surface protection portion 33 described later. The connecting region 314 extends outward from the molded coil 1. In the pressing surface protection portion 31a, the connecting region 314 extends further outward than the wide surface 313.

[0049] A connecting portion 32 is disposed between the pressing surface protection portions 31, connecting the two pressing surface protection portions 31. That is, the connecting portion 32 is connected to each pressing surface protection portion 31. An opening 321 is provided in the central part of the connecting portion 32.

[0050] The vertical length of opening 321 is shorter than that of opening 311. The upper base of opening 321 is located lower than the upper base of opening 311. The lower base of opening 321 is located higher than the lower base of opening 311. Therefore, the flat surface 322 extends above the upper base and below the lower base of opening 321. The flat surface 322 is a flat surface without steps.

[0051] The curved surface protection portion 33 extends along the spool from the surface of the pressing surface protection portion 31 opposite to the pressing surface 26 of the coil 2. The length of the curved surface protection portion 33 in the spool direction is approximately the same as the length of the coil 2 in the spool direction. The curved surface protection portion 33 covers the curved portion 25, which connects the lower surface flat portion 24 and the side flat portion 23b. That is, the inner circumferential surface of the curved surface protection portion 33 becomes the shape of the curved surface 25. The lower surface 331 of the curved surface protection portion 33 contacts the lower mold during molding. A plurality of notches 332 are formed on the lower surface 331 of the curved surface protection portion 33.

[0052] The side protection portion 34 is disposed above the curved surface protection portion 33. The side protection portion 34 is connected to the curved surface protection portion 33. The length of the side protection portion 34 in the winding direction is approximately the same as the length of the coil 2 in the winding direction. The side protection portion 34 covers at least a portion of the flat side portion 23b of the coil 2.

[0053] A plate-shaped portion 35 is disposed in the gap between the coils 2. The plate-shaped portion 35 extends along the spool from the end face of the connecting portion 32 opposite to the coil 2. The length of the plate-shaped portion 35 in the spool direction is approximately the same as the length of the coil 2 in the spool direction. The plate-shaped portion 35 covers the curved portion 25, which connects the lower surface flat portion 24 and the side surface flat portion 23a. That is, the inner circumferential surface of the plate-shaped portion 35 becomes the shape of the contoured curved surface 25. The lower surface 351 of the plate-shaped portion 35 contacts the lower mold during molding. A plurality of notches 352 are formed on the lower surface 351 of the plate-shaped portion 35.

[0054] In addition, such as Figure 5 As shown, even when the lower cover 3 is installed on the coil 2, at least a portion of the lower surface of the coil 2, namely the lower surface flat portion 24 and the two curved portions 25 connected to the lower surface flat portion 24, are not covered by the lower cover 3, but are exposed. Furthermore, the lower cover 3 does not cover the fixing surface 27 of the coil 2. Of course, the fixing surface 27 of the coil 2 is covered by a resin cover 10 (see reference 10), which is different from the lower cover 3 and the upper cover 4. Figure 1 , 11 ) Cover.

[0055] Figure 7 This is an oblique view of the top cover 4 when viewed from above. Figure 8 This is an oblique view of the top cover 4 viewed from below. The top cover 4 has an upper surface protection part 41, a curved surface protection part 42, a connecting part 43, a fixed surface protrusion part 44, and a pressing surface protrusion part 45.

[0056] The upper surface protection part 41 covers the flat upper surface part 22 of the coil 2. The upper surface protection part 41 is a plate-shaped component. The size of the upper surface protection part 41 is approximately the same as that of the flat upper surface part 22. Two upper surface protection parts 41 are provided, each covering the flat upper surface part 22 of the coil 2. The upper surface protection part 41 abuts against the upper mold during molding.

[0057] The curved surface protection portion 42 covers the curved portion 25, which connects the upper surface flat portion 22 and the side flat portion 23a. The curved surface protection portion 42 is shaped to mimic the curved shape of the curved portion 25. The curved surface protection portion 42 is connected to the upper surface protection portion 41. The length of the curved surface protection portion 42 in the axial direction is shorter than the length of the upper surface protection portion 41 in the axial direction. The curved surface protection portion 42 is positioned biased towards the fixed surface protrusion 44. That is, the distance from one end 421 of the curved surface protection portion 42 in the axial direction to the fixed surface protrusion 44 is shorter than the distance from the other end 422 of the curved surface protection portion 42 in the axial direction to the pressing surface protrusion 45. Two curved surface protection portions 42 are provided. Each curved surface protection portion 42 is connected to the upper surface flat portion 22 and covers the opposite curved portion 25.

[0058] A connecting portion 43 is disposed between the coils 2. The connecting portion 43 is a flat plate-shaped component. The connecting portion 43 connects to two curved surface protection portions 42. That is, the connecting portion 43 is connected to each of the curved surface protection portions 42. A plurality of holes 431 are provided in the connecting portion 43. In this embodiment, four holes 431 are provided.

[0059] The protruding part 44 is connected to the end of the fixed surface 27 in the spool direction of the upper surface protection part 41. The protruding part 44 extends toward the lower surface of the coil 2. The extension length of the protruding part 44 is the length to which it covers the conductive components constituting the coil 2. The protruding part 44 is disposed in the upper central part of the fixed surface 27 of the coil 2. Although the protruding part 44 can abut against the fixed surface 27 during the stage of installing the upper cover 4 onto the coil 2, there is a gap during the installation stage, so it is sufficient to abut against it during molding. Figure 9 This is an enlarged view of the protruding part 44 of the fixed surface. (See image below.) Figure 9 As shown, the length of the fixed surface protrusion 44 in the transverse arrangement direction of coil 2 is shorter than that of the upper surface protection part 41.

[0060] The pressing surface protrusion 45 is connected to the pressing surface 26 side end of the upper surface protection portion 41 in the spool direction. The pressing surface protrusion 45 extends toward the lower surface of the coil 2. The extension length of the pressing surface protrusion 45 is approximately the same as or shorter than the length of the conductive component constituting the coil 2. The pressing surface protrusion 45 is disposed at the upper central portion of the pressing surface 26 of the coil 2. The pressing surface protrusion 45 covers the pressing surface 26 from above the pressing surface protection portion 31 of the lower cover 3. In this embodiment, the extension length of the pressing surface protrusion 45 is shorter than the pressing surface protection portion 31 of the lower cover 3, and when the pressing surface protrusion 45 covers the pressing surface 26, a portion of the pressing surface protection portion 31 (the lower end portion of the pressing surface protection portion 31 that covers the upper side of the pressing surface 26) is exposed.

[0061] Figure 10 This is a side view of the top cover (4). For example... Figure 10 As shown, the length d1 of the pressing surface protrusion 45 in the spool direction is shorter than the length d2 of the fixed surface protrusion 44 in the spool direction. The length of the pressing surface protrusion 45 in the transverse arrangement direction of the coil 2 is approximately the same as the length of the coil 2 in the transverse arrangement direction of the upper surface protection part 41.

[0062] 5. Initial molding resin part Figure 1 The coil 2, lower cover 3, and upper cover 4 are surrounded by the resin part 5. The initial molding resin part 5 integrates the coil 2, lower cover 3, and upper cover 4. Figure 11 This is an oblique view of the molded coil 1 as seen from below. (As shown) Figure 11 As shown, the initial molding resin part 5 does not cover the lower surface of the coil 2, namely the lower surface flat part 24 and a portion of the curved part 25 connected to the lower surface flat part 24, but leaves them exposed. By exposing the bottom surface of the coil 2, the heat of the coil 2 will not accumulate and can be released to the outside.

[0063] The initial molding resin section 5 is made of resin. Examples of resins used in the initial molding resin section 5 include epoxy resin, unsaturated polyester resin, polyurethane resin, BMC (Bulk Molding Compound), PPS (Polyphenylene Sulfide), and PBT (Polybutylene Terephthalate). In particular, a resin with high thermal conductivity is preferred. By using a resin with high thermal conductivity, heat from the coil 2 can be conducted to the outside.

[0064] Figure 12 This is a perspective view of molded coil 1. (Example) Figure 12 As shown, the initial molding resin part 5 has a pressing cover part 51. The pressing cover part 51 covers the pressing surface 26 of the coil 2 through the pressing surface protection part 31. The pressing cover part 51 is annular with an opening the size of the inner diameter of the coil 2. The pressing cover part 51 has an injection mark M1 and a recessed part 511.

[0065] The injection mark M1 is a gate mark indicating the location where resin is injected during the molding of the coil 2 through the initial molding resin section 5. The injection mark M1 is located at the lower center of the pressing surface protrusion 45, and is positioned above the pressing surface protection section 31. Specifically, the injection mark M1 is located at the lower end of the pressing surface protection section 31 (the portion of the pressing surface protection section 31 exposed from the pressing surface protrusion 45) that covers the upper side of the pressing surface 26 when it is covered by the pressing surface protrusion 45. In other words, the injection mark M1 is located outside the projection area of ​​the pressing surface protrusion 45 in the spool direction. Two injection marks M1 are provided.

[0066] Furthermore, in this embodiment, the injection mark M1 is circular, but the shape of the injection mark M1 is not limited to this. Alternatively, the injection mark M1 may also be provided around the periphery of the pressing surface protrusion 45. Figure 12 The area indicated by the diagonal line is the range of the gate G. That is, the injection mark M1 may not be located in the lower center of the pressing surface protrusion 45, but may be located in the lower corner, or may be located at the end of the pressing surface protrusion 45 near the lateral arrangement direction of the coil 2.

[0067] The recess 511 is a recess formed by the pressing surface covering portion 51 facing the pressing surface protection portion 31. The recess 511 extends from the surface of the pressing surface covering portion 51 to the pressing surface protection portion 31. That is, the pressing surface protection portion 31 or the connecting portion 32 protrudes from the recess 511. As will be described later, the recess 511 is formed by the pressing member 9 (see reference 9). Figure 15 It is formed by pressing coil 2 in.

[0068] Five recesses 511 are provided. Three recesses 511 are provided on the lower side of the pressing surface 26 of the coil 2, and two recesses 511 are provided in the center of the pressing surface 26 of the coil 2. Specifically, recesses 511a and 511b are respectively provided on the outer corner of the lower side of the pressing surface 26 of each coil 2. Recess 511c is provided on the lower side between the coils 2, that is, on the lower side of the connecting part 32. Recess 511d is located above recess 511a and is provided in the central part of the coil 2 in the vertical direction. Recess 511e is located above recess 511b and is provided in the central part of the coil 2 in the vertical direction.

[0069] The shape of the recess 511 conforms to the shape of the pressing member 9. Of course, the recess 511 is preferably as follows: Figure 12 The recess 511 is circular. When the recess 511 is circular, it can suppress the deterioration of resin flowability during molding.

[0070] The outer diameter of the recess 511 is more than half the line width of the conductive component constituting the coil 2, and preferably smaller than the line width. If the outer diameter of the recess 511 is too large, the gap between the pressing member 9 and the mold becomes smaller, and the resin does not flow easily. On the other hand, if the outer diameter of the recess 511 is too small, the pressure becomes larger, and there is a risk that the pressing surface protection part 31 or the pressing surface 26 of the coil 2 may deform.

[0071] In this embodiment, the molded coil 1 is the main structural component of the reactor 8. Figure 13 This is a perspective view showing the state in which the core 6 is installed in the molded coil 1. Figure 14 This is a perspective view showing the overall structure of the reactor 8. The reactor 8 is manufactured by mounting the core 6 on the molded coil 1 and molding it using a secondary molding resin section 7.

[0072] Core 6 contains a magnetic material. Core 6 can use pressed powder cores, ferrite cores, laminated steel plates, or metal composite cores, etc. Metal composite cores refer to magnetic materials formed by mixing magnetic powder with resin and then hardening the resin.

[0073] Core 6 is composed of a U-shaped core component, which has a pair of legs and a magnetic yoke connecting the legs. Two U-shaped core components are provided, and by joining their legs, core 6 becomes a ring. Alternatively, spacers can be inserted between the legs. The spacers can be made of non-magnetic materials, ceramics, non-metals, resin, carbon fiber, or a combination of two or more of these materials, or spacer paper. By inserting spacers, a magnetic gap of a specified width is provided, preventing a decrease in the inductance of reactor 8. Alternatively, an air gap can be used instead of spacers.

[0074] The secondary molding resin section 7 covers the molded coil 1 and the core 6. The secondary molding resin section 7 integrates the molded coil 1 and the core 6. The secondary molding resin section 7 is formed by molding.

[0075] The secondary molding resin section 7 is made of resin. The resin used in the secondary molding resin section 7 can be of the same type as that used in the primary molding resin section 5. The secondary molding resin section 7 covers the pressing cover section 51. That is, the secondary molding resin section 7 enters the recess 511 formed in the pressing cover section 51. Furthermore, an injection mark M2 is formed above the yoke section in the secondary molding resin section 7. This injection mark M2 is a gate mark indicating the injection position of the resin during the molding process of forming the secondary molding resin section.

[0076] (Manufacturing method)

[0077] Next, the manufacturing method of the molded coil 1 of this embodiment will be described with reference to the accompanying drawings. Figure 15 This is a schematic diagram showing the state of coil 2 during molding. Furthermore, in Figure 15 The resin cap 10 is not shown in the figure. The manufacturing method of the molded coil 1 in this embodiment includes a coil winding process, a cap installation process, a mold receiving process, a pressing component insertion process, and a spraying process.

[0078] The coil winding process is a process of manufacturing a coil by winding a conductive component. In the coil winding process, the conductive component is wound into a cylindrical shape while offsetting the winding position along the axial direction. The coil 2 manufactured by the coil winding process is configured such that its length in the axial direction is slightly longer than the desired length. The term "configured to be slightly longer than the desired length" includes the following cases: cases where it is intentionally set to be longer; and cases where it is unexpectedly longer due to winding deviation.

[0079] The cover installation process is the process of installing the lower cover 3 and the upper cover 4 on the coil 2. First, the lower cover 3 is installed on the coil 2. By installing the lower cover 3 on the coil 2, the pressing surface protection part 31 covers the pressing surface 26. Then, the upper cover 4 is installed on the coil 2. The pressing surface protrusion 45 covers the pressing surface 26 from above the pressing surface protection part 31.

[0080] After the cover installation process, the process moves to the mold housing process. The mold housing process involves housing the coil 2, with the lower cover 3 and upper cover 4 installed, in the mold. The mold is divided into two parts: an upper mold and a lower mold. The coil 2, with the lower cover 3 and upper cover 4 installed, is placed in the lower mold, and then pressed in by the upper mold, causing the upper mold and lower mold to fit together. At this time, the upper cover 4 abuts against the upper mold, and the lower cover 3 abuts against the lower mold. Of course, the curved surface protection part 33, the side protection part 34, and the extended front end face of the plate-shaped part 35 of the lower cover 3 do not abut against the mold. That is, the lower cover 3 is housed in a way that allows it to move towards the fixed surface 27 within the mold. In addition, the fixed surface 27 of the coil 2 abuts against the upper mold, lower mold, or clamp through the resin cover 10, and is housed in a way that prevents the fixed surface 27 from moving.

[0081] After the cover installation process, the process moves to the pressing component insertion process. For example... Figure 15 As shown, the pressing component insertion process involves inserting the pressing component 9 into the mold. Five pressing components 9 are inserted to the position forming the recess 511. The pressing components 9 are inserted into the mold until they abut against the pressing surface protection part 31. The pressing components 9 press the pressing surface 26 of the coil 2 towards the fixing surface 27 through the pressing surface protection part 31. The pressing surface protection part 31 protects the pressing surface 26 of the coil 2. Alternatively, in the pressing component insertion process, only the pressing components 9 may be inserted, and the pressing performed by the pressing components 9 may occur simultaneously with or immediately after the resin spraying in the spraying process.

[0082] After the pressing component insertion process, the process proceeds to the spraying process. The spraying process is the process of injecting resin into the mold to form the initial molding resin portion 5. The resin injection gate G is provided in the peripheral area of ​​the pressing surface protrusion 45. In this embodiment, the gate G is located at the lower center of the pressing surface protrusion 45 (the position where the injection mark M1 is formed). In addition, the gate G is provided above the projection area of ​​the pressing surface protection portion 31 in the roll direction. The resin is sprayed in the roll direction. That is, the resin is sprayed toward the pressing surface protection portion 31.

[0083] The upper side of the pressing surface 26 of the coil 2 is pressed by the resin spray pressure through the pressing surface protection part 31. The center and lower side of the pressing surface 26 are pressed by the pressing member 9 through the pressing surface protection part 31. Since the fixing surface 27 of the coil 2 is fixed by the mold or jig through the resin cover 10, the coil 2 is compressed toward the fixing surface 27 by the resin spray pressure or the pressing of the pressing member. On the other hand, the curved surface protection part 33, the side protection part 34 and the extended front end face of the plate-shaped part 35 of the pressing surface protection part 31 do not abut against the mold or the like, and therefore move toward the fixing surface 27 in conjunction with the compression of the coil 2.

[0084] Thus, through the spraying and pressing component 9, the length of the coil 2 is pressed to the desired length. In this state, the initial molding resin portion 5 hardens, and the coil 2 is fixed to the desired length. The molded coil 1 is produced through the spraying process.

[0085] (Effects)

[0086] As described above, the manufacturing method of the molded coil 1 in this embodiment includes the following steps: a winding step, in which the coil 2 is wound such that its length in the spool direction is longer than a desired length; a housing step, in which the coil 2 is housed in a mold; a pressing step, in which, after the housing step, the coil 2 is pressed in the spool direction by a pressing member 9; and a spraying step, in which, after the pressing step, resin is sprayed into the mold. The coil 2 has an end face orthogonal to the spool, namely a pressing surface 26. In the pressing step, the pressing surface 26 is pressed by the pressing member 9, and in the spraying step, resin is sprayed toward the pressing surface 26.

[0087] In this way, the pressing surface 26 is pressed by the resin and the pressing member 9. As a result, deformation of the coil can be suppressed, and the length of the coil in the winding direction can be adjusted. That is, by the injection pressure of the pressing member 9 and the resin, the coil 2 is pressed along the winding direction to the desired length.

[0088] Furthermore, the spray pressure achieved by the resin is stronger than the pressing force achieved by the pressing component 9. Therefore, as Figure 16 As shown, if the coil 200 is pressed without using the pressing member, the coil 200 will deform. However, as in this embodiment, the pressing surface 26 of the coil 2 is pressed not only by the injection pressure achieved by the resin but also by the pressing member 9, thereby suppressing the deformation of the coil 2 caused by the injection pressure. Therefore, compared to the case where the coil 200 is pressed only by the injection pressure, the deformation of the coil 2 is suppressed.

[0089] Leads 28 and 29 extend from the fixing surface 27 side of coil 2. Furthermore, the resin injected during molding is sprayed from the pressing surface 26 side. This allows the positional displacement of leads 28 and 29 to be suppressed by the spray pressure of the resin. Therefore, the positions of leads 28 and 29, which are connected to the busbar by welding or the like, can be precisely formed, facilitating welding and other similar operations.

[0090] The length of the fixed surface protrusion 44 in the transverse direction of the coil 2 is shorter than that of the upper surface protection portion 41, and the length of the pressing surface protrusion 45 in the transverse direction of the coil 2 is approximately the same as the length of the coil 2 in the transverse direction of the upper surface protection portion 41. Furthermore, the length d1 of the pressing surface protrusion 45 in the spool direction is shorter than the length d2 of the fixed surface protrusion 44 in the spool direction. Thus, the pressing surface protrusion 45 and the fixed surface protrusion 44 have different shapes, therefore, when the upper cover 4 is installed on the coil 2, it is possible to prevent the pressing surface protrusion 45 from being installed on the fixed surface 27 and the fixed surface protrusion 44 from being installed on the pressing surface 26.

[0091] Specifically, in this embodiment, the distance from the fixed surface protrusion 44 to one end 421 of the curved surface protection portion 42 of the upper cover 4 is shorter than the distance from the pressing surface protrusion 45 to the other end 422 of the curved surface protection portion 42. Furthermore, when the pressing surface protection portion 31 is pressed by the resin spray and the pressing member 9, it moves towards the fixed surface 27. Assuming that the upper cover 4 is mounted on the coil 2 in the opposite direction—that is, the pressing surface protrusion 45 covers the fixed surface 27 of the coil 2, and the fixed surface protrusion 44 covers the pressing surface 26—the pressing surface protection portion 31 of the lower cover 3 is positioned close to one end 421 of the curved surface protection portion 42. Therefore, during molding, the pressing surface protection portion 31 of the lower cover 3 may come into contact with one end 421 of the curved surface protection portion 42 due to slight movement, hindering the compression of the coil 2 and preventing the coil 2 from being adjusted to the desired length.

[0092] However, in this embodiment, it is possible to prevent the upper cover 4 from being installed in the opposite direction. Therefore, the pressing surface protection portion 31 of the lower cover 3 can move a longer distance toward the fixed surface 27. In other words, the pressing surface protection portion 31 of the lower cover 3 can prevent contact with the other end 422 of the curved surface protection portion 42. As a result, the coil 2 can be adjusted to the desired length by the resin injection pressure and the pressing member 9.

[0093] (Other implementation methods)

[0094] This specification describes embodiments of the invention, but these embodiments are merely illustrative and do not limit the scope of the invention. Such embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the scope of the invention. The embodiments or variations thereof are included within the scope or spirit of the invention, and similarly within the scope of the claims and their equivalents.

[0095] In the above embodiment, the recessed portion 511 is also provided in the central portion and the lower side of the pressing surface 26 in the vertical direction, but it is not limited to this. For example, the recessed portions 511d and 511e in the central portion of the pressing surface 26 may not be provided, and only the recessed portions 511a, 511b and 511c may be provided.

[0096] Furthermore, the number of recesses 511 provided on the lower side of the pressing surface 26 does not need to be three. For example, there could be two recesses 511. If there are two recesses 511, they could be provided, for example, on the lower side opposite to the injection mark M1. Figure 12 Between the recessed portion 511a and the recessed portion 511b, and between the recessed portion 511b and the recessed portion 511c.

[0097] Furthermore, the recessed portion 511 can also be provided on the upper side of the pressing surface 26. For example, two recessed portions 511 formed on the upper surface of the pressing surface 26 can be provided. The two recessed portions can also be provided at the upper corner of the pressing surface 26 respectively. Figure 12 Above the recesses 511d and 511e shown, at the position where they intersect with the arrangement direction of the injection marks M1. In this case, since the part closer to the resin injection position is pressed by the pressing member 9, the deformation of the coil 2 caused by the injection pressure can be further suppressed.

[0098] Explanation of the label

[0099] 1. Molded coil

[0100] 2 coils

[0101] 21 Connecting parts

[0102] 22 Flat part of the upper surface

[0103] 23, 23a, 23b Flat side sections

[0104] 24. Flat portion of the lower surface

[0105] 25. Bend

[0106] 26 Pressing surfaces

[0107] 27 Fixed surface

[0108] 28 Lead wires

[0109] 29 Lead wire

[0110] 3. Bottom Cover

[0111] 31, 31a, 31b Pressing surface protection part

[0112] 311 Opening

[0113] 312 Thick-walled section

[0114] 32 Connecting parts

[0115] 321 Opening

[0116] 33. Bending section protection section

[0117] 331 Lower surface

[0118] 332 Gap

[0119] 34 Side protection section

[0120] 35 plate-shaped part

[0121] 351 Lower surface

[0122] 352 Gap

[0123] 4. Top Cover

[0124] 41 Upper surface protection section

[0125] 42. Curved surface protection section

[0126] 421 One end

[0127] 422 Another end

[0128] 43 Connecting parts

[0129] 431 holes

[0130] 44. Fixed surface protrusion

[0131] 45 Pressing surface protrusion

[0132] 5. Initial molding resin section

[0133] 51 Press the bread covering part

[0134] 511, 511a, 511b, 511c, 511d, 511e Recesses

[0135] 6 core

[0136] 7. Secondary molding resin section

[0137] 8 Reactors

[0138] 9 Pressing component

[0139] 10 Resin Cap

[0140] 200 coil

[0141] 90 Pressing component

[0142] M1 Injection Mark

[0143] M2 Injection Mark

[0144] G gate

Claims

1. A method for manufacturing a molded coil, comprising molding a coil into a molded coil. The feature is that it includes the following steps: The winding process involves winding a conductive component to create the coil; The housing process involves housing the coil within a mold; In the pressing process, after the receiving process, the coil is pressed in along the spool direction by a pressing component; and In the spraying process, after the pressing process, resin is sprayed into the mold. The coil has an end face, or pressing surface, that is orthogonal to the reel. In the pressing process, the pressing component presses the pressing surface. In the spraying process, the resin is sprayed toward the pressing surface, and the pressing surface is pressed by the resin.

2. The method for manufacturing a molded coil according to claim 1, characterized in that, In the pressing process, the pressing component presses down on the lower side of the pressing surface. In the spraying process, the resin is sprayed toward the upper side of the pressing surface.

3. A molded coil, characterized in that, have: coil; and A molding resin section that covers the coil. The coil has an end face, or pressing surface, that is orthogonal to the reel. The molding resin part has a pressing cover portion that covers the pressing cover. An injection mark is formed on the upper side of the press-covered portion, indicating that the resin constituting the molding resin portion was sprayed during molding. A recess is formed on the lower side of the pressing and covering portion.

Images